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He, You-Wen

Overview:

We study T cell biology in health and disease. Our current study is divided into two parts. Part I is to investigate T lymphocyte-mediated anti-caner immunity. We have found that host complement inhibits the cytokine IL-10 production in CD8+ tumor infiltrating lymphocytes through complement receptors C3aR and C5aR. Complement-deficient animals are resistant to tumor development in a T cell- and IL-10-dependent manner. CD8+ tumor infiltrating T cells express IL-10 when complement signaling is disabled. We found that tumor infiltrating lymphocytes from human cancers expanded with IL-2 plus IL-10 are potent tumor killers. Complement-mediated inhibition on antitumor immunity is independent of the PD-1/PD-L1 immune checkpoint pathway. Our findings suggest that complement receptors C3aR and C5aR expressed on CD8+ tumor infiltrating lymphocytes represent a novel class of immune checkpoints that needs to be targeted for tumor immunotherapy. Our current effort is to enhance cancer immunotherapy through several strategies. First, we investigate a combined blockade of complement signaling and anti-PD-1 to enhance the antitumor efficacy; second, we are studying the antitumor efficacy of a targeted delivery of IL-10 to antitumor CD8+ T cells by using anti-PD1-IL-10 or anti-CTLA-4-IL-10 fusion proteins; third, we are studying the tumor killing efficacy of addition of IL-10 in the expansion protocol of tumor infiltrating lymphocytes for adaptive cellular therapy.


Part II is to investigate the intracellular process termed autophagy in T lymphocyte function. Autophagy is a highly conserved self-digestion pathway that plays essential roles in maintaining the homeostasis of organelles, degrading long-lived proteins and recycling amino acids under starvation conditions. We have found that autophagy related molecules are expressed in T lymphocytes and autophagy occurs inside T lymphocytes. We have generated autophagy-deficient T lymphocytes in multiple genetic models and investigated the roles of autophagy in T lymphocytes. We found that autophagy plays a critical role in T lymphocyte function. Our current effort is to elucidate the molecular pathways by which TCR signal induces autophagy and the impact of autophagy on intracellular organelle homeostasis in dividing T cells.   


 


 


 

Positions:

Professor of Immunology

Immunology
School of Medicine

Member of the Duke Cancer Institute

Duke Cancer Institute
School of Medicine

Education:

M.D. 1986

M.D. — Fourth Military Medical University (China)

Ph.D. 1996

Ph.D. — University of Miami

Grants:

Organization and Function of Cellular Structure

Administered By
Basic Science Departments
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
July 01, 1975
End Date
June 30, 2020

Basic Immunology Training Program

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
July 01, 2014
End Date
June 30, 2019

Regulation of T cell exhaustion by microRNA-720

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
May 01, 2015
End Date
October 31, 2017

Training Program in Inflammatory and Immunological Diseases

Administered By
Medicine, Rheumatology and Immunology
AwardedBy
National Institutes of Health
Role
Preceptor
Start Date
September 30, 1980
End Date
August 31, 2017

Quinolizidines as Novel HIV-1 Entry Inhibitors

Administered By
Surgery, Surgical Sciences
AwardedBy
National Institutes of Health
Role
Co Investigator
Start Date
August 17, 2016
End Date
July 31, 2017

Medical Scientist Training Program

Administered By
School of Medicine
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
July 01, 1997
End Date
June 30, 2017

Validation of a microRNA signature for the prediction, diagnosis and prognosis of acute graft-versus-host disease

Administered By
Immunology
AwardedBy
Blood and Marrow Transplant Clinical Trials Network
Role
Principal Investigator
Start Date
January 20, 2015
End Date
December 31, 2015

Plasma microRNAs as non-invasive biomarker for acute graft-versus-host diseases

Administered By
Immunology
AwardedBy
The Biomarker Factory
Role
Principal Investigator
Start Date
February 01, 2014
End Date
April 30, 2015

Autophagy in T lymphocyte function

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
May 01, 2009
End Date
April 30, 2015

BcI-2 family in T lymphocyte homeostasis

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
December 01, 2008
End Date
November 30, 2014

Regulation of thymocyte maturation and mature T lymphocyte homeostasis by c-FLIP

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
March 01, 2008
End Date
May 31, 2013

The effects of Nlrp12 and IL-1b in inflammatory disorders

Administered By
Medicine, Cardiology
AwardedBy
National Institutes of Health
Role
Collaborator
Start Date
July 01, 2010
End Date
February 29, 2012

A novel pathway regulating cytokine production and asthma development

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
May 15, 2009
End Date
April 30, 2011

Function of thymic epithelial cells in T lymphocyte maturation

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
September 15, 2008
End Date
February 28, 2011

Extracellular Matrix Protein in Innate Immunity

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
March 01, 2003
End Date
July 31, 2008

Pattern Recognition Molecule Mindin As Adjuvant

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
March 15, 2005
End Date
February 29, 2008

Orphan Nuclear Receptor in Thymocyte Differentiation

Administered By
Immunology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
August 28, 2002
End Date
July 31, 2007
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Publications:

Autocrine Complement Inhibits IL10-Dependent T-cell-Mediated Antitumor Immunity to Promote Tumor Progression.

In contrast to its inhibitory effects on many cells, IL10 activates CD8(+) tumor-infiltrating lymphocytes (TIL) and enhances their antitumor activity. However, CD8(+) TILs do not routinely express IL10, as autocrine complement C3 inhibits IL10 production through complement receptors C3aR and C5aR. CD8(+) TILs from C3-deficient mice, however, express IL10 and exhibit enhanced effector function. C3-deficient mice are resistant to tumor development in a T-cell- and IL10-dependent manner; human TILs expanded with IL2 plus IL10 increase the killing of primary tumors in vitro compared with IL2-treated TILs. Complement-mediated inhibition of antitumor immunity is independent of the programmed death 1/programmed death ligand 1 (PD-1/PD-L1) immune checkpoint pathway. Our findings suggest that complement receptors C3aR and C5aR expressed on CD8(+) TILs represent a novel class of immune checkpoints that could be targeted for tumor immunotherapy. Moreover, incorporation of IL10 in the expansion of TILs and in gene-engineered T cells for adoptive cell therapy enhances their antitumor efficacy.Our data suggest novel strategies to enhance immunotherapies: a combined blockade of complement signaling by antagonists to C3aR, C5aR, and anti-PD-1 to enhance anti-PD-1 efficacy; a targeted IL10 delivery to CD8(+) TILs using anti-PD-1-IL10 or anti-CTLA4-IL10 fusion proteins; and the addition of IL10 in TIL expansion for adoptive cellular therapy. Cancer Discov; 6(9); 1022-35. ©2016 AACR.See related commentary by Peng et al., p. 953This article is highlighted in the In This Issue feature, p. 932.

Authors
Wang, Y; Sun, S-N; Liu, Q; Yu, Y-Y; Guo, J; Wang, K; Xing, B-C; Zheng, Q-F; Campa, MJ; Patz, EF; Li, S-Y; He, Y-W
MLA Citation
Wang, Y, Sun, S-N, Liu, Q, Yu, Y-Y, Guo, J, Wang, K, Xing, B-C, Zheng, Q-F, Campa, MJ, Patz, EF, Li, S-Y, and He, Y-W. "Autocrine Complement Inhibits IL10-Dependent T-cell-Mediated Antitumor Immunity to Promote Tumor Progression." Cancer discovery 6.9 (September 2016): 1022-1035.
PMID
27297552
Source
epmc
Published In
Cancer Discovery
Volume
6
Issue
9
Publish Date
2016
Start Page
1022
End Page
1035
DOI
10.1158/2159-8290.cd-15-1412

Autophagy Genes Enhance Murine Gammaherpesvirus 68 Reactivation from Latency by Preventing Virus-Induced Systemic Inflammation.

Host genes that regulate systemic inflammation upon chronic viral infection are incompletely understood. Murine gammaherpesvirus 68 (MHV68) infection is characterized by latency in macrophages, and reactivation is inhibited by interferon-γ (IFN-γ). Using a lysozyme-M-cre (LysMcre) expression system, we show that deletion of autophagy-related (Atg) genes Fip200, beclin 1, Atg14, Atg16l1, Atg7, Atg3, and Atg5, in the myeloid compartment, inhibited MHV68 reactivation in macrophages. Atg5 deficiency did not alter reactivation from B cells, and effects on reactivation from macrophages were not explained by alterations in productive viral replication or the establishment of latency. Rather, chronic MHV68 infection triggered increased systemic inflammation, increased T cell production of IFN-γ, and an IFN-γ-induced transcriptional signature in macrophages from Atg gene-deficient mice. The Atg5-related reactivation defect was partially reversed by neutralization of IFN-γ. Thus Atg genes in myeloid cells dampen virus-induced systemic inflammation, creating an environment that fosters efficient MHV68 reactivation from latency.

Authors
Park, S; Buck, MD; Desai, C; Zhang, X; Loginicheva, E; Martinez, J; Freeman, ML; Saitoh, T; Akira, S; Guan, J-L; He, Y-W; Blackman, MA; Handley, SA; Levine, B; Green, DR; Reese, TA; Artyomov, MN; Virgin, HW
MLA Citation
Park, S, Buck, MD, Desai, C, Zhang, X, Loginicheva, E, Martinez, J, Freeman, ML, Saitoh, T, Akira, S, Guan, J-L, He, Y-W, Blackman, MA, Handley, SA, Levine, B, Green, DR, Reese, TA, Artyomov, MN, and Virgin, HW. "Autophagy Genes Enhance Murine Gammaherpesvirus 68 Reactivation from Latency by Preventing Virus-Induced Systemic Inflammation." Cell host & microbe 19.1 (January 2016): 91-101.
PMID
26764599
Source
epmc
Published In
Cell Host & Microbe
Volume
19
Issue
1
Publish Date
2016
Start Page
91
End Page
101
DOI
10.1016/j.chom.2015.12.010

Cellular FLIP Inhibits Myeloid Cell Activation by Suppressing Selective Innate Signaling.

Cellular FLIP (c-FLIP) specifically inhibits caspase-8 and suppresses death receptor-induced apoptosis. c-FLIP has also been reported to transmit activation signals. In this study, we report a novel function of c-FLIP involving inhibition of myeloid cell activation through antagonizing the selective innate signaling pathway. We found that conditional knockout of c-FLIP in dendritic cells (DCs) led to neutrophilia and splenomegaly. Peripheral DC populations, including CD11b(+) conventional DCs (cDCs), CD8(+) cDCs, and plasmacytoid DCs, were not affected by c-FLIP deficiency. We also found that c-FLIP knockout cDCs, plasmacytoid DCs, and bone marrow-derived DCs (BMDCs) displayed enhanced production of TNF-α, IL-2, or G-CSF in response to stimulation of TLR4, TLR2, and dectin-1. Consistent with the ability of c-FLIP to inhibit the activation of p38 MAPK, the enhanced activation of c-FLIP-deficient BMDCs could be partly linked to an elevated activation of p38 MAPK after engagement of innate receptors. Increased activation was also found in c-FLIP(+/-) macrophages. Additionally, the increased activation in c-FLIP-deficient DCs was independent of caspase-8. Our results reveal a novel inhibitory role of c-FLIP in myeloid cell activation and demonstrate the unexpected anti-inflammatory activity of c-FLIP. Additionally, our observations suggest that cancer therapy targeting c-FLIP downregulation may facilitate DC activation and increase T cell immunity.

Authors
Wu, Y-J; Wu, Y-H; Mo, S-T; Hsiao, H-W; He, Y-W; Lai, M-Z
MLA Citation
Wu, Y-J, Wu, Y-H, Mo, S-T, Hsiao, H-W, He, Y-W, and Lai, M-Z. "Cellular FLIP Inhibits Myeloid Cell Activation by Suppressing Selective Innate Signaling." Journal of immunology (Baltimore, Md. : 1950) 195.6 (September 2015): 2612-2623.
PMID
26238491
Source
epmc
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
195
Issue
6
Publish Date
2015
Start Page
2612
End Page
2623
DOI
10.4049/jimmunol.1402944

Regulation of T cell function by microRNA-720.

Chronic hepatitis B virus (HBV) infection is a major global health burden. Functional exhaustion and numerical reduction of HBV-specific cytotoxic T lymphocytes (CTLs) in the liver and peripheral blood limit anti-HBV CTL activity in patients with chronic HBV infection (CHB). However, the ongoing anti-HBV CD8(+) T cell responses in the lymphoid organs are largely unknown due to the infeasibility of obtaining lymphoid organs from CHB patients. Here we demonstrate that the percentage of HBV-specific CD8(+) T cells is higher in the spleen of CHB patients than that from peripheral blood and liver. Although they do respond to TCR stimulation and produce IFNγ, the cells proliferate poorly. Furthermore, miR-720 expression is upregulated in HBV-specific CD8(+) T cells. Overexpression of miR-720 in primary human CD8(+) T cells inhibits TCR stimulation-induced proliferation. We also demonstrate that TGFβ sustains miR-720 upregulation after TCR stimulation, and blood TGFβ levels are associated with the outcome of type I interferon treatment of CHB patients. Thus, therapies targeting miR-720 may help restore impaired immunity in CHB patients.

Authors
Wang, Y; Zhang, Z; Ji, D; Chen, G-F; Feng, X; Gong, L-L; Guo, J; Li, Z-W; Chen, C-F; Zhao, B-B; Li, Z-G; Li, Q-J; Yan, H-P; Sempowski, G; Wang, F-S; He, Y-W
MLA Citation
Wang, Y, Zhang, Z, Ji, D, Chen, G-F, Feng, X, Gong, L-L, Guo, J, Li, Z-W, Chen, C-F, Zhao, B-B, Li, Z-G, Li, Q-J, Yan, H-P, Sempowski, G, Wang, F-S, and He, Y-W. "Regulation of T cell function by microRNA-720." Scientific reports 5 (July 22, 2015): 12159-.
PMID
26199080
Source
epmc
Published In
Scientific Reports
Volume
5
Publish Date
2015
Start Page
12159
DOI
10.1038/srep12159

The lung is protected from spontaneous inflammation by autophagy in myeloid cells.

The lung is constantly exposed to the outer environment; thus, it must maintain a state of immune ignorance or tolerance not to overrespond to harmless environmental stimuli. How cells in the lung control immune responses under nonpathogenic condition is not fully understood. In this study, we found that autophagy plays a critical role in the lung-specific immune regulation that prevents spontaneous inflammation. Autophagy in pulmonary myeloid cells plays a role in maintaining low burdens of environmental microbes in the lung, as well as in lowering mitochondrial reactive oxygen species production and preventing overresponse to TLR4 ligands in alveolar macrophages. Based on these mechanisms, we also found that intranasal instillation of antibiotics or an inhibitor of reactive oxygen species was efficient in preventing spontaneous pulmonary inflammation. Thus, autophagy in myeloid cells, particularly alveolar macrophages, is critical for inhibiting spontaneous pulmonary inflammation, and pulmonary inflammation caused by dysfunctional autophagy is pharmacologically prevented.

Authors
Kanayama, M; He, Y-W; Shinohara, ML
MLA Citation
Kanayama, M, He, Y-W, and Shinohara, ML. "The lung is protected from spontaneous inflammation by autophagy in myeloid cells." Journal of immunology (Baltimore, Md. : 1950) 194.11 (June 2015): 5465-5471.
PMID
25911758
Source
epmc
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
194
Issue
11
Publish Date
2015
Start Page
5465
End Page
5471
DOI
10.4049/jimmunol.1403249

CHCHD2 inhibits apoptosis by interacting with Bcl-x L to regulate Bax activation.

Mitochondrial outer membrane permeabilization (MOMP) is a critical control point during apoptosis that results in the release of pro-apoptotic mitochondrial contents such as cytochrome c. MOMP is largely controlled by Bcl-2 family proteins such as Bax, which under various apoptotic stresses becomes activated and oligomerizes on the outer mitochondrial membrane. Bax oligomerization helps promote the diffusion of the mitochondrial contents into the cytoplasm activating the caspase cascade. In turn, Bax is regulated primarily by anti-apoptotic Bcl-2 proteins including Bcl-xL, which was recently shown to prevent Bax from accumulating at the mitochondria. However, the exact mechanisms by which Bcl-xL regulates Bax and thereby MOMP remain partially understood. In this study, we show that the small CHCH-domain-containing protein CHCHD2 binds to Bcl-xL and inhibits the mitochondrial accumulation and oligomerization of Bax. Our data show that in response to apoptotic stimuli, mitochondrial CHCHD2 decreases prior to MOMP. Furthermore, when CHCHD2 is absent from the mitochondria, the ability of Bcl-xL to inhibit Bax activation and to prevent apoptosis is attenuated, which results in increases in Bax oligomerization, MOMP and apoptosis. Collectively, our findings establish CHCHD2, a previously uncharacterized small mitochondrial protein with no known homology to the Bcl-2 family, as one of the negative regulators of mitochondria-mediated apoptosis.

Authors
Liu, Y; Clegg, HV; Leslie, PL; Di, J; Tollini, LA; He, Y; Kim, T-H; Jin, A; Graves, LM; Zheng, J; Zhang, Y
MLA Citation
Liu, Y, Clegg, HV, Leslie, PL, Di, J, Tollini, LA, He, Y, Kim, T-H, Jin, A, Graves, LM, Zheng, J, and Zhang, Y. "CHCHD2 inhibits apoptosis by interacting with Bcl-x L to regulate Bax activation." Cell death and differentiation 22.6 (June 2015): 1035-1046.
PMID
25476776
Source
epmc
Published In
Cell Death & Differentiation
Volume
22
Issue
6
Publish Date
2015
Start Page
1035
End Page
1046
DOI
10.1038/cdd.2014.194

Acute organ failure following the loss of anti-apoptotic cellular FLICE-inhibitory protein involves activation of innate immune receptors.

Apoptosis signaling is involved in both physiological tissue homeostasis and acute and chronic diseases. The role of regulatory apoptosis signaling molecules and their organ-specific functions are less defined. Therefore, we investigated the loss of the anti-apoptotic cellular FLICE-inhibitory protein (cFLIP) and the mechanisms of the resulting lethal organ failure in vivo using inducible knockout mice. These were generated by crossing floxed cFLIP mice to a tamoxifen inducible Rosa26-creERT2 mouse strain. Death following global loss of cFLIP resulted from liver failure, accumulation of M1-polarized macrophages and accompanying hepatic cell death and inflammation. Apoptosis was also prominent in immune cells, the kidney and intestinal epithelial cells (IECs) but not in cardiomyocytes. Cellular injury led to the release of damage-associated molecular patterns (DAMPs) and the induction of innate immune receptors including toll-like receptors (TLRs) 4 and 9, and stimulator of interferon genes (STING). Transplantation of bone marrow with intact cFLIP or depletion of macrophages prevented the phenotype of acute liver failure. Interestingly, compound deletion of cFLIP in bone marrow-derived cells and hepatocytes did not promote organ failure. Thus, cFLIP exerts a critical role in tissue homeostasis by preventing the activation of monocytic cells and innate immunity, which causes cell death and inflammation in susceptible tissues. These results encourage the development of organ-specific anti-apoptotic and anti-inflammatory therapies in acute organ failure.

Authors
Gehrke, N; Garcia-Bardon, D; Mann, A; Schad, A; Alt, Y; Wörns, MA; Sprinzl, MF; Zimmermann, T; Menke, J; Engstler, AJ; Bergheim, I; He, Y-W; Galle, PR; Schuchmann, M; Schattenberg, JM
MLA Citation
Gehrke, N, Garcia-Bardon, D, Mann, A, Schad, A, Alt, Y, Wörns, MA, Sprinzl, MF, Zimmermann, T, Menke, J, Engstler, AJ, Bergheim, I, He, Y-W, Galle, PR, Schuchmann, M, and Schattenberg, JM. "Acute organ failure following the loss of anti-apoptotic cellular FLICE-inhibitory protein involves activation of innate immune receptors." Cell death and differentiation 22.5 (May 2015): 826-837.
PMID
25342470
Source
epmc
Published In
Cell Death & Differentiation
Volume
22
Issue
5
Publish Date
2015
Start Page
826
End Page
837
DOI
10.1038/cdd.2014.178

Characterization of a novel neutrophil-deficient mouse strain

Authors
Csepregi, JZ; Kasa, O; Szikszai, D; He, YW; Mocsai, A
MLA Citation
Csepregi, JZ, Kasa, O, Szikszai, D, He, YW, and Mocsai, A. "Characterization of a novel neutrophil-deficient mouse strain." EUROPEAN JOURNAL OF CLINICAL INVESTIGATION 45 (May 2015): 49-49.
Source
wos-lite
Published In
European Journal of Clinical Investigation
Volume
45
Publish Date
2015
Start Page
49
End Page
49

c-FLIP protects T lymphocytes from apoptosis in the intrinsic pathway.

Apoptosis can be induced by either death receptors on the plasma membrane (extrinsic pathway) or the damage of the genome and/or cellular organelles (intrinsic pathway). Previous studies suggest that cellular caspase 8 (FLICE)-like inhibitory protein (c-FLIP) promotes cell survival in death receptor-induced apoptosis pathway in T lymphocytes. Independent of death receptor signaling, mitochondria sense apoptotic stimuli and mediate the activation of effector caspases. Whether c-FLIP regulates mitochondrion-dependent apoptotic signals remains unknown. In this study, c-FLIP gene was deleted in mature T lymphocytes in vitro, and the role of c-FLIP protein in intrinsic apoptosis pathway was studied. In resting T cells treated with the intrinsic apoptosis inducer, c-FLIP suppressed cytochrome c release from mitochondria. Bim-deletion rescued the enhanced apoptosis in c-FLIP-deficient T cells, whereas inhibition of caspase 8 did not. Different from activated T cells, there was no necroptosis or increase in reactive oxygen species in c-FLIP-deficient resting T cells. These data suggest that c-FLIP is a negative regulator of intrinsic apoptosis pathway in T lymphocytes.

Authors
He, M-X; He, Y-W
MLA Citation
He, M-X, and He, Y-W. "c-FLIP protects T lymphocytes from apoptosis in the intrinsic pathway." Journal of immunology (Baltimore, Md. : 1950) 194.7 (April 2015): 3444-3451.
PMID
25725104
Source
epmc
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
194
Issue
7
Publish Date
2015
Start Page
3444
End Page
3451
DOI
10.4049/jimmunol.1400469

Involvement of BCL-XL in regulation of mast cell survival

Authors
Foerster, A; Rabenhorst, A; Seeger, JM; He, Y; Kashkar, H; Roers, A; Hartmann, K
MLA Citation
Foerster, A, Rabenhorst, A, Seeger, JM, He, Y, Kashkar, H, Roers, A, and Hartmann, K. "Involvement of BCL-XL in regulation of mast cell survival." March 2015.
Source
wos-lite
Published In
Experimental Dermatology
Volume
24
Issue
3
Publish Date
2015
Start Page
E8
End Page
E8

Autophagy enhances NFκB activity in specific tissue macrophages by sequestering A20 to boost antifungal immunity.

Immune responses must be well restrained in a steady state to avoid excessive inflammation. However, such restraints are quickly removed to exert antimicrobial responses. Here we report a role of autophagy in an early host antifungal response by enhancing NFκB activity through A20 sequestration. Enhancement of NFκB activation is achieved by autophagic depletion of A20, an NFκB inhibitor, in F4/80(hi) macrophages in the spleen, peritoneum and kidney. We show that p62, an autophagic adaptor protein, captures A20 to sequester it in the autophagosome. This allows the macrophages to release chemokines to recruit neutrophils. Indeed, mice lacking autophagy in myeloid cells show higher susceptibility to Candida albicans infection due to impairment in neutrophil recruitment. Thus, at least in the specific aforementioned tissues, autophagy appears to break A20-dependent suppression in F4/80(hi) macrophages, which express abundant A20 and contribute to the initiation of efficient innate immune responses.

Authors
Kanayama, M; Inoue, M; Danzaki, K; Hammer, G; He, Y-W; Shinohara, ML
MLA Citation
Kanayama, M, Inoue, M, Danzaki, K, Hammer, G, He, Y-W, and Shinohara, ML. "Autophagy enhances NFκB activity in specific tissue macrophages by sequestering A20 to boost antifungal immunity." Nature communications 6 (January 22, 2015): 5779-.
Website
http://hdl.handle.net/10161/9376
PMID
25609235
Source
epmc
Published In
Nature Communications
Volume
6
Publish Date
2015
Start Page
5779
DOI
10.1038/ncomms6779

Autophagy regulates T lymphocyte proliferation through selective degradation of the cell-cycle inhibitor CDKN1B/p27Kip1.

The highly conserved cellular degradation pathway, macroautophagy, regulates the homeostasis of organelles and promotes the survival of T lymphocytes. Previous results indicate that Atg3-, Atg5-, or Pik3c3/Vps34-deficient T cells cannot proliferate efficiently. Here we demonstrate that the proliferation of Atg7-deficient T cells is defective. By using an adoptive transfer and Listeria monocytogenes (LM) mouse infection model, we found that the primary immune response against LM is intrinsically impaired in autophagy-deficient CD8(+) T cells because the cell population cannot expand after infection. Autophagy-deficient T cells fail to enter into S-phase after TCR stimulation. The major negative regulator of the cell cycle in T lymphocytes, CDKN1B, is accumulated in autophagy-deficient naïve T cells and CDKN1B cannot be degraded after TCR stimulation. Furthermore, our results indicate that genetic deletion of one allele of CDKN1B in autophagy-deficient T cells restores proliferative capability and the cells can enter into S-phase after TCR stimulation. Finally, we found that natural CDKN1B forms polymers and is physiologically associated with the autophagy receptor protein SQSTM1/p62 (sequestosome 1). Collectively, autophagy is required for maintaining the expression level of CDKN1B in naïve T cells and selectively degrades CDKN1B after TCR stimulation.

Authors
Jia, W; He, M-X; McLeod, IX; Guo, J; Ji, D; He, Y-W
MLA Citation
Jia, W, He, M-X, McLeod, IX, Guo, J, Ji, D, and He, Y-W. "Autophagy regulates T lymphocyte proliferation through selective degradation of the cell-cycle inhibitor CDKN1B/p27Kip1." Autophagy 11.12 (January 2015): 2335-2345.
PMID
26569626
Source
epmc
Published In
Autophagy
Volume
11
Issue
12
Publish Date
2015
Start Page
2335
End Page
2345
DOI
10.1080/15548627.2015.1110666

Applications of RNA interference high-throughput screening technology in cancer biology and virology.

RNA interference (RNAi) is an ancient intra-cellular mechanism that regulates gene expression and cell function. Large-scale gene silencing using RNAi high-throughput screening (HTS) has opened an exciting frontier to systematically study gene function in mammalian cells. This approach enables researchers to identify gene function in a given biological context and will provide considerable novel insight. Here, we review RNAi HTS strategies and applications using case studies in cancer biology and virology.

Authors
Gao, S; Yang, C; Jiang, S; Xu, X-N; Lu, X; He, Y-W; Cheung, A; Wang, H
MLA Citation
Gao, S, Yang, C, Jiang, S, Xu, X-N, Lu, X, He, Y-W, Cheung, A, and Wang, H. "Applications of RNA interference high-throughput screening technology in cancer biology and virology." Protein & cell 5.11 (November 2014): 805-815. (Review)
PMID
24952721
Source
epmc
Published In
Protein & Cell
Volume
5
Issue
11
Publish Date
2014
Start Page
805
End Page
815
DOI
10.1007/s13238-014-0076-6

Regulation of T cell proliferation by JMJD6 and PDGF-BB during chronic hepatitis B infection.

T cell functional exhaustion during chronic hepatitis B virus (HBV) infection may contribute to the failed viral clearance; however, the underlying molecular mechanisms remain largely unknown. Here we demonstrate that jumonji domain-containing protein 6 (JMJD6) is a potential regulator of T cell proliferation during chronic HBV infection. The expression of JMJD6 was reduced in T lymphocytes in chronic hepatitis B (CHB) patients, and this reduction in JMJD6 expression was associated with impaired T cell proliferation. Moreover, silencing JMJD6 expression in primary human T cells impaired T cell proliferation. We found that JMJD6 promotes T cell proliferation by suppressing the mRNA expression of CDKN3. Furthermore, we have identified platelet derived growth factor-BB (PDGF-BB) as a regulator of JMJD6 expression. PDGF-BB downregulates JMJD6 expression and inhibits the proliferation of human primary T cells. Importantly, the expression levels of JMJD6 and PDGF-BB in lymphocytes from CHB patients were correlated with the degree of liver damage and the outcome of chronic HBV infection treatment. Our results demonstrate that PDGF-BB and JMJD6 regulate T cell function during chronic HBV infection and may provide insights for the treatment strategies for CHB patients.

Authors
Chen, C-F; Feng, X; Liao, H-Y; Jin, W-J; Zhang, J; Wang, Y; Gong, L-L; Liu, J-J; Yuan, X-H; Zhao, B-B; Zhang, D; Chen, G-F; Wan, Y; Guo, J; Yan, H-P; He, Y-W
MLA Citation
Chen, C-F, Feng, X, Liao, H-Y, Jin, W-J, Zhang, J, Wang, Y, Gong, L-L, Liu, J-J, Yuan, X-H, Zhao, B-B, Zhang, D, Chen, G-F, Wan, Y, Guo, J, Yan, H-P, and He, Y-W. "Regulation of T cell proliferation by JMJD6 and PDGF-BB during chronic hepatitis B infection." Scientific reports 4 (September 15, 2014): 6359-.
PMID
25219359
Source
epmc
Published In
Scientific Reports
Volume
4
Publish Date
2014
Start Page
6359
DOI
10.1038/srep06359

Participation of c-FLIP in NLRP3 and AIM2 inflammasome activation

Cellular FLICE-inhibitory protein (c-FLIP) is an inhibitor of caspase-8 and is required for macrophage survival. Recent studies have revealed a selective role of caspase-8 in noncanonical IL-1β production that is independent of caspase-1 or inflammasome. Here we demonstrated that c-FLIP L is an unexpected contributor to canonical inflammasome activation for the generation of caspase-1 and active IL-1β. Hemizygotic deletion of c-FLIP impaired ATP- and monosodium uric acid (MSU)-induced IL-1β production in macrophages primed through Toll-like receptors (TLRs). Decreased IL-1β expression was attributed to a reduced activation of caspase-1 in c-FLIP hemizygotic cells. In contrast, the production of TNF-α was not affected by downregulation in c-FLIP. c-FLIP L interacted with NLRP3 or procaspase-1. c-FLIP is required for the full NLRP3 inflammasome assembly and NLRP3 mitochondrial localization, and c-FLIP is associated with NLRP3 inflammasome. c-FLIP downregulation also reduced AIM2 inflammasome activation. In contrast, c-FLIP inhibited SMAC mimetic-, FasL-, or Dectin-1-induced IL-1β generation that is caspase-8-mediated. Our results demonstrate a prominent role of c-FLIP L in the optimal activation of the NLRP3 and AIM2 inflammasomes, and suggest that c-FLIP could be a valid target for treatment of inflammatory diseases caused by over-activation of inflammasomes. © 2014 Macmillan Publishers Limited All rights reserved.

Authors
Wu, YH; Kuo, WC; Wu, YJ; Yang, KT; Chen, ST; Jiang, ST; Gordy, C; He, YW; Lai, MZ
MLA Citation
Wu, YH, Kuo, WC, Wu, YJ, Yang, KT, Chen, ST, Jiang, ST, Gordy, C, He, YW, and Lai, MZ. "Participation of c-FLIP in NLRP3 and AIM2 inflammasome activation." Cell Death and Differentiation 21.3 (March 1, 2014): 451-461.
Source
scopus
Published In
Cell Death & Differentiation
Volume
21
Issue
3
Publish Date
2014
Start Page
451
End Page
461
DOI
10.1038/cdd.2013.165

The role of Mcl-1 and Bcl-xL in homeostasis and function of murine mast cells

Authors
Foerster, A; Rabenhorst, A; Bouillet, P; Strasser, A; He, Y; Roers, A; Hartmann, K
MLA Citation
Foerster, A, Rabenhorst, A, Bouillet, P, Strasser, A, He, Y, Roers, A, and Hartmann, K. "The role of Mcl-1 and Bcl-xL in homeostasis and function of murine mast cells." March 2014.
Source
wos-lite
Published In
Experimental Dermatology
Volume
23
Issue
3
Publish Date
2014
Start Page
E8
End Page
E8

Epidermal cFLIP regulates skin homeostasis and protects adult skin from TNF-induced keratinocyte apoptosis: beneficial effect of TNF-R2-Fc

Authors
Panayotova-Dimitrova, D; Feoktistova, M; Ploesser, M; Kellert, B; Hupe, M; Horn, S; Makarov, R; Jensen, F; Porubsky, S; Schmieder, A; Zenclussen, AC; Marx, A; Kerstan, A; Geserick, P; He, Y; Leverkus, M
MLA Citation
Panayotova-Dimitrova, D, Feoktistova, M, Ploesser, M, Kellert, B, Hupe, M, Horn, S, Makarov, R, Jensen, F, Porubsky, S, Schmieder, A, Zenclussen, AC, Marx, A, Kerstan, A, Geserick, P, He, Y, and Leverkus, M. "Epidermal cFLIP regulates skin homeostasis and protects adult skin from TNF-induced keratinocyte apoptosis: beneficial effect of TNF-R2-Fc." March 2014.
Source
wos-lite
Published In
Experimental Dermatology
Volume
23
Issue
3
Publish Date
2014
Start Page
E10
End Page
E10

The c-FLIPL cleavage product p43FLIP promotes activation of extracellular signal-regulated kinase (ERK), nuclear factor κB (NF-κB), and caspase-8 and T cell survival.

Caspase-8 is now appreciated to govern both apoptosis following death receptor ligation and cell survival and growth via inhibition of the Ripoptosome. Cells must therefore carefully regulate the high level of caspase-8 activity during apoptosis versus the modest levels observed during cell growth. The caspase-8 paralogue c-FLIP is a good candidate for a molecular rheostat of caspase-8 activity. c-FLIP can inhibit death receptor-mediated apoptosis by competing with caspase-8 for recruitment to FADD. However, full-length c-FLIPL can also heterodimerize with caspase-8 independent of death receptor ligation and activate caspase-8 via an activation loop in the C terminus of c-FLIPL. This triggers cleavage of c-FLIPL at Asp-376 by caspase-8 to produce p43FLIP. The continued function of p43FLIP has, however, not been determined. We demonstrate that acute deletion of endogenous c-FLIP in murine effector T cells results in loss of caspase-8 activity and cell death. The lethality and caspase-8 activity can both be rescued by the transgenic expression of p43FLIP. Furthermore, p43FLIP associates with Raf1, TRAF2, and RIPK1, which augments ERK and NF-κB activation, IL-2 production, and T cell proliferation. Thus, not only is c-FLIP the initiator of caspase-8 activity during T cell activation, it is also an initial caspase-8 substrate, with cleaved p43FLIP serving to both stabilize caspase-8 activity and promote activation of pathways involved with T cell growth.

Authors
Koenig, A; Buskiewicz, IA; Fortner, KA; Russell, JQ; Asaoka, T; He, Y-W; Hakem, R; Eriksson, JE; Budd, RC
MLA Citation
Koenig, A, Buskiewicz, IA, Fortner, KA, Russell, JQ, Asaoka, T, He, Y-W, Hakem, R, Eriksson, JE, and Budd, RC. "The c-FLIPL cleavage product p43FLIP promotes activation of extracellular signal-regulated kinase (ERK), nuclear factor κB (NF-κB), and caspase-8 and T cell survival." The Journal of biological chemistry 289.2 (January 2014): 1183-1191.
PMID
24275659
Source
epmc
Published In
The Journal of biological chemistry
Volume
289
Issue
2
Publish Date
2014
Start Page
1183
End Page
1191
DOI
10.1074/jbc.m113.506428

c-FLIP protects eosinophils from TNF-α-mediated cell death in vivo.

Understanding the signals that regulate eosinophil survival and death is critical to developing new treatments for asthma, atopy, and gastrointestinal disease. Previous studies suggest that TNF-α stimulation protects eosinophils from apoptosis, and this TNF-α-mediated protection is mediated by the upregulation of an unknown protein by NF-κB. Here, we show for the first time that eosinophils express the caspase 8-inhibitory protein c-FLIP, and c-FLIP expression is upregulated upon TNF-α stimulation. Considering that c-FLIP expression is regulated by NF-κB, we hypothesized that c-FLIP might serve as the "molecular switch" that converts TNFRI activation to a pro-survival signal in eosinophils. Indeed, we found that one c-FLIP isoform, c-FLIPL, is required for mouse eosinophil survival in the presence of TNF-α both in vitro and in vivo. Importantly, our results suggest c-FLIP as a potential therapeutic target for the treatment of eosinophil-mediated disease.

Authors
Gordy, C; Liang, J; Pua, H; He, Y-W
MLA Citation
Gordy, C, Liang, J, Pua, H, and He, Y-W. "c-FLIP protects eosinophils from TNF-α-mediated cell death in vivo." PloS one 9.10 (January 2014): e107724-.
PMID
25333625
Source
epmc
Published In
PloS one
Volume
9
Issue
10
Publish Date
2014
Start Page
e107724
DOI
10.1371/journal.pone.0107724

Cellular FLICE-like inhibitory protein secures intestinal epithelial cell survival and immune homeostasis by regulating caspase-8

Background & Aims The intestinal epithelium generates a barrier that protects mammals from potentially harmful intestinal contents, such as pathogenic bacteria. Dysregulation of epithelial cell death has been implicated in barrier dysfunction and in the pathogenesis of intestinal inflammation. We investigated mechanisms of cell-death regulation in the intestinal epithelium of mice. Methods Conditional knockout mice (either inducible or permanent) with deletion of cellular FLICE-inhibitory protein (cFlip) or caspase-8 in the intestinal epithelium were analyzed by histology and high-resolution endoscopy. We assessed the effects of cFlip or caspase-8 deficiency on intestinal homeostasis. Results Expression of cFlip in the intestinal epithelium was required for constitutive activation of caspase-8 under steady-state conditions. Intestinal expression of cFlip was required for development; disruption of the gene encoding cFlip from the intestinal epithelium (cFlipfl/fl VillinCre+ mice) resulted in embryonic lethality. When cFlip was deleted from the intestinal epithelium of adult mice (cFlip iΔIEC mice), the animals died within a few days from severe tissue destruction, epithelial cell death, and intestinal inflammation. Death of cFlip-depleted intestinal epithelial cells was regulated extrinsically and required the presence of death receptor ligands, such as tumor necrosis factor-α and CD95 ligand, but was independent of receptor-interacting protein 3. cFlip deficiency was associated with strong up-regulation of caspase-8 and caspase-3 activity and excessive apoptosis in intestinal crypts. Conclusions cFlip is required for intestinal tissue homeostasis in mice. It controls the level of activation of caspase-8 to promote survival of intestinal epithelial cells. © 2013 by the AGA Institute.

Authors
Wittkopf, N; Günther, C; Martini, E; He, G; Amann, K; He, YW; Schuchmann, M; Neurath, MF; Becker, C
MLA Citation
Wittkopf, N, Günther, C, Martini, E, He, G, Amann, K, He, YW, Schuchmann, M, Neurath, MF, and Becker, C. "Cellular FLICE-like inhibitory protein secures intestinal epithelial cell survival and immune homeostasis by regulating caspase-8." Gastroenterology 145.6 (December 1, 2013): 1369-1379.
Source
scopus
Published In
Gastroenterology
Volume
145
Issue
6
Publish Date
2013
Start Page
1369
End Page
1379
DOI
10.1053/j.gastro.2013.08.059

Plasma microRNA signature as a noninvasive biomarker for acute graft-versus-host disease.

Acute graft-versus-host disease (aGVHD) is the leading cause of morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT). Approximately 35% to 50% of HCT recipients develop aGVHD; however, there are no validated diagnostic and predictive blood biomarkers for aGVHD in clinical use. Here, we show that plasma samples from aGVHD patients have a distinct microRNA (miRNA) expression profile. We found that 6 miRNAs (miR-423, miR-199a-3p, miR-93*, miR-377, miR-155, and miR-30a) were significantly upregulated in the plasma of aGVHD patients (n = 116) when compared with non-GVHD patients (n = 52) in training and validation phases. We have developed a model including 4 miRNAs (miR-423, miR-199a-3p, miR-93*, and miR-377) that can predict the probability of aGVHD with an area under the curve of 0.80. Moreover, these elevated miRNAs were detected before the onset of aGVHD (median = 16 days before diagnosis). In addition, the levels of these miRNAs were positively associated with aGVHD severity, and high expression of the miRNA panel was associated with poor overall survival. Furthermore, the miRNA signature for aGVHD was not detected in the plasma of lung transplant or nontransplant sepsis patients. Our results have identified a specific plasma miRNA signature that may serve as an independent biomarker for the prediction, diagnosis, and prognosis of aGVHD.

Authors
Xiao, B; Wang, Y; Li, W; Baker, M; Guo, J; Corbet, K; Tsalik, EL; Li, Q-J; Palmer, SM; Woods, CW; Li, Z; Chao, NJ; He, Y-W
MLA Citation
Xiao, B, Wang, Y, Li, W, Baker, M, Guo, J, Corbet, K, Tsalik, EL, Li, Q-J, Palmer, SM, Woods, CW, Li, Z, Chao, NJ, and He, Y-W. "Plasma microRNA signature as a noninvasive biomarker for acute graft-versus-host disease." Blood 122.19 (November 7, 2013): 3365-3375.
PMID
24041574
Source
pubmed
Published In
Blood
Volume
122
Issue
19
Publish Date
2013
Start Page
3365
End Page
3375
DOI
10.1182/blood-2013-06-510586

CFLIP Regulates Skin Homeostasis and Protects against TNF-Induced Keratinocyte Apoptosis

FADD, caspase-8, and cFLIP regulate the outcome ofcell death signaling. Mice that constitutively lack these molecules die at an early embryonic age, whereas tissue-specific constitutive deletion of FADD or caspase-8 results in inflammatory skin disease caused by increased necroptosis. The function of cFLIP in the skin invivo is unknown. In contrast to tissue-specific caspase-8 knockout, we show that mice constitutively lacking cFLIP in the epidermis die around embryonic days 10 and 11. When cFLIP expression was abrogated in adult skin of cFLIPfl/fl-K14CreERtam mice, severe inflammation of the skin with concomitant caspase activation and apoptotic, but not necroptotic, cell death developed. Apoptosis was dependent of autocrine tumor necrosis factor production triggered by loss of cFLIP. Inaddition, epidermal cFLIP protein was lost in patients with severe drug reactions associated with epidermal apoptosis. Our data demonstrate the importance of cFLIP for the integrity of the epidermis and for silencing of spontaneous skin inflammation

Authors
Panayotova-Dimitrova, D; Feoktistova, M; Ploesser, M; Kellert, B; Hupe, M; Horn, S; Makarov, R; Jensen, F; Porubsky, S; Schmieder, A; Zenclussen, A; Marx, A; Kerstan, A; Geserick, P; He, YW; Leverkus, M
MLA Citation
Panayotova-Dimitrova, D, Feoktistova, M, Ploesser, M, Kellert, B, Hupe, M, Horn, S, Makarov, R, Jensen, F, Porubsky, S, Schmieder, A, Zenclussen, A, Marx, A, Kerstan, A, Geserick, P, He, YW, and Leverkus, M. "CFLIP Regulates Skin Homeostasis and Protects against TNF-Induced Keratinocyte Apoptosis." Cell Reports 5.2 (October 28, 2013): 397-408.
PMID
24209745
Source
scopus
Published In
Cell Reports
Volume
5
Issue
2
Publish Date
2013
Start Page
397
End Page
408
DOI
10.1016/j.celrep.2013.09.035

T Lymphocytes from Chronic HCV-Infected Patients Are Primed for Activation-Induced Apoptosis and Express Unique Pro-Apoptotic Gene Signature

Although extensive studies have demonstrated the functional impairment of antigen-specific CD4+ and CD8+ T-cells during chronic hepatitis C virus (HCV) infection, the functional status of global CD4+ and CD8+ T-cells remains unclear. In this report, we recruited 42 long-term (~20 years) treatment-naïve chronic HCV (CHC) patients and 15 healthy donors (HDs) to investigate differences in global CD4+ and CD8+ T-cells function. We show that CD4+ and CD8+ T-cells from CHC patients underwent increased apoptosis after TCR stimulation. Furthermore, IFN-γ, IL-9 and IP-10 were elevated in CHC patients' plasma and promoted activation-induced T-cells death. Global CD4+ and CD8+ T-cells also showed unique transcriptional profiles in the expression of apoptosis-related genes. We identified BCL2, PMAIP1, and CASP1 in CD4+ T-cells and IER3 and BCL2A1 in CD8+ T-cells from CHC patients as HCV-specific gene signatures. Importantly, the gene expression patterns of CD4+ and CD8+ T-cells from CHC patients differ from those in CD4+ and CD8+ T-cells from human immunodeficiency virus type 1 (HIV-1) or hepatitis B virus (HBV) infected individuals. Our results indicate that chronic HCV infection causes a systemic change in cytokine levels that primes T-cells for activation-induced apoptosis. Furthermore, HCV infection programs unique apoptosis-related gene expression profiles in CD4+ and CD8+ T-cells, leading to their enhanced activation-induced apoptosis. These results provide novel insights to the pathogenesis of chronic HCV infection. © 2013 Zhao et al.

Authors
Zhao, BB; Zheng, SJ; Gong, LL; Wang, Y; Chen, CF; Jin, WJ; Zhang, D; Yuan, XH; Guo, J; Duan, ZP; He, YW
MLA Citation
Zhao, BB, Zheng, SJ, Gong, LL, Wang, Y, Chen, CF, Jin, WJ, Zhang, D, Yuan, XH, Guo, J, Duan, ZP, and He, YW. "T Lymphocytes from Chronic HCV-Infected Patients Are Primed for Activation-Induced Apoptosis and Express Unique Pro-Apoptotic Gene Signature." PLoS ONE 8.10 (October 10, 2013).
PMID
24130824
Source
scopus
Published In
PloS one
Volume
8
Issue
10
Publish Date
2013
DOI
10.1371/journal.pone.0077008

Role of the Autophagy Gene Atg5 in T Lymphocyte Survival and Proliferation

Macroautophagy (referred to as autophagy) is a highly conserved intracellular process that involves sequestration of cytoplasmic contents by intracellular double-membrane vacuoles. In the adaptive immune system, autophagy is essential for antigen presentation, survival, and activation-induced proliferation of T lymphocytes. Autophagy-related proteins, such as Atg5, Atg7, and LC3, are expressed in T lymphocytes. The basal level of autophagy occurs in resting T lymphocytes, and is enhanced in activated T cells. Both our own and other groups' data show that the autophagy-related gene Atg5 is critical for T cell development, survival, and function. The mitochondrial content of Atg5-deficient naïve T lymphocytes is abnormally high, which leads to defective survival. These findings suggest that autophagy is critical for promoting T lymphocyte survival by regulating intracellular organelle homeostasis. © 2014 Elsevier Inc. All rights reserved.

Authors
He, MX; Wan, Y; He, YW
MLA Citation
He, MX, Wan, Y, and He, YW. "Role of the Autophagy Gene Atg5 in T Lymphocyte Survival and Proliferation." (October 1, 2013): 239-244. (Chapter)
Source
scopus
Publish Date
2013
Start Page
239
End Page
244
DOI
10.1016/B978-0-12-405877-4.00016-0

Epidermal cFLIP is a critical regulator of skin homeostasis and protects from TNF-induced keratinocyte apoptosis

Authors
Panayotova-Dimitrova, D; Feoktistova, M; Kellert, B; Ploesser, M; Marx, A; Porubsky, S; Hupe, M; Jensen, F; Zenclussen, A; Geserick, P; He, Y; Leverkus, M
MLA Citation
Panayotova-Dimitrova, D, Feoktistova, M, Kellert, B, Ploesser, M, Marx, A, Porubsky, S, Hupe, M, Jensen, F, Zenclussen, A, Geserick, P, He, Y, and Leverkus, M. "Epidermal cFLIP is a critical regulator of skin homeostasis and protects from TNF-induced keratinocyte apoptosis." May 2013.
Source
wos-lite
Published In
Journal of Investigative Dermatology
Volume
133
Publish Date
2013
Start Page
S32
End Page
S32

Epidermal cFLIP is a critical regulator of skin homeostasis and protects embryonic development in mice

Authors
Panayotova-Dimitrova, D; Feoktistova, M; Ploesser, M; Kellert, B; Hupe, M; Horn, S; Makarov, R; Jensen, F; Porubsky, S; Schmieder, A; Zenclussen, A; Marx, A; Kerstan, A; Geserick, P; He, Y; Leverkus, M
MLA Citation
Panayotova-Dimitrova, D, Feoktistova, M, Ploesser, M, Kellert, B, Hupe, M, Horn, S, Makarov, R, Jensen, F, Porubsky, S, Schmieder, A, Zenclussen, A, Marx, A, Kerstan, A, Geserick, P, He, Y, and Leverkus, M. "Epidermal cFLIP is a critical regulator of skin homeostasis and protects embryonic development in mice." March 2013.
Source
wos-lite
Published In
Experimental Dermatology
Volume
22
Issue
3
Publish Date
2013
Start Page
E8
End Page
E8

Transfer of CD8+ T cell memory using Bcl-2 as a marker.

The processes that regulate T cell memory generation are important for therapeutic design and the immune response to disease. However, what allows a subset of effector T cells to survive the contraction period to become memory cells is incompletely understood. The Bcl-2 family is critical for T cell survival, and Bcl-2 has been proposed to be important for the survival of memory cells. However, previous studies have relied on double-knockout models, potentially skewing the role of Bcl-2, and the use of Bcl-2 as a marker in adoptive transfer experiments, a method required to confirm the memory potential of cell subsets, has not been possible because of the intracellular localization of the protein. In this study, we present a novel Bcl-2 reporter mouse model and, to our knowledge, show for the first time that a distinct subset of effector T cells, and also a subset within the CD127(hi)KLRG1(lo) memory precursor effector cell population, retains high Bcl-2 expression at the peak of the CD8(+) T cell response to Listeria monocytogenes. Furthermore, we show that Bcl-2 correlates with memory potential in adoptive transfer experiments using both total responding CD8(+) T cells and memory precursor effector cells. These results show that even within the memory precursor effector cell population, Bcl-2 confers a survival advantage in a subset of effector CD8(+) T cells that allows differentiation into memory cells and cement Bcl-2 as a critical factor for T cell memory.

Authors
Dunkle, A; Dzhagalov, I; Gordy, C; He, Y-W
MLA Citation
Dunkle, A, Dzhagalov, I, Gordy, C, and He, Y-W. "Transfer of CD8+ T cell memory using Bcl-2 as a marker." J Immunol 190.3 (February 1, 2013): 940-947.
PMID
23269245
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
190
Issue
3
Publish Date
2013
Start Page
940
End Page
947
DOI
10.4049/jimmunol.1103481

A role for c-FLIP(L) in the regulation of apoptosis, autophagy, and necroptosis in T lymphocytes.

Caspase 8 plays a dual role in the survival of T lymphocytes. Although active caspase 8 mediates apoptosis upon death receptor signaling, the loss of caspase 8 activity leads to receptor-interacting protein (RIP)-1/RIP-3-dependent necrotic cell death (necroptosis) upon TCR activation. The anti-apoptotic protein c-FLIP (cellular caspase 8 (FLICE)-like inhibitory protein) suppresses death receptor-induced caspase 8 activation. Moreover, recent findings suggest that c-FLIP is also involved in inhibiting necroptosis and autophagy. It remains unclear whether c-FLIP protects primary T lymphocytes from necroptosis or regulates the threshold at which autophagy occurs. Here, we used a c-FLIP isoform-specific conditional deletion model to show that c-FLIP(L)-deficient T cells underwent RIP-1-dependent necroptosis upon TCR stimulation. Interestingly, although previous studies have only described necroptosis in the absence of caspase 8 activity, we found that pro-apoptotic caspase 8 activity and apoptosis were also enhanced in c-FLIP(L)-deficient T lymphocytes. Furthermore, c-FLIP(L)-deficient T cells exhibited enhanced autophagy, which served a cytoprotective function. Together, these findings indicate that c-FLIP(L) plays an important antinecroptotic role and is a key regulator of apoptosis, autophagy, and necroptosis in T lymphocytes.

Authors
He, M-X; He, Y-W
MLA Citation
He, M-X, and He, Y-W. "A role for c-FLIP(L) in the regulation of apoptosis, autophagy, and necroptosis in T lymphocytes." Cell Death Differ 20.2 (February 2013): 188-197.
PMID
23175183
Source
pubmed
Published In
Cell Death & Differentiation
Volume
20
Issue
2
Publish Date
2013
Start Page
188
End Page
197
DOI
10.1038/cdd.2012.148

A novel antibody humanization method based on epitopes scanning and molecular dynamics simulation.

1-17-2 is a rat anti-human DEC-205 monoclonal antibody that induces internalization and delivers antigen to dendritic cells (DCs). The potentially clinical application of this antibody is limited by its murine origin. Traditional humanization method such as complementarity determining regions (CDRs) graft often leads to a decreased or even lost affinity. Here we have developed a novel antibody humanization method based on computer modeling and bioinformatics analysis. First, we used homology modeling technology to build the precise model of Fab. A novel epitope scanning algorithm was designed to identify antigenic residues in the framework regions (FRs) that need to be mutated to human counterpart in the humanization process. Then virtual mutation and molecular dynamics (MD) simulation were used to assess the conformational impact imposed by all the mutations. By comparing the root-mean-square deviations (RMSDs) of CDRs, we found five key residues whose mutations would destroy the original conformation of CDRs. These residues need to be back-mutated to rescue the antibody binding affinity. Finally we constructed the antibodies in vitro and compared their binding affinity by flow cytometry and surface plasmon resonance (SPR) assay. The binding affinity of the refined humanized antibody was similar to that of the original rat antibody. Our results have established a novel method based on epitopes scanning and MD simulation for antibody humanization.

Authors
Zhang, D; Chen, C-F; Zhao, B-B; Gong, L-L; Jin, W-J; Liu, J-J; Wang, J-F; Wang, T-T; Yuan, X-H; He, Y-W
MLA Citation
Zhang, D, Chen, C-F, Zhao, B-B, Gong, L-L, Jin, W-J, Liu, J-J, Wang, J-F, Wang, T-T, Yuan, X-H, and He, Y-W. "A novel antibody humanization method based on epitopes scanning and molecular dynamics simulation." PloS one 8.11 (January 2013): e80636-.
PMID
24278299
Source
epmc
Published In
PloS one
Volume
8
Issue
11
Publish Date
2013
Start Page
e80636
DOI
10.1371/journal.pone.0080636

Participation of c-FLIP in NLRP3 and AIM2 inflammasome activation

Authors
Wu, Y-H; Kuo, W-C; Wu, Y-J; Yang, K-T; Chen, S-T; Jiang, S-T; Gordy, C; He, Y-W; Lai, M-Z
MLA Citation
Wu, Y-H, Kuo, W-C, Wu, Y-J, Yang, K-T, Chen, S-T, Jiang, S-T, Gordy, C, He, Y-W, and Lai, M-Z. "Participation of c-FLIP in NLRP3 and AIM2 inflammasome activation." Cell Death and Differentiation (2013).
PMID
24270411
Source
scopus
Published In
Cell Death & Differentiation
Publish Date
2013

CFLAR/c-FLIPL: A star in the autophagy, apoptosis and necroptosis alliance

Necroptosis, a caspase-independent, receptor (TNFRSF)-interacting serine-threonine kinase 1 (RIPK1)/ RIPK3-dependent necrotic cell death, occurs in cells when apoptosis is blocked. A high level of macroautophagy (herein referred to as autophagy) is usually detected in necroptotic cells, although it is still controversial as to whether excessive autophagy leads to cell death or is cytoprotective. In a recently published paper, we show that the anti-apoptotic protein CFLAR (CASP8 and FADDlike apoptosis regulator) long isoform (CFLARL) plays a critical role in all three fundamental intracellular processes: autophagy, necroptosis, and apoptosis in T lymphocytes. CFLARL-deficient T cells suffer from severe cell death upon T cell receptor stimulation, in which both apoptosis and necroptosis are involved. Autophagy is enhanced in both naive and activated CFLARL-deficient T cells and plays a cytoprotective function. Here, we summarize our findings and discuss the future direction in the study of the interplay of autophagy, apoptosis and necroptosis in T lymphocytes. © 2013 Landes Bioscience.

Authors
He, M-X; He, Y-W
MLA Citation
He, M-X, and He, Y-W. "CFLAR/c-FLIPL: A star in the autophagy, apoptosis and necroptosis alliance." Autophagy 9.5 (2013): 791-793.
PMID
23392074
Source
scival
Published In
Autophagy
Volume
9
Issue
5
Publish Date
2013
Start Page
791
End Page
793
DOI
10.4161/auto.23785

Transcriptomic analysis of peripheral blood mononuclear cells in rapid progressors in early HIV infection identifies a signature closely correlated with disease progression

BACKGROUND: A substantial percentage (10%-15%) of HIV-infected individuals experience a sharp decline in CD4μ T-cell counts and progress to AIDS quickly after primary infection. Identification of biomarkers distinguishing rapid progressors (RPs) vs chronic progressors (CPs) is critical for early clinical intervention and could provide novel strategies to facilitate vaccine design and immune therapy. METHODS: mRNAand microRNA (miRNA) expression profiles in the peripheral blood mononuclear cells (PBMCs) of RPs and CPs were investigated at 111 (22) days [mean (SD)] of HIV infection. The association of mRNA and miRNA expression with disease progression was examined by ROC analysis and Kaplan-Meier survival analysis. RESULTS: Pathway enrichment analysis showed that genes with deregulated expression in RPs were primarily involved in apoptosis pathways. Furthermore, we found that 5 miRNAs (miR-31, -200c, -526a, -99a, and -503) in RPs were significantly decreased compared to those in CPs (P<0.05). The decreased expression of these miRNAs was associated with a rapid disease of progression of HIV infection with a 94% predictive value as measured by the area under the curve. The upregulated predicted targets from the 5 signature miRNAs and all upregulated genes identified from mRNA microarray analysis converged to the apoptosis pathway. Moreover, overexpression of miR-31 in primary human T cells promoted their survival. CONCLUSIONS: Our results have identified a distinct transcriptomic signature in PBMCs of RPs and provided novel insights to the pathogenesis of HIV infection. © 2013 American Association for Clinical Chemistry.

Authors
Zhang, Z-N; Xu, J-J; Fu, Y-J; Liu, J; Jiang, Y-J; Cui, H-L; Zhao, B; Sun, H; He, Y-W; Li, Q-J; Shang, H
MLA Citation
Zhang, Z-N, Xu, J-J, Fu, Y-J, Liu, J, Jiang, Y-J, Cui, H-L, Zhao, B, Sun, H, He, Y-W, Li, Q-J, and Shang, H. "Transcriptomic analysis of peripheral blood mononuclear cells in rapid progressors in early HIV infection identifies a signature closely correlated with disease progression." Clinical Chemistry 59.8 (2013): 1175-1186.
PMID
23592504
Source
scival
Published In
Clinical chemistry
Volume
59
Issue
8
Publish Date
2013
Start Page
1175
End Page
1186
DOI
10.1373/clinchem.2012.197335

Diabetic liver injury from streptozotocin is regulated through the caspase-8 homolog cFLIP involving activation of JNK2 and intrahepatic immunocompetent cells

The endemic occurrence of obesity and the associated risk factors that constitute the metabolic syndrome have been predicted to lead to a dramatic increase in chronic liver disease. Non-alcoholic steatohepatitis (NASH) has become the most frequent liver disease in countries with a high prevalence of obesity. In addition, hepatic steatosis and insulin resistance have been implicated in disease progression of other liver diseases, including chronic viral hepatitis and hepatocellular carcinoma. The molecular mechanisms underlying the link between insulin signaling and hepatocellular injury are only partly understood. We have explored the role of the antiapoptotic caspase-8 homolog cellular FLICE-inhibitory protein (cFLIP) on liver cell survival in a diabetic model with hypoinsulinemic diabetes in order to delineate the role of insulin signaling on hepatocellular survival. cFLIP regulates cellular injury from apoptosis signaling pathways, and loss of cFLIP was previously shown to promote injury from activated TNF and CD95/Apo-1 receptors. In mice lacking cFLIP in hepatocytes (flip-/-), loss of insulin following streptozotocin treatment resulted in caspase-and c-Jun N-terminal kinase (JNK)-dependent liver injury after 21 days. Substitution of insulin, inhibition of JNK using the SP600125 compound in vivo or genetic deletion of the mitogen-activated protein kinase (MAPK)9 (JNK2) in all tissues abolished the injurious effect. Strikingly, the difference in injury between wild-type and cFLIP-deficient mice occurred only in vivo and was accompanied by liver-infiltrating inflammatory cells with a trend toward increased amounts of NK1.1-positive cells and secretion of proinflammatory cytokines. Transfer of bone marrow from rag-1-deficient mice that are depleted from B and T lymphocytes prevented liver injury in flip-/- mice. These findings support a direct role of insulin on cellular survival by alternating the activation of injurious MAPK, caspases and the recruitment of inflammatory cells to the liver. Thus, increasing resistance to insulin signaling pathways in hepatocytes appears to be an important factor in the initiation and progression of chronic liver disease. © 2013 Macmillan Publishers Limited All rights reserved.

Authors
Kohl, T; Gehrke, N; Schad, A; Nagel, M; Wörns, MA; Sprinzl, MF; Zimmermann, T; He, Y-W; Galle, PR; Schuchmann, M; Schattenberg, JM
MLA Citation
Kohl, T, Gehrke, N, Schad, A, Nagel, M, Wörns, MA, Sprinzl, MF, Zimmermann, T, He, Y-W, Galle, PR, Schuchmann, M, and Schattenberg, JM. "Diabetic liver injury from streptozotocin is regulated through the caspase-8 homolog cFLIP involving activation of JNK2 and intrahepatic immunocompetent cells." Cell Death and Disease 4.7 (2013).
PMID
23828575
Source
scival
Published In
Cell Death and Disease
Volume
4
Issue
7
Publish Date
2013
DOI
10.1038/cddis.2013.228

Autophagy, a novel pathway to regulate calcium mobilization in T lymphocytes

The T lymphocyte response initiates with the recognition of MHC/peptides on antigen presenting cells by the T cell receptor (TCR). After the TCR engagement, the proximal signaling pathways are activated for downstream cellular events. Among these pathways, the calcium-signaling flux is activated through the depletion of endoplasmic reticulum (ER) calcium stores and plays pivotal roles in T cell proliferation, cell survival, and apoptosis. In studying the roles of macroautophagy (hereafter referred to as autophagy) in T cell function, we found that a pathway for intracellular degradation, autophagy, regulates calcium signaling by developmentally maintaining the homeostasis of the ER. Using mouse genetic models with specific deletion of autophagy-related genes in T lymphocytes, we found that the calcium influx is defective and the calcium efflux is increased in autophagy-deficient T cells. The abnormal calcium flux is related to the expansion of the ER and higher calcium stores in the ER. Because of this, treatment with the ER sarco/ER Ca2+-ATPase pump inhibitor, thapsigargin, rescues the calcium influx defect in autophagy-deficient T cells. Therefore, autophagy regulates calcium mobilization in T lymphocytes through ER homeostasis. © 2013 Jia, He, McLeod and He.

Authors
Jia, W; He, MX; McLeod, IX; He, YW
MLA Citation
Jia, W, He, MX, McLeod, IX, and He, YW. "Autophagy, a novel pathway to regulate calcium mobilization in T lymphocytes." Frontiers in Immunology 4.JUL (2013).
Source
scival
Published In
Frontiers in Immunology
Volume
4
Issue
JUL
Publish Date
2013
DOI
10.3389/fimmu.2013.00179

cFLIP Regulates Skin Homeostasis and Protects against TNF-Induced Keratinocyte Apoptosis

Authors
Panayotova-Dimitrova, D; Feoktistova, M; Ploesser, M; Kellert, B; Hupe, M; Horn, S; Makarov, R; Jensen, F; Porubsky, S; Schmieder, A; Zenclussen, A; Marx, A; Kerstan, A; Geserick, P; He, Y-W; Leverkus, M
MLA Citation
Panayotova-Dimitrova, D, Feoktistova, M, Ploesser, M, Kellert, B, Hupe, M, Horn, S, Makarov, R, Jensen, F, Porubsky, S, Schmieder, A, Zenclussen, A, Marx, A, Kerstan, A, Geserick, P, He, Y-W, and Leverkus, M. "cFLIP Regulates Skin Homeostasis and Protects against TNF-Induced Keratinocyte Apoptosis." Cell Reports (2013).
Source
scopus
Published In
Cell Reports
Publish Date
2013

c-FLIP maintains tissue homeostasis by preventing apoptosis and programmed necrosis.

As a catalytically inactive homolog of caspase-8, a proapoptotic initiator caspase, c-FLIP blocks apoptosis by binding to and inhibiting caspase-8. The transcription factor nuclear factor κB (NF-κB) plays a pivotal role in maintaining the homeostasis of the intestine and the liver by preventing death receptor-induced apoptosis, and c-FLIP plays a role in the NF-κB-dependent protection of cells from death receptor signaling. Because c-Flip-deficient mice die in utero, we generated conditional c-Flip-deficient mice to investigate the contribution of c-FLIP to homeostasis of the intestine and the liver at developmental and postnatal stages. Intestinal epithelial cell (IEC)- or hepatocyte-specific deletion of c-Flip resulted in perinatal lethality as a result of the enhanced apoptosis and programmed necrosis of the IECs and the hepatocytes. Deficiency in the gene encoding tumor necrosis factor-α (TNF-α) receptor 1 (Tnfr1) partially rescued perinatal lethality and the development of colitis in IEC-specific c-Flip-deficient mice but did not rescue perinatal lethality in hepatocyte-specific c-Flip-deficient mice. Moreover, adult mice with interferon (IFN)-inducible deficiency in c-Flip died from hepatitis soon after depletion of c-FLIP. Pretreatment of IFN-inducible c-Flip-deficient mice with a mixture of neutralizing antibodies against TNF-α, Fas ligand (FasL), and TNF-related apoptosis-inducing ligand (TRAIL) prevented hepatitis. Together, these results suggest that c-FLIP controls the homeostasis of IECs and hepatocytes by preventing cell death induced by TNF-α, FasL, and TRAIL.

Authors
Piao, X; Komazawa-Sakon, S; Nishina, T; Koike, M; Piao, J-H; Ehlken, H; Kurihara, H; Hara, M; Van Rooijen, N; Schütz, G; Ohmuraya, M; Uchiyama, Y; Yagita, H; Okumura, K; He, Y-W; Nakano, H
MLA Citation
Piao, X, Komazawa-Sakon, S, Nishina, T, Koike, M, Piao, J-H, Ehlken, H, Kurihara, H, Hara, M, Van Rooijen, N, Schütz, G, Ohmuraya, M, Uchiyama, Y, Yagita, H, Okumura, K, He, Y-W, and Nakano, H. "c-FLIP maintains tissue homeostasis by preventing apoptosis and programmed necrosis. (Published online)" Sci Signal 5.255 (December 18, 2012): ra93-.
PMID
23250397
Source
pubmed
Published In
Science Signaling
Volume
5
Issue
255
Publish Date
2012
Start Page
ra93
DOI
10.1126/scisignal.2003558

The diverse roles of autophagy in immunity

Autophagy is a highly conserved process in all eukaryotic organisms that has been adapted for a multitude of divergent functions. The mammalian immune system is no exception, with various hematopoietic cells utilizing this intracellular remodeling process for immune homeostasis. In this chapter, we will focus on the role of autophagy in three major areas of immune function: homeostasis of lymphocytes, antigen presentation and pathogen clearance, and thymic selection for immune tolerance. First, autophagy has been shown to be crucial and indispensible for the survival and intracellular homeostasis of both T and B lymphocytes in vivo. This has been demonstrated using multiple genetic models of autophagy ablation as well as pharmacological inhibition of various autophagic signaling pathways. Second, autophagy has been shown to enhance antigen presentation in several types of leukocytes of the innate immune system, including macrophages and dendritic cells, and to both promote and inhibit the clearance of several intracellular pathogens. Lastly, in a very nascent field of autophagy in thymic epithelial cells, autophagy promotes the processing and surface display of many endogenous antigens in order to influence negative selection and tolerance of developing thymocytes. These examples will clearly demonstrate the complex applications that the panoply of immune cells has evolved to initiate and maintain immune function using an archaic process found in the most primal of eukaryotes. © 2012 by Nova Science Publishers, Inc. All rights reserved.

Authors
McLeod, IX; Jia, W; He, YW
MLA Citation
McLeod, IX, Jia, W, and He, YW. "The diverse roles of autophagy in immunity." (December 1, 2012): 1-24. (Chapter)
Source
scopus
Publish Date
2012
Start Page
1
End Page
24

The contribution of autophagy to lymphocyte survival and homeostasis.

Over the life span of a T lymphocyte, from thymic development to death, it is subjected to a variety of stresses and stimuli. Upon receipt of each stress or stimulus, a potentially life-changing fate decision must be made, namely, whether to commit to a form of programmed cell death or to make the necessary adaptations to effectively deal with the changing environment. In our laboratory, we have identified several stresses that a T lymphocyte will encounter during a normal life span. Our studies have focused on how T cells utilize autophagy to get a grasp on the situation, or in cases in which survival is untenable, how T cells use autophagy to hasten their demise. This review focuses on the functions of T-cell autophagy in maintaining homeostasis, eliminating excess or dangerous levels of mitochondria, trimming levels of endoplasmic reticulum, and promoting a healthy metabolic level to allow cells to perform as productive components of the immune system. In addition, the use of autophagy signaling molecules to perform autophagy-independent tasks involved in the maintenance of immune homeostasis is discussed.

Authors
McLeod, IX; Jia, W; He, Y-W
MLA Citation
McLeod, IX, Jia, W, and He, Y-W. "The contribution of autophagy to lymphocyte survival and homeostasis." Immunol Rev 249.1 (September 2012): 195-204. (Review)
PMID
22889223
Source
pubmed
Published In
Immunological Reviews
Volume
249
Issue
1
Publish Date
2012
Start Page
195
End Page
204
DOI
10.1111/j.1600-065X.2012.01143.x

Editorial: TRPV1: how thymocytes sense stress and respond with autophagy.

Authors
McLeod, IX; He, Y-W
MLA Citation
McLeod, IX, and He, Y-W. "Editorial: TRPV1: how thymocytes sense stress and respond with autophagy." J Leukoc Biol 92.3 (September 2012): 409-411.
PMID
22936836
Source
pubmed
Published In
Journal of leukocyte biology
Volume
92
Issue
3
Publish Date
2012
Start Page
409
End Page
411
DOI
10.1189/jlb.0612269

Autophagic activity dictates the cellular response to oncogenic RAS.

RAS is frequently mutated in human cancers and has opposing effects on autophagy and tumorigenesis. Identifying determinants of the cellular responses to RAS is therefore vital in cancer research. Here, we show that autophagic activity dictates the cellular response to oncogenic RAS. N-terminal Apoptosis-stimulating of p53 protein 2 (ASPP2) mediates RAS-induced senescence and inhibits autophagy. Oncogenic RAS-expressing ASPP2((Δ3/Δ3)) mouse embryonic fibroblasts that escape senescence express a high level of ATG5/ATG12. Consistent with the notion that autophagy levels control the cellular response to oncogenic RAS, overexpressing ATG5, but not autophagy-deficient ATG5 mutant K130R, bypasses RAS-induced senescence, whereas ATG5 or ATG3 deficiency predisposes to it. Mechanistically, ASPP2 inhibits RAS-induced autophagy by competing with ATG16 to bind ATG5/ATG12 and preventing ATG16/ATG5/ATG12 formation. Hence, ASPP2 modulates oncogenic RAS-induced autophagic activity to dictate the cellular response to RAS: to proliferate or senesce.

Authors
Wang, Y; Wang, XD; Lapi, E; Sullivan, A; Jia, W; He, Y-W; Ratnayaka, I; Zhong, S; Goldin, RD; Goemans, CG; Tolkovsky, AM; Lu, X
MLA Citation
Wang, Y, Wang, XD, Lapi, E, Sullivan, A, Jia, W, He, Y-W, Ratnayaka, I, Zhong, S, Goldin, RD, Goemans, CG, Tolkovsky, AM, and Lu, X. "Autophagic activity dictates the cellular response to oncogenic RAS." Proc Natl Acad Sci U S A 109.33 (August 14, 2012): 13325-13330.
PMID
22847423
Source
pubmed
Published In
Proceedings of the National Academy of Sciences of USA
Volume
109
Issue
33
Publish Date
2012
Start Page
13325
End Page
13330
DOI
10.1073/pnas.1120193109

Selective autophagy of the adaptor protein Bcl10 modulates T cell receptor activation of NF-κB.

The adaptor protein Bcl10 is a critically important mediator of T cell receptor (TCR)-to-NF-κB signaling. Bcl10 degradation is a poorly understood biological phenomenon suggested to reduce TCR activation of NF-κB. Here we have shown that TCR engagement triggers the degradation of Bcl10 in primary effector T cells but not in naive T cells. TCR engagement promoted K63 polyubiquitination of Bcl10, causing Bcl10 association with the autophagy adaptor p62. Paradoxically, p62 binding was required for both Bcl10 signaling to NF-κB and gradual degradation of Bcl10 by autophagy. Bcl10 autophagy was highly selective, as shown by the fact that it spared Malt1, a direct Bcl10 binding partner. Blockade of Bcl10 autophagy enhanced TCR activation of NF-κB. Together, these data demonstrate that selective autophagy of Bcl10 is a pathway-intrinsic homeostatic mechanism that modulates TCR signaling to NF-κB in effector T cells. This homeostatic process may protect T cells from adverse consequences of unrestrained NF-κB activation, such as cellular senescence.

Authors
Paul, S; Kashyap, AK; Jia, W; He, Y-W; Schaefer, BC
MLA Citation
Paul, S, Kashyap, AK, Jia, W, He, Y-W, and Schaefer, BC. "Selective autophagy of the adaptor protein Bcl10 modulates T cell receptor activation of NF-κB." Immunity 36.6 (June 29, 2012): 947-958.
PMID
22658522
Source
pubmed
Published In
Immunity
Volume
36
Issue
6
Publish Date
2012
Start Page
947
End Page
958
DOI
10.1016/j.immuni.2012.04.008

Guidelines for the use and interpretation of assays for monitoring autophagy.

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.

Authors
Klionsky, DJ; Abdalla, FC; Abeliovich, H; Abraham, RT; Acevedo-Arozena, A; Adeli, K; Agholme, L; Agnello, M; Agostinis, P; Aguirre-Ghiso, JA; Ahn, HJ; Ait-Mohamed, O; Ait-Si-Ali, S; Akematsu, T; Akira, S; Al-Younes, HM; Al-Zeer, MA; Albert, ML; Albin, RL; Alegre-Abarrategui, J; Aleo, MF; Alirezaei, M; Almasan, A; Almonte-Becerril, M; Amano, A; Amaravadi, R; Amarnath, S; Amer, AO; Andrieu-Abadie, N; Anantharam, V; Ann, DK; Anoopkumar-Dukie, S; Aoki, H; Apostolova, N; Arancia, G; Aris, JP et al.
MLA Citation
Klionsky, DJ, Abdalla, FC, Abeliovich, H, Abraham, RT, Acevedo-Arozena, A, Adeli, K, Agholme, L, Agnello, M, Agostinis, P, Aguirre-Ghiso, JA, Ahn, HJ, Ait-Mohamed, O, Ait-Si-Ali, S, Akematsu, T, Akira, S, Al-Younes, HM, Al-Zeer, MA, Albert, ML, Albin, RL, Alegre-Abarrategui, J, Aleo, MF, Alirezaei, M, Almasan, A, Almonte-Becerril, M, Amano, A, Amaravadi, R, Amarnath, S, Amer, AO, Andrieu-Abadie, N, Anantharam, V, Ann, DK, Anoopkumar-Dukie, S, Aoki, H, Apostolova, N, Arancia, G, and Aris, JP et al. "Guidelines for the use and interpretation of assays for monitoring autophagy." Autophagy 8.4 (April 2012): 445-544.
PMID
22966490
Source
pubmed
Published In
Autophagy
Volume
8
Issue
4
Publish Date
2012
Start Page
445
End Page
544

ACUTE LIVER FAILURE IN MICE FOLLOWING DELETION OF CFLIP - A KEY ROLE OF APOPTOSIS SIGNALING PATHWAYS IN TISSUE HOMEOSTASIS

Authors
Schattenberg, JM; Bardon, DG; Wagner, I; Woerns, MA; Zimmermann, T; Schad, A; He, YW; Galle, PR; Schuchmann, M
MLA Citation
Schattenberg, JM, Bardon, DG, Wagner, I, Woerns, MA, Zimmermann, T, Schad, A, He, YW, Galle, PR, and Schuchmann, M. "ACUTE LIVER FAILURE IN MICE FOLLOWING DELETION OF CFLIP - A KEY ROLE OF APOPTOSIS SIGNALING PATHWAYS IN TISSUE HOMEOSTASIS." April 2012.
Source
wos-lite
Published In
Journal of Hepatology
Volume
56
Publish Date
2012
Start Page
S135
End Page
S135

Macroautophagy in T lymphocyte development and function.

Macroautophagy (referred to as autophagy) is a fundamental intracellular process characterized by the sequestration of cytoplasmic compartments through double-membrane vesicles, termed autophagosomes. Recent studies have established important roles of autophagy in regulating T lymphocyte development and function. Resting T lymphocytes have basal levels of autophagy that is upregulated by T cell receptor stimulation. Several specific knockout or transgenic models have been developed during the past few years, and it has been revealed that autophagy plays an essential role in regulating thymocyte selection, peripheral T cell survival, and proliferation. The regulation of T cell development and function by autophagy is mediated through its role in regulating self-antigen presentation, intracellular organelle homeostasis, and energy production. Here we will review the current findings concerning how autophagy regulates T cell function, as well as compare different models in studying autophagy in T lymphocytes.

Authors
He, M-X; McLeod, IX; Jia, W; He, Y-W
MLA Citation
He, M-X, McLeod, IX, Jia, W, and He, Y-W. "Macroautophagy in T lymphocyte development and function. (Published online)" Front Immunol 3 (2012): 22-.
PMID
22566906
Source
pubmed
Published In
Frontiers in Immunology
Volume
3
Publish Date
2012
Start Page
22
DOI
10.3389/fimmu.2012.00022

Downregulation of the AU-rich RNA-binding protein ZFP36 in chronic HBV patients: implications for anti-inflammatory therapy.

Inflammation caused by chronic hepatitis B virus (HBV) infection is associated with the development of cirrhosis and hepatocellular carcinoma; however, the mechanisms by which HBV infection induces inflammation and inflammatory cytokine production remain largely unknown. We analyzed the gene expression patterns of lymphocytes from chronic HBV-infected patients and found that the expression of ZFP36, an AU-rich element (ARE)-binding protein, was dramatically reduced in CD4(+) and CD8(+) T lymphocytes from chronic HBV patients. ZFP36 expression was also reduced in CD14(+) monocytes and in total PBMCs from chronic HBV patients. To investigate the functional consequences of reduced ZFP36 expression, we knocked down ZFP36 in PBMCs from healthy donors using siRNA. siRNA-mediated silencing of ZFP36 resulted in dramatically increased expression of multiple inflammatory cytokines, most of which were also increased in the plasma of chronic HBV patients. Furthermore, we found that IL-8 and RANTES induced ZFP36 downregulation, and this effect was mediated through protein kinase C. Importantly, we found that HBsAg stimulated PBMCs to express IL-8 and RANTES, resulting in decreased ZFP36 expression. Our results suggest that an inflammatory feedback loop involving HBsAg, ZFP36, and inflammatory cytokines may play a critical role in the pathogenesis of chronic HBV and further indicate that ZFP36 may be an important target for anti-inflammatory therapy during chronic HBV infection.

Authors
Jin, W-J; Chen, C-F; Liao, H-Y; Gong, L-L; Yuan, X-H; Zhao, B-B; Zhang, D; Feng, X; Liu, J-J; Wang, Y; Chen, G-F; Yan, H-P; He, Y-W
MLA Citation
Jin, W-J, Chen, C-F, Liao, H-Y, Gong, L-L, Yuan, X-H, Zhao, B-B, Zhang, D, Feng, X, Liu, J-J, Wang, Y, Chen, G-F, Yan, H-P, and He, Y-W. "Downregulation of the AU-rich RNA-binding protein ZFP36 in chronic HBV patients: implications for anti-inflammatory therapy." PLoS One 7.3 (2012): e33356-.
PMID
22428029
Source
pubmed
Published In
PloS one
Volume
7
Issue
3
Publish Date
2012
Start Page
e33356
DOI
10.1371/journal.pone.0033356

Suppressing autoimmunity by TGF-β: Not just through T reg cells

Authors
He, M-X; He, Y-W
MLA Citation
He, M-X, and He, Y-W. "Suppressing autoimmunity by TGF-β: Not just through T reg cells." Cellular and Molecular Immunology 9.5 (2012): 371-372.
PMID
22885526
Source
scival
Published In
Cellular & molecular immunology
Volume
9
Issue
5
Publish Date
2012
Start Page
371
End Page
372
DOI
10.1038/cmi.2012.24

Disruption of mindin exacerbates cardiac hypertrophy and fibrosis

Cardiac hypertrophy is a response of the myocardium to increased workload and is characterised by an increase of myocardial mass and an accumulation of extracellular matrix (ECM). As an ECM protein, an integrin ligand, and an angiogenesis inhibitor, all of which are key players in cardiac hypertrophy, mindin is an attractive target for therapeutic intervention to treat or prevent cardiac hypertrophy and heart failure. In this study, we investigated the role of mindin in cardiac hypertrophy using littermate Mindin knockout (Mindin-/-) and wild-type (WT) mice. Cardiac hypertrophy was induced by aortic banding (AB) or angiotensin II (Ang II) infusion in Mindin-/- and WT echocardiography and by pathological and molecular analyses of heart samples. Mindin-/- mice were more susceptible to cardiac hypertrophy and fibrosis in response to AB or Ang II stimulation than wild type. Cardiac function was also markedly exacerbated during both systole and diastole in Mindin-/- mice in response to hypertrophic stimuli.Western blot assays further showed that the activation of AKT/glycogen synthase kinase 3β (GSK3β) signalling in response to hypertrophic stimuli was significantly increased in Mindin-/- mice. Moreover, blocking AKT/GSK3β signalling with a pharmacological AKT inhibitor reversed cardiac abnormalities in Mindin-/- mice. Our data show that mindin, as an intrinsic cardioprotective factor, prevents maladaptive remodelling and the transition to heart failure by blocking AKT/GSK3β signalling. © Springer-Verlag 2012.

Authors
Bian, Z-Y; Wei, X; Deng, S; Tang, Q-Z; Feng, J; Zhang, Y; Liu, C; Jiang, D-S; Yan, L; Zhang, L-F; Chen, M; Fassett, J; Chen, Y; He, Y-W; Yang, Q; Liu, PP; Li, H
MLA Citation
Bian, Z-Y, Wei, X, Deng, S, Tang, Q-Z, Feng, J, Zhang, Y, Liu, C, Jiang, D-S, Yan, L, Zhang, L-F, Chen, M, Fassett, J, Chen, Y, He, Y-W, Yang, Q, Liu, PP, and Li, H. "Disruption of mindin exacerbates cardiac hypertrophy and fibrosis." Journal of Molecular Medicine 90.8 (2012): 895-910.
PMID
22367478
Source
scival
Published In
Journal of Molecular Medicine
Volume
90
Issue
8
Publish Date
2012
Start Page
895
End Page
910
DOI
10.1007/s00109-012-0883-2

Increased hepatic fibrosis and JNK2-dependent liver injury in mice exhibiting hepatocyte-specific deletion of cFLIP

Chronic liver disease promotes hepatocellular injury involving apoptosis and triggers compensatory regeneration that leads to the activation of quiescent stellate cells in the liver. The deposition of extracellular matrix from activated myofibroblasts promotes hepatic fibrosis and the progression to cirrhosis with deleterious effects on liver physiology. The role of apoptosis signaling pathways in the development of fibrosis remains undefined. The aim of the current study was to determine the involvement of the caspase-8 homologue cellular FLICE-inhibitory protein (cFLIP) during the initiation and progression of fibrosis. Liver injury and fibrosis from carbon tetrachloride (CCl 4) and thioacetamide (TAA) were examined in mice exhibiting a hepatocyte-specific deletion of cFLIP (flip -/-). Acute liver injury from CCl4 and TAA were enhanced in flip -/- mice. This was accompanied by increased activation of caspase-3 and -9, pronounced phosphorylation of JNK, and decreased phosphorylation of Erk. Deletion of the cJun NH2-terminal kinase 2 (JNK2) in flip -/- mice protected from injury. Hepatic fibrosis was increased at baseline in 12-wk-old flip -/- mice, and progression of fibrosis from TAA was accelerated compared with the wild type. In conclusion, deletion of cFLIP in hepatocytes leads to increased fibrosis and accelerated fibrosis progression. This is accompanied by increased injury involving the activation of caspases and JNK2. Thus predisposition to liver injury involving increased hepatocellular apoptosis is a critical mediator of accelerated fibrogenesis, and prevention of liver injury will be a most important measure for patients with chronic liver disease. © 2012 the American Physiological Society.

Authors
Schattenberg, JM; Nagel, M; Kim, YO; Kohl, T; Wörns, MA; Zimmermann, T; Schad, A; Longerich, T; Schuppan, D; He, Y-W; Galle, PR; Schuchmann, M
MLA Citation
Schattenberg, JM, Nagel, M, Kim, YO, Kohl, T, Wörns, MA, Zimmermann, T, Schad, A, Longerich, T, Schuppan, D, He, Y-W, Galle, PR, and Schuchmann, M. "Increased hepatic fibrosis and JNK2-dependent liver injury in mice exhibiting hepatocyte-specific deletion of cFLIP." American Journal of Physiology - Gastrointestinal and Liver Physiology 303.4 (2012): G498-G506.
PMID
22700824
Source
scival
Published In
American journal of physiology. Gastrointestinal and liver physiology
Volume
303
Issue
4
Publish Date
2012
Start Page
G498
End Page
G506
DOI
10.1152/ajpgi.00525.2011

The role of death effector domain-containing proteins in acute oxidative cell injury in hepatocytes

Apoptosis is a mechanism that regulates hepatic tissue homeostasis and contributes to both acute and chronic injury in liver disease. The apoptotic signaling cascade involves activation of the death-inducing signaling complex (DISC) and subsequent recruitment of proteins containing death effector domains (DED), which regulate downstream effector molecules. Prominent among these are the Fas-associated death domain (FADD) and the cellular caspase 8-like inhibitory protein (cFLIP), and alterations in these proteins can lead to severe disruption of physiological processes, including acute liver failure or hepatocellular carcinoma. Their role in cell signaling events independent of the DISC remains undetermined. Oxidative stress can cause cell injury from direct effects on molecules or by activating intracellular signaling pathways including the mitogen-activated protein kinases (MAPKs). In this context, prolonged activation of the cJun N-terminal kinase (JNK)/AP-1/cJun signaling pathway promotes hepatocellular apoptosis, whereas activation of the extracellular signal-regulated kinase (Erk) exerts protection. We investigated the roles of FADD and cFLIP in acute oxidant stress induced by the superoxide generator menadione in hepatocytes. Menadione resulted in dose-dependent predominantly necrotic cell death. Hepatocytes expressing a truncated, dominant-negative FADD protein were partially protected, whereas cFLIP-deficient hepatocytes displayed increased cell death from menadione. In parallel, Erk phosphorylation was enhanced in hepatocytes expressing dnFADD and decreased in cFLIP-deficient hepatocytes. Hepatocyte injury was accompanied by increased release of proapoptotic factors and increased JNK/cJun activation. Thus, FADD and cFLIP contribute to the regulation of cell death from acute oxidant stress in hepatocytes involving MAPK signaling. This implies that DED-containing proteins are involved in the regulation of cellular survival beyond their role in cell death receptor-ligand-mediated apoptosis. © 2012 Elsevier Inc. All rights reserved.

Authors
Schattenberg, JM; Wörns, MA; Zimmermann, T; He, Y-W; Galle, PR; Schuchmann, M
MLA Citation
Schattenberg, JM, Wörns, MA, Zimmermann, T, He, Y-W, Galle, PR, and Schuchmann, M. "The role of death effector domain-containing proteins in acute oxidative cell injury in hepatocytes." Free Radical Biology and Medicine 52.9 (2012): 1911-1917.
PMID
22406316
Source
scival
Published In
Free Radical Biology & Medicine
Volume
52
Issue
9
Publish Date
2012
Start Page
1911
End Page
1917
DOI
10.1016/j.freeradbiomed.2012.02.049

Structure-based high-throughput epitope analysis of hexon proteins in B and C species human adenoviruses (HAdVs)

Human adenoviruses (HAdVs) are the etiologic agent of many human infectious diseases. The existence of at least 54 different serotypes of HAdVs has resulted in difficulties in clinical diagnosis. Acute respiratory tract disease (ARD) caused by some serotypes from B and C species is particularly serious. Hexon, the main coat protein of HAdV, contains the major serotype-specific B cell epitopes; however, few studies have addressed epitope mapping in most HAdV serotypes. In this study, we utilized a novel and rapid method for the modeling of homologous proteins based on the phylogenetic tree of protein families and built three-dimensional (3D) models of hexon proteins in B and C species HAdVs. Based on refined hexon structures, we used reverse evolutionary trace (RET) bioinformatics analysis combined with a specially designed hexon epitope screening algorithm to achieve high-throughput epitope mapping of all 13 hexon proteins in B and C species HAdVs. This study has demonstrated that all of the epitopes from the 13 hexon proteins are located in the proteins' tower regions; however, the exact number, location, and size of the epitopes differ among the HAdV serotypes. © 2012 Yuan et al.

Authors
Yuan, X-H; Wang, Y-C; Jin, W-J; Zhao, B-B; Chen, C-F; Yang, J; Wang, J-F; Guo, Y-Y; Liu, J-J; Zhang, D; Gong, L-L; He, Y-W
MLA Citation
Yuan, X-H, Wang, Y-C, Jin, W-J, Zhao, B-B, Chen, C-F, Yang, J, Wang, J-F, Guo, Y-Y, Liu, J-J, Zhang, D, Gong, L-L, and He, Y-W. "Structure-based high-throughput epitope analysis of hexon proteins in B and C species human adenoviruses (HAdVs)." PLoS ONE 7.3 (2012).
PMID
22427913
Source
scival
Published In
PloS one
Volume
7
Issue
3
Publish Date
2012
DOI
10.1371/journal.pone.0032938

The prolyl isomerase Pin1 modulates development of CD8+ cDC in mice.

BACKGROUND: Pin1 has previously been described to regulate cells that participate in both innate and adaptive immunity. Thus far, however, no role for Pin1 has been described in modulating conventional dendritic cells, innate antigen presenting cells that potently activate naïve T cells, thereby bridging innate and adaptive immune responses. METHODOLOGY/PRINCIPAL FINDINGS: When challenged with LPS, Pin1-null mice failed to accumulate spleen conventional dendritic cells (cDC). Analysis of steady-state spleen DC populations revealed that Pin1-null mice had fewer CD8+ cDC. This defect was recapitulated by culturing Pin1-null bone marrow with the DC-instructive cytokine Flt3 Ligand. Additionally, injection of Flt3 Ligand for 9 days failed to induce robust expansion of CD8+ cDC in Pin1-null mice. Upon infection with Listeria monocytogenes, Pin1-null mice were defective in stimulating proliferation of adoptively transferred WT CD8+ T cells, suggesting that decreases in Pin1 null CD8+ cDC may affect T cell responses to infection in vivo. Finally, upon analyzing expression of proteins involved in DC development, elevated expression of PU.1 was detected in Pin1-null cells, which resulted from an increase in PU.1 protein half-life. CONCLUSIONS/SIGNIFICANCE: We have identified a novel role for Pin1 as a modulator of CD8+ cDC development. Consistent with reduced numbers of CD8+ cDC in Pin1-null mice, we find that the absence of Pin1 impairs CD8+ T cell proliferation in response to infection with Listeria monocytogenes. These data suggest that, via regulation of CD8+ cDC production, Pin1 may serve as an important modulator of adaptive immunity.

Authors
Barberi, TJ; Dunkle, A; He, Y-W; Racioppi, L; Means, AR
MLA Citation
Barberi, TJ, Dunkle, A, He, Y-W, Racioppi, L, and Means, AR. "The prolyl isomerase Pin1 modulates development of CD8+ cDC in mice." PLoS One 7.1 (2012): e29808-.
PMID
22238658
Source
pubmed
Published In
PloS one
Volume
7
Issue
1
Publish Date
2012
Start Page
e29808
DOI
10.1371/journal.pone.0029808

The crosstalk between autophagy and apoptosis: Where does this lead?

Recent advances in the understanding of the molecular processes contributing to autophagy have provided insight into the relationship between autophagy and apoptosis. In contrast to the concept of "autophagic cell death," accumulating evidence suggests that autophagy serves a largely cytoprotective role in physiologically relevant conditions. The cytoprotective function of autophagy is mediated in many circumstances by negative modulation of apoptosis. Apoptotic signaling, in turn, serves to inhibit autophagy. While the mechanisms mediating the complex counter-regulation of apoptosis and autophagy are not yet fully understood, important points of crosstalk include the interactions between Beclin-1 and Bcl-2/Bcl-xL and between FADD and Atg5, caspase- and calpain-mediated cleavage of autophagy-related proteins, and autophagic degradation of caspases. Continued investigation of these and other means of crosstalk between apoptosis and autophagy is necessary to elucidate the mechanisms controlling the balance between survival and death both under normal conditions and in diseases including cancer. © 2012 Higher Education Press and Springer-Verlag Berlin Heidelberg.

Authors
Gordy, C; He, Y-W
MLA Citation
Gordy, C, and He, Y-W. "The crosstalk between autophagy and apoptosis: Where does this lead?." Protein and Cell 3.1 (2012): 17-27.
PMID
22314807
Source
scival
Published In
Protein & Cell
Volume
3
Issue
1
Publish Date
2012
Start Page
17
End Page
27
DOI
10.1007/s13238-011-1127-x

Endocytosis by target cells: An essential means for perforin-and granzyme-mediated killing

Authors
Gordy, C; He, YW
MLA Citation
Gordy, C, and He, YW. "Endocytosis by target cells: An essential means for perforin-and granzyme-mediated killing." Cellular and Molecular Immunology 9.1 (2012): 5-6.
Source
scival
Published In
Cellular & molecular immunology
Volume
9
Issue
1
Publish Date
2012
Start Page
5
End Page
6
DOI
10.1038/cmi.2011.45

Ablation of c-FLIP in hepatocytes enhances death-receptor mediated apoptosis and toxic liver injury in vivo.

BACKGROUND & AIMS: Apoptosis is crucially involved in acute and chronic liver injury, including viral, cholestatic, toxic, and metabolic liver disease. Additionally, dysregulation of apoptosis signaling pathways has been implicated in hepatocarcinogenesis. The most prominent members of the apoptosis-mediating tumor necrosis factor receptor superfamily are the TNF-R1 (CD120a) and the CD95 (Apo-1/Fas) receptor. Although extensively studied, the intracellular signaling events in hepatocytes are only incompletely understood. METHODS: To examine the role of the caspase-8 homolog cellular FLICE-inhibitory protein (c-FLIP) in liver injury, we generated mice with hepatocyte specific deletion of c-FLIP. Three models of acute liver injury were employed: the agonistic anti-CD95 antibody Jo2, d-galactosamine and LPS (GalN/LPS), and concanavalin A. RESULTS: Conditional ablation of c-FLIP in hepatocytes augmented liver injury and cell death in all three models of liver injury. CD95- and GalN/LPS-induced liver injury was ameliorated by a pancaspase inhibitor, while ConA-induced injury was unaffected by caspase inhibition. Augmented activation of the MAPK JNK was observed in parallel to liver injury in c-FLIP knockout mice in all injury models; however, inhibition of JNK only affected TNF- and ConA-mediated injury. CONCLUSIONS: In summary, c-FLIP is a central regulator of cell death in hepatocytes, involving increased activation of caspases and the MAPK JNK.

Authors
Schattenberg, JM; Zimmermann, T; Wörns, M; Sprinzl, MF; Kreft, A; Kohl, T; Nagel, M; Siebler, J; Schulze Bergkamen, H; He, Y-W; Galle, PR; Schuchmann, M
MLA Citation
Schattenberg, JM, Zimmermann, T, Wörns, M, Sprinzl, MF, Kreft, A, Kohl, T, Nagel, M, Siebler, J, Schulze Bergkamen, H, He, Y-W, Galle, PR, and Schuchmann, M. "Ablation of c-FLIP in hepatocytes enhances death-receptor mediated apoptosis and toxic liver injury in vivo." J Hepatol 55.6 (December 2011): 1272-1280.
PMID
21703207
Source
pubmed
Published In
Journal of Hepatology
Volume
55
Issue
6
Publish Date
2011
Start Page
1272
End Page
1280
DOI
10.1016/j.jhep.2011.03.008

The class III kinase Vps34 promotes T lymphocyte survival through regulating IL-7Rα surface expression.

IL-7Rα-mediated signals are essential for naive T lymphocyte survival. Recent studies show that IL-7Rα is internalized and either recycled to cell surface or degraded. However, how the intracellular process of IL-7Rα trafficking is regulated is unclear. In this paper, we show that Vps34, the class III PI3K, plays a critical role in proper IL-7Rα intracellular trafficking. Mice lacking Vps34 in T lymphocytes had a severely reduced T lymphocyte compartment. Vps34-deficient T lymphocytes exhibit increased death and reduced IL-7Rα surface expression, although three major forms of autophagy remain intact. Intracellular IL-7Rα in normal T lymphocytes at steady state is trafficked through either early endosome/multivesicular bodies to the late endosome-Golgi for surface expression or to the lysosome for degradation. However, Vps34-deficient T cells have mislocalized intracellular Eea1, HGF-regulated tyrosine kinase substrate, and Vps36 protein levels, the combined consequence of which is the inability to mobilize internalized IL-7Rα into the retromer pathway for surface display. Our studies reveal that Vps34, though dispensable for autophagy induction, is a critical regulator of naive T cell homeostasis, modulating IL-7Rα trafficking, signaling, and recycling.

Authors
McLeod, IX; Zhou, X; Li, Q-J; Wang, F; He, Y-W
MLA Citation
McLeod, IX, Zhou, X, Li, Q-J, Wang, F, and He, Y-W. "The class III kinase Vps34 promotes T lymphocyte survival through regulating IL-7Rα surface expression." J Immunol 187.10 (November 15, 2011): 5051-5061.
PMID
22021616
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
187
Issue
10
Publish Date
2011
Start Page
5051
End Page
5061
DOI
10.4049/jimmunol.1100710

Cytokine-dependent and cytokine-independent roles for Mcl-1: genetic evidence for multiple mechanisms by which Mcl-1 promotes survival in primary T lymphocytes.

Myeloid cell leukemia sequence-1 (Mcl-1) is a critical anti-apoptotic factor in T lymphocytes. However, in spite of the many pro-apoptotic proteins with proposed binding to Mcl-1, the specific interactions by which Mcl-1 regulates primary T-cell survival under different conditions have not been fully explored. Further, how different trophic cytokines modulate the specific role(s) of Mcl-1 is unknown. Here, we use genetic mouse models to dissect the roles of Mcl-1 in primary T lymphocytes. Using the inducible Mcl-1-floxed estrogen receptor-Cre fusion protein (Mcl-1(f/f)ERCre) deletion system in combination with genetic modification of other B-cell lymphoma 2 (Bcl-2) family members, we show that loss of pro-apoptotic Bcl-2 homologous antagonist/killer (Bak) rescues the survival of Mcl-1-deficient T cells in the presence of IL-7. Without IL-7, the survival of Mcl-1-deficient cells cannot be rescued by loss of Bak, but is partially rescued by overexpression of Bcl-2 or loss of Bcl-2-interacting mediator of cell death (Bim). Thus, Mcl-1 and Bcl-2 have a shared role, the inhibition of Bim, in promoting T-cell survival during cytokine withdrawal. Finally, we show that other common gamma-chain (γc) cytokines differentially modulate the roles of Mcl-1. IL-15 has effects similar to those of IL-7 in memory T cells and naïve CD8(+) cells, but not naïve CD4(+) cells. However, IL-4 maintains Mcl-1 and Bcl-2 but also upregulates Bim and Bcl-2-associated X protein (Bax), thus altering the cell's dependence on Mcl-1.

Authors
Dunkle, A; Dzhagalov, I; He, Y-W
MLA Citation
Dunkle, A, Dzhagalov, I, and He, Y-W. "Cytokine-dependent and cytokine-independent roles for Mcl-1: genetic evidence for multiple mechanisms by which Mcl-1 promotes survival in primary T lymphocytes. (Published online)" Cell Death Dis 2 (October 6, 2011): e214-.
PMID
21975296
Source
pubmed
Published In
Cell Death and Disease
Volume
2
Publish Date
2011
Start Page
e214
DOI
10.1038/cddis.2011.95

The role of the extracellular matrix protein mindin in airway response to environmental airways injury.

BACKGROUND: Our previous work demonstrated that the extracellular matrix protein mindin contributes to allergic airways disease. However, the role of mindin in nonallergic airways disease has not previously been explored. OBJECTIVES: We hypothesized that mindin would contribute to airways disease after inhalation of either lipopolysaccharide (LPS) or ozone. METHODS: We exposed C57BL/6J and mindin-deficient (-/-) mice to aerosolized LPS (0.9 μg/m3 for 2.5 hr), saline, ozone (1 ppm for 3 hr), or filtered air (FA). All mice were evaluated 4 hr after LPS/saline exposure or 24 hr after ozone/FA exposure. We characterized the physiological and biological responses by analysis of airway hyperresponsiveness (AHR) with a computer-controlled small-animal ventilator (FlexiVent), inflammatory cellular recruitment, total protein in bronchoalveolar lavage fluid (BALF), proinflammatory cytokine profiling, and ex vivo bronchial ring studies. RESULTS: After inhalation of LPS, mindin-/- mice demonstrated significantly reduced total cell and neutrophil recruitment into the airspace compared with their wild-type counterparts. Mindin-/- mice also exhibited reduced proinflammatory cytokine production and lower AHR to methacholine challenge by FlexiVent. After inhalation of ozone, mice had no detectible differences in cellular inflammation or total BALF protein dependent on mindin. However, mindin-/- mice were protected from increased proinflammatory cytokine production and AHR compared with their C57BL/6J counterparts. After ozone exposure, bronchial rings derived from mindin-/- mice demonstrated reduced constriction in response to carbachol. CONCLUSIONS: These data demonstrate that the extracellular matrix protein mindin modifies the airway response to both LPS and ozone. Our data support a conserved role of mindin in production of proinflammatory cytokines and the development of AHR in two divergent models of reactive airways disease, as well as a role of mindin in airway smooth muscle contractility after exposure to ozone.

Authors
Frush, S; Li, Z; Potts, EN; Du, W; Eu, JP; Garantziotis, S; He, Y-W; Foster, WM; Hollingsworth, JW
MLA Citation
Frush, S, Li, Z, Potts, EN, Du, W, Eu, JP, Garantziotis, S, He, Y-W, Foster, WM, and Hollingsworth, JW. "The role of the extracellular matrix protein mindin in airway response to environmental airways injury." Environ Health Perspect 119.10 (October 2011): 1403-1408.
PMID
21684833
Source
pubmed
Published In
Environmental health perspectives
Volume
119
Issue
10
Publish Date
2011
Start Page
1403
End Page
1408
DOI
10.1289/ehp.1003339

Temporal regulation of intracellular organelle homeostasis in T lymphocytes by autophagy.

The highly conserved self-degradation pathway known as autophagy plays important roles in regulating T lymphocyte homeostasis. Recently, we found that T lymphocytes lacking the autophagy-related gene Atg5 or Atg7 have defective survival and contain expanded mitochondria and endoplasmic reticulum (ER); however, whether these defects are caused by impaired autophagy or by defects in their autophagy-independent signaling capacity of Atg5 or Atg7 in T lymphocytes remains unknown. Furthermore, the function of the microtubule-associated protein L chain 3 (LC3) conjugation system in T lymphocytes remains unclear. To address these questions, we generated conditional knockout mice with specific deletion of Atg3, a ubiquitin enzyme E2-like molecule involved in the LC3 conjugation system, in T lymphocytes. Atg3-deficient T lymphocytes displayed a phenotype similar to those of Atg7- and Atg5-deficient T cells. The survival of Atg3-deficient naive CD4(+) and CD8(+) T cells was defective. Furthermore, the mitochondria and ER were expanded in Atg3-deficient T cells. Interestingly, mitochondrial and ER content did not change instantly upon inducible deletion of Atg3 in mature T lymphocytes in vitro. Instead, it began to expand 10 d after inducible deletion of Atg3 in mature T lymphocytes, and mitochondrial content continued to increase on day 18. Cell death began to increase 24 d after inducible deletion of Atg3. These data show that the LC3 conjugation system is essential for autophagy in T lymphocytes. Our data suggest that autophagy promotes T lymphocyte survival by regulating organelle homeostasis and that the decreased survival of autophagy-deficient T cells is due to the temporal accumulation of these autophagy-related defects.

Authors
Jia, W; He, Y-W
MLA Citation
Jia, W, and He, Y-W. "Temporal regulation of intracellular organelle homeostasis in T lymphocytes by autophagy." J Immunol 186.9 (May 1, 2011): 5313-5322.
PMID
21421856
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
186
Issue
9
Publish Date
2011
Start Page
5313
End Page
5322
DOI
10.4049/jimmunol.1002404

Autophagy is essential to suppress cell stress and to allow BCR-Abl-mediated leukemogenesis.

Hematopoietic cells normally require cell extrinsic signals to maintain metabolism and survival. In contrast, cancer cells can express constitutively active oncogenic kinases such as BCR-Abl that promote these processes independent of extrinsic growth factors. When cells receive insufficient growth signals or when oncogenic kinases are inhibited, glucose metabolism decreases and the self-digestive process of autophagy is elevated to degrade bulk cytoplasm and organelles. Although autophagy has been proposed to provide a cell-intrinsic nutrient supply for mitochondrial oxidative metabolism and to maintain cellular homeostasis through degradation of damaged organelles or protein aggregates, its acute role in growth factor deprivation or inhibition of oncogenic kinases remains poorly understood. We therefore developed a growth factor-dependent hematopoietic cell culture model in which autophagy can be acutely disrupted through conditional Cre-mediated excision of the autophagy-essential gene Atg3. Treated cells rapidly lost their ability to perform autophagy and underwent cell cycle arrest and apoptosis. Although Atg3 was essential for optimal upregulation of mitochondrial oxidative pathways in growth factor withdrawal, this metabolic contribution of autophagy did not appear critical for cell survival, as provision of exogenous pyruvate or lipids could not completely rescue Atg3 deficiency. Instead, autophagy suppressed a stress response that otherwise led to p53 phosphorylation and upregulation of p21 and the pro-apoptotic Bcl-2 family protein Puma. Importantly, BCR-Abl-expressing cells had low basal levels of autophagy, but were highly dependent on this process, and rapidly underwent apoptosis upon disruption of autophagy through Atg3 deletion or treatment with chemical autophagy inhibitors. This dependence on autophagy extended in vivo, as Atg3 deletion also prevented BCR-Abl-mediated leukemogenesis in a cell transfer model. Together these data demonstrate a critical role for autophagy to mitigate cell stress, and that cells expressing the oncogenic kinase BCR-Abl appear particularly dependent on autophagy for cell survival and leukemogenesis.

Authors
Altman, BJ; Jacobs, SR; Mason, EF; Michalek, RD; MacIntyre, AN; Coloff, JL; Ilkayeva, O; Jia, W; He, Y-W; Rathmell, JC
MLA Citation
Altman, BJ, Jacobs, SR, Mason, EF, Michalek, RD, MacIntyre, AN, Coloff, JL, Ilkayeva, O, Jia, W, He, Y-W, and Rathmell, JC. "Autophagy is essential to suppress cell stress and to allow BCR-Abl-mediated leukemogenesis." Oncogene 30.16 (April 21, 2011): 1855-1867.
PMID
21151168
Source
pubmed
Published In
Oncogene: Including Oncogene Reviews
Volume
30
Issue
16
Publish Date
2011
Start Page
1855
End Page
1867
DOI
10.1038/onc.2010.561

Apoptosis and autophagy in the regulation of T lymphocyte function.

During the development and normal function of T lymphocytes, the cells are subject to several checkpoints at which they must "decide" to live or die. At these critical times and during homeostasis, the molecules that regulate the classical apoptotic pathways and survival pathways such as autophagy have critical roles in controlling this decision. Our laboratory has focused on the roles of apoptotic and autophagic proteins in T lymphocyte development and function. Using genetic models in mice and in vitro analyses of T cell functions, we have outlined critical roles for the Bcl-2 family (regulators of the intrinsic pathway of apoptosis), c-FLIP (an anti-apoptotic protein in the extrinsic pathway of apoptosis), and autophagy in T lymphocytes.

Authors
Dunkle, A; He, Y-W
MLA Citation
Dunkle, A, and He, Y-W. "Apoptosis and autophagy in the regulation of T lymphocyte function." Immunol Res 49.1-3 (April 2011): 70-86. (Review)
PMID
21128005
Source
pubmed
Published In
Immunologic Research
Volume
49
Issue
1-3
Publish Date
2011
Start Page
70
End Page
86
DOI
10.1007/s12026-010-8195-5

DELETION OF CFLIP IN HEPATOCYTES AUGMENTS CCL4-INDUCED LIVER INJURY INVOLVING ACTIVATION OF MITOGEN ACTIVATED PROTEIN KINASES

Authors
Schattenberg, JM; Nagel, M; Kohl, T; Longerich, T; Schirmacher, P; Kreft, A; He, Y-W; Galle, PR; Schuchmann, M
MLA Citation
Schattenberg, JM, Nagel, M, Kohl, T, Longerich, T, Schirmacher, P, Kreft, A, He, Y-W, Galle, PR, and Schuchmann, M. "DELETION OF CFLIP IN HEPATOCYTES AUGMENTS CCL4-INDUCED LIVER INJURY INVOLVING ACTIVATION OF MITOGEN ACTIVATED PROTEIN KINASES." March 2011.
Source
wos-lite
Published In
Journal of Hepatology
Volume
54
Publish Date
2011
Start Page
S415
End Page
S415

HEPATOCYTE-SPECIFIC DELETION OF CFLIP ENHANCES LIVER INJURY FROM STREPTOZOTOCIN-INDUCED HYPERGLYCEMIA INVOLVING ACTIVATION OF JNK

Authors
Schattenberg, JM; Kohl, T; Nagel, M; Wagner, I; Kreft, A; He, Y-W; Galle, PR; Schuchmann, M
MLA Citation
Schattenberg, JM, Kohl, T, Nagel, M, Wagner, I, Kreft, A, He, Y-W, Galle, PR, and Schuchmann, M. "HEPATOCYTE-SPECIFIC DELETION OF CFLIP ENHANCES LIVER INJURY FROM STREPTOZOTOCIN-INDUCED HYPERGLYCEMIA INVOLVING ACTIVATION OF JNK." March 2011.
Source
wos-lite
Published In
Journal of Hepatology
Volume
54
Publish Date
2011
Start Page
S271
End Page
S272

Autophagy regulates endoplasmic reticulum homeostasis and calcium mobilization in T lymphocytes.

Macroautophagy (hereafter referred to as autophagy) is an evolutionarily conserved intracellular bulk degradation pathway that plays critical roles in eliminating intracellular pathogens, presenting endogenous Ags, and regulating T lymphocyte survival and proliferation. In this study, we have investigated the role of autophagy in regulating the endoplasmic reticulum (ER) compartment in T lymphocytes. We found that ER content is expanded in mature autophagy-related protein (Atg) 7-deficient T lymphocytes. Atg7-deficient T cells stimulated through the TCR display impaired influx, but not efflux, of calcium, and ER calcium stores are increased in Atg7-deficient T cells. Treatment with the ER sarco/ER Ca(2+)-ATPase pump inhibitor thapsigargin rescues the calcium influx defect in Atg7-deficient T lymphocytes, suggesting that this impairment is caused by an intrinsic defect in ER. Furthermore, we found that the stimulation-induced redistribution of stromal interaction molecule-1, a critical event for the store-operated Ca(2+) release-activated Ca(2+) channel opening, is impaired in Atg7-deficient T cells. Together, these findings indicate that the expanded ER compartment in Atg7-deficient T cells contains increased calcium stores, and the inability of these stores to be depleted causes defective calcium influx in these cells. Our results demonstrate that autophagy plays an important role in maintaining ER and calcium homeostasis in T lymphocytes.

Authors
Jia, W; Pua, HH; Li, Q-J; He, Y-W
MLA Citation
Jia, W, Pua, HH, Li, Q-J, and He, Y-W. "Autophagy regulates endoplasmic reticulum homeostasis and calcium mobilization in T lymphocytes." J Immunol 186.3 (February 1, 2011): 1564-1574.
PMID
21191072
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
186
Issue
3
Publish Date
2011
Start Page
1564
End Page
1574
DOI
10.4049/jimmunol.1001822

Regulation of steady-state neutrophil homeostasis by macrophages.

The timely clearance of apoptotic neutrophils from inflammation sites is an important function of macrophages; however, the role of macrophages in maintaining neutrophil homeostasis under steady-state conditions is less well understood. By conditionally deleting the antiapoptotic gene cellular FLICE-like inhibitory protein (C-FLIP) in myeloid cells, we have generated a novel mouse model deficient in marginal zone and bone marrow stromal macrophages. These mice develop severe neutrophilia, splenomegaly, extramedullary hematopoiesis, decreased body weight, and increased production of granulocyte colony-stimulating factor (G-CSF) and IL-1β, but not IL-17. c-FLIP(f/f) LysM-Cre mice exhibit delayed clearance of circulating neutrophils, suggesting that failure of macrophages to efficiently clear apoptotic neutrophils causes production of cytokines that drive excess granulopoiesis. Further, blocking G-CSF but not IL-1R signaling in vivo rescues this neutrophilia, suggesting that a G-CSF-dependent, IL-1β-independent pathway plays a role in promoting neutrophil production in mice with defective clearance of apoptotic cells.

Authors
Gordy, C; Pua, H; Sempowski, GD; He, Y-W
MLA Citation
Gordy, C, Pua, H, Sempowski, GD, and He, Y-W. "Regulation of steady-state neutrophil homeostasis by macrophages." Blood 117.2 (January 13, 2011): 618-629.
PMID
20980680
Source
pubmed
Published In
Blood
Volume
117
Issue
2
Publish Date
2011
Start Page
618
End Page
629
DOI
10.1182/blood-2010-01-265959

IL-15 regulates homeostasis and terminal maturation of NKT cells

Semi-invariant NKT cells are thymus-derived innate-like lymphocytes that modulate microbial and tumor immunity as well as autoimmune diseases. These immunoregulatory properties of NKT cells are acquired during their development. Much has been learned regarding the molecular and cellular cues that promote NKT cell development, yet how these cells are maintained in the thymus and the periphery and how they acquire functional competence are incompletely understood.We found that IL-15 induced several Bcl-2 family survival factors in thymic and splenic NKT cells in vitro. Yet, IL-15-mediated thymic and peripheral NKT cell survival critically depended on Bcl-x L expression. Additionally, IL-15 regulated thymic developmental stage 2 to stage 3 lineage progression and terminal NKT cell differentiation. Global gene expression analyses and validation revealed that IL-15 regulated Tbx21 (T-bet) expression in thymic NKT cells. The loss of IL-15 also resulted in poor expression of key effector molecules such as IFN-γ, granzyme A and C, as well as several NK cell receptors, which are also regulated by T-bet in NKT cells. Taken together, our findings reveal a critical role for IL-15 in NKT cell survival, which is mediated by Bcl-x L, and effector differentiation, which is consistent with a role of T-bet in regulating terminal maturation. Copyright © 2011 by The American Association of Immunologists, Inc.

Authors
Gordy, LE; Bezbradica, JS; Flyak, AI; Spencer, CT; Dunkle, A; Sun, J; Stanic, AK; Boothby, MR; He, Y-W; Zhao, Z; Kaer, LV; Joyce, S
MLA Citation
Gordy, LE, Bezbradica, JS, Flyak, AI, Spencer, CT, Dunkle, A, Sun, J, Stanic, AK, Boothby, MR, He, Y-W, Zhao, Z, Kaer, LV, and Joyce, S. "IL-15 regulates homeostasis and terminal maturation of NKT cells." Journal of Immunology 187.12 (2011): 6335-6345.
PMID
22084435
Source
scival
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
187
Issue
12
Publish Date
2011
Start Page
6335
End Page
6345
DOI
10.4049/jimmunol.1003965

Regulation of T-cell survival and mitochondrial homeostasis by TSC1

The mammalian target of rapamycin (mTOR) is a key regulator of cell growth and metabolism. It associates with multiple proteins and forms two distinct signaling complexes, mTORC1 and mTORC2. Accumulating evidence has revealed critical roles for intact mTOR signaling during T-cell activation and responses to microbial infection. However, the importance of mTOR regulation in T cells has yet to be explored. The TSC1/TSC2 complex has been shown to inhibit mTORC1 signaling in cell line models. We show here that deletion of TSC1 in the murine T-cell lineage results in a dramatic reduction of the peripheral T-cell pool, correlating with increased cell death. While mTORC1 is constitutively activated, mTORC2 signaling, reflected by Akt phosphorylation and activity, is decreased in TSC1-deficient T cells. Furthermore, TSC1-deficient T cells contain elevated reactive oxygen species (ROS) and exhibit decreased mitochondrial content and membrane potential, which is correlated with the activation of the intrinsic death pathway. Overall, our results demonstrate that TSC1 differentially regulates mTORC1 and mTORC2 activity, promotes T-cell survival, and is critical for normal mitochondrial homeostasis in T cells. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Authors
O'Brien, TF; Gorentla, BK; Xie, D; Srivatsan, S; Mcleod, IX; He, Y-W; Zhong, X-P
MLA Citation
O'Brien, TF, Gorentla, BK, Xie, D, Srivatsan, S, Mcleod, IX, He, Y-W, and Zhong, X-P. "Regulation of T-cell survival and mitochondrial homeostasis by TSC1." European Journal of Immunology 41.11 (2011): 3361-3370.
PMID
21805467
Source
scival
Published In
European Journal of Immunology
Volume
41
Issue
11
Publish Date
2011
Start Page
3361
End Page
3370
DOI
10.1002/eji.201141411

Cardiac-specific mindin overexpression attenuates cardiac hypertrophy via blocking AKT/GSK3β and TGF-β1Smad signalling

Aims Mindin is a secreted extracellular matrix protein, an integrin ligand, and an angiogenesis inhibitor, other examples of which are all key players in the progression of cardiac hypertrophy. However, its function during cardiac hypertrophy remains unclear. This study was aimed to identify the effect of mindin on cardiac hypertrophy and the underlying mechanisms. Methods and resultsA significant down-regulation of mindin expression was observed in human failing hearts. To further investigate the role of mindin in cardiac hypertrophy, we used cultured neonatal rat cardiomyocytes with gain and loss of mindin function and cardiac-specific Mindin-overexpressing transgenic (TG) mice. In cultured cardiomyocytes, mindin negatively regulated angiotensin II (Ang II)-mediated hypertrophic growth, as detected by [ 3H]-Leucine incorporation, cardiac myocyte area, and hypertrophic marker protein levels. Cardiac hypertrophy in vivo was produced by aortic banding (AB) or Ang II infusion in TG mice and their wild-type controls. The extent of cardiac hypertrophy was evaluated by echocardiography as well as by pathological and molecular analyses of heart samples. Mindin overexpression in the heart markedly attenuated cardiac hypertrophy, fibrosis, and left ventricular dysfunction in mice in response to AB or Ang II. Further analysis of the signalling events in vitro and in vivo indicated that these beneficial effects of mindin were associated with the interruption of AKT/glycogen synthase kinase 3β (GSK3β) and transforming growth factor (TGF)-β1Smad signalling. ConclusionThe present study demonstrates for the first time that mindin serves as a novel mediator that protects against cardiac hypertrophy and the transition to heart failure by blocking AKT/GSK3β and TGF-β1Smad signalling. © 2011 The Author.

Authors
Yan, L; Wei, X; Tang, Q-Z; Feng, J; Zhang, Y; Liu, C; Bian, Z-Y; Zhang, L-F; Chen, M; Bai, X; Wang, A-B; Fassett, J; Chen, Y; He, Y-W; Yang, Q; Liu, PP; Li, H
MLA Citation
Yan, L, Wei, X, Tang, Q-Z, Feng, J, Zhang, Y, Liu, C, Bian, Z-Y, Zhang, L-F, Chen, M, Bai, X, Wang, A-B, Fassett, J, Chen, Y, He, Y-W, Yang, Q, Liu, PP, and Li, H. "Cardiac-specific mindin overexpression attenuates cardiac hypertrophy via blocking AKT/GSK3β and TGF-β1Smad signalling." Cardiovascular Research 92.1 (2011): 85-94.
PMID
21632881
Source
scival
Published In
Cardiovascular Research
Volume
92
Issue
1
Publish Date
2011
Start Page
85
End Page
94
DOI
10.1093/cvr/cvr159

ABLATION OF c-FLIP AUGMENTS CD95-AND GALACTOSAMINE/LPS-INDUCED LIVER INJURY THROUGH ACTIVATION OF c-JUN N-TERMINAL KINASE (JNK)

Authors
Schattenberg, JM; He, Y; Galle, PR; Schuchmann, M
MLA Citation
Schattenberg, JM, He, Y, Galle, PR, and Schuchmann, M. "ABLATION OF c-FLIP AUGMENTS CD95-AND GALACTOSAMINE/LPS-INDUCED LIVER INJURY THROUGH ACTIVATION OF c-JUN N-TERMINAL KINASE (JNK)." 2011.
Source
wos-lite
Published In
Advances in experimental medicine and biology
Volume
691
Publish Date
2011
Start Page
791
End Page
792

Mcl-1 promotes survival of thymocytes by inhibition of Bak in a pathway separate from Bcl-2.

The antiapoptotic proteins Mcl-1 and Bcl-2 have been shown to be critical in T-cell development and homeostasis, but the precise mechanism by which these proteins function in T cells and other cells of the body is unclear. Potential mechanisms have allowed both for overlapping and unique roles for these proteins because of their abilities to bind different proapoptotic Bcl-2 family members, but it is unclear which of these mechanisms are important in an in vivo context. By generation of various genetic mouse models, we found that Mcl-1-deficient thymocytes die largely by a Bak-specific mechanism. In vivo deletion of Bak rescued the survival and developmental blocks of Mcl-1-deficient thymocytes at the double-negative and single-positive stages. Transgenic overexpression of Bcl-2 and in vivo deletion of Bax or Bim were unable to rescue Mcl-1-deficient thymocytes. Thus, Mcl-1 functions in a unique pathway from Bcl-2 in T lymphocytes, likely because of its specific ability to bind and sequester proapoptotic Bak. Together, these data provide an in vivo model for Mcl-1 activity and present us with a greater understanding of the pathways that promote thymocyte survival.

Authors
Dunkle, A; Dzhagalov, I; He, Y-W
MLA Citation
Dunkle, A, Dzhagalov, I, and He, Y-W. "Mcl-1 promotes survival of thymocytes by inhibition of Bak in a pathway separate from Bcl-2." Cell Death Differ 17.6 (June 2010): 994-1002.
PMID
20057504
Source
pubmed
Published In
Cell Death & Differentiation
Volume
17
Issue
6
Publish Date
2010
Start Page
994
End Page
1002
DOI
10.1038/cdd.2009.201

Deletion of PIK3C3/Vps34 in sensory neurons causes rapid neurodegeneration by disrupting the endosomal but not the autophagic pathway.

The lipid kinase PIK3C3 (also called Vps34) regulates both the endosomal and autophagic pathways. However, the effect of inactivating PIK3C3 on neuronal endosomal versus autophagic processes in vivo has not been studied. We generated mice in which Pik3c3 was conditionally deleted in differentiated sensory neurons. Within a few days after Pik3c3 deletion, mutant large-diameter myelinated neurons accumulated numerous enlarged vacuoles and ubiquitin-positive aggregates and underwent rapid degeneration. By contrast, Pik3c3-deficient small-diameter unmyelinated neurons accumulated excessive numbers of lysosome-like organelles and degenerated more slowly. These differential degenerative phenotypes are unlikely caused by a disruption in the autophagy pathway, because inhibiting autophagy alone by conditional deletion of Atg7 results in a completely distinct phenotype in all sensory neurons (i.e., formation of very large intracellular inclusion bodies and slow degeneration over a period of several months). More surprisingly, a noncanonical PIK3C3-independent LC3-positive autophagosome formation pathway was activated in Pik3c3-deficient small-diameter neurons. Analyses of Pik3c3/Atg7 double mutant neurons revealed that this unconventional initiation pathway still depends on ATG7. Our studies represent in vivo characterization of PIK3C3 functions in mammals and provide insights into the complexity of neuronal endo-lysosomal and autophagic pathways.

Authors
Zhou, X; Wang, L; Hasegawa, H; Amin, P; Han, B-X; Kaneko, S; He, Y; Wang, F
MLA Citation
Zhou, X, Wang, L, Hasegawa, H, Amin, P, Han, B-X, Kaneko, S, He, Y, and Wang, F. "Deletion of PIK3C3/Vps34 in sensory neurons causes rapid neurodegeneration by disrupting the endosomal but not the autophagic pathway." Proc Natl Acad Sci U S A 107.20 (May 18, 2010): 9424-9429.
PMID
20439739
Source
pubmed
Published In
Proceedings of the National Academy of Sciences of USA
Volume
107
Issue
20
Publish Date
2010
Start Page
9424
End Page
9429
DOI
10.1073/pnas.0914725107

Roles of autophagy in lymphocytes: reflections and directions.

Recent studies have revealed that autophagy, a fundamental intracellular process, plays many different roles in lymphocyte development and function. Autophagy regulates naive T-lymphocyte homeostasis, specifically by regulating mitochondrial quality and turnover, and is necessary for the proliferation of mature T cells. Autophagy also acts as a cellular death pathway in lymphocytes, both upon prolonged cytokine withdrawal and during acute antigen-receptor stimulation if improperly regulated. Furthermore, during HIV infection, hyperinduction of autophagy leads to massive T-cell death in uninfected CD4(+) T cells, and is rescued by inhibiting autophagic initiation. Constitutively high levels of autophagy in thymic epithelial cells are necessary for optimal processing and presentation of endogenous antigens, and required for proper positive and negative selection of developing thymocytes. Autophagy also promotes the survival of B lymphocytes, as well as the development of early B-cell progenitors. In B cells, autophagy is an alternative death pathway, as antigen-receptor stimulation in the absence of costimulation induces a potent autophagic death. Thus, autophagy plays a complex role in lymphocytes and is regulated during their lifespan to ensure a healthy immune system.

Authors
McLeod, IX; He, Y
MLA Citation
McLeod, IX, and He, Y. "Roles of autophagy in lymphocytes: reflections and directions." Cell Mol Immunol 7.2 (March 2010): 104-107. (Review)
PMID
20118969
Source
pubmed
Published In
Cellular & molecular immunology
Volume
7
Issue
2
Publish Date
2010
Start Page
104
End Page
107
DOI
10.1038/cmi.2009.115

THE CASPASE-8 HOMOLOGUE FLIP MODULATES HEPATOCARCINOGENESIS IN MICE

Authors
Schattenberg, JM; Lowin, V; Zimmermann, T; Longerich, T; Schirmacher, P; Schulze-Bergkamen, H; He, Y-W; Galle, PR; Schuchmann, M
MLA Citation
Schattenberg, JM, Lowin, V, Zimmermann, T, Longerich, T, Schirmacher, P, Schulze-Bergkamen, H, He, Y-W, Galle, PR, and Schuchmann, M. "THE CASPASE-8 HOMOLOGUE FLIP MODULATES HEPATOCARCINOGENESIS IN MICE." 2010.
Source
wos-lite
Published In
Journal of Hepatology
Volume
52
Publish Date
2010
Start Page
S32
End Page
S32

Mitophagy in the little lymphocytes: an essential role for autophagy in mitochondrial clearance in T lymphocytes.

Authors
Pua, HH; He, Y-W
MLA Citation
Pua, HH, and He, Y-W. "Mitophagy in the little lymphocytes: an essential role for autophagy in mitochondrial clearance in T lymphocytes." Autophagy 5.5 (July 2009): 745-746.
PMID
19398889
Source
pubmed
Published In
Autophagy
Volume
5
Issue
5
Publish Date
2009
Start Page
745
End Page
746

Autophagy is essential for mitochondrial clearance in mature T lymphocytes.

Macroautophagy plays an important role in the regulation of cell survival, metabolism, and the lysosomal degradation of cytoplasmic material. In the immune system, autophagy contributes to the clearance of intracellular pathogens, MHCII cross-presentation of endogenous Ags, as well as cell survival. We and others have demonstrated that autophagy occurs in T lymphocytes and contributes to the regulation of their cellular function, including survival and proliferation. Here we show that the essential autophagy gene Atg7 is required in a cell-intrinsic manner for the survival of mature primary T lymphocytes. We also find that mitochondrial content is developmentally regulated in T but not in B cells, with exit from the thymus marking a transition from high mitochondrial content in thymocytes to lower mitochondrial content in mature T cells. Macroautophagy has been proposed to play an important role in the clearance of intracellular organelles, and autophagy-deficient mature T cells fail to reduce their mitochondrial content in vivo. Consistent with alterations in mitochondrial content, autophagy-deficient T cells have increased reactive oxygen species production as well as an imbalance in pro- and antiapoptotic protein expression. With much recent interest in the possibility of autophagy-dependent developmentally programmed clearance of organelles in lens epithelial cells and erythrocytes, our data demonstrate that autophagy may have a physiologically significant role in the clearance of superfluous mitochondria in T lymphocytes as part of normal T cell homeostasis.

Authors
Pua, HH; Guo, J; Komatsu, M; He, Y-W
MLA Citation
Pua, HH, Guo, J, Komatsu, M, and He, Y-W. "Autophagy is essential for mitochondrial clearance in mature T lymphocytes." J Immunol 182.7 (April 1, 2009): 4046-4055.
PMID
19299702
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
182
Issue
7
Publish Date
2009
Start Page
4046
End Page
4055
DOI
10.4049/jimmunol.0801143

Differential regulation of phagocyte development by the intrinsic and extrinsic apoptotic pathways

Authors
Gordy, C; Pua, HH; Dzhagalov, I; Zhang, N; He, Y-W
MLA Citation
Gordy, C, Pua, HH, Dzhagalov, I, Zhang, N, and He, Y-W. "Differential regulation of phagocyte development by the intrinsic and extrinsic apoptotic pathways." EUROPEAN JOURNAL OF CLINICAL INVESTIGATION 39 (April 2009): 30-30.
Source
wos-lite
Published In
European Journal of Clinical Investigation
Volume
39
Publish Date
2009
Start Page
30
End Page
30

Structure of the F-spondin domain of mindin, an integrin ligand and pattern recognition molecule.

Mindin (spondin-2) is an extracellular matrix protein of unknown structure that is required for efficient T-cell priming by dendritic cells. Additionally, mindin functions as a pattern recognition molecule for initiating innate immune responses. These dual functions are mediated by interactions with integrins and microbial pathogens, respectively. Mindin comprises an N-terminal F-spondin (FS) domain and C-terminal thrombospondin type 1 repeat (TSR). We determined the structure of the FS domain at 1.8-A resolution. The structure revealed an eight-stranded antiparallel beta-sandwich motif resembling that of membrane-targeting C2 domains, including a bound calcium ion. We demonstrated that the FS domain mediates integrin binding and identified the binding site by mutagenesis. The mindin FS domain therefore represents a new integrin ligand. We further showed that mindin recognizes lipopolysaccharide (LPS) through its TSR domain, and obtained evidence that C-mannosylation of the TSR influences LPS binding. Through these dual interactions, the FS and TSR domains of mindin promote activation of both adaptive and innate immune responses.

Authors
Li, Y; Cao, C; Jia, W; Yu, L; Mo, M; Wang, Q; Huang, Y; Lim, J-M; Ishihara, M; Wells, L; Azadi, P; Robinson, H; He, Y-W; Zhang, L; Mariuzza, RA
MLA Citation
Li, Y, Cao, C, Jia, W, Yu, L, Mo, M, Wang, Q, Huang, Y, Lim, J-M, Ishihara, M, Wells, L, Azadi, P, Robinson, H, He, Y-W, Zhang, L, and Mariuzza, RA. "Structure of the F-spondin domain of mindin, an integrin ligand and pattern recognition molecule." EMBO J 28.3 (February 4, 2009): 286-297.
PMID
19153605
Source
pubmed
Published In
EMBO Journal
Volume
28
Issue
3
Publish Date
2009
Start Page
286
End Page
297
DOI
10.1038/emboj.2008.288

Regulation of CD8(+) T cell functions by RARgamma.

Retinoic acid plays a key role in the development and function of the immune system; however, the contribution of each of the three retinoic acid receptors (RARs) to the T cell immune response is not yet well understood. Of these receptors, both RARalpha and RARgamma are expressed in T lymphocytes. While possible functional redundancy thus complicates understanding of the role of each receptor in T cells, emerging data suggest that RARalpha and RARgamma function differently in thymocyte development and that RARgamma is required for both primary and secondary CD8(+) T cell immune responses.

Authors
Gordy, C; Dzhagalov, I; He, Y-W
MLA Citation
Gordy, C, Dzhagalov, I, and He, Y-W. "Regulation of CD8(+) T cell functions by RARgamma." Semin Immunol 21.1 (February 2009): 2-7. (Review)
PMID
18715802
Source
pubmed
Published In
Seminars in Immunology
Volume
21
Issue
1
Publish Date
2009
Start Page
2
End Page
7
DOI
10.1016/j.smim.2008.07.002

The extracellular matrix protein mindin regulates trafficking of murine eosinophils into the airspace.

Asthma remains a major cause of morbidity and hospitalizations in developed nations. Despite the widespread prevalence of this disease, the genetic and environmental factors that mediate development and progression of allergic airways disease remain poorly understood. Pulmonary recruitment of eosinophils is believed to contribute to many cardinal features of allergic airways disease. Therefore, it is paramount to understand host factors that contribute to pulmonary eosinophil recruitment into the lungs. Mindin is a component of pulmonary extracellular matrix, which can regulate inflammatory cell recruitment. We characterized the role of mindin in the severity of allergic airways disease using established murine models. There were no baseline differences in wild-type and mindin-deficient animals in cell counts or airway physiology. Using the OVA murine model of allergic airways disease, we observed that mindin-deficient animals have less-severe allergic airways disease with fewer airspace eosinophils and lower lung-lavage levels of inflammatory Th2 cytokines such as IL-13 and IL-4. Furthermore, mindin-deficient animals have reduced airway hyper-responsiveness after methacholine challenge. To determine the role of mindin in eosinophil trafficking, independent of antigen immunization or T lymphocyte activation, we instilled IL-13 directly into the lungs of mice. In this model, mindin regulates eosinophil recruitment into the airspace. In vitro experiments demonstrate that mindin can enhance eotaxin-mediated eosinophil adhesion and migration, which are dependent on the expression of integrins alphaMbeta2 and alpha4beta1. In conclusion, these data suggest that mindin participates in integrin-dependent trafficking of eosinophils and can contribute to the severity of allergic airways disease.

Authors
Li, Z; Garantziotis, S; Jia, W; Potts, EN; Lalani, S; Liu, Z; He, Y-W; Foster, WM; Hollingsworth, JW
MLA Citation
Li, Z, Garantziotis, S, Jia, W, Potts, EN, Lalani, S, Liu, Z, He, Y-W, Foster, WM, and Hollingsworth, JW. "The extracellular matrix protein mindin regulates trafficking of murine eosinophils into the airspace." J Leukoc Biol 85.1 (January 2009): 124-131.
PMID
18818374
Source
pubmed
Published In
Journal of leukocyte biology
Volume
85
Issue
1
Publish Date
2009
Start Page
124
End Page
131
DOI
10.1189/jlb.0208135

Autophagy and lymphocyte homeostasis.

Lymphocyte homeostasis is tightly regulated in vivo by various factors including cytokines, antigens, and costimulatory signals. Central to this regulation is the intricate balance between survival and apoptosis determined by pro- and antiapoptotic factors, including Bcl-2/Bcl-xL of the Bcl-2 family in the intrinsic death pathway and Fas/FADD of the TNF death receptor superfamily in the extrinsic death pathway. Recent studies have identified a critical role for autophagy, a well-conserved catabolic process in eukaryotic cells, in T and B lymphocyte homeostasis. Autophagy is essential for mature T lymphocyte survival and proliferation. In addition, autophagy can promote T cell death in defined physiologic or pathologic conditions. Autophagy also contributes to the survival of subsets of B lymphocytes, including developing pre-B cells as well as B1 B cells in vivo. Thus, autophagy represents a novel pathway regulating both developing and mature lymphocytes. Future studies are required to investigate the role of autophagy in regulating T and B cell homeostasis during immune responses to pathogens, as well as to define the mechanisms by which autophagy regulates lymphocyte death and survival.

Authors
Pua, HH; He, Y-W
MLA Citation
Pua, HH, and He, Y-W. "Autophagy and lymphocyte homeostasis." Curr Top Microbiol Immunol 335 (2009): 85-105. (Review)
PMID
19802561
Source
pubmed
Published In
Current topics in microbiology and immunology
Volume
335
Publish Date
2009
Start Page
85
End Page
105
DOI
10.1007/978-3-642-00302-8_4

A single amino acid defines cross-species reactivity of tree shrew (Tupaia belangeri) CD1d to human invariant natural killer T (iNKT) cells

The non-classical major histocompatibility complex (MHC) class I molecule CD1d presents lipid antigens to invariant natural killer T (iNKT) cells, which are an important part of the innate immune system. CD1d-iNKT systems are highly conserved in evolution, and cross-species reactivity has been suggested to be a common feature of different animals based on research in humans and mice. However, we found that CD1d from the tree shrew (Tupaia belangeri), a close evolutionary relative of primates, failed to stimulate human iNKT cells, despite being more homologous to human CD1d than that of mouse. Sequence comparison and molecular modelling showed that two of the key amino acid residues in human CD1d proposed to be in direct contact with T-cell receptors were mutated in tree shrew CD1d. Substitution of one of the residues, but not the other, with the human residue enabled tree shrew CD1d to regain the ability to present lipid antigen to human iNKT cells. These results indicate that CD1d-iNKT recognition is species-specific, and that cross-species reactivity may be less common than currently proposed. Also, a naturally occurring CD1d mutation(s) that confers inability to stimulate iNKT cell function may have implications for future studies on CD1d-iNKT-associated diseases. © 2009 Blackwell Publishing Ltd.

Authors
Zhang, P; Li, D; Stewart-Jones, G; Shao, X; Zhang, Y; Chen, Q; Li, Y; He, Y-W; Xu, X-N; Zhang, H-T
MLA Citation
Zhang, P, Li, D, Stewart-Jones, G, Shao, X, Zhang, Y, Chen, Q, Li, Y, He, Y-W, Xu, X-N, and Zhang, H-T. "A single amino acid defines cross-species reactivity of tree shrew (Tupaia belangeri) CD1d to human invariant natural killer T (iNKT) cells." Immunology 128.4 (2009): 500-510.
PMID
19863613
Source
scival
Published In
Immunology
Volume
128
Issue
4
Publish Date
2009
Start Page
500
End Page
510
DOI
10.1111/j.1365-2567.2009.03133.x

Identification of a tumor associated antigen that can induce tumor specific cytotoxicity

Authors
Dunkle, A; He, Y-W
MLA Citation
Dunkle, A, and He, Y-W. "Identification of a tumor associated antigen that can induce tumor specific cytotoxicity." Cancer Biology and Therapy 8.9 (2009): 844-845.
PMID
19377280
Source
scival
Published In
Cancer Biology and Therapy
Volume
8
Issue
9
Publish Date
2009
Start Page
844
End Page
845

Autophagy and lymphocyte homeostasis

Lymphocyte homeostasis is tightly regulated in vivo by various factors including cytokines, antigens, and costimulatory signals. Central to this regulation is the intricate balance between survival and apoptosis determined by pro- and antiapoptotic factors, including Bcl-2/Bcl-xL of the Bcl-2 family in the intrinsic death pathway and Fas/FADD of the TNF death receptor superfamily in the extrinsic death pathway. Recent studies have identified a critical role for autophagy, a well-conserved catabolic process in eukaryotic cells, in T and B lymphocyte homeostasis. Autophagy is essential for mature T lymphocyte survival and proliferation. In addition, autophagy can promote T cell death in defined physiologic or pathologic conditions. Autophagy also contributes to the survival of subsets of B lymphocytes, including developing pre-B cells as well as B1 B cells in vivo. Thus, autophagy represents a novel pathway regulating both developing and mature lymphocytes. Future studies are required to investigate the role of autophagy in regulating T and B cell homeostasis during immune responses to pathogens, as well as to define the mechanisms by which autophagy regulates lymphocyte death and survival. © 2010 Springer-Verlag Berlin Heidelberg.

Authors
Pua, HH; He, YW
MLA Citation
Pua, HH, and He, YW. "Autophagy and lymphocyte homeostasis." Current Topics in Microbiology and Immunology 335.1 (2009): 85-105.
Source
scival
Published In
Current topics in microbiology and immunology
Volume
335
Issue
1
Publish Date
2009
Start Page
85
End Page
105
DOI
10.1007/978-3-642-00302-8-4

A role for cFLIP in B cell proliferation and stress MAPK regulation

Fas/Apo-1 signals through the FADD (Fas-associated death domain) adaptor protein, which recruits and activates the apical caspase 8 and leads to apoptosis. Cellular FLIP (cFLIP) is a homolog of caspase 8 and is also capable of binding to FADD. Previous studies suggest that cFLIP could either enhance or inhibit apoptosis and lead to NF-κB and Erk1/2 activation. Like FADD or caspase 8 deficiency, a lack of cFLIP disrupts embryogenesis and T cell proliferation. It has been demonstrated that B cells lacking either FADD or caspase 8 were defective in both Fas-induced apoptosis and TLR-induced proliferation, which indicates that these death-inducing proteins have an additional role in regulating innate immunity. To analyze the function of cFLIP in B cells, conditional deletion of cFLIP was induced by using CD19 Cre. The resulting B cell-specific cFLIP-deficient mice were found to have reduced numbers of peripheral B cells that were hypersensitive to Fas-induced apoptosis and impaired in proliferation induced by TLRs and the BCR. Furthermore, there was aberrant expression of costimulatory proteins and activation markers in cFLIP-deficient B cells. Whereas LPS-induced activation of NF-κB and Erk1/2 appears to be unaffected, p38 and Jnk were spontaneously activated and hyperinduced in cFLIP-deficient B cells. Therefore, these data revealed novel functions of cFLIP in B cells. Copyright © 2008 by The American Association of Immunologists, Inc.

Authors
Zhang, H; Rosenberg, S; Coffey, FJ; He, Y-W; Manser, T; Hardy, RR; Zhang, J
MLA Citation
Zhang, H, Rosenberg, S, Coffey, FJ, He, Y-W, Manser, T, Hardy, RR, and Zhang, J. "A role for cFLIP in B cell proliferation and stress MAPK regulation." Journal of Immunology 182.1 (2009): 207-215.
PMID
19109151
Source
scival
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
182
Issue
1
Publish Date
2009
Start Page
207
End Page
215

c-FLIP protects mature T lymphocytes from TCR-mediated killing.

Although c-FLIP has been identified as an important player in the extrinsic (death receptor-induced) apoptosis pathway, its endogenous function in mature T lymphocytes remains undefined. c-FLIP may inhibit or promote T cell death as previous data demonstrate that the c-FLIP(L) isoform can promote or inhibit caspase 8 activation while the c-FLIP(S) isoform promotes or inhibits T cell death when overexpressed. Although the c-FLIP(R) isoform inhibits cell death in cell lines, its function in T cells remains unknown. To investigate the function of c-FLIP in mature T cells, we have generated several genetic mouse models with c-FLIP or its individual isoforms deleted in mature T cells. Surprisingly, we found that c-FLIP protects mature T cells not only from apoptosis induced by the death receptors Fas and TNFR but also from TCR-mediated and spontaneous apoptosis. Thus, c-FLIP plays an essential role in protecting mature T cells from a death signal induced through the TCR itself and is required for naive T cell survival. Our results demonstrate that c-FLIP functions beyond the extrinsic death pathway.

Authors
Zhang, N; Hopkins, K; He, Y-W
MLA Citation
Zhang, N, Hopkins, K, and He, Y-W. "c-FLIP protects mature T lymphocytes from TCR-mediated killing." J Immunol 181.8 (October 15, 2008): 5368-5373.
PMID
18832693
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
181
Issue
8
Publish Date
2008
Start Page
5368
End Page
5373

The anti-apoptotic Bcl-2 family member Mcl-1 promotes T lymphocyte survival at multiple stages.

T lymphocyte development and function are tightly regulated by the intrinsic death pathway through members of the Bcl-2 family. Genetic studies have demonstrated that the Bcl-2 family member Mcl-1 is an important anti-apoptotic protein in the development of multiple cell types including T lymphocytes. However, the expression pattern and anti-apoptotic roles of Mcl-1 in T lymphocytes at different developmental stages remain to be fully determined. In this study, we examined the expression pattern of Mcl-1 in different populations of T cells at the single-cell level and found that Mcl-1 protein is constitutively expressed in all T cell populations and up-regulated upon TCR stimulation. We then investigated the role of Mcl-1 in the survival of these different populations by conditionally deleting Mcl-1 at various T cell stages. Our results show that Mcl-1 is required for the survival of double-negative and single-positive thymocytes as well as naive and activated T cells. Furthermore, we demonstrate that Mcl-1 functions together with Bcl-xL to promote double-positive thymocyte survival. Thus, Mcl-1 is a critical anti-apoptotic factor for the survival of T cells at multiple stages in vivo.

Authors
Dzhagalov, I; Dunkle, A; He, Y-W
MLA Citation
Dzhagalov, I, Dunkle, A, and He, Y-W. "The anti-apoptotic Bcl-2 family member Mcl-1 promotes T lymphocyte survival at multiple stages." J Immunol 181.1 (July 1, 2008): 521-528.
PMID
18566418
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
181
Issue
1
Publish Date
2008
Start Page
521
End Page
528

Pattern recognition molecule mindin promotes intranasal clearance of influenza viruses.

The innate immune response is essential for host defense against microbial pathogen infections and is mediated by pattern recognition molecules recognizing pathogen-associated molecular patterns. Our previous work has demonstrated that the extracellular matrix protein mindin functions as a pattern recognition molecule for bacterial pathogens. In this study, we examined the role of mindin in influenza virus infection. We found that intranasal infection of mindin-deficient mice by influenza virus resulted in dramatically increased virus titers in the lung and intranasal cavity of mutant mice. In contrast, lungs from intratracheally infected mindin-deficient mice contained similar influenza virus titers. We showed that mindin interacted with influenza virus particles directly and that mindin-deficient macrophages exhibited impaired activation after influenza virus infection in vitro. Furthermore, intranasal administration of recombinant mindin significantly enhanced the clearance of influenza virus in wild-type mice. Together, these results demonstrate that mindin plays an essential role in the host innate immune response to influenza virus infection and suggest that mindin may be used as an immune-enhancing agent in influenza infection.

Authors
Jia, W; Li, H; He, Y-W
MLA Citation
Jia, W, Li, H, and He, Y-W. "Pattern recognition molecule mindin promotes intranasal clearance of influenza viruses." J Immunol 180.9 (May 1, 2008): 6255-6261.
PMID
18424748
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
180
Issue
9
Publish Date
2008
Start Page
6255
End Page
6261

The long isoform of cellular FLIP is essential for T lymphocyte proliferation through an NF-kappaB-independent pathway.

Although the long isoform of cellular FLIP (c-FLIP(L)) has been implicated in TCR-mediated signaling, its role in T cell proliferation remains controversial. Some studies have demonstrated that overexpression of c-FLIP(L) promotes T cell proliferation and NF-kappaB activation, whereas others have reported that c-FLIP(L) overexpression has no effect or even inhibits T cell proliferation. To establish the role of c-FLIP(L) in T lymphocyte proliferation, we have generated a conditional knockout mouse strain specifically lacking c-FLIP(L) in T lymphocytes. c-FLIP(L)(-/-) mice exhibit severely impaired effector T cell development after Listeria monocytogenes infection in vivo and c-FLIP(L)-deficient T cells display defective TCR-mediated proliferation in vitro. However, c-FLIP(L)(-/-) T cells exhibit normal NF-kappaB activity upon TCR stimulation. These results demonstrate that c-FLIP(L) is essential for T lymphocyte proliferation through an NF-kappaB-independent pathway.

Authors
Zhang, N; Hopkins, K; He, Y-W
MLA Citation
Zhang, N, Hopkins, K, and He, Y-W. "The long isoform of cellular FLIP is essential for T lymphocyte proliferation through an NF-kappaB-independent pathway." J Immunol 180.8 (April 15, 2008): 5506-5511.
PMID
18390734
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
180
Issue
8
Publish Date
2008
Start Page
5506
End Page
5511

The autophagy gene ATG5 plays an essential role in B lymphocyte development.

Macroautophagy (herein autophagy) is an evolutionarily conserved process, requiring the gene ATG5, by which cells degrade cytoplasmic constituents and organelles. Here we show that ATG5 is required for efficient B cell development and for the maintenance of B-1a B cell numbers. Deletion of ATG5 in B lymphocytes using Cre-LoxP technology or repopulation of irradiated mice with ATG5-/- fetal liver progenitors resulted in a dramatic reduction in B-1 B cells in the peritoneum. ATG5-/- progenitors exhibited a significant defect in B cell development at the pro- to pre-B cell transition, although a proportion of pre-B cells survived to populate the periphery. Inefficient B cell development in the bone marrow was associated with increased cell death, indicating that ATG5 is important for B cell survival during development. In addition, B-1a B cells require ATG5 for their maintenance in the periphery. We conclude that ATG5 is differentially required at discrete stages of development in distinct, but closely related, cell lineages.

Authors
Miller, BC; Zhao, Z; Stephenson, LM; Cadwell, K; Pua, HH; Lee, HK; Mizushima, NN; Iwasaki, A; He, Y-W; Swat, W; Virgin, HW
MLA Citation
Miller, BC, Zhao, Z, Stephenson, LM, Cadwell, K, Pua, HH, Lee, HK, Mizushima, NN, Iwasaki, A, He, Y-W, Swat, W, and Virgin, HW. "The autophagy gene ATG5 plays an essential role in B lymphocyte development." Autophagy 4.3 (April 2008): 309-314.
PMID
18188005
Source
pubmed
Published In
Autophagy
Volume
4
Issue
3
Publish Date
2008
Start Page
309
End Page
314

Integrin beta 1 regulates phagosome maturation in macrophages through Rac expression.

Phagocytosis and subsequent phagosome maturation by professional phagocytes are essential in the clearance of infectious microbial pathogens. The molecular regulation of phagosome maturation is largely unknown. We show that integrin beta(1) plays critical roles in the phagocytosis of microbial pathogens and phagosome maturation. Macrophages lacking integrin beta(1) expression exhibit reduced phagocytosis of bacteria, including group B streptococcus and Staphylococcus aureus. Furthermore, phagosomes from macrophages lacking integrin beta(1) show lowered maturation rate, defective acquisition of lysosome membrane markers, and reduced F-actin accumulation in the periphagosomal region. Integrin beta(1)-deficient macrophages exhibit impaired bactericidal activity. We found that the expression of the Rho family GTPases Rac1, Rac2, and Cdc42 was reduced in integrin beta(1)-deficient macrophages. Ectopic expression of Rac1, but not Cdc42, in integrin beta(1)-deficient macrophages restored defective phagosome maturation and F-actin accumulation in the periphagosomal region. Importantly, macrophages lacking Rac1/2 also exhibit defective maturation of phagosomes derived from opsonized Escherichia coli or IgG beads. Taken together, these results suggest that integrin beta(1) regulates phagosome maturation in macrophages through Rac expression.

Authors
Wang, Q-Q; Li, H; Oliver, T; Glogauer, M; Guo, J; He, Y-W
MLA Citation
Wang, Q-Q, Li, H, Oliver, T, Glogauer, M, Guo, J, and He, Y-W. "Integrin beta 1 regulates phagosome maturation in macrophages through Rac expression." J Immunol 180.4 (February 15, 2008): 2419-2428.
PMID
18250451
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
180
Issue
4
Publish Date
2008
Start Page
2419
End Page
2428

Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes

Research in autophagy continues to accelerate,1 and as a result many new scientists are entering the field. Accordingly, it is important to establish a standard set of criteria for monitoring macroautophagy in different organisms. Recent reviews have described the range of assays that have been used for this purpose.2,3 There are many useful and convenient methods that can be used to monitor macroautophagy in yeast, but relatively few in other model systems, and there is much confusion regarding acceptable methods to measure macroautophagy in higher eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers of autophagosomes versus those that measure flux through the autophagy pathway; thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from fully functional autophagy that includes delivery to, and degradation within, lysosomes (in most higher eukaryotes) or the vacuole (in plants and fungi). Here, we present a set of guidelines for the selection and interpretation of the methods that can be used by investigators who are attempting to examine macroautophagy and related processes, as well as by reviewers who need to provide realistic and reasonable critiques of papers that investigate these processes. This set of guidelines is not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to verify an autophagic response. ©2008 Landes Bioscience.

Authors
Klionsky, DJ; Abeliovich, H; Agostinis, P; Agrawal, DK; Aliev, G; Askew, DS; Baba, M; Baehrecke, EH; Bahr, BA; Ballabio, A; Bamber, BA; Bassham, DC; Bergamini, E; Bi, X; Biard-Piechaczyk, M; Blum, JS; Bredesen, DE; Brodsky, JL; Brumell, JH; Brunk, UT; Bursch, W; Camougrand, N; Cebollero, E; Cecconi, F; Chen, Y; Chin, L-S; Choi, A; Chu, CT; Chung, J; Clarke, PGH; Clark, RSB; Clarke, SG; Clavé, C; Cleveland, JL; Codogno, P; Colombo, MI; Cotomontes, A; Cregg, JM; Cuervo, AM; Debnath, J et al.
MLA Citation
Klionsky, DJ, Abeliovich, H, Agostinis, P, Agrawal, DK, Aliev, G, Askew, DS, Baba, M, Baehrecke, EH, Bahr, BA, Ballabio, A, Bamber, BA, Bassham, DC, Bergamini, E, Bi, X, Biard-Piechaczyk, M, Blum, JS, Bredesen, DE, Brodsky, JL, Brumell, JH, Brunk, UT, Bursch, W, Camougrand, N, Cebollero, E, Cecconi, F, Chen, Y, Chin, L-S, Choi, A, Chu, CT, Chung, J, Clarke, PGH, Clark, RSB, Clarke, SG, Clavé, C, Cleveland, JL, Codogno, P, Colombo, MI, Cotomontes, A, Cregg, JM, Cuervo, AM, and Debnath, J et al. "Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes." Autophagy 4.2 (2008): 151-175.
PMID
18188003
Source
scival
Published In
Autophagy
Volume
4
Issue
2
Publish Date
2008
Start Page
151
End Page
175

Ablation of C-FLIP augments CD95- and galactosamine/LPS-induced liver injury through activation of c-Jun N-terminal kinase (JNK)

Authors
Schattenberg, JM; Sammet, D; Lowin, V; Siebler, J; Kreft, A; He, Y; Galle, PR; Schuchmann, M
MLA Citation
Schattenberg, JM, Sammet, D, Lowin, V, Siebler, J, Kreft, A, He, Y, Galle, PR, and Schuchmann, M. "Ablation of C-FLIP augments CD95- and galactosamine/LPS-induced liver injury through activation of c-Jun N-terminal kinase (JNK)." 2008.
Source
wos-lite
Published In
Journal of Hepatology
Volume
48
Publish Date
2008
Start Page
S20
End Page
S20
DOI
10.1016/S0168-8278(08)60048-3

Defective T cell development and function in the absence of Abelson kinases.

Thymocyte proliferation, survival, and differentiation are tightly controlled by signaling from the pre-TCR. In this study, we show for the first time that the Abelson (Abl) kinases regulate proximal signaling downstream of the pre-TCR. Conditional deletion of Abl kinases in thymocytes reveals a cell-autonomous role for these proteins in T cell development. The conditional knockout mice have reduced numbers of thymocytes, exhibit an increase in the percentage of the CD4(-)CD8(-) double-negative population, and are partially blocked in the transition to the CD4(+)CD8(+) double-positive stage. Moreover, the total number of T cells is greatly reduced in the Abl mutant mice, and the null T cells exhibit impaired TCR-induced signaling, proliferation, and cytokine production. Notably, Abl mutant mice are compromised in their ability to produce IFN-positive CD8 T cells and exhibit impaired CD8(+) T cell expansion in vivo upon Listeria monocytogenes infection. Furthermore, Ab production in response to T cell-dependent Ag is severely impaired in the Abl mutant mice. Together these findings reveal cell-autonomous roles for the Abl family kinases in both T cell development and mature T cell function, and show that loss of these kinases specifically in T cells results in compromised immunity.

Authors
Gu, JJ; Zhang, N; He, Y-W; Koleske, AJ; Pendergast, AM
MLA Citation
Gu, JJ, Zhang, N, He, Y-W, Koleske, AJ, and Pendergast, AM. "Defective T cell development and function in the absence of Abelson kinases." J Immunol 179.11 (December 1, 2007): 7334-7343.
PMID
18025176
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
179
Issue
11
Publish Date
2007
Start Page
7334
End Page
7343

Maintaining T lymphocyte homeostasis: another duty of autophagy.

First identified as a pathway for nutrient recovery during periods of starvation, the role of autophagy has expanded to the clearance of "toxic" intracellular material including ubiquitin-positive protein aggregates, damaged organelles as well as microbial pathogens in various cell types. We have examined the role of autophagy in the development and function of the adaptive immune system. Genes encoding autophagy machinery are expressed in T lymphocytes, and autophagy occurs in primary CD4+ and CD8+ T cells. By generating fetal liver chimeric mice, we found that thymocyte development is largely normal but the mature T cell compartment is severely reduced in the absence of the essential autophagy gene Atg5. Consistent with a critical role for autophagy in promoting T cell survival, Atg5-/- CD8+ T cells display high levels of apoptosis. Surprisingly, Atg5-deficient T cells were also unable to efficiently proliferate after T-cell receptor (TCR) stimulation. These findings suggest that autophagy regulates T lymphocyte homeostasis by promoting both survival and proliferation. In addition, T cells offer a new, physiologically relevant system to study the regulation and function of autophagy pathways in vivo.

Authors
Pua, HH; He, Y-W
MLA Citation
Pua, HH, and He, Y-W. "Maintaining T lymphocyte homeostasis: another duty of autophagy." Autophagy 3.3 (May 2007): 266-267.
PMID
17329964
Source
pubmed
Published In
Autophagy
Volume
3
Issue
3
Publish Date
2007
Start Page
266
End Page
267

The antiapoptotic protein Mcl-1 is essential for the survival of neutrophils but not macrophages.

The antiapoptotic protein Mcl-1, a member of the Bcl-2 family, plays critical roles in promoting the survival of lymphocytes and hematopoietic stem cells. Although previous studies have implicated Mcl-1 in regulating the survival of neutrophils and macrophages, the in vivo function of Mcl-1 in these 2 cell lineages remained unclear. To address this, we have generated mice conditionally lacking Mcl-1 expression in neutrophils and macrophages. We show that Mcl-1 conditional knockout mice had a severe defect in neutrophil survival, whereas macrophage survival was normal. The granulocyte compartment in the blood, spleen, and bone marrow of Mcl-1 conditional knockout mice exhibited an approximately 2- to 3-fold higher apoptotic rate than control cells. In contrast, resting and activated macrophages from Mcl-1-deficient mice exhibited normal survival and contained up-regulated expression of Bcl-2 and Bcl-xL. These data suggest that Mcl-1 plays a nonredundant role in promoting the survival of neutrophils but not macrophages.

Authors
Dzhagalov, I; St John, A; He, Y-W
MLA Citation
Dzhagalov, I, St John, A, and He, Y-W. "The antiapoptotic protein Mcl-1 is essential for the survival of neutrophils but not macrophages." Blood 109.4 (February 15, 2007): 1620-1626.
PMID
17062731
Source
pubmed
Published In
Blood
Volume
109
Issue
4
Publish Date
2007
Start Page
1620
End Page
1626
DOI
10.1182/blood-2006-03-013771

Regulation of CD8+ T lymphocyte effector function and macrophage inflammatory cytokine production by retinoic acid receptor gamma.

Vitamin A and its derivatives regulate a broad array of immune functions. The effects of these retinoids are mediated through members of retinoic acid receptors (RARs) and retinoid X receptors. However, the role of individual retinoid receptors in the pleiotropic effects of retinoids remains unclear. To dissect the role of these receptors in the immune system, we analyzed immune cell development and function in mice conditionally lacking RARgamma, the third member of the RAR family. We show that RARgamma is dispensable for T and B lymphocyte development, the humoral immune response to a T-dependent Ag and in vitro Th cell differentiation. However, RARgamma-deficient mice had a defective primary and memory CD8(+) T cell response to Listeria monocytogenes infection. Unexpectedly, RARgamma-deficient macrophages exhibited impaired inflammatory cytokine production upon TLR stimulation. These results suggest that under physiological condition, RARgamma is a positive regulator of inflammatory cytokine production.

Authors
Dzhagalov, I; Chambon, P; He, Y-W
MLA Citation
Dzhagalov, I, Chambon, P, and He, Y-W. "Regulation of CD8+ T lymphocyte effector function and macrophage inflammatory cytokine production by retinoic acid receptor gamma." J Immunol 178.4 (February 15, 2007): 2113-2121.
PMID
17277115
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
178
Issue
4
Publish Date
2007
Start Page
2113
End Page
2121

A critical role for the autophagy gene Atg5 in T cell survival and proliferation.

Macroautophagy (hereafter referred to as autophagy) is a well-conserved intracellular degradation process. Recent studies examining cells lacking the autophagy genes Atg5 and Atg7 have demonstrated that autophagy plays essential roles in cell survival during starvation, in innate cell clearance of microbial pathogens, and in neural cell maintenance. However, the role of autophagy in T lymphocyte development and survival is not known. Here, we demonstrate that autophagosomes form in primary mouse T lymphocytes. By generating Atg5-/- chimeric mice, we found that Atg5-deficient T lymphocytes underwent full maturation. However, the numbers of total thymocytes and peripheral T and B lymphocytes were reduced in Atg5 chimeras. In the periphery, Atg5-/- CD8+ T lymphocytes displayed dramatically increased cell death. Furthermore, Atg5-/- CD4+ and CD8+ T cells failed to undergo efficient proliferation after TCR stimulation. These results demonstrate a critical role for Atg5 in multiple aspects of lymphocyte development and function and suggest that autophagy may be essential for both T lymphocyte survival and proliferation.

Authors
Pua, HH; Dzhagalov, I; Chuck, M; Mizushima, N; He, Y-W
MLA Citation
Pua, HH, Dzhagalov, I, Chuck, M, Mizushima, N, and He, Y-W. "A critical role for the autophagy gene Atg5 in T cell survival and proliferation." J Exp Med 204.1 (January 22, 2007): 25-31.
PMID
17190837
Source
pubmed
Published In
The Journal of Experimental Medicine
Volume
204
Issue
1
Publish Date
2007
Start Page
25
End Page
31
DOI
10.1084/jem.20061303

Regulation of innate and adaptive immune responses by a novel pattern recognition molecule mindin

Extracellular matrix proteins play important roles in many different biological processes. Our recent work has discovere important roles for the ECM protein mindin in both innate and adaptive immune responses. Mindin is a member of the F-spondin family of extracellular matrix proteins, which are classified by the presence of an FSI/FS2 domain and one or more thrombospondin type 1 (TSR) repeats. Madin is highly conserved throughout evolution and is broadly expressed in several organs including central and peripheral lymphoid tissues. As a component of the extracellular matrix, mindin exerts several important functions in immune responses. Mindin functions as a pattern recognition molecule for microbial pathogen recognition and is required for effective macrophage activation as well as phagocytosis of microbes. In addition, it promotes leukocyte trafficking during inflammatio in vivo. Mindin is also essential for the adaptive immune response by inducing small GTPase expression in dendritic cells which is required for efficient T cell priming. These effects are largely mediated through the interaction of mindin with multiple cell surface integrins, which likely results in integrin clustering and the induction of downstream signaling cascades. The focus of this review is to highlight these recent discoveries that demonstrate the necessary roles for mindin during innate and adaptive immunity. © 2007 Bentham Science Publishers Ltd.

Authors
Draper, DW; He, YW
MLA Citation
Draper, DW, and He, YW. "Regulation of innate and adaptive immune responses by a novel pattern recognition molecule mindin." Current Immunology Reviews 3.4 (2007): 233-239.
Source
scival
Published In
Current immunology reviews
Volume
3
Issue
4
Publish Date
2007
Start Page
233
End Page
239
DOI
10.2174/157339507783334237

Efficient dendritic cell priming of T lymphocytes depends on the extracellular matrix protein mindin.

Rho guanosine triphosphatases (GTPases) regulate multiple aspects of dendritic cell (DC) function, but what regulates the expression of Rho GTPases in DCs is unknown. Here, we show that the extracellular matrix protein mindin regulates the expression of Rho GTPases in DCs. Mindin(-/-) mice displayed defective CD4+ T-cell priming and impaired humoral immune responses to T-dependent antigens. Mindin(-/-) DCs had reduced expression of Rac1/2 and impaired priming capacity owing to inefficient engagement with T lymphocytes. Ectopic Rac1 expression restored the priming capability of Mindin(-/-) DCs. Furthermore, we show that DC adhesion to mindin matrix was blocked by antibodies to alpha4, alpha5 and beta1 integrins. DCs lacking beta1 integrin had reduced adhesion to mindin matrix, decreased expression of Rac1/2 and impaired priming capacity. These results suggest that mindin-integrin interactions play a key role in regulating Rho GTPase expression in DCs and DC priming of T lymphocytes.

Authors
Li, H; Oliver, T; Jia, W; He, Y-W
MLA Citation
Li, H, Oliver, T, Jia, W, and He, Y-W. "Efficient dendritic cell priming of T lymphocytes depends on the extracellular matrix protein mindin." EMBO J 25.17 (September 6, 2006): 4097-4107.
PMID
16917498
Source
pubmed
Published In
EMBO Journal
Volume
25
Issue
17
Publish Date
2006
Start Page
4097
End Page
4107
DOI
10.1038/sj.emboj.7601289

Toll-like receptor 2-dependent and -independent activation of macrophages by group B streptococci

Group B streptococcus (GBS), a capsulated gram-positive bacterium, is a major cause of newborn infections. Although the innate immune receptor Toll-like receptor (TLR) 2 has been shown to primarily recognize gram-positive bacterial products, the production of TNF by macrophages treated with heat-killed GBS (HK-GBS) does not depend on TLR2. In this report, we have characterized HK-GBS-induced activation of macrophages derived from wildtype and TLR2-deficient mice. Microarray analysis demonstrated that HK-GBS activation of macrophages induces both TLR2-independent and -dependent signals. While the expression of a major fraction of genes in macrophages induced by HK-GBS does not depend on TLR2, induction of several important molecules involved in host innate immunity such as IL-6, IL-1β, and lipocalin 2 is severely impaired in the absence of TLR2 signaling. Furthermore, we show that HK-GBS utilizes centrifugation sensitive components to induce rapid activation of TLR2 -/- macrophages and that HK-GBS-induced activation of macrophages is not mediated through its genomic DNA. Together, our results demonstrate that HK-GBS induces TLR2-dependent antimicrobial gene activation and provide further understanding of the molecular basis of host innate response to GBS infection. © 2005 Elsevier B.V. All rights reserved.

Authors
Draper, DW; Bethea, HN; He, Y-W
MLA Citation
Draper, DW, Bethea, HN, and He, Y-W. "Toll-like receptor 2-dependent and -independent activation of macrophages by group B streptococci." Immunology Letters 102.2 (2006): 202-214.
PMID
16242782
Source
scival
Published In
Immunology Letters
Volume
102
Issue
2
Publish Date
2006
Start Page
202
End Page
214
DOI
10.1016/j.imlet.2005.09.005

The extracellular matrix protein mindin serves as an integrin ligand and is critical for inflammatory cell recruitment.

Leukocyte recruitment to inflammation sites depends on interactions between integrins and extracellular matrix (ECM). In this report we show that mice lacking the ECM protein mindin exhibit severely impaired recruitment of neutrophils and macrophages in 4 different inflammation models. Furthermore, neutrophils directly bind to immobilized mindin, and mindin matrix mediates neutrophil migration in vitro. The adhesion of neutrophils to mindin is blocked by anti-integrin alpha4, anti-integrin alpha(M), and anti-integrin beta2 antibodies. We also show that HEK-293 cells transfected with cDNA encoding these integrins exhibit enhanced binding to immobilized mindin matrix and the increased binding can be blocked by anti-integrin antibodies. Our results suggest that mindin serves as a novel ligand for integrins and mindin-integrin interactions are critical for inflammatory cell recruitment in vivo.

Authors
Jia, W; Li, H; He, Y-W
MLA Citation
Jia, W, Li, H, and He, Y-W. "The extracellular matrix protein mindin serves as an integrin ligand and is critical for inflammatory cell recruitment." Blood 106.12 (December 1, 2005): 3854-3859.
PMID
16105980
Source
pubmed
Published In
Blood
Volume
106
Issue
12
Publish Date
2005
Start Page
3854
End Page
3859
DOI
10.1182/blood-2005-04-1658

An essential function for the calcium-promoted Ras inactivator in Fcgamma receptor-mediated phagocytosis.

Fc receptor (FcR)-mediated phagocytosis requires activation of the Rho GTPases Cdc42 and Rac1, but how they are recruited to the FcR is unknown. Here we show that the calcium-promoted Ras inactivator (CAPRI), a Ras GTPase-activating protein, functions as an adaptor for Cdc42 and Rac1 during FcR-mediated phagocytosis. CAPRI-deficient macrophages had impaired FcgammaR-mediated phagocytosis and oxidative burst, as well as defective activation of Cdc42 and Rac1. CAPRI interacted constitutively with both Cdc42 and Rac1 and translocated to phagocytic cups during FcgammaR-mediated phagocytosis. CAPRI-deficient mice had an impaired innate immune response to bacterial infection. These results suggest that CAPRI provides a link between FcgammaR and Cdc42 and Rac1 and is essential for innate immune responses.

Authors
Zhang, J; Guo, J; Dzhagalov, I; He, Y-W
MLA Citation
Zhang, J, Guo, J, Dzhagalov, I, and He, Y-W. "An essential function for the calcium-promoted Ras inactivator in Fcgamma receptor-mediated phagocytosis." Nat Immunol 6.9 (September 2005): 911-919.
PMID
16041389
Source
pubmed
Published In
Nature Immunology
Volume
6
Issue
9
Publish Date
2005
Start Page
911
End Page
919
DOI
10.1038/ni1232

An essential role for c-FLIP in the efficient development of mature T lymphocytes.

Apoptosis-related genes play important roles in thymocyte maturation. We show that cellular FLICE-like inhibitory protein (c-FLIP), a procaspase-8-like apoptotic regulator, plays an essential role in the efficient development of mature T lymphocytes. Mice conditionally lacking c-FLIP in T lymphocytes display severe defects in the development of mature T cells, as indicated by a dramatically reduced number of CD4+ and CD8+ T cells in the spleen and lymph nodes of mutant mice. The impaired T lymphocyte maturation in c-FLIP conditional knockout mice occurs at the single-positive thymocyte stage and may be caused by enhanced apoptosis in vivo. Moreover, although c-FLIP has been implicated in T cell receptor signaling through nuclear factor (NF)-kappaB and Erk pathways, activation of NF-kappaB and Erk in c-FLIP-deficient thymocytes appears largely intact. Collectively, our data suggest that the primary role of c-FLIP in thymocyte maturation is to protect cells from apoptosis.

Authors
Zhang, N; He, Y-W
MLA Citation
Zhang, N, and He, Y-W. "An essential role for c-FLIP in the efficient development of mature T lymphocytes." J Exp Med 202.3 (August 1, 2005): 395-404.
PMID
16043517
Source
pubmed
Published In
The Journal of Experimental Medicine
Volume
202
Issue
3
Publish Date
2005
Start Page
395
End Page
404
DOI
10.1084/jem.20050117

The antiapoptotic protein Bcl-xL is dispensable for the development of effector and memory T lymphocytes.

The antiapoptotic protein Bcl-x(L) is induced in activated T lymphocytes upon costimulation through CD28, 4-1BB, and OX40. Bcl-x(L) is also highly enriched in memory T lymphocytes. Based on this body of evidence, it was thought that Bcl-x(L) plays an essential role in the generation of effector and memory T lymphocytes. We report that mice with a conditional deletion of Bcl-x in T lymphocytes develop a normal CD8(+) T cell response to Listeria monocytogenes infection. Furthermore, Bcl-x conditional knockout mice exhibit normal T-dependent humoral immune responses. These results indicate that Bcl-x is dispensable for the generation of effector and memory T lymphocytes and suggest that costimulation of T lymphocytes promotes their survival through a Bcl-x(L) independent mechanism.

Authors
Zhang, N; He, Y-W
MLA Citation
Zhang, N, and He, Y-W. "The antiapoptotic protein Bcl-xL is dispensable for the development of effector and memory T lymphocytes." J Immunol 174.11 (June 1, 2005): 6967-6973.
PMID
15905539
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
174
Issue
11
Publish Date
2005
Start Page
6967
End Page
6973

The role of apoptosis in the development and function of T lymphocytes

Apoptosis plays an essential role in T cell biology. Thymocytes expressing nonfunctional or autoreactive TCRs are eliminated by apoptosis during development. Apoptosis also leads to the deletion of expanded effector T cells during immune responses. The dysregulation of apoptosis in the immune system results in autoimmunity, tumorogenesis and immunodeficiency. Two major pathways lead to apoptosis: the intrinsic cell death pathway controlled by Bcl-2 family members and the extrinsic cell death pathway controlled by death receptor signaling. These two pathways work together to regulate T lymphocyte development and function.

Authors
Zhang, N; Hartig, H; Dzhagalov, I; Draper, D; He, YW
MLA Citation
Zhang, N, Hartig, H, Dzhagalov, I, Draper, D, and He, YW. "The role of apoptosis in the development and function of T lymphocytes." Cell Research 15.10 (2005): 749-769.
PMID
16246265
Source
scival
Published In
Cell Research
Volume
15
Issue
10
Publish Date
2005
Start Page
749
End Page
769
DOI
10.1038/sj.cr.7290345

Lymphocyte development and function in the absence of retinoic acid-related orphan receptor alpha.

The orphan nuclear receptor, retinoid acid-related orphan receptor (ROR)alpha, is essential for the development of cerebellar Purkinje cells and bone tissue. RORalpha may also play a critical role in lymphocyte development and function because staggerer mice, a natural mutant strain with a disrupted expression of RORalpha, have reduced thymic and splenic cellularity. In this report, we analyzed the role of RORalpha in lymphocyte development by examining lymphoid compartments in RORalpha(-/-) mice and Rag-2(-/-) mice reconstituted with RORalpha(-/-) bone marrow. We found that T and B cell development was severely defective in RORalpha(-/-) mice, but not in Rag-2(-/-)/RORalpha(-/-) chimeric mice. We also analyzed cellular and humoral immune responses in Rag-2(-/-)/RORalpha(-/-) chimeric mice. Our results show that serum IgG levels were elevated in Rag-2(-/-)/RORalpha(-/-) chimeric mice after immunization with a T-dependent Ag compared with control chimeras. IFN-gamma production by RORalpha(-/-) CD8(+) T cells after TCR stimulation was also increased. Furthermore, RORalpha(-/-) mast cells and macrophages produced an increased amount of TNF-alpha and IL-6 upon activation. These results indicate that RORalpha indirectly regulates lymphocyte development by providing an appropriate microenvironment and controls immune responses by negatively regulating cytokine production in innate immune cells and lymphocytes.

Authors
Dzhagalov, I; Giguère, V; He, Y-W
MLA Citation
Dzhagalov, I, Giguère, V, and He, Y-W. "Lymphocyte development and function in the absence of retinoic acid-related orphan receptor alpha." J Immunol 173.5 (September 1, 2004): 2952-2959.
PMID
15322153
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
173
Issue
5
Publish Date
2004
Start Page
2952
End Page
2959

The extracellular matrix protein mindin is a pattern-recognition molecule for microbial pathogens.

Microbial pathogens use a variety of their surface molecules to bind to host extracellular matrix (ECM) components to establish an effective infection. However, ECM components can also serve as an integral part of the innate immunity. Mice lacking expression of mindin (spondin 2), a highly conserved ECM protein, have an impaired ability to clear bacterial infection, and mindin-deficient macrophages show defective responses to a broad spectrum of microbial stimuli. Moreover, mindin binds directly to bacteria and their components and functions as an opsonin for macrophage phagocytosis of bacteria. Thus, mindin is essential in the initiation of the innate immune response and represents a unique pattern-recognition molecule in the ECM for microbial pathogens.

Authors
He, Y-W; Li, H; Zhang, J; Hsu, C-L; Lin, E; Zhang, N; Guo, J; Forbush, KA; Bevan, MJ
MLA Citation
He, Y-W, Li, H, Zhang, J, Hsu, C-L, Lin, E, Zhang, N, Guo, J, Forbush, KA, and Bevan, MJ. "The extracellular matrix protein mindin is a pattern-recognition molecule for microbial pathogens." Nat Immunol 5.1 (January 2004): 88-97.
PMID
14691481
Source
pubmed
Published In
Nature Immunology
Volume
5
Issue
1
Publish Date
2004
Start Page
88
End Page
97
DOI
10.1038/ni1021

The roles of orphan nuclear receptors in the development and function of the immune system.

Hormones and their receptors regulate cell growth, differentiation and apoptosis and also play important roles in immune function. Recent studies on the subfamily of the orphan nuclear receptors known as retinoid-acid related orphan receptors (ROR) have shed important insights on the roles of this group of nuclear proteins in the development and function of the immune system. RORalpha regulates inflammatory cytokine production in both innate and adaptive immune system while RORgamma regulates the normal development of T lymphocyte repertoire and secondary lymphoid organs.

Authors
Dzhagalov, I; Zhang, N; He, Y-W
MLA Citation
Dzhagalov, I, Zhang, N, and He, Y-W. "The roles of orphan nuclear receptors in the development and function of the immune system." Cellular & molecular immunology. 1.6 (2004): 401-407.
PMID
16293208
Source
scival
Published In
Cellular & molecular immunology
Volume
1
Issue
6
Publish Date
2004
Start Page
401
End Page
407

Lymphocyte accumulation in the spleen of retinoic acid receptor-related orphan receptor gamma-deficient mice.

The hormone nuclear receptor retinoic acid receptor-related orphan receptor gamma (RORgamma) plays important roles in thymocyte development and lymphoid organogenesis. RORgamma and its thymus-specific isoform RORgammat are expressed in the thymus, but not in the spleen and bone marrow (BM). However, RORgamma(-/-) mice have 2- to 3-fold more splenocytes than wild-type controls due to an accumulation of conventional resting B lymphocytes. The increase in B lymphocytes in RORgamma(-/-) mice is caused neither by abnormal B cell development in the BM nor by an obvious defect in the peripheral T cell compartment. Furthermore, analyses of BM chimeras using either RORgamma(-/-) or recombinase-activating gene-2(-/-) mice as recipients and wild-type or RORgamma(-/-) mice as donors, respectively, demonstrate that the splenic microenvironment of RORgamma(-/-) mice is defective, since wild-type T and B lymphocytes accumulated in these chimeric mice. In addition, T lymphocyte homeostasis was altered due to a lowered thymic output in RORgamma(-/-) mice. Collectively, these results suggest that RORgamma regulates lymphocyte homeostasis at multiple levels.

Authors
Zhang, N; Guo, J; He, Y-W
MLA Citation
Zhang, N, Guo, J, and He, Y-W. "Lymphocyte accumulation in the spleen of retinoic acid receptor-related orphan receptor gamma-deficient mice." J Immunol 171.4 (August 15, 2003): 1667-1675.
PMID
12902464
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
171
Issue
4
Publish Date
2003
Start Page
1667
End Page
1675

Orphan nuclear receptors in T lymphocyte development.

Lymphocyte development is initiated from hematopoietic stem cells and can be divided into multiple phenotypically distinct stages. Transcription factors play important roles in programming the developmental process of lymphocytes. Recent studies have identified key roles of several orphan nuclear receptors in T lymphocyte development. The orphan nuclear receptor RORgamma has been shown to promote thymocyte survival by activating the expression of antiapoptotic protein Bcl-x(L). RORgamma is also required for the development of lymph nodes and Peyer's patches. The orphan receptors Nur77 and Nor1 are involved in TCR-mediated cell death and thymocyte-negative selection. These studies provide novel insights into the molecular mechanisms of T lymphocyte development.

Authors
He, Y-W
MLA Citation
He, Y-W. "Orphan nuclear receptors in T lymphocyte development." J Leukoc Biol 72.3 (September 2002): 440-446. (Review)
PMID
12223510
Source
pubmed
Published In
Journal of leukocyte biology
Volume
72
Issue
3
Publish Date
2002
Start Page
440
End Page
446

Regulation of the TCRalpha repertoire by the survival window of CD4(+)CD8(+) thymocytes.

T cell receptor (TCR) alpha alleles undergo primary and secondary rearrangement in double-positive (DP) thymocytes. By analyzing TCRalpha rearrangement in orphan nuclear receptor RORgamma-deficient mice, in which the DP lifespan is shorter, and in Bcl-x(L)-transgenic mice, in which the DP lifespan is extended, we show that the progression of secondary V(alpha) to J(alpha) rearrangements is controlled by DP thymocyte survival. In addition, because Bcl-x(L) induces a bias towards 3' J(alpha) usage in peripheral T cells, we conclude that the programmed cell death of DP thymocytes is not simply a consequence of failed positive selection. Rather, it limits the progression of rearrangement along the J(alpha) locus and the opportunities for positive selection, thereby regulating the TCRalpha repertoire.

Authors
Guo, J; Hawwari, A; Li, H; Sun, Z; Mahanta, SK; Littman, DR; Krangel, MS; He, Y-W
MLA Citation
Guo, J, Hawwari, A, Li, H, Sun, Z, Mahanta, SK, Littman, DR, Krangel, MS, and He, Y-W. "Regulation of the TCRalpha repertoire by the survival window of CD4(+)CD8(+) thymocytes." Nat Immunol 3.5 (May 2002): 469-476.
PMID
11967541
Source
pubmed
Published In
Nature Immunology
Volume
3
Issue
5
Publish Date
2002
Start Page
469
End Page
476
DOI
10.1038/ni791

Down-regulation of the orphan nuclear receptor ROR gamma t is essential for T lymphocyte maturation.

Thymocyte development is a tightly regulated process. CD4+CD8+ double-positive (DP) immature thymocytes exhibit distinct phenotypic features from mature T cells; they express only 10% of surface TCR that are found on mature T cells and do not proliferate and produce IL-2 in response to stimulation. In this report we show that transgenic expression of the orphan nuclear receptor ROR gamma t in mature T cells down-regulates their surface TCR expression. The ROR gamma t transgene inhibits IL-2 production by mature T cells, and this inhibition may be partially due to the inhibitory effect of ROR gamma t on c-Rel transcription. Furthermore, ectopic expression of ROR gamma t inhibits the proliferation of mature and immature T cells. These results, together with its predominant expression in DP thymocytes, suggest that ROR gamma t controls these distinct phenotypic features of DP thymocytes. Our data suggest that down-regulation of ROR gamma t expression in thymocytes is essential for their maturation.

Authors
He, YW; Beers, C; Deftos, ML; Ojala, EW; Forbush, KA; Bevan, MJ
MLA Citation
He, YW, Beers, C, Deftos, ML, Ojala, EW, Forbush, KA, and Bevan, MJ. "Down-regulation of the orphan nuclear receptor ROR gamma t is essential for T lymphocyte maturation." J Immunol 164.11 (June 1, 2000): 5668-5674.
PMID
10820242
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
164
Issue
11
Publish Date
2000
Start Page
5668
End Page
5674

The role of orphan nuclear receptor in thymocyte differentiation and lymphoid organ development.

T lymphocytes differentiate in the thymus through several phenotypically distinct stages that are tightly regulated by multiple nuclear transcription factors. Immature CD4+CD8+ double positive (DP) thymocytes make up a majority of the population in the thymus, and exhibit several phenotypic features distinct from mature T cells. DP thymocytes express only about 10% of surface TCR that are found on mature T cells and do not proliferate and produce IL-2 in response to stimulation. Several critical events of T lymphocyte maturation such as TCRalpha gene recombination, positive and negative selection, and CD4/CD8 lineage commitment occur around the DP stage. Recent studies from our group and others on the orphan nuclear receptor RORgamma and its thymus-specific isoform RORgammat support a critical role for this nuclear receptor in the regulation of DP thymocyte function. In addition, RORgamma is required for the development of lymph nodes and Peyer's patches.

Authors
He, YW
MLA Citation
He, YW. "The role of orphan nuclear receptor in thymocyte differentiation and lymphoid organ development." Immunol Res 22.2-3 (2000): 71-82. (Review)
PMID
11339367
Source
pubmed
Published In
Immunologic Research
Volume
22
Issue
2-3
Publish Date
2000
Start Page
71
End Page
82
DOI
10.1385/IR:22:2-3:71

High level expression of CD43 inhibits T cell receptor/CD3-mediated apoptosis.

In a screen designed to identify genes that regulate T cell receptor (TCR)/CD3-mediated apoptosis, we found that high level expression of CD43 protected T cell hybridomas from activation-induced cell death. The protection appears to result from its capacity to block Fas-mediated death signals rather than from inhibition of the upregulation of Fas and/or Fas ligand after T cell stimulation. We found that peripheral CD4(+) T cells can be divided into two subsets based on the level of CD43 surface expression. The CD4(+)CD43(low) subset exhibits a naive T cell phenotype, being CD62L(high)CD45RB(high)CD44(low), whereas CD4(+)CD43(high) cells exhibit a memory phenotype, being CD62L(low)CD45RB(low)CD44(high). Recent studies have demonstrated that engagement of TCR and Fas induces naive CD4(+) T cells to undergo apoptosis, and the same treatment enhances the proliferation of memory CD4(+) T cells. We confirm here that peripheral CD4(+)CD43(high) T cells are resistant to TCR/CD3-mediated cell death. These results suggest that the expression levels of CD43 on naive and memory CD4(+) T cells determine their susceptibility to Fas-dependent cell death and that high level expression of CD43 may be used as a marker to define CD4(+) memory T cells. Expression of CD43 provides a novel mechanism by which tumor cells expressing abnormally high levels of CD43 may escape Fas-mediated killing.

Authors
He, YW; Bevan, MJ
MLA Citation
He, YW, and Bevan, MJ. "High level expression of CD43 inhibits T cell receptor/CD3-mediated apoptosis." J Exp Med 190.12 (December 20, 1999): 1903-1908.
PMID
10601365
Source
pubmed
Published In
The Journal of Experimental Medicine
Volume
190
Issue
12
Publish Date
1999
Start Page
1903
End Page
1908

Multiple gamma c-dependent cytokines regulate T-cell development.

Mutations in the common gamma chain (gamma c) of cytokine receptors account for human X-linked severe combined immunodeficiency disease. gamma c contributes to ligand binding and signaling as a component of five cytokine receptors: interleukin-2-receptor (IL-2R), IL-4R, IL-7R, IL-9R and IL-15R. Here, Thomas Malek and colleagues discuss the contribution of individual gamma c-dependent cytokines in both conventional and intraepithelial T-cell development.

Authors
Malek, TR; Porter, BO; He, YW
MLA Citation
Malek, TR, Porter, BO, and He, YW. "Multiple gamma c-dependent cytokines regulate T-cell development." Immunol Today 20.2 (February 1999): 71-76. (Review)
PMID
10098325
Source
pubmed
Published In
Immunology Today
Volume
20
Issue
2
Publish Date
1999
Start Page
71
End Page
76

Correlating notch signaling with thymocyte maturation.

The Notch receptor and its ligands are involved in many developmental processes. They are highly expressed in the thymus and have been implicated in the CD4 versus CD8 lineage decision. We identified the constitutively active intracellular fragment of murine Notch-1 as capable of rendering thymomas resistant to glucocorticoid-induced apoptosis. This effect was confirmed in other T cell lines and in CD4+ CD8+ DP thymocytes. Activation of the Notch signaling pathway also upregulated a number of other markers that, like steroid resistance, correlate with DP maturation into both the CD4 and CD8 lineages. These results suggest that Notch signaling is critically involved in the maturation of DP thymocytes into both CD4+ and CD8+ SP thymocytes.

Authors
Deftos, ML; He, YW; Ojala, EW; Bevan, MJ
MLA Citation
Deftos, ML, He, YW, Ojala, EW, and Bevan, MJ. "Correlating notch signaling with thymocyte maturation." Immunity 9.6 (December 1998): 777-786.
PMID
9881968
Source
pubmed
Published In
Immunity
Volume
9
Issue
6
Publish Date
1998
Start Page
777
End Page
786

RORgamma t, a novel isoform of an orphan receptor, negatively regulates Fas ligand expression and IL-2 production in T cells.

We have identified RORgamma t, a novel, thymus-specific isoform of the orphan nuclear receptor RORgamma that is expressed predominantly in CD4+ CD8+ double-positive thymocytes. Ectopic expression of RORgamma t protects T cell hybridomas from activation-induced cell death by inhibiting the upregulation of Fas ligand. Following hybridoma stimulation, RORgamma t also inhibits IL-2 production but does not affect the induction of Nur-77 and Egr-3 nor the upregulation of CD69. Both the ligand-binding and DNA-binding domains of RORgamma t are required for this effect. We propose that the role of RORgamma t expression in immature thymocytes is to inhibit Fas ligand expression and cytokine secretion following engagement of their TCR during positive or negative selection.

Authors
He, YW; Deftos, ML; Ojala, EW; Bevan, MJ
MLA Citation
He, YW, Deftos, ML, Ojala, EW, and Bevan, MJ. "RORgamma t, a novel isoform of an orphan receptor, negatively regulates Fas ligand expression and IL-2 production in T cells." Immunity 9.6 (December 1998): 797-806.
PMID
9881970
Source
pubmed
Published In
Immunity
Volume
9
Issue
6
Publish Date
1998
Start Page
797
End Page
806

Monoclonal antibodies to the common gamma-chain as cytokine receptor antagonists in vivo: effect on intrathymic and intestinal intraepithelial T lymphocyte development.

Mice lacking a functional gamma c subunit of cytokine receptors exhibit profound defects in the development of multiple lymphoid lineages. To investigate the role of gamma c-dependent cytokines in T cell development, the phenotype of developing T cells was compared in interleukin (IL)-7Ralpha-deficient mice and anti-gamma c mAb-treated chimeric mice reconstituted with adult bone marrow cells or subsets of pro-T cells. These studies indicate that gamma c contributes to T cell development at multiple stages of pro-T cell maturation and that IL-7/IL-7R is the primary cytokine for thymic-dependent T cell development. However, our data also implicate other gamma c-dependent cytokines during thymic T cell development. By contrast, substantial intestinal intraepithelial lymphocytes (IEL) development was observed in the intestinal intraepithelium in both types of mice. Analysis of IL-7Ralpha-deficient mice indicates that the IL-7/IL-7R system is critical only for the development of TCR gammadelta+ IEL. However, the inhibitory activity of the anti-deltac mAb in the chimeric mouse model suggests that additional gamma cutilizing cytokines regulate the development of the remaining subsets of IEL.

Authors
Malek, TR; Levy, RB; Adkins, B; He, YW
MLA Citation
Malek, TR, Levy, RB, Adkins, B, and He, YW. "Monoclonal antibodies to the common gamma-chain as cytokine receptor antagonists in vivo: effect on intrathymic and intestinal intraepithelial T lymphocyte development." J Leukoc Biol 63.6 (June 1998): 643-649. (Review)
PMID
9620654
Source
pubmed
Published In
Journal of leukocyte biology
Volume
63
Issue
6
Publish Date
1998
Start Page
643
End Page
649

The structure and function of gamma c-dependent cytokines and receptors: regulation of T lymphocyte development and homeostasis.

Five cytokines, IL-2, IL-4, IL-7, IL-9, and IL-15, form one group that is characterized by utilizing the common gamma chain (gamma c) as a receptor subunit. Examination of the phenotype of various cytokine or cytokine receptor "knockout" mice demonstrates that these cytokines are critical for normal lymphocyte development and subsequent functional activity of the peripheral immune compartment. This review summarizes the structural and functional properties of each of these five cytokines and their receptors, including the known redundant pathways for each cytokine or receptor. The contribution of these cytokines and receptors will then be considered in detail with respect to regulation of T lymphocyte development and homeostasis of the peripheral T cell compartment.

Authors
He, YW; Malek, TR
MLA Citation
He, YW, and Malek, TR. "The structure and function of gamma c-dependent cytokines and receptors: regulation of T lymphocyte development and homeostasis." Crit Rev Immunol 18.6 (1998): 503-524. (Review)
PMID
9862091
Source
pubmed
Published In
Critical Reviews in Immunology
Volume
18
Issue
6
Publish Date
1998
Start Page
503
End Page
524

RORγt, a novel isoform of an orphan receptor, negatively regulates Fas ligand expression and IL-2 production in T cells

We have identified RORγt, a novel, thymus-specific isoform of the orphan nuclear receptor RORγ that is expressed predominantly in CD4+ CD8+ double-positive thymocytes. Ectopic expression of RORγt protects T cell hybridomas from activation-induced cell death by inhibiting the upregulation of Fas ligand. Following hybridoma stimulation, RORγt also inhibits IL-2 production but does not affect the induction of Nur-77 and Egr-3 nor the upregulation of CD69. Both the ligand-binding and DNA-binding domains of RORγt are required for this effect. We propose that the role of RORγt expression in immature thymocytes is to inhibit Fas ligand expression and cytokine secretion following engagement of their TCR during positive or negative selection.

Authors
He, YW; Deftos, ML; Ojala, EW; Bevan, MJ
MLA Citation
He, YW, Deftos, ML, Ojala, EW, and Bevan, MJ. "RORγt, a novel isoform of an orphan receptor, negatively regulates Fas ligand expression and IL-2 production in T cells." Immunity 9.6 (1998): 797-806.
Source
scival
Published In
Immunity
Volume
9
Issue
6
Publish Date
1998
Start Page
797
End Page
806
DOI
10.1016/S1074-7613(00)80645-7

The common gamma-chain of cytokine receptors regulates intrathymic T cell development at multiple stages.

Signaling through the common gamma chain (gamma c), a subunit of the receptors for IL-2, -4, -7, -9, and -15, is critical for lymphocyte development, with the IL-7/IL-7R representing one important interaction. To investigate the stages of intrathymic T cell development that are dependent on gamma c and to determine whether gamma c controls T cell development solely as a component of the IL-7R, intrathymic T cell development was compared in IL-7R alpha-deficient mice and anti-gamma c-treated chimeric mice reconstituted with bone marrow and purified pro-T cells. In the presence of anti-gamma c, each of four phenotypically distinguishable stages of CD4- CD8- thymocytes failed to reconstitute T cell development, suggesting that each of these subsets of pro-T cells required gamma c for their differentiation and/or growth. Reconstitution of anti-gamma c-treated chimeric mice with bone marrow from IL-7R alpha-deficient mice indicated that IL-7R only partially contributed to intrathymic T cell development. Furthermore, when compared with IL-7R-deficient mice, anti-gamma c chimeric and gamma c-deficient mice exhibited a distinct phenotypic pattern of pro-T cell development. Collectively, these results indicate that several gamma c-sharing cytokines may contribute to T cell development in the thymus and suggest that one of these cytokines may be novel.

Authors
He, YW; Nakajima, H; Leonard, WJ; Adkins, B; Malek, TR
MLA Citation
He, YW, Nakajima, H, Leonard, WJ, Adkins, B, and Malek, TR. "The common gamma-chain of cytokine receptors regulates intrathymic T cell development at multiple stages." J Immunol 158.6 (March 15, 1997): 2592-2599.
PMID
9058791
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
158
Issue
6
Publish Date
1997
Start Page
2592
End Page
2599

Rotavirus RNA polymerase requires the core shell protein to synthesize the double-stranded RNA genome

Rotavirus cores contain the double-stranded RNA (dsRNA) genome, RNA polymerase VP1, and guanylyltransferase VP3 and are enclosed within a lattice formed by the RNA-binding protein VP2. Analysis of baculovirus-expressed core-like particles (CLPs) has shown that VP1 and VP2 assemble into the simplest core-like structures with replicase activity and that VP1, but not VP3, is essential for replicase activity. To further define the role of VP1 and VP2 in the synthesis of dsRNA from viral mRNA, recombinant baculoviruses containing gene 1 (rBVg1) and gene 2 (rBVg2) of SA11 rotavirus were generated and used to express recombinant VP1 (rVP1) and rVP2, respectively. After purification, the proteins were assayed individually and together for the ability to catalyze the synthesis of dsRNA in a cell-free replication system. The results showed that dsRNA was synthesized only in assays containing rVP1 and rVP2, thus establishing that both proteins are essential for replicase activity. Even in assays containing a primer-linked mRNA template, neither rVP1 nor rVP2 alone directed RNA synthesis. Characterization of the cis- acting replication signals in mRNA recognized by the replicase of rVP1 and rVP2 showed that they were the same as those recognized by the replicase of virion-derived cores, thus excluding a role for VP3 in recognition of the mRNA template by the replicase. Analysis of RNA-protein interactions indicated that the mRNA template binds strongly to VP2 in replicase assays but that the majority of the dsRNA product neither is packaged nor stably associates with VP2. The results of replicase assays performed with mutant VP2 containing a deletion in its RNA-binding domain suggests that the essential role for VP2 in replication is linked to the protein's ability to bind the mRNA template for minus-strand synthesis.

Authors
Patton, JT; Jones, MT; Kalbach, AN; He, Y-W; Xiaobo, J
MLA Citation
Patton, JT, Jones, MT, Kalbach, AN, He, Y-W, and Xiaobo, J. "Rotavirus RNA polymerase requires the core shell protein to synthesize the double-stranded RNA genome." Journal of Virology 71.12 (1997): 9618-9626.
PMID
9371626
Source
scival
Published In
Journal of virology
Volume
71
Issue
12
Publish Date
1997
Start Page
9618
End Page
9626

Interleukin-7 receptor alpha is essential for the development of gamma delta + T cells, but not natural killer cells.

Mice that lack a functional gamma c subunit of the receptors for interleukin (IL)-2, IL-4, IL-7, IL-9, and IL-15 display profound defects in lymphoid development. The IL-7/IL-7R system represents a critical interaction for conventional T and B cell development. In this report, the role of IL-7R alpha in the development of lymphoid lineages other than conventional T and B cells was examined. We demonstrate that gamma delta + T cells were absent in IL-7R alpha-deficient mice, whereas the development and function of natural killer cells were normal. Thus, IL-7R alpha function is required for the development of gamma delta + T cells but not natural killer cells.

Authors
He, YW; Malek, TR
MLA Citation
He, YW, and Malek, TR. "Interleukin-7 receptor alpha is essential for the development of gamma delta + T cells, but not natural killer cells." J Exp Med 184.1 (July 1, 1996): 289-293.
PMID
8691145
Source
pubmed
Published In
The Journal of Experimental Medicine
Volume
184
Issue
1
Publish Date
1996
Start Page
289
End Page
293

The IL-2 receptor gamma c chain does not function as a subunit shared by the IL-4 and IL-13 receptors. Implication for the structure of the IL-4 receptor.

The IL-2 receptor (IL-2R) gamma c subunit is also a component of the receptors for IL-4, IL-7, IL-9, and IL-15. The IL-4R and IL-13R appear to share a common subunit, and gamma c was proposed to be this shared subunit. In this study, we have assessed the relative contribution of gamma c to the mouse IL-4R and IL-13R. The MC/9 mast cell line constitutively expresses gamma c and proliferates to IL-4 and IL-13, but only the response to IL-4 was blocked by anti-gamma c mAbs. After transfection of the IL-4- and IL-13-responsive gamma c-negative B9 plasmacytoma with full length (m gamma) or cytoplasmic-tailless gamma c cDNA (m gamma t), only the proliferative response to IL-4 was affected by the surface expression of these gamma c molecules. The inability of m gamma or m gamma t expression to affect IL-13-induced proliferation by B9 indicates that gamma c does not obviously contribute to the IL-13R and does not function as the shared subunit of the IL-4R and IL-13R. This study suggests that there are two distinct IL-4R, one of which is independent of gamma c.

Authors
He, YW; Malek, TR
MLA Citation
He, YW, and Malek, TR. "The IL-2 receptor gamma c chain does not function as a subunit shared by the IL-4 and IL-13 receptors. Implication for the structure of the IL-4 receptor." J Immunol 155.1 (July 1, 1995): 9-12.
PMID
7602126
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
155
Issue
1
Publish Date
1995
Start Page
9
End Page
12

Blockade of T- and B-lymphocyte development by antibody to the gamma c subunit of the receptors for interleukins 2, 4, and 7.

Cytokines are important regulators of hematopoesis. Mutations in gamma c, which is a subunit shared by the receptors for interleukin (IL) 2, IL-4, and IL-7, have been causally associated with human X chromosome-linked severe combined immunodeficiency disease. This finding indicates a mandatory role for cytokine receptor signaling at one or more stages of lymphocyte development. To evaluate the cellular level at which gamma c is critical for lymphopoiesis, the effect of monoclonal antibodies to gamma c on the capacity of syngeneic bone marrow cells to reconstitute the hematopoietic compartment of lethally irradiated recipient mice was examined. We show that monoclonal antibody to gamma c blocked lymphocyte development at or before the appearance of pro-B cells and prior to or at the seeding of the thymus by precursor cells while erythromyeloid cell development was normal. These results suggest that one level of lymphocyte development that requires gamma c is a point in hematopoietic cell differentiation near the divergence of lymphopoiesis and erythromyelopoesis.

Authors
He, YW; Levy, RB; Malek, TR
MLA Citation
He, YW, Levy, RB, and Malek, TR. "Blockade of T- and B-lymphocyte development by antibody to the gamma c subunit of the receptors for interleukins 2, 4, and 7." Proc Natl Acad Sci U S A 92.12 (June 6, 1995): 5689-5693.
PMID
7777571
Source
pubmed
Published In
Proceedings of the National Academy of Sciences of USA
Volume
92
Issue
12
Publish Date
1995
Start Page
5689
End Page
5693

Biochemical identity and characterization of the mouse interleukin-2 receptor beta and gamma c subunits.

Although the mouse IL-2 receptor (IL-2R) beta and gamma c subunits have been identified by molecular cloning, the biochemical identity of these subunits has not yet been established. In the present study, the mouse IL-2R was biochemically characterized from cell lines expressing normal and aberrant IL-2R. Using novel monoclonal antibodies specific for the beta or gamma c subunits, we established that the M(r) of the beta chain is 90,000-100,000 and that of the gamma c subunit is 75,000-80,000. Analysis of transfected EL4 cells that expressed alpha, gamma c, and truncated beta subunits or mutant EL4 cells, which selectively lacked cell surface gamma c, revealed that no other material migrated to a position on SDS-PAGE characteristic of IL-2/IL-2R beta and IL-2/IL-2R gamma c cross-linked complexes, respectively. Thus, the beta and gamma c subunits appear to be the sole IL-2R constituents of these IL-2 cross-linked complexes. The IL-2/IL-2R gamma c, but not the IL-2/IL-2R beta, complex exhibited enhanced mobility after SDS-polyacrylamide gel electrophoresis under nonreducing conditions, suggesting a more compact structure for gamma c as a result of intrachain disulfide bonds. The primary posttranslational modification of the mouse beta and gamma c subunits is N-linked glycosylation. These biochemical studies reconcile past uncertainties concerning the subunit composition of the mouse IL-2R and are consistent with a model of the IL-2R containing only three subunits.

Authors
Malek, TR; Furse, RK; Fleming, ML; Fadell, AJ; He, YW
MLA Citation
Malek, TR, Furse, RK, Fleming, ML, Fadell, AJ, and He, YW. "Biochemical identity and characterization of the mouse interleukin-2 receptor beta and gamma c subunits." J Interferon Cytokine Res 15.5 (May 1995): 447-454.
PMID
7648447
Source
pubmed
Published In
Journal of Interferon & Cytokine Research
Volume
15
Issue
5
Publish Date
1995
Start Page
447
End Page
454
DOI
10.1089/jir.1995.15.447

Expression and function of the gamma c subunit of the IL-2, IL-4, and IL-7 receptors. Distinct interaction of gamma c in the IL-4 receptor.

IL-2R, IL-4R, and IL-7R share a common subunit referred to as gamma c and the IL-13R has been proposed to contain gamma c as a subunit. In this report we have used two novel mAbs (3E12 and 4G3) to distinct epitopes of mouse gamma c to determine its lymphoid cell distribution and to examine whether gamma c uses similar epitopes to interact with different cytokines and cytokine receptors. FACS analysis revealed that gamma c is expressed in most lymphocytes, myeloid cells, embryonic thymocytes, and lymphoid cell lines. Results from radiolabeled ligand binding studies, biochemical analysis of ligand-receptor cross-linked complexes, and cytokine bioassays indicate that the epitope defined by mAb 4G3 closely defines the IL-7 binding region of gamma c and overlaps the IL-2 binding region of gamma c. These studies also indicate that gamma c interacts with IL-4 in the context of the IL-4R in a manner that is distinct from its role in the IL-2R and IL-7R and suggest that the 3E12 epitope defines a region of gamma c that intimately interacts with the IL-4R. The B9 plasmacytoma, which proliferates in response to IL-4 and IL-13, was shown to not express gamma c. Thus, at least in some circumstances, gamma c is dispensable for signaling via the IL-4R and is not a required subunit of the IL-13R.

Authors
He, YW; Adkins, B; Furse, RK; Malek, TR
MLA Citation
He, YW, Adkins, B, Furse, RK, and Malek, TR. "Expression and function of the gamma c subunit of the IL-2, IL-4, and IL-7 receptors. Distinct interaction of gamma c in the IL-4 receptor." J Immunol 154.4 (February 15, 1995): 1596-1605.
PMID
7530740
Source
pubmed
Published In
Journal of immunology (Baltimore, Md. : 1950)
Volume
154
Issue
4
Publish Date
1995
Start Page
1596
End Page
1605
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