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Garg M, Wahid M, Khan F. Regulation of peripheral and central immunity: Understanding the role of Src homology 2 domain-containing tyrosine phosphatases, SHP-1 & SHP-2. Immunobiology 2019; 225:151847. [PMID: 31561841 DOI: 10.1016/j.imbio.2019.09.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 08/25/2019] [Accepted: 09/03/2019] [Indexed: 01/20/2023]
Abstract
Protein tyrosine phosphorylation is a potent post-translational regulatory mechanism necessary for maintaining normal physiological functioning of immune cells and it is under the stringent control of antagonizing actions of Protein tyrosine phosphatases and kinases. Two such important Non-Receptor protein tyrosine phosphatases, SHP-1 and SHP-2, have been found to be expressed in immune cells and reported to be key regulators of immune cell development, functions, and differentiation by modulating the duration and amplitude of the downstream cascade transduced via receptors. They also have been conceded as the immune checkpoints & therapeutic targets and hence, it is important to understand their significance intricately. This review compares the roles of these two important cytoplasmic PTPs, SHP1 & SHP-2 in the regulation of peripheral as well as central immunity.
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Affiliation(s)
- Manika Garg
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, Hamdard Nagar, New Delhi-110062, India.
| | - Mohd Wahid
- Research and Scientific Studies Unit, College of Nursing and Allied Health Sciences, Jazan University, Jazan, 45142, Saudi Arabia.
| | - Farah Khan
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, Hamdard Nagar, New Delhi-110062, India.
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Li Z, Gong P, Wang W, Qu S, Wang X, He Z, Wang G, Kong Q, Mu L, Wang J, Fang S, Zhao W, Sun B, Li H. Functional network analysis reveals biological roles of lncRNAs and mRNAs in MOG35–55 specific CD4+T helper cells. Genomics 2018; 110:337-346. [DOI: 10.1016/j.ygeno.2018.01.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 01/04/2018] [Accepted: 01/17/2018] [Indexed: 01/03/2023]
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Sharma Y, Bashir S, Bhardwaj P, Ahmad A, Khan F. Protein tyrosine phosphatase SHP-1: resurgence as new drug target for human autoimmune disorders. Immunol Res 2017; 64:804-19. [PMID: 27216862 DOI: 10.1007/s12026-016-8805-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Recognition of self-antigen and its destruction by the immune system is the hallmark of autoimmune diseases. During the developmental stages, immune cells are introduced to the self-antigen, for which tolerance develops. The inflammatory insults that break the immune tolerance provoke immune system against self-antigen, progressively leading to autoimmune diseases. SH2 domain containing protein tyrosine phosphatase (PTP), SHP-1, was identified as hematopoietic cell-specific PTP that regulates immune function from developing immune tolerance to mediating cell signaling post-immunoreceptor activation. The extensive research on SHP-1-deficient mice elucidated the diversified role of SHP-1 in immune regulation, and inflammatory process and related disorders such as cancer, autoimmunity, and neurodegenerative diseases. The present review focalizes upon the implication of SHP-1 in the pathogenesis of autoimmune disorders, such as allergic asthma, neutrophilic dermatosis, atopic dermatitis, rheumatoid arthritis, and multiple sclerosis, so as to lay the background in pursuance of developing therapeutic strategies targeting SHP-1. Also, new SHP-1 molecular targets have been suggested like SIRP-α, PIPKIγ, and RIP-1 that may prove to be the focal point for the development of therapeutic strategies.
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Affiliation(s)
- Yadhu Sharma
- Department of Biochemistry, Faculty of Science, Jamia Hamdard, New Delhi, 110062, India
| | - Samina Bashir
- Department of Biochemistry, Faculty of Science, Jamia Hamdard, New Delhi, 110062, India
| | - Puja Bhardwaj
- Department of Biochemistry, Faculty of Science, Jamia Hamdard, New Delhi, 110062, India
| | - Altaf Ahmad
- Department of Botany, Aligarh Muslim University, Aligarh, Uttar Pradesh, 202002, India
| | - Farah Khan
- Department of Biochemistry, Faculty of Science, Jamia Hamdard, New Delhi, 110062, India.
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Downmodulation of Effector Functions in NK Cells upon Toxoplasma gondii Infection. Infect Immun 2017; 85:IAI.00069-17. [PMID: 28760930 DOI: 10.1128/iai.00069-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 07/15/2017] [Indexed: 12/29/2022] Open
Abstract
The obligate intracellular parasite Toxoplasma gondii can actively infect any nucleated cell type, including cells from the immune system. The rapid transfer of T. gondii from infected dendritic cells to effector natural killer (NK) cells may contribute to the parasite's sequestration and shielding from immune recognition shortly after infection. However, subversion of NK cell functions, such as cytotoxicity or production of proinflammatory cytokines, such as gamma interferon (IFN-γ), upon parasite infection might also be beneficial to the parasite. In the present study, we investigated the effects of T. gondii infection on NK cells. In vitro, infected NK cells were found to be poor at killing target cells and had reduced levels of IFN-γ production. This could be attributed in part to the inability of infected cells to form conjugates with their target cells. However, even upon NK1.1 cross-linking of NK cells, the infected NK cells also exhibited poor degranulation and IFN-γ production. Similarly, NK cells infected in vivo were also poor at killing target cells and producing IFN-γ. Increased levels of transforming growth factor β production, as well as increased levels of expression of SHP-1 in the cytosol of infected NK cells upon infection, were observed in infected NK cells. However, the phosphorylation of STAT4 was not altered in infected NK cells, suggesting that transcriptional regulation mediates the reduced IFN-γ production, which was confirmed by quantitative PCR. These data suggest that infection of NK cells by T. gondii impairs NK cell recognition of target cells and cytokine release, two mechanisms that independently could enhance T. gondii survival.
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Overexpression of CD45RA isoforms in carriers of the C77G mutation leads to hyporeactivity of CD4+CD25highFoxp3+ regulatory T cells. Genes Immun 2015; 16:519-27. [PMID: 26355564 DOI: 10.1038/gene.2015.39] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 07/10/2015] [Accepted: 08/03/2015] [Indexed: 02/07/2023]
Abstract
Disorders in regulatory T-cell (T(reg)) function can result in the breakdown of immunological self-tolerance. Thus, the identification of mechanisms controlling the activity of T(reg) is of great relevance. We used T(reg) from individuals carrying the C77G polymorphism as models to study the role of CD45 molecules in humans. C77G prevents splicing of CD45 exon A thereby leading to an aberrant expression pattern of CD45 isoforms in affected individuals. Resting and in vitro expanded/activated CD4(+)CD25(high)Foxp3(+) T(reg) from carriers of C77G strongly expressed CD45RA isoforms whereas these isoforms were almost absent in cells from individuals with wild-type CD45. C77G T(reg) showed diminished upregulation of activation markers, lower phosphorylation of p56(lck)(Y505) and a reduced proliferative potential when stimulated with anti-TcR or anti-TcR plus CD28 mAb suggesting decreased responsiveness to activating stimuli. In addition, the capacity to suppress proliferation of conventional CD4(+) T cells was impaired in C77G T(reg). Furthermore, microarray studies revealed distinct gene expression patterns in T(reg) from C77G carriers. These data suggest that the changes in CD45 isoform combination resulting from the C77G mutation alter the responsiveness of T(reg) to TcR-mediated signaling. Targeting CD45 isoform expression might be a useful approach to modulate T(reg) function.
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Becerra-Díaz M, Terrazas LI. Taenia crassiceps infection and its excreted/secreted products inhibit STAT1 activation in response to IFN-γ. Int J Parasitol 2014; 44:613-23. [PMID: 24837622 DOI: 10.1016/j.ijpara.2014.03.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 03/21/2014] [Accepted: 03/25/2014] [Indexed: 01/08/2023]
Abstract
It is well understood that helminth infections modulate the immune responses of their hosts but the mechanisms involved in this modulation are not fully known. Macrophages and dendritic cells appear to be consistently affected during this type of infection and are common target cells for helminth-derived molecules. In this report, we show that macrophages obtained from chronically Taenia crassiceps-infected mice displayed an impaired response to recombinant murine IFN-γ, but not to recombinant murine IL-4, as measured based on the phosphorylation of STAT1 and STAT6, respectively. These macrophages expressed high levels of SOCS3. However, the inhibition of phosphatase activity by orthovanadate restored the IFN-γ response of these macrophages by increasing STAT1 phosphorylation without affecting SOCS3 expression. Therefore, we aimed to identify the phosphatases associated with IFN-γ signaling inhibition and found that macrophages from T. crassiceps-infected mice displayed enhanced SHP-1 expression. Interestingly, the exposure of naïve macrophages to T. crassiceps excreted/secreted products similarly interfered with IFN-γ-induced STAT1 phosphorylation. Moreover, macrophages exposed to T. crassiceps excreted/secreted products expressed high levels of SOCS3 as well as SHP-1. Strikingly, human peripheral blood mononuclear cells that were exposed to T. crassiceps excreted/secreted products in vitro also displayed impaired STAT1 phosphorylation in response to IFN-γ; again, phosphatase inhibition abrogated the T. crassiceps excreted/secreted product-altered IFN-γ signaling. These data demonstrate a new mechanism by which helminth infection and the products derived during this infection target intracellular pathways to block the response to inflammatory cytokines such as IFN-γ in both murine and human cells.
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Affiliation(s)
- Mireya Becerra-Díaz
- Unidad de Biomedicina, Facultad de Estudios Superiores (FES)-Iztacala, Universidad Nacional Autónoma de México (UNAM), Av. De los Barrios 1, Los Reyes Iztacala, Tlalnepantla, Edo. de Mexico 54090, Mexico
| | - Luis I Terrazas
- Unidad de Biomedicina, Facultad de Estudios Superiores (FES)-Iztacala, Universidad Nacional Autónoma de México (UNAM), Av. De los Barrios 1, Los Reyes Iztacala, Tlalnepantla, Edo. de Mexico 54090, Mexico.
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Abstract
The hormonal milieu influences immune tolerance and the immune response against viruses and cancer, but the direct effect of androgens on cellular immunity remains largely uncharacterized. We therefore sought to evaluate the effect of androgens on murine and human T cells in vivo and in vitro. We found that murine androgen deprivation in vivo elicited RNA expression patterns conducive to IFN signaling and T-cell differentiation. Interrogation of mechanism showed that testosterone regulates T-helper 1 (Th1) differentiation by inhibiting IL-12-induced Stat4 phosphorylation: in murine models, we determined that androgen receptor binds a conserved region within the phosphatase, Ptpn1, and consequent up-regulation of Ptpn1 then inhibits IL-12 signaling in CD4 T cells. The clinical relevance of this mechanism, whereby the androgen milieu modulates CD4 T-cell differentiation, was ascertained as we found that androgen deprivation reduced expression of Ptpn1 in CD4 cells from patients undergoing androgen deprivation therapy for prostate cancer. Our findings, which demonstrate a clinically relevant mechanism by which androgens inhibit Th1 differentiation of CD4 T cells, provide rationale for targeting androgens to enhance CD4-mediated immune responses in cancer or, conversely, for modulating androgens to mitigate CD4 responses in disorders of autoimmunity.
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Johnson DJ, Pao LI, Dhanji S, Murakami K, Ohashi PS, Neel BG. Shp1 regulates T cell homeostasis by limiting IL-4 signals. ACTA ACUST UNITED AC 2013; 210:1419-31. [PMID: 23797092 PMCID: PMC3698519 DOI: 10.1084/jem.20122239] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Absence of the phosphatase Shp1 in T cells does not affect the TCR signaling threshold but results in IL-4 sensitivity and memory phenotype cells. The protein-tyrosine phosphatase Shp1 is expressed ubiquitously in hematopoietic cells and is generally viewed as a negative regulatory molecule. Mutations in Ptpn6, which encodes Shp1, result in widespread inflammation and premature death, known as the motheaten (me) phenotype. Previous studies identified Shp1 as a negative regulator of TCR signaling, but the severe systemic inflammation in me mice may have confounded our understanding of Shp1 function in T cell biology. To define the T cell–intrinsic role of Shp1, we characterized mice with a T cell–specific Shp1 deletion (Shp1fl/fl CD4-cre). Surprisingly, thymocyte selection and peripheral TCR sensitivity were unaltered in the absence of Shp1. Instead, Shp1fl/fl CD4-cre mice had increased frequencies of memory phenotype T cells that expressed elevated levels of CD44. Activation of Shp1-deficient CD4+ T cells also resulted in skewing to the Th2 lineage and increased IL-4 production. After IL-4 stimulation of Shp1-deficient T cells, Stat 6 activation was sustained, leading to enhanced Th2 skewing. Accordingly, we observed elevated serum IgE in the steady state. Blocking or genetic deletion of IL-4 in the absence of Shp1 resulted in a marked reduction of the CD44hi population. Therefore, Shp1 is an essential negative regulator of IL-4 signaling in T lymphocytes.
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Affiliation(s)
- Dylan J Johnson
- Campbell Family Institute for Breast Cancer Research, Princess Margaret Cancer Center, University Health Network, Toronto, ON M5G 2C1, Canada
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Lee YS, Won KJ, Park SW, Lee HW, Kim B, Kim JH, Kim DK. Mesenchymal stem cells regulate the proliferation of T cells via the growth-related oncogene/CXC chemokine receptor, CXCR2. Cell Immunol 2012; 279:1-11. [DOI: 10.1016/j.cellimm.2012.08.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 07/21/2012] [Accepted: 08/24/2012] [Indexed: 12/29/2022]
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Kundu S, Fan K, Cao M, Lindner DJ, Zhao ZJ, Borden E, Yi T. Novel SHP-1 inhibitors tyrosine phosphatase inhibitor-1 and analogs with preclinical anti-tumor activities as tolerated oral agents. THE JOURNAL OF IMMUNOLOGY 2010; 184:6529-36. [PMID: 20421638 DOI: 10.4049/jimmunol.0903562] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Src homology region 2 domain-containing phosphatase 1 (SHP-1) has been implicated as a potential cancer therapeutic target by its negative regulation of immune cell activation and the activity of the SHP-1 inhibitor sodium stibogluconate that induced IFN-gamma(+) cells for anti-tumor action. To develop more potent SHP-1-targeted anti-cancer agents, inhibitory leads were identified from a library of 34,000 drug-like compounds. Among the leads and active at low nM for recombinant SHP-1, tyrosine phosphatase inhibitor-1 (TPI-1) selectively increased SHP-1 phospho-substrates (pLck-pY394, pZap70, and pSlp76) in Jurkat T cells but had little effects on pERK1/2 or pLck-pY505 regulated by phosphatases SHP-2 or CD45, respectively. TPI-1 induced mouse splenic-IFN-gamma(+) cells in vitro, approximately 58-fold more effective than sodium stibogluconate, and increased mouse splenic-pLck-pY394 and -IFN-gamma(+) cells in vivo. TPI-1 also induced IFN-gamma(+) cells in human peripheral blood in vitro. Significantly, TPI-1 inhibited ( approximately 83%, p < 0.002) the growth of B16 melanoma tumors in mice at a tolerated oral dose in a T cell-dependent manner but had little effects on B16 cell growth in culture. TPI-1 also inhibited B16 tumor growth and prolonged tumor mice survival as a tolerated s.c. agent. TPI-1 analogs were identified with improved activities in IFN-gamma(+) cell induction and in anti-tumor actions. In particular, analog TPI-1a4 as a tolerated oral agent completely inhibited the growth of K1735 melanoma tumors and was more effective than the parental lead against MC-26 colon cancer tumors in mice. These results designate TPI-1 and the analogs as novel SHP-1 inhibitors with anti-tumor activity likely via an immune mechanism, supporting SHP-1 as a novel target for cancer treatment.
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Affiliation(s)
- Suman Kundu
- Department of Cancer Biology, Lerner Research Institute, The Cleveland Clinic, Cleveland, OH 44195, USA
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Fan K, Borden E, Yi T. Interferon-gamma is induced in human peripheral blood immune cells in vitro by sodium stibogluconate/interleukin-2 and mediates its antitumor activity in vivo. J Interferon Cytokine Res 2009; 29:451-60. [PMID: 19514839 DOI: 10.1089/jir.2008.0061] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Sodium stibogluconate (SSG), an inhibitor of SHP-1 that negatively regulates cytokine signaling and immunity, suppressed growth of murine Renca tumors in combination with interleukin-2 (IL-2) via a T-cell-dependent mechanism. The ability of SSG to interact with IL-2 in activating primary human immune cells was evaluated herein by assessing its induction of interferon (IFN)-gamma(+) TH1 cells in human peripheral blood in vitro. The significance of IFN-gamma(+) cells was also investigated by assessing SSG/IL-2 antitumor activity in wild-type and IFN-gamma(-/-) mice. IFN-gamma(+) cells but not IL-5(+) cells were induced markedly (9.1x) in healthy peripheral blood by SSG/IL-2 in contrast to the modest induction by SSG alone (2.1x) at its clinically achievable dose (20 microg/mL) or by IL-2 (3.1x) at its C(max) of low-dose schedule (30 IU/mL). SSG at a higher dose (100 microg/mL) was less effective alone (1.5x) or in combination with IL-2 (7.8x). Peripheral IFN-gamma(+) cells were induced after 4 or 16 h treatment with SSG/IL-2 within CD4(+) and CD8(+) lymphocytes coincided with heightened CD69 expression (approximately 3-4x). SSG/IL-2 was also more effective than the single agents in inducing IFN-gamma(+) cells in the peripheral blood of melanoma patients, whose basal IFN-gamma(+) cell levels were approximately 5% of healthy controls. Renca tumor growth was inhibited by SSG/IL-2 in wild-type but not IFN-gamma(-/-) mice. These results demonstrate SSG interactions with IL-2 in vitro to activate key antitumor immune cells in peripheral blood of healthy and melanoma donors, providing further evidence for proof of concept clinical trials for effecting augmentation of IL-2 through inhibiting negative regulatory protein tyrosine phosphatases.
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Affiliation(s)
- Keke Fan
- Department of Cancer Biology, Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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Abstract
Tyrosine phosphorylation and dephosphorylation of proteins play a critical role for many T-cell functions. The opposing actions of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs) determine the level of tyrosine phosphorylation at any time. It is well accepted that PTKs are essential during T-cell signaling; however, the role and importance of PTPs are much less known and appreciated. Both transmembrane and cytoplasmic tyrosine phosphatases have been identified in T cells and shown to regulate T-cell responses. This review focuses on the roles of the two cytoplasmic PTPs, the Src-homology 2 domain (SH2)-containing SHP-1 and SHP-2, in T-cell signaling, development, differentiation, and function.
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Affiliation(s)
- Ulrike Lorenz
- Department of Microbiology and The Beirne Carter Center for Immunology Research, University of Virginia, Charlottesville, VA 22908-0734, USA.
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Abstract
Protein tyrosine phosphatases (PTPases) are attractive targets for developing novel cancer therapeutics. Activated via gain-of-function point mutations or overexpression, several PTPases have been identified as critical oncogenic molecules in human malignancies that may be targeted with small chemical inhibitors as a therapeutic strategy. Tumor suppressor PTPases have also been discovered as contributing factors in cancer development that may be targeted via intervention of downstream signaling events for therapeutic purposes. In addition, PTPases have been identified as key negative regulators of cytokines or immune cells. Targeting these negative PTPases may improve the efficacy of cytokine therapy and immunotherapy, which currently have modest response rates and limited survival benefit. Inhibitors of selective PTPases have demonstrated significant preclinical antitumor activity, leading to early-phase clinical trials. Further research and development could lead to PTPase-targeted cancer therapeutics in the near future.
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Abstract
Tyrosyl phosphorylation plays a critical role in multiple signaling pathways regulating innate and acquired immunity. Although tyrosyl phosphorylation is a reversible process, we know much more about the functions of protein-tyrosine kinases (PTKs) than about protein-tyrosine phosphatases (PTPs). Genome sequencing efforts have revealed a large and diverse superfamily of PTPs, which can be subdivided into receptor-like (RPTPs) and nonreceptor (NRPTPs). The role of the RPTP CD45 in immune cell signaling is well known, but those of most other PTPs remain poorly understood. Here, we review the mechanism of action, regulation, and physiological functions of NRPTPs in immune cell signaling. Such an analysis indicates that PTPs are as important as PTKs in regulating the immune system.
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Affiliation(s)
- Lily I Pao
- Cancer Biology Program, Division of Hematology-Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA.
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Park IK, Shultz LD, Letterio JJ, Gorham JD. TGF-beta1 inhibits T-bet induction by IFN-gamma in murine CD4+ T cells through the protein tyrosine phosphatase Src homology region 2 domain-containing phosphatase-1. THE JOURNAL OF IMMUNOLOGY 2005; 175:5666-74. [PMID: 16237056 DOI: 10.4049/jimmunol.175.9.5666] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
TGF-beta1 prevents the development of autoimmune disease by restraining the development of autoreactive Th1 cells. TGF-beta1 inhibits Th1 development in part by suppressing the expression of T-bet, an IFN-gamma-induced transcription factor that promotes Th1 differentiation, but how TGF-beta1 suppresses T-bet is not known. In this study we show that TGF-beta1 suppresses IFN-gamma-induced T-bet expression through the hemopoietic protein tyrosine phosphatase (PTP) Src homology region 2 domain-containing phosphatase-1 (Shp-1). In murine CD4+ T cells, IFN-gamma rapidly induced the expression of T-bet as well as of IFN regulatory factor-1, another transcription factor important for Th1 development. TGF-beta1 antagonized the effects of IFN-gamma, inhibiting IFN-gamma's induction of both Th1 transcription factors. In the presence of IFN-gamma, TGF-beta1 rapidly induced in Th cells the synthesis of the PTP Shp-1, but did not induce Shp-2 or several members of the suppressor of cytokine signaling family of Jak-Stat inhibitors. We tested the requirement for Shp-1 by using T cells from the Shp-1-deficient me(v)/me(v) mouse strain. Shp-1 was required for TGF-beta1's suppressive effects, because its suppression of T-bet and IFN regulatory factor-1 was completely abrogated in me(v)/me(v) CD4+ T cells. Receptor-proximal responses to IFN-gamma, such as the induction of Jak-Stat phosphorylation, were inhibited by TGF-beta1 in wild-type T cells, but not in me(v)/me(v) T cells. Consistent with a direct role for Shp-1, TGF-beta1's inhibition of IFN-gamma-induced Stat1 phosphorylation was sensitive to the general PTP inhibitor pervanadate. Together, these data show that TGF-beta1 suppresses IFN-gamma signaling and transcriptional responses in CD4+ T cells through the PTP Shp-1.
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Affiliation(s)
- Il-Kyoo Park
- Department of Pathology, Dartmouth Medical School, Lebanon, NH 03756, USA
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Kwon J, Qu CK, Maeng JS, Falahati R, Lee C, Williams MS. Receptor-stimulated oxidation of SHP-2 promotes T-cell adhesion through SLP-76-ADAP. EMBO J 2005; 24:2331-41. [PMID: 15933714 PMCID: PMC1173147 DOI: 10.1038/sj.emboj.7600706] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2005] [Accepted: 05/11/2005] [Indexed: 11/08/2022] Open
Abstract
Receptor-stimulated generation of intracellular reactive oxygen species (ROS) modulates signal transduction, although the mechanism(s) is unclear. One potential basis is the reversible oxidation of the active site cysteine of protein tyrosine phosphatases (PTPs). Here, we show that activation of the antigen receptor of T cells (TCR), which induces production of ROS, induces transient inactivation of the SH2 domain-containing PTP, SHP-2, but not the homologous SHP-1. SHP-2 is recruited to the LAT-Gads-SLP-76 complex and directly regulates the phosphorylation of key signaling proteins Vav1 and ADAP. Furthermore, the association of ADAP with the adapter SLP-76 is regulated by SHP-2 in a redox-dependent manner. The data indicate that TCR-mediated ROS generation leads to SHP-2 oxidation, which promotes T-cell adhesion through effects on an SLP-76-dependent signaling pathway to integrin activation.
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Affiliation(s)
- Jaeyul Kwon
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Rockville, MD, USA
| | - Cheng-Kui Qu
- Department of Pathology, University of Maryland School of Medicine, Rockville, MD, USA
| | - Jin-Soo Maeng
- Laboratory of Biophysical Chemistry, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Rustom Falahati
- Department of Immunology, George Washington University School of Medicine, Washington, DC, USA
| | | | - Mark S Williams
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Rockville, MD, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, 15601 Crabbs Branch Way, Rockville, MD 20855, USA. Tel.: +1 301 738 0468; Fax: +1 301 517 0344; E-mail:
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