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Dayton A, Almutlaq RN, Guntipally S, Ross J, Evans LC. T-cells regulate albuminuria but not hypertension, renal histology, or the medullary transcriptome in the Dahl SSCD247 +/+ rat. Am J Physiol Renal Physiol 2024; 326:F95-F104. [PMID: 37916287 PMCID: PMC11194049 DOI: 10.1152/ajprenal.00229.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/10/2023] [Accepted: 10/27/2023] [Indexed: 11/03/2023] Open
Abstract
In the current study, we took advantage of the loss of protection from hypertension in SSCD247-/- rats to characterize the pathological effects of renal T-cells in isolation from the confounding effects of elevated renal perfusion pressure. Male SSCD247-/- and SSCD247+/+ littermates were fed 4.0% NaCl (high salt) diet to induce hypertension. Blood pressure was assessed continuously throughout the time course with radiotelemetry. Urine albumin and protein excretion were assessed on the final day of high salt. Renal injury and medullary transcriptome were assessed after completion of the high salt protocol. In contrast to previous studies, mean arterial pressure was not significantly different between SSCD247-/- and SSCD247+/+ rats. Despite this lack of pressure difference, urinary albumin was significantly lower in SSCD247-/- rats than their wild-type littermates. In the outer medulla, substantially more transcriptomic changes were found to correlate with endpoint blood pressure than with the absence of presence of renal T-cells. We also demonstrated that renal histological damage was driven by elevated renal perfusion pressure rather than the presence of renal T-cells. In conclusion, using the loss of protection from hypertension in SSCD247-/- rats, we demonstrated that renal perfusion pressure has more profound pathological effects on the kidney than renal T-cells. However, renal T-cells, independently of blood pressure, modulate the progression of albuminuria.NEW & NOTEWORTHY In vivo studies in a T-cell-deficient rat model of salt-sensitive hypertension (SSCD247-/- rats) were used to evaluate the role of T-cells on the development of hypertension and renal damage. Detailed physiological and transcriptomic analysis demonstrated no difference in blood pressure between rats with (SSCD247+/+) or without (SSCD247-/-) T-cells. Despite this, albuminuria was significantly lower in SSCD247-/- rats than SSCD247+/+ rats.
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Affiliation(s)
- Alex Dayton
- Division of Nephrology and Hypertension, University of Minnesota, Minneapolis, Minnesota, United States
| | - Rawan N Almutlaq
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, Minnesota, United States
| | - Sridhatri Guntipally
- Department of Surgery, University of Minnesota, Minneapolis, Minnesota, United States
| | - Jaryd Ross
- Department of Surgery, University of Minnesota, Minneapolis, Minnesota, United States
| | - Louise C Evans
- Department of Surgery, University of Minnesota, Minneapolis, Minnesota, United States
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2
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Ren P, Lu L, Cai S, Chen J, Lin W, Han F. Alternative Splicing: A New Cause and Potential Therapeutic Target in Autoimmune Disease. Front Immunol 2021; 12:713540. [PMID: 34484216 PMCID: PMC8416054 DOI: 10.3389/fimmu.2021.713540] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 07/29/2021] [Indexed: 11/13/2022] Open
Abstract
Alternative splicing (AS) is a complex coordinated transcriptional regulatory mechanism. It affects nearly 95% of all protein-coding genes and occurs in nearly all human organs. Aberrant alternative splicing can lead to various neurological diseases and cancers and is responsible for aging, infection, inflammation, immune and metabolic disorders, and so on. Though aberrant alternative splicing events and their regulatory mechanisms are widely recognized, the association between autoimmune disease and alternative splicing has not been extensively examined. Autoimmune diseases are characterized by the loss of tolerance of the immune system towards self-antigens and organ-specific or systemic inflammation and subsequent tissue damage. In the present review, we summarized the most recent reports on splicing events that occur in the immunopathogenesis of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) and attempted to clarify the role that splicing events play in regulating autoimmune disease progression. We also identified the changes that occur in splicing factor expression. The foregoing information might improve our understanding of autoimmune diseases and help develop new diagnostic and therapeutic tools for them.
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Affiliation(s)
- Pingping Ren
- Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Nephropathy, Zhejiang Province, Hangzhou, China.,Institute of Nephropathy, Zhejiang University, Hangzhou, China
| | - Luying Lu
- Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Nephropathy, Zhejiang Province, Hangzhou, China.,Institute of Nephropathy, Zhejiang University, Hangzhou, China
| | - Shasha Cai
- Department of Nephrology, The First People's Hospital of Wenling, Taizhou, China
| | - Jianghua Chen
- Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Nephropathy, Zhejiang Province, Hangzhou, China.,Institute of Nephropathy, Zhejiang University, Hangzhou, China
| | - Weiqiang Lin
- Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Nephropathy, Zhejiang Province, Hangzhou, China.,Institute of Nephropathy, Zhejiang University, Hangzhou, China.,Institute of Translational Medicine, Zhejiang University of Medicine, Hangzhou, China
| | - Fei Han
- Kidney Disease Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Nephropathy, Zhejiang Province, Hangzhou, China.,Institute of Nephropathy, Zhejiang University, Hangzhou, China
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3
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Dadwal N, Mix C, Reinhold A, Witte A, Freund C, Schraven B, Kliche S. The Multiple Roles of the Cytosolic Adapter Proteins ADAP, SKAP1 and SKAP2 for TCR/CD3 -Mediated Signaling Events. Front Immunol 2021; 12:703534. [PMID: 34295339 PMCID: PMC8290198 DOI: 10.3389/fimmu.2021.703534] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 06/21/2021] [Indexed: 12/24/2022] Open
Abstract
T cells are the key players of the adaptive immune response. They coordinate the activation of other immune cells and kill malignant and virus-infected cells. For full activation T cells require at least two signals. Signal 1 is induced after recognition of MHC/peptide complexes presented on antigen presenting cells (APCs) by the clonotypic TCR (T-cell receptor)/CD3 complex whereas Signal 2 is mediated via the co-stimulatory receptor CD28, which binds to CD80/CD86 molecules that are present on APCs. These signaling events control the activation, proliferation and differentiation of T cells. In addition, triggering of the TCR/CD3 complex induces the activation of the integrin LFA-1 (leukocyte function associated antigen 1) leading to increased ligand binding (affinity regulation) and LFA-1 clustering (avidity regulation). This process is termed "inside-out signaling". Subsequently, ligand bound LFA-1 transmits a signal into the T cells ("outside-in signaling") which enhances T-cell interaction with APCs (adhesion), T-cell activation and T-cell proliferation. After triggering of signal transducing receptors, adapter proteins organize the proper processing of membrane proximal and intracellular signals as well as the activation of downstream effector molecules. Adapter proteins are molecules that lack enzymatic or transcriptional activity and are composed of protein-protein and protein-lipid interacting domains/motifs. They organize and assemble macromolecular complexes (signalosomes) in space and time. Here, we review recent findings regarding three cytosolic adapter proteins, ADAP (Adhesion and Degranulation-promoting Adapter Protein), SKAP1 and SKAP2 (Src Kinase Associated Protein 1 and 2) with respect to their role in TCR/CD3-mediated activation, proliferation and integrin regulation.
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Affiliation(s)
- Nirdosh Dadwal
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Charlie Mix
- Institute of Molecular and Clinical Immunology, Health Campus Immunology, Infectiology and Inflammation (GCI3), Medical Faculty of the Otto-von-Guericke University, Magdeburg, Germany
| | - Annegret Reinhold
- Institute of Molecular and Clinical Immunology, Health Campus Immunology, Infectiology and Inflammation (GCI3), Medical Faculty of the Otto-von-Guericke University, Magdeburg, Germany
| | - Amelie Witte
- Coordination Center of Clinical Trials, University Medicine Greifswald, Greifswald, Germany
| | - Christian Freund
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Burkhart Schraven
- Institute of Molecular and Clinical Immunology, Health Campus Immunology, Infectiology and Inflammation (GCI3), Medical Faculty of the Otto-von-Guericke University, Magdeburg, Germany
| | - Stefanie Kliche
- Institute of Molecular and Clinical Immunology, Health Campus Immunology, Infectiology and Inflammation (GCI3), Medical Faculty of the Otto-von-Guericke University, Magdeburg, Germany
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4
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Figueiredo CR, Kalirai H, Sacco JJ, Azevedo RA, Duckworth A, Slupsky JR, Coulson JM, Coupland SE. Loss of BAP1 expression is associated with an immunosuppressive microenvironment in uveal melanoma, with implications for immunotherapy development. J Pathol 2020; 250:420-439. [PMID: 31960425 PMCID: PMC7216965 DOI: 10.1002/path.5384] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 12/28/2019] [Accepted: 01/14/2020] [Indexed: 12/22/2022]
Abstract
Immunotherapy using immune checkpoint inhibitors (ICIs) induces durable responses in many metastatic cancers. Metastatic uveal melanoma (mUM), typically occurring in the liver, is one of the most refractory tumours to ICIs and has dismal outcomes. Monosomy 3 (M3), polysomy 8q, and BAP1 loss in primary uveal melanoma (pUM) are associated with poor prognoses. The presence of tumour-infiltrating lymphocytes (TILs) within pUM and surrounding mUM - and some evidence of clinical responses to adoptive TIL transfer - strongly suggests that UMs are indeed immunogenic despite their low mutational burden. The mechanisms that suppress TILs in pUM and mUM are unknown. We show that BAP1 loss is correlated with upregulation of several genes associated with suppressive immune responses, some of which build an immune suppressive axis, including HLA-DR, CD38, and CD74. Further, single-cell analysis of pUM by mass cytometry confirmed the expression of these and other markers revealing important functions of infiltrating immune cells in UM, most being regulatory CD8+ T lymphocytes and tumour-associated macrophages (TAMs). Transcriptomic analysis of hepatic mUM revealed similar immune profiles to pUM with BAP1 loss, including the expression of IDO1. At the protein level, we observed TAMs and TILs entrapped within peritumoural fibrotic areas surrounding mUM, with increased expression of IDO1, PD-L1, and β-catenin (CTNNB1), suggesting tumour-driven immune exclusion and hence the immunotherapy resistance. These findings aid the understanding of how the immune response is organised in BAP1 - mUM, which will further enable functional validation of detected biomarkers and the development of focused immunotherapeutic approaches. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
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Affiliation(s)
- Carlos R Figueiredo
- Department of Molecular and Clinical Cancer Medicine, ITMUniversity of LiverpoolLiverpoolUK
- Department of the Faculty of Medicine, MediCity Research Laboratory and Institute of BiomedicineUniversity of TurkuTurkuFinland
| | - Helen Kalirai
- Department of Molecular and Clinical Cancer Medicine, ITMUniversity of LiverpoolLiverpoolUK
| | - Joseph J Sacco
- Department of Molecular and Clinical Cancer Medicine, ITMUniversity of LiverpoolLiverpoolUK
- Department of Medical OncologyThe Clatterbridge Cancer CentreWirralUK
| | - Ricardo A Azevedo
- Department of Cancer BiologyThe University of Texas–MD Anderson Cancer CenterHoustonTXUSA
| | - Andrew Duckworth
- Department of Molecular and Clinical Cancer Medicine, ITMUniversity of LiverpoolLiverpoolUK
| | - Joseph R Slupsky
- Department of Molecular and Clinical Cancer Medicine, ITMUniversity of LiverpoolLiverpoolUK
| | - Judy M Coulson
- Department of Cellular and Molecular PhysiologyUniversity of LiverpoolLiverpoolUK
| | - Sarah E Coupland
- Department of Molecular and Clinical Cancer Medicine, ITMUniversity of LiverpoolLiverpoolUK
- Liverpool Clinical LaboratoriesRoyal Liverpool University HospitalLiverpoolUK
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5
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Crk adaptor proteins regulate CD3ζ chain phosphorylation and TCR/CD3 down-modulation in activated T cells. Cell Signal 2017; 36:117-126. [PMID: 28465009 DOI: 10.1016/j.cellsig.2017.04.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/15/2017] [Accepted: 04/26/2017] [Indexed: 01/06/2023]
Abstract
T cell receptor (TCR) recognition of a peptide antigen in the context of MHC molecules initiates positive and negative cascades that regulate T cell activation, proliferation and differentiation, and culminate in the acquisition of effector T cell functions. These processes are a prerequisite for the induction of specific T cell-mediated adaptive immune responses. A key event in the activation of TCR-coupled signaling pathways is the phosphorylation of tyrosine residues within the cytoplasmic tails of the CD3 subunits, predominantly CD3ζ. These transiently formed phosphotyrosyl epitopes serve as docking sites for SH2-domain containing effector molecules, predominantly the ZAP70 protein tyrosine kinase, which is critical for signal propagation. We found that CrkI and CrkII adaptor proteins also interact with CD3ζ in TCR activated-, but not in resting-, T cells. Crk binding to CD3ζ was independent of ZAP70 and also occurred in ZAP70-deficient T cells. Binding was mediated by Crk-SH2 domain interaction with phosphotyrosine-containing motifs on CD3ζ, via a direct physical interaction, as demonstrated by Far-Western blot. CrkII binding to CD3ζ could also be demonstrated in a heterologous system, where coexpression of a catalytically active Lck was used to phosphorylate the CD3ζ chain. TCR activation-induced Crk binding to CD3ζ resulted in increased and prolonged phosphorylation of CD3ζ, as well as ZAP70 and LAT, suggesting a positive role for CrkI/II binding to CD3ζ in regulation of TCR-coupled signaling pathways. Furthermore, Crk-dependent increased phosphorylation of CD3ζ coincided with inhibition of TCR downmodulation, supporting a positive role for Crk adaptor proteins in TCR-mediated signal amplification.
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6
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A cycle of Zap70 kinase activation and release from the TCR amplifies and disperses antigenic stimuli. Nat Immunol 2016; 18:86-95. [PMID: 27869819 PMCID: PMC5490839 DOI: 10.1038/ni.3631] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 10/28/2016] [Indexed: 12/14/2022]
Abstract
Cell-surface-receptor pathways amplify weak, rare and local stimuli to induce cellular responses. This task is accomplished despite signaling components that segregate into nanometer-scale membrane domains. Here we describe a 'catch-and-release' mechanism that amplified and dispersed stimuli by releasing activated kinases from receptors lacking intrinsic catalytic activity. Specifically, we discovered a cycle of recruitment, activation and release for Zap70 kinases at phosphorylated T cell antigen receptors (TCRs). This turned the TCR into a 'catalytic unit' that amplified antigenic stimuli. Zap70 released from the TCR remained at the membrane, translocated, and phosphorylated spatially distinct substrates. The mechanisms described here are based on widely used protein domains and post-translational modifications; therefore, many membrane-associated pathways might employ similar mechanisms for signal amplification and dispersion.
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7
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Holmberg D, Ruikka K, Lindgren P, Eliasson M, Mayans S. Association of CD247 (CD3ζ) gene polymorphisms with T1D and AITD in the population of northern Sweden. BMC MEDICAL GENETICS 2016; 17:70. [PMID: 27716086 PMCID: PMC5050583 DOI: 10.1186/s12881-016-0333-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 09/29/2016] [Indexed: 12/31/2022]
Abstract
Background T1D and AITD are autoimmune disorders commonly occurring in the same family and even in the same individual. The genetic contribution to these disorders is complex making uncovering of susceptibility genes very challenging. The general aim of this study was to identify loci and genes contributing to T1D/AITD susceptibility. Our strategy was to perform linkage and association studies in the relatively genetically homogenous population of northern Sweden. We performed a GWLS to find genomic regions linked to T1D/AITD in families from northern Sweden and we performed an association study in the families to test for association between T1D/AITD and variants in previously published candidate genes as well as a novel candidate gene, CD247. Methods DNA prepared from 459 individuals was used to perform a linkage and an association study. The ABI PRISM Linkage Mapping Set v2.5MD10 was employed for an initial 10-cM GWLS, and additional markers were added for fine mapping. Merlin was used for linkage calculations. For the association analysis, a GoldenGate Custom Panel from Illumina containing 79 SNPs of interest was used and FBAT was used for association calculations. Results Our study revealed linkage to two previously identified chromosomal regions, 4q25 and 6p22, as well as to a novel chromosomal region, 1q23. The association study replicated association to PTPN22, HLA-DRB1, INS, IFIH1, CTLA4 and C12orf30. Evidence in favor of association was also found for SNPs in the novel susceptibility gene CD247. Conclusions Several risk loci for T1D/AITD identified in published association studies were replicated in a family material, of modest size, from northern Sweden. This provides evidence that these loci confer disease susceptibility in this population and emphasizes that small to intermediate sized family studies in this population can be used in a cost-effective manner for the search of genes involved in complex diseases. The linkage study revealed a chromosomal region in which a novel T1D/AITD susceptibility gene, CD247, is located. The association study showed association between T1D/AITD and several variants in this gene. These results suggests that common susceptibility genes act in concert with variants of CD247 to generate genetic risk for T1D/AITD in this population. Electronic supplementary material The online version of this article (doi:10.1186/s12881-016-0333-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Dan Holmberg
- Department of Medical Biosciences - Medical Genetics, Umeå University, SE-901 85, Umeå, Sweden.,EMV, Immunology, BMC, Lund University, SE-221 00, Lund, Sweden
| | - Karin Ruikka
- Department of Medicine, Sunderby Hospital, SE-971 80, Luleå, Sweden
| | - Petter Lindgren
- Department of Medical Biosciences - Medical Genetics, Umeå University, SE-901 85, Umeå, Sweden
| | - Mats Eliasson
- Department of Medicine, Sunderby Hospital, SE-971 80, Luleå, Sweden.,Department of Public Health and Clinical Medicine, Umeå University, SE-901 85, Umeå, Sweden
| | - Sofia Mayans
- Department of Medical Biosciences - Medical Genetics, Umeå University, SE-901 85, Umeå, Sweden. .,Department of Clinical Microbiology, Division of Immunology, Umeå University, Building 6C, SE-90185, Umeå, Sweden.
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8
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Moogk D, Zhong S, Yu Z, Liadi I, Rittase W, Fang V, Dougherty J, Perez-Garcia A, Osman I, Zhu C, Varadarajan N, Restifo NP, Frey AB, Krogsgaard M. Constitutive Lck Activity Drives Sensitivity Differences between CD8+ Memory T Cell Subsets. THE JOURNAL OF IMMUNOLOGY 2016; 197:644-54. [PMID: 27271569 DOI: 10.4049/jimmunol.1600178] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 05/04/2016] [Indexed: 12/16/2022]
Abstract
CD8(+) T cells develop increased sensitivity following Ag experience, and differences in sensitivity exist between T cell memory subsets. How differential TCR signaling between memory subsets contributes to sensitivity differences is unclear. We show in mouse effector memory T cells (TEM) that >50% of lymphocyte-specific protein tyrosine kinase (Lck) exists in a constitutively active conformation, compared with <20% in central memory T cells (TCM). Immediately proximal to Lck signaling, we observed enhanced Zap-70 phosphorylation in TEM following TCR ligation compared with TCM Furthermore, we observed superior cytotoxic effector function in TEM compared with TCM, and we provide evidence that this results from a lower probability of TCM reaching threshold signaling owing to the decreased magnitude of TCR-proximal signaling. We provide evidence that the differences in Lck constitutive activity between CD8(+) TCM and TEM are due to differential regulation by SH2 domain-containing phosphatase-1 (Shp-1) and C-terminal Src kinase, and we use modeling of early TCR signaling to reveal the significance of these differences. We show that inhibition of Shp-1 results in increased constitutive Lck activity in TCM to levels similar to TEM, as well as increased cytotoxic effector function in TCM Collectively, this work demonstrates a role for constitutive Lck activity in controlling Ag sensitivity, and it suggests that differential activities of TCR-proximal signaling components may contribute to establishing the divergent effector properties of TCM and TEM. This work also identifies Shp-1 as a potential target to improve the cytotoxic effector functions of TCM for adoptive cell therapy applications.
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Affiliation(s)
- Duane Moogk
- Laura and Isaac Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016
| | - Shi Zhong
- Laura and Isaac Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016
| | - Zhiya Yu
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Ivan Liadi
- Department of Chemical and Biomolecular Engineering, University of Houston, TX 77004
| | - William Rittase
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Victoria Fang
- Laura and Isaac Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016; New York University Medical Scientist Training Program, New York, NY 10016
| | - Janna Dougherty
- Laura and Isaac Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016
| | - Arianne Perez-Garcia
- Laura and Isaac Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016
| | - Iman Osman
- Laura and Isaac Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016; Ronald Perelman Department of Dermatology, New York University School of Medicine, New York, NY 10016
| | - Cheng Zhu
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Navin Varadarajan
- Department of Chemical and Biomolecular Engineering, University of Houston, TX 77004
| | - Nicholas P Restifo
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Alan B Frey
- Department of Cell Biology, New York University School of Medicine, New York, NY 10016; and
| | - Michelle Krogsgaard
- Laura and Isaac Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016; Department of Pathology, New York University School of Medicine, New York, NY 10016
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Ji Q, Ding Y, Salomon AR. SRC homology 2 domain-containing leukocyte phosphoprotein of 76 kDa (SLP-76) N-terminal tyrosine residues regulate a dynamic signaling equilibrium involving feedback of proximal T-cell receptor (TCR) signaling. Mol Cell Proteomics 2014; 14:30-40. [PMID: 25316710 DOI: 10.1074/mcp.m114.037861] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
SRC homology 2 domain-containing leukocyte phosphoprotein of 76 kDa (SLP-76) is a cytosolic adaptor protein that plays an important role in the T-cell receptor-mediated T-cell signaling pathway. SLP-76 links proximal receptor stimulation to downstream effectors through interaction with many signaling proteins. Previous studies showed that mutation of three tyrosine residues, Tyr(112), Tyr(128), and Tyr(145), in the N terminus of SLP-76 results in severely impaired phosphorylation and activation of Itk and PLCγ1, which leads to defective calcium mobilization, Erk activation, and NFAT activation. To expand our knowledge of the role of N-terminal phosphorylation of SLP-76 from these three tyrosine sites, we characterized nearly 1000 tyrosine phosphorylation sites via mass spectrometry in SLP-76 reconstituted wild-type cells and SLP-76 mutant cells in which three tyrosine residues were replaced with phenylalanines (Y3F mutant). Mutation of the three N-terminal tyrosine residues of SLP-76 phenocopied SLP-76-deficient cells for the majority of tyrosine phosphorylation sites observed, including feedback on proximal T-cell receptor signaling proteins. Meanwhile, reversed phosphorylation changes were observed on Tyr(192) of Lck when we compared mutants to the complete removal of SLP-76. In addition, N-terminal tyrosine sites of SLP-76 also perturbed phosphorylation of Tyr(440) of Fyn, Tyr(702) of PLCγ1, Tyr(204), Tyr(397), and Tyr(69) of ZAP-70, revealing new modes of regulation on these sites. All these findings confirmed the central role of N-terminal tyrosine sites of SLP-76 in the pathway and also shed light on novel signaling events that are uniquely regulated by SLP-76 N-terminal tyrosine residues.
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Affiliation(s)
- Qinqin Ji
- From the ‡Department of Chemistry, Brown University Providence, RI 02903
| | - Yiyuan Ding
- From the ‡Department of Chemistry, Brown University Providence, RI 02903
| | - Arthur R Salomon
- From the ‡Department of Chemistry, Brown University Providence, RI 02903; §Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University Providence, RI 02903
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10
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Helou YA, Nguyen V, Beik SP, Salomon AR. ERK positive feedback regulates a widespread network of tyrosine phosphorylation sites across canonical T cell signaling and actin cytoskeletal proteins in Jurkat T cells. PLoS One 2013; 8:e69641. [PMID: 23874979 PMCID: PMC3714263 DOI: 10.1371/journal.pone.0069641] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Accepted: 06/11/2013] [Indexed: 11/18/2022] Open
Abstract
Competing positive and negative signaling feedback pathways play a critical role in tuning the sensitivity of T cell receptor activation by creating an ultrasensitive, bistable switch to selectively enhance responses to foreign ligands while suppressing signals from self peptides. In response to T cell receptor agonist engagement, ERK is activated to positively regulate T cell receptor signaling through phosphorylation of Ser59 Lck. To obtain a wide-scale view of the role of ERK in propagating T cell receptor signaling, a quantitative phosphoproteomic analysis of 322 tyrosine phosphorylation sites by mass spectrometry was performed on the human Jurkat T cell line in the presence of U0126, an inhibitor of ERK activation. Relative to controls, U0126-treated cells showed constitutive decreases in phosphorylation through a T cell receptor stimulation time course on tyrosine residues found on upstream signaling proteins (CD3 chains, Lck, ZAP-70), as well as downstream signaling proteins (VAV1, PLCγ1, Itk, NCK1). Additional constitutive decreases in phosphorylation were found on the majority of identified proteins implicated in the regulation of actin cytoskeleton pathway. Although the majority of identified sites on T cell receptor signaling proteins showed decreases in phosphorylation, Tyr598 of ZAP-70 showed elevated phosphorylation in response to U0126 treatment, suggesting differential regulation of this site via ERK feedback. These findings shed new light on ERK’s role in positive feedback in T cell receptor signaling and reveal novel signaling events that are regulated by this kinase, which may fine tune T cell receptor activation.
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Affiliation(s)
- Ynes A. Helou
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, Rhode Island, United States of America
| | - Vinh Nguyen
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island, United States of America
| | - Samantha P. Beik
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island, United States of America
| | - Arthur R. Salomon
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, Rhode Island, United States of America
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island, United States of America
- Department of Chemistry, Brown University, Providence, Rhode Island, United States of America
- * E-mail:
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11
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Gelkop S, Weisman B, Pulak RN, Zharhary D, Isakov N. Development of unique antibodies directed against each of the six different phosphotyrosine residues within the T cell receptor CD3ζ chain. J Immunol Methods 2012; 375:129-37. [PMID: 22020291 DOI: 10.1016/j.jim.2011.10.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 10/02/2011] [Accepted: 10/03/2011] [Indexed: 10/16/2022]
Abstract
Signal transduction from the T cell antigen receptor (TCR)/CD3 complex involves six different immunoreceptor tyrosine-based activation motifs (ITAM) located within the cytoplasmic tails of the CD3 chains. Each ITAM possesses two conserved tyrosine residues that can undergo phosphorylation upon TCR/CD3 crosslinking and become a docking site for SH2-containing effector molecules. Specificity of the SH2 domains is determined by their ability to bind a phosphorylated tyrosine in the context of a longer peptide motif within the target protein. As a result, phosphorylation of different tyrosines within the CD3 cytoplasmic tails creates docking sites for distinct SH2-containing signaling proteins that differentially impact on the quality of the T cell response. In the present study, we prepared antibodies specific for each of the six different phosphotyrosines of the mouse CD3ζ chain. The antibodies were characterized with respect to their cross-reactivity, ability to recognize the phosphorylated versus non-phosphorylated forms of tyrosine-containing motifs, and cross-reactivity with the homologous phospho-motifs on the human CD3ζ protein. The antibodies were found to be specific and selective for phospho-CD3ζ. They can serve as useful tools for distinguishing between the six potential tyrosine phosphorylation sites on the CD3ζ chain, and for correlating the phosphorylation of specific CD3ζ tyrosine residues with activation of signaling pathways that dictate T cell differentiation into responding, anergic, or apoptotic cells.
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Affiliation(s)
- Sigal Gelkop
- Cell Biology, Department of Research & Development, Sigma-Aldrich Israel, Rehovot 76100, Israel
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12
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Lundholm M, Mayans S, Motta V, Löfgren-Burström A, Danska J, Holmberg D. Variation in the Cd3 zeta (Cd247) gene correlates with altered T cell activation and is associated with autoimmune diabetes. THE JOURNAL OF IMMUNOLOGY 2010; 184:5537-44. [PMID: 20400699 DOI: 10.4049/jimmunol.0904012] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Tuning of TCR-mediated activation was demonstrated to be critical for lineage fate in T cell development, as well as in the control of autoimmunity. In this study, we identify a novel diabetes susceptibility gene, Idd28, in the NOD mouse and provide evidence that Cd3zeta (Cd247) constitutes a prime candidate gene for this locus. Moreover, we show that the allele of the Cd3zeta gene expressed in NOD and DBA/2 mouse strains confers lower levels of T cell activation compared with the allele expressed by C57BL/6 (B6), BALB/c, and C3H/HeJ mice. These results support a model in which the development of autoimmune diabetes is dependent on a TCR signal mediated by a less-efficient NOD allele of the Cd3zeta gene.
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Affiliation(s)
- Marie Lundholm
- Department of Medical Biosciences, Medical and Clinical Genetics, Umeå University, Umeå, Sweden
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13
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Cai G, Anumanthan A, Brown JA, Greenfield EA, Zhu B, Freeman GJ. CD160 inhibits activation of human CD4+ T cells through interaction with herpesvirus entry mediator. Nat Immunol 2008; 9:176-85. [PMID: 18193050 DOI: 10.1038/ni1554] [Citation(s) in RCA: 260] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2007] [Accepted: 12/05/2007] [Indexed: 11/10/2022]
Abstract
CD160, a glycosylphosphatidylinositol-anchored member of the immunoglobulin superfamily, is expressed on both cytolytic lymphocytes and some unstimulated CD4+ T cells. Here we show that CD160 expression was increased after activation of human CD4+ T cells and that crosslinking CD160 with monoclonal antibody strongly inhibited CD3- and CD28-mediated activation. We found that herpesvirus entry mediator (HVEM) was a ligand of CD160 that acted as a 'bidirectional switch' for T cell activation, producing a positive or negative outcome depending on the engagement of HVEM by CD160 and known HVEM ligands such as B and T lymphocyte attenuator (BTLA) and the T lymphocyte receptor LIGHT. Inhibition of CD4+ T cell activation by HVEM-transfected cells was dependent on CD160 and BTLA; when the cysteine-rich domain 1 of HVEM was deleted, this inhibition was lost, resulting in strong T cell activation. CD160 thus serves as a negative regulator of CD4+ T cell activation through its interaction with HVEM.
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Affiliation(s)
- Guifang Cai
- Department of Medical Oncology, Dana-Farber Cancer Institute, Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115, USA
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14
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Amon MA, Manolios N. Hypothesis: TCR signal transduction--A novel tri-modular signaling system. Mol Immunol 2007; 45:876-80. [PMID: 17915329 DOI: 10.1016/j.molimm.2007.08.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2007] [Accepted: 08/10/2007] [Indexed: 11/21/2022]
Abstract
Antigenic peptides initiate an immune response in T cells via the T cell receptor (TCR). The TCR itself is widely regarded as one of the most complex receptors in nature, as it is comprised of at least six different subunits, the antigen recognizing TCRalpha and beta chains, and the signal transmitting CD3deltavarepsilon, gammaepsilon, and zeta2 dimers. In order for a signal to be transmitted from the TCR to the cytoplasm, the CD3 chains must "sense" that an antigenic peptide has been presented to the TCRalpha and beta subunits. After accomplishing this, there are a total of 10 different immunoreceptor tyrosine activation motifs (ITAMs) present within the CD3 chains which effectively activate the T cell and hence the immune response. The importance of each CD3 chain and subsequently each ITAM has been the focus of intense research. However, the precise role(s) played by each CD3 chain has remained elusive. Using the immunomodulatory peptide termed core peptide (CP), which is proposed to inhibit TCR activation by disrupting TCR-CD3 interactions, a tri-modular signaling system for T cell activation is proposed. By contrast to the existing two distinct signaling model (zeta2, CD3epsilongamma/epsilondelta), in this model each of the three dimers, CD3gammaepsilon, deltaepsilon, and zeta2, are proposed to act as three separate and distinct signaling modules, performing both specific and redundant functions.
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Affiliation(s)
- Michael A Amon
- Rheumatology Department, Westmead Hospital, Westmead, NSW 2145, Australia
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15
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Nika K, Tautz L, Arimura Y, Vang T, Williams S, Mustelin T. A weak Lck tail bite is necessary for Lck function in T cell antigen receptor signaling. J Biol Chem 2007; 282:36000-9. [PMID: 17897955 DOI: 10.1074/jbc.m702779200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Src family kinases are suppressed by a "tail bite" mechanism, in which the binding of a phosphorylated tyrosine in the C terminus of the protein to the Src homology (SH) 2 domain in the N-terminal half of the protein forces the catalytic domain into an inactive conformation stabilized by an additional SH3 interaction. In addition to this intramolecular suppressive function, the SH2 domain also mediates intermolecular interactions, which are crucial for T cell antigen receptor (TCR) signaling. To better understand the relative importance of these two opposite functions of the SH2 domain of the Src family kinase Lck in TCR signaling, we created three mutants of Lck in which the intramolecular binding of the C terminus to the SH2 domain was strengthened. The mutants differed from wild-type Lck only in one to three amino acid residues following the negative regulatory tyrosine 505, which was normally phosphorylated by Csk and dephosphorylated by CD45 in the mutants. In the Lck-negative JCaM1 cell line, the Lck mutants had a much reduced ability to transduce signals from the TCR in a manner that directly correlated with SH2-Tyr(P)(505) affinity. The mutant with the strongest tail bite was completely unable to support any ZAP-70 phosphorylation, mitogen-activated protein kinase activation, or downstream gene activation in response to TCR ligation, whereas other mutants had intermediate abilities. Lipid raft targeting was not affected. We conclude that Lck is regulated by a weak tail bite to allow for its activation and service in TCR signaling, perhaps through a competitive SH2 engagement mechanism.
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Affiliation(s)
- Konstantina Nika
- Program on Inflammatory Disease Research, Infectious and Inflammatory Disease Center, The Burnham Institute for Medical Research, La Jolla, California 92037, USA.
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16
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Duchardt E, Sigalov AB, Aivazian D, Stern LJ, Schwalbe H. Structure induction of the T-cell receptor zeta-chain upon lipid binding investigated by NMR spectroscopy. Chembiochem 2007; 8:820-7. [PMID: 17410622 DOI: 10.1002/cbic.200600413] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The conformation of the cytoplasmic part of the zeta-chain of the T-cell receptor (TCR) in its free form and bound to detergent micelles has been investigated by heteronuclear NMR spectroscopy. The zeta-chain is considered to be a mediator between the extracellular antigen and the intracellular signal-transduction cascade leading to T-cell activation. Earlier studies suggested a T-cell activation mechanism that involved a TCR-state-dependent lipid incorporation propensity of the zeta-chain accompanied by a helical folding transition. In order to support this proposed mechanism, standard protein NMR assignment and secondary-structure-elucidation techniques have been applied to the free TCR zeta-chain and to the zeta-chain bound to the detergent LMPG, which forms a micelle, in order to obtain the structural characteristics of this folding transition in a residue-resolved manner. We could assign the resonances of the free zeta-chain at 278 K, and this formed the basis for chemical-shift-perturbation studies to identify lipid binding sites. Our NMR results show that the free TCR zeta-chain is indeed intrinsically unstructured. Regions around the ITAM2 and ITAM3 sequences are involved in a highly dynamic binding of the free zeta-chain to a detergent micelle formed by the acidic lipid LMPG.
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Affiliation(s)
- Elke Duchardt
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Johann Wolfgang Goethe University Frankfurt, 60439 Frankfurt, Germany
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17
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DeFord-Watts LM, Young JA, Pitcher LA, van Oers NSC. The membrane-proximal portion of CD3 epsilon associates with the serine/threonine kinase GRK2. J Biol Chem 2007; 282:16126-34. [PMID: 17420248 DOI: 10.1074/jbc.m609418200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The activation of protein kinases is one of the primary mechanisms whereby T cell receptors (TCR) propagate intracellular signals. To date, the majority of kinases known to be involved in the early stages of TCR signaling are protein-tyrosine kinases such as Lck, Fyn, and ZAP-70. Here we report a constitutive association between the TCR and a serine/threonine kinase, which was mediated through the membrane-proximal portion of CD3 epsilon. Mass spectrometry analysis of CD3 epsilon-associated proteins identified G protein-coupled receptor kinase 2 (GRK2) as a candidate Ser/Thr kinase. Transient transfection assays and Western blot analysis verified the ability of GRK2 to interact with the cytoplasmic domain of CD3 epsilon within a cell. These findings are consistent with recent reports demonstrating the ability of certain G protein-coupled receptors (GPCR) and G proteins to physically associate with the alpha/beta TCR. Because GRK2 is primarily involved in arresting GPCR signals, its interaction with CD3 epsilon may provide a novel means whereby the TCR can negatively regulate signals generated through GPCRs.
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Affiliation(s)
- Laura M DeFord-Watts
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9093, USA
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18
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Pillai MR, Lefevre EA, Carr BV, Charleston B, O'Grady P. Workshop cluster 1, a γδ T cell specific receptor is phosphorylated and down regulated by activation induced Src family kinase activity. Mol Immunol 2007; 44:1691-703. [PMID: 16997376 DOI: 10.1016/j.molimm.2006.08.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2006] [Revised: 07/12/2006] [Accepted: 08/03/2006] [Indexed: 11/28/2022]
Abstract
Workshop cluster 1(+) gamma delta (WC1(+)gammadelta) T cells have been shown to play important roles in the immune response to infections. WC1 is a transmembrane glycoprotein, uniquely expressed on the surface of gammadelta T cells of ruminants and pigs. A role for WC1 in inducing a reversible growth arrest of gammadelta T cells has been previously demonstrated. WC1-induced growth inhibition has been shown to be overcome following gammadelta T cell activation with Concanavalin A (Con A). However, molecular mechanism(s) by which WC1 signalling might be modulated following activation have not been elucidated. In this paper we show that Con A activation of bovine lymphocytes induces the tyrosine phosphorylation of WC1 in a Src-family kinase-dependent manner. Src family kinases also phosphorylated WC1 in a COS-7 co-transfection system. Furthermore, a glutathione-S-transferase (GST)-WC1 cytoplasmic domain fusion protein was directly phosphorylated by recombinant Lck (rLck) in vitro. The Y(1303) of WC1 was identified by mutational analysis as the only one of the five WC1 tyrosine residues to be critical for Src family phosphorylation. The importance of activation-induced Src family activity for WC1 function was investigated with the Src-family specific inhibitor PP2. These studies show that the surface levels of WC1 are down regulated in a Src-family-dependent manner following activation of bovine lymphocytes. Down regulation of surface WC1 was accompanied by a Src-family-dependent accumulation of intracellular WC1. These data show that WC1 is modulated by activation-induced tyrosine phosphorylation thus providing a new insight into the signalling mechanisms by which WC1 and gammadelta T cell activation are regulated in this important and unique cell population.
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Affiliation(s)
- Meenu R Pillai
- Department of Immunology, Institute for Animal Health, Pirbright Laboratory, Pirbright, Woking, Surrey GU24 0NF, UK
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19
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Pitcher LA, Mathis MA, Young JA, DeFord LM, Purtic B, Wulfing C, van Oers NSC. The CD3 gamma epsilon/delta epsilon signaling module provides normal T cell functions in the absence of the TCR zeta immunoreceptor tyrosine-based activation motifs. Eur J Immunol 2006; 35:3643-54. [PMID: 16259006 DOI: 10.1002/eji.200535136] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
T cell receptor (TCR) signal transduction is mediated by the immunoreceptor tyrosine-based activation motifs (ITAM). The ten ITAM in the TCR complex are distributed in two distinct signaling modules termed TCR zetazeta and CD3 gammaepsilon/deltaepsilon. To delineate the specific role of the zeta ITAM in T cell development and TCR signal transmission, we compared the properties of T cells from different TCR zeta-transgenic lines wherein tyrosine-to-phenylalanine substitutions had been introduced in the zeta subunit. These lines lack selected phosphorylated forms of TCR zeta including just p23, both p21 and p23, or all phospho-zeta derivatives. We report herein that the efficiency of positive selection in HY TCR-transgenic female mice was directly related to the number of zeta ITAM in the TCR. In contrast, TCR-mediated signal transmission and T cell proliferative responses following agonist peptide stimulation were similar and independent of the zeta ITAM. Only the duration of MAPK activation was affected by multiple zeta ITAM substitutions. These results strongly suggest that the ITAM in the CD3 gammaepsilon/deltaepsilon module can provide normal TCR signal transmission, with zeta ITAM providing a secondary function facilitating MAPK activation and positive selection.
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Affiliation(s)
- Lisa A Pitcher
- Center for Immunology, The University of Texas Southwestern Medical Center, Dallas, TX, USA
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20
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Hou P, Araujo E, Zhao T, Zhang M, Massenburg D, Veselits M, Doyle C, Dinner AR, Clark MR. B cell antigen receptor signaling and internalization are mutually exclusive events. PLoS Biol 2006; 4:e200. [PMID: 16719564 PMCID: PMC1470458 DOI: 10.1371/journal.pbio.0040200] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2005] [Accepted: 04/13/2006] [Indexed: 02/03/2023] Open
Abstract
Engagement of the B cell antigen receptor initiates two concurrent processes, signaling and receptor internalization. While both are required for normal humoral immune responses, the relationship between these two processes is unknown. Herein, we demonstrate that following receptor ligation, a small subpopulation of B cell antigen receptors are inductively phosphorylated and selectively retained at the cell surface where they can serve as scaffolds for the assembly of signaling molecules. In contrast, the larger population of non-phosphorylated receptors is rapidly endocytosed. Each receptor can undergo only one of two mutually exclusive fates because the tyrosine-based motifs that mediate signaling when phosphorylated mediate internalization when not phosphorylated. Mathematical modeling indicates that the observed competition between receptor phosphorylation and internalization enhances signaling responses to low avidity ligands.
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Affiliation(s)
- Ping Hou
- 1Department of Medicine and Section of Rheumatology, University of Chicago, Chicago, Illinois, United States of America
- 2Committee on Immunology, University of Chicago, Chicago, Illinois, United States of America
| | - Elizabeth Araujo
- 1Department of Medicine and Section of Rheumatology, University of Chicago, Chicago, Illinois, United States of America
- 2Committee on Immunology, University of Chicago, Chicago, Illinois, United States of America
| | - Tong Zhao
- 3Department of Chemistry, University of Chicago, Chicago, Illinois, United States of America
- 4Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois, United States of America
- 5James Franck Institute, University of Chicago, Chicago, Illinois, United States of America
| | - Miao Zhang
- 1Department of Medicine and Section of Rheumatology, University of Chicago, Chicago, Illinois, United States of America
| | - Don Massenburg
- 1Department of Medicine and Section of Rheumatology, University of Chicago, Chicago, Illinois, United States of America
- 2Committee on Immunology, University of Chicago, Chicago, Illinois, United States of America
| | - Margaret Veselits
- 1Department of Medicine and Section of Rheumatology, University of Chicago, Chicago, Illinois, United States of America
- 2Committee on Immunology, University of Chicago, Chicago, Illinois, United States of America
| | - Colleen Doyle
- 2Committee on Immunology, University of Chicago, Chicago, Illinois, United States of America
| | - Aaron R Dinner
- 2Committee on Immunology, University of Chicago, Chicago, Illinois, United States of America
- 3Department of Chemistry, University of Chicago, Chicago, Illinois, United States of America
- 4Institute for Biophysical Dynamics, University of Chicago, Chicago, Illinois, United States of America
- 5James Franck Institute, University of Chicago, Chicago, Illinois, United States of America
| | - Marcus R Clark
- 1Department of Medicine and Section of Rheumatology, University of Chicago, Chicago, Illinois, United States of America
- 2Committee on Immunology, University of Chicago, Chicago, Illinois, United States of America
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21
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Lysechko TL, Ostergaard HL. Differential Src family kinase activity requirements for CD3 zeta phosphorylation/ZAP70 recruitment and CD3 epsilon phosphorylation. THE JOURNAL OF IMMUNOLOGY 2005; 174:7807-14. [PMID: 15944285 DOI: 10.4049/jimmunol.174.12.7807] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The current model of T cell activation is that TCR engagement stimulates Src family tyrosine kinases (SFK) to phosphorylate CD3zeta. CD3zeta phosphorylation allows for the recruitment of the tyrosine kinase ZAP70, which is phosphorylated and activated by SFK, leading to the phosphorylation of downstream targets. We stimulated mouse CTLs with plate-bound anti-CD3 and, after cell lysis, recovered proteins that associated with the CD3 complex. The protein complexes were not preformed, and a number of tyrosine-phosphorylated proteins were inducibly and specifically associated with the TCR/CD3 complex. These results suggest that complex formation only occurs at the site of TCR engagement. The recruitment and tyrosine phosphorylation of most proteins were abolished when T cells were stimulated in the presence of the SFK inhibitor PP2. Surprisingly, CD3zeta, but not CD3epsilon, was inducibly tyrosine phosphorylated in the presence of PP2. Furthermore, ZAP70 was recruited, but not phosphorylated, after TCR stimulation in the presence of PP2, thus confirming the phosphorylation status of CD3zeta. These data suggest that there is a differential requirement for SFK activity in phosphorylation of CD3zeta vs CD3epsilon. Consistent with this possibility, ZAP70 recruitment was also detected with anti-CD3-stimulated, Lck-deficient human Jurkat T cells. We conclude that TCR/CD3-induced CD3zeta phosphorylation and ZAP70 recruitment do not absolutely require Lck or other PP2-inhibitable SFK activity, but that SFK activity is absolutely required for CD3epsilon and ZAP70 phosphorylation. These data reveal the potential for regulation of signaling through the TCR complex by the differential recruitment or activation of SFK.
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Affiliation(s)
- Tara L Lysechko
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
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22
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Babichev Y, Tamir A, Park M, Muallem S, Isakov N. Cloning, expression and functional characterization of the putative regeneration and tolerance factor (RTF/TJ6) as a functional vacuolar ATPase proton pump regulatory subunit with a conserved sequence of immunoreceptor tyrosine-based activation motif. Int Immunol 2005; 17:1303-13. [PMID: 16113235 DOI: 10.1093/intimm/dxh308] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In an attempt to identify new immunoreceptor tyrosine-based activation motif (ITAM)-containing human molecules that may regulate hitherto unknown immune cell functions, we BLAST searched the National Center for Biotechnology Information database for ITAM-containing sequences. A human expressed sequence tag showing partial homology to the murine TJ6 (mTJ6) gene and encoding a putative ITAM sequence has been identified and used to clone the human TJ6 (hTJ6) gene from an HL-60-derived cDNA library. hTJ6 was found to encode a protein of 856 residues with a calculated mass of 98 155 Da. Immunolocalization and sequence analysis revealed that hTJ6 is a membrane protein with predicted six transmembrane-spanning regions, typical of ion channels, and a single putative ITAM (residues 452-466) in a juxtamembrane or hydrophobic intramembrane region. hTJ6 is highly homologous to Bos taurus 116-kDa subunit of the vacuolar proton-translocating ATPase. Over-expression of hTJ6 in HEK 293 cells increased H+ uptake into intracellular organelles, an effect that was sensitive to inhibition by bafilomycin, a selective inhibitor of vacuolar H+ pump. Northern blot analysis demonstrated three different hybridizing mRNA transcripts corresponding to 3.2, 5.0 and 7.3 kb, indicating the presence of several splice variants. Significant differences in hTJ6 mRNA levels in human tissues of different origins point to possible tissue-specific function. Although hTJ6 was found to be a poor substrate for tyrosine-phosphorylating enzymes, suggesting that its ITAM sequence is non-functional in protein tyrosine kinase-mediated signaling pathways, its role in organellar H+ pumping suggests that hTJ6 function may participate in protein trafficking/processing.
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Affiliation(s)
- Yael Babichev
- Department of Microbiology and Immunology, Cancer Research Center, Faculty of Health Sciences, Ben Gurion University of the Negev, PO Box 653, Beer Sheva 84105, Israel
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23
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Abrahamsen H, Baillie G, Ngai J, Vang T, Nika K, Ruppelt A, Mustelin T, Zaccolo M, Houslay M, Taskén K. TCR- and CD28-mediated recruitment of phosphodiesterase 4 to lipid rafts potentiates TCR signaling. THE JOURNAL OF IMMUNOLOGY 2004; 173:4847-58. [PMID: 15470025 DOI: 10.4049/jimmunol.173.8.4847] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Ligation of the TCR along with the coreceptor CD28 is necessary to elicit T cell activation in vivo, whereas TCR triggering alone does not allow a full T cell response. Upon T cell activation of human peripheral blood T cells, we found that the majority of cAMP was generated in T cell lipid rafts followed by activation of protein kinase A. However, upon TCR and CD28 coligation, beta-arrestin in complex with cAMP-specific phosphodiesterase 4 (PDE4) was recruited to lipid rafts which down-regulated cAMP levels. Whereas inhibition of protein kinase A increased TCR-induced immune responses, inhibition of PDE4 blunted T cell cytokine production. Conversely, overexpression of either PDE4 or beta-arrestin augmented TCR/CD28-stimulated cytokine production. We show here for the first time that the T cell immune response is potentiated by TCR/CD28-mediated recruitment of PDE4 to lipid rafts, which counteracts the local, TCR-induced production of cAMP. The specific recruitment of PDE4 thus serves to abrogate the negative feedback by cAMP which is elicited in the absence of a coreceptor stimulus.
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24
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Housden HR, Skipp PJS, Crump MP, Broadbridge RJ, Crabbe T, Perry MJ, Gore MG. Investigation of the kinetics and order of tyrosine phosphorylation in the T-cell receptor zeta chain by the protein tyrosine kinase Lck. EUROPEAN JOURNAL OF BIOCHEMISTRY 2003; 270:2369-76. [PMID: 12755691 DOI: 10.1046/j.1432-1033.2003.03604.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report experiments to investigate the role of the physiologically relevant protein tyrosine kinase Lck in the ordered phosphorylation of the T-cell receptor zeta chain. Six synthetic peptides were designed based on the sequences of the immunoreceptor tyrosine-based activation motifs (ITAMs) of the zeta chain. Preliminary 1H-NMR studies of recombinant zeta chain suggested that it is essentially unstructured and therefore that peptide mimics would serve as useful models for investigating individual ITAM tyrosines. Phosphorylation kinetics were determined for each tyrosine by assaying the transfer of 32P by recombinant Lck on to each of the peptides. The rates of phosphorylation were found to depend on the location of the tyrosine, leading to the proposal that Lck phosphorylates the six zeta chain ITAM tyrosines in the order 1N (first) > 3N > 3C > 2N > 1C > 2C (last) as a result of differences in the amino-acid sequence surrounding each tyrosine. This proposal was then tested on cytosolic, recombinant T-cell receptor zeta chain. After in vitro phosphorylation by Lck, the partially phosphorylated zeta chain was digested with trypsin. Separation and identification of the zeta chain fragments using LC-MS showed, as predicted by the peptide phosphorylation studies, that tyrosine 1N is indeed the first to be phosphorylated by Lck. We conclude that differences in the amino-acid context of the six zeta chain ITAM tyrosines affect the efficiency of their phosphorylation by the kinase Lck, which probably contributes to the distinct patterns of phosphorylation observed in vivo.
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Affiliation(s)
- Hazel R Housden
- Division of Biochemistry and Molecular Biology, School of Biological Sciences, University of Southampton, UK
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25
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Pitcher LA, Young JA, Mathis MA, Wrage PC, Bartók B, van Oers NSC. The formation and functions of the 21- and 23-kDa tyrosine-phosphorylated TCR zeta subunits. Immunol Rev 2003; 191:47-61. [PMID: 12614351 DOI: 10.1034/j.1600-065x.2003.00003.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The interaction between the T cell receptor (TCR) and its cognate antigen/major histocompatibility complex (MHC) complex activates a cascade of intracellular protein phosphorylations within the T cell. The signals are initiated by the specific phosphorylation of two tyrosine residues located in a conserved sequence motif termed an ITAM (immune receptor-based tyrosine activation motif). There are 10 ITAMs in the TCR complex, and 6 of these ITAMs are present in the TCR zeta homodimer. Following TCR stimulation, the TCR zeta subunit forms two tyrosine-phosphorylated intermediates of 21- and 23-kDa, respectively. The dramatic and diverse biological responses of T cells are proposed to be partly regulated by the relative ratios of the 21- vs. 23-kDa phosphorylated forms of TCR zeta that are induced following TCR ligation. In this review, we describe a stepwise model of zeta phosphorylation required for the formation of these two phosphorylated derivatives. We describe the kinases and phosphatases controlling these phosphorylation processes. In addition, we present some preliminary findings from ongoing studies that discuss the contributions of each phosphorylated form of zeta on T cell development, TCR signaling, T cell anergy induction, and T cell survival.
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Affiliation(s)
- Lisa A Pitcher
- Center for Immunology, The University of Texas Southwestern Medical Center, Dallas, TX 75390-9093, USA
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Paolini R, Molfetta R, Beitz LO, Zhang J, Scharenberg AM, Piccoli M, Frati L, Siraganian R, Santoni A. Activation of Syk tyrosine kinase is required for c-Cbl-mediated ubiquitination of Fcepsilon RI and Syk in RBL cells. J Biol Chem 2002; 277:36940-7. [PMID: 12145291 DOI: 10.1074/jbc.m204948200] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Engagement of the high affinity receptor for IgE (FcepsilonRI) on mast cells and basophils results in FcepsilonRI beta and gamma subunits ubiquitination by an as yet undefined mechanism. Here we show that, upon FcepsilonRI engagement on RBL-2H3 cells Syk undergoes ubiquitination and Syk kinase activity is required for its own ubiquitination and that of FcepsilonRI beta and gamma chains. This requirement was demonstrated by overexpression of Syk wild-type or its kinase-dead mutant in RBL cells or using an Syk-deficient RBL-derived cell line transfected with wild-type or a kinase inactive form of Syk. We also identify c-Cbl as the E3 ligase responsible for both Syk and receptor ubiquitination. Furthermore, we demonstrate that Syk controls tyrosine phosphorylation of Syk-associated Cbl induced after receptor engagement. These data suggest a mutual regulation between Syk and Cbl activities. Finally, we show that a selective inhibitor of proteasome degradation induces persistence of tyrosine-phosphorylated receptor complexes, of activated Syk, and of FcepsilonRI-triggered degranulation. Our results provide a molecular mechanism for down-regulation of engaged receptor complexes by targeting ubiquitinated FcepsilonRI and activated Syk to the proteasome for degradation.
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Affiliation(s)
- Rossella Paolini
- Department of Experimental Medicine and Pathology, Institute Pasteur-Fondazione Cenci Bolognetti, University La Sapienza, Rome 00161, Italy.
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27
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Nambiar MP, Enyedy EJ, Fisher CU, Krishnan S, Warke VG, Gilliland WR, Oglesby RJ, Tsokos GC. Abnormal expression of various molecular forms and distribution of T cell receptor zeta chain in patients with systemic lupus erythematosus. ARTHRITIS AND RHEUMATISM 2002; 46:163-74. [PMID: 11817588 DOI: 10.1002/1529-0131(200201)46:1<163::aid-art10065>3.0.co;2-j] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE T cells from the majority of patients with systemic lupus erythematosus (SLE) display antigen receptor-mediated signaling aberrations associated with defective T cell receptor (TCR) zeta chain expression. The TCR zeta chain, a critical signaling molecule, exists in multiple molecular forms and membrane fractions with distinct functions in antigen-mediated signaling processes. This study was undertaken to investigate the complete spectrum of expression of the different forms and distribution of the TCR zeta chain in SLE T cells. METHODS T cells were isolated from 48 SLE patients and 21 healthy subjects. The expression of various forms of the TCR zeta chain was investigated by immunoblotting with specific antibodies. The lipid raft-associated form of the zeta chain was determined by quantitating the solubilized zeta chain after disruption of the lipid rafts by cholesterol depletion using methyl-betacyclodextrin. The distribution of the zeta chain was investigated by fluorescence microscopy. RESULTS The phosphorylated 21- and 23-kd forms and the detergent-insoluble membrane-associated form of the TCR zeta chain and alternatively spliced zeta chain were significantly decreased in SLE T cells. In contrast, major ubiquitinated forms of the zeta chain were increased in these cells. We also identified up-regulation of a novel 14-kd form of the zeta chain in SLE T cells. Resting SLE T cell membranes had an increased percentage of the residual membrane-bound zeta chain in the lipid rafts. Fluorescence microscopy findings indicated that the residual zeta chain is more clustered on the cell membranes of SLE T cells. CONCLUSION These results suggest that, in addition to the 16-kd form, expression of other molecular forms and fractions of the TCR zeta chain as well as its membrane distribution are abnormal in SLE T cells. Increased lipid raft association and surface clustering of the zeta chain may explain the molecular mechanisms underlying the signaling abnormalities in these cells.
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van Oers NS, Tohlen B, Malissen B, Moomaw CR, Afendis S, Slaughter CA. The 21- and 23-kD forms of TCR zeta are generated by specific ITAM phosphorylations. Nat Immunol 2000; 1:322-8. [PMID: 11017104 DOI: 10.1038/79774] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The T cell receptor (TCR) zeta subunit contains three immunoreceptor tyrosine-based activation motifs (ITAMs) that translate effective extracellular ligand binding into intracellular signals by becoming phosphorylated into 21- and 23-kD forms. We report here that the 21-kD form of TCR zeta is generated by phosphorylation of the tyrosines in the second and third ITAMs, whereas the 23-kD form is formed by the additional phosphorylation of the membrane-proximal ITAM tyrosines. The stable formation of the 21- and 23-kD species requires the binding of the tandem SH2 domains of ZAP-70. We also report that TCR-mediated signaling processes can proceed independently of either the 21- or 23-kD species of TCR zeta.
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Affiliation(s)
- N S van Oers
- Center for Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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29
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Dix AR, Brooks WH, Roszman TL, Morford LA. Immune defects observed in patients with primary malignant brain tumors. J Neuroimmunol 1999; 100:216-32. [PMID: 10695732 DOI: 10.1016/s0165-5728(99)00203-9] [Citation(s) in RCA: 242] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Malignant glioblastomas (gliomas) account for approximately one third of all diagnosed brain tumors. Yet, a decade of research has made little progress in advancing the treatment of these tumors. In part this lack of progress is linked to the challenge of discovering how glial tumors are capable of both modulating host immune function and neutralizing immune-based therapies. Patients with gliomas exhibit a broad suppression of cell-mediated immunity. The impaired cell-mediated immunity observed in patients with gliomas appears to result from immunosuppressive factor(s) secreted by the tumor. This article reviews what has been elucidated about the immune defects of patients harboring glioma and the glioma-derived factors which mediate this immunosuppression. A model involving systemic cytokine dysregulation is presented to suggest how the immune defects arise in these individuals.
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Affiliation(s)
- A R Dix
- Department of Microbiology and Immunology, University of Kentucky Medical Center, Lexington 40536-0084, USA
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Gelkop S, Isakov N. T cell activation stimulates the association of enzymatically active tyrosine-phosphorylated ZAP-70 with the Crk adapter proteins. J Biol Chem 1999; 274:21519-27. [PMID: 10419455 DOI: 10.1074/jbc.274.31.21519] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Engagement of the T cell antigen receptor initiates signal transduction involving tyrosine phosphorylation of multiple effector molecules and the formation of multimolecular complexes at the receptor site. Adapter proteins that possess SH2 and SH3 protein-protein interaction domains are implicated in the assembly of cell activation-induced signaling complexes. We found that Crk adapter proteins undergo activation-induced interaction with the zeta-chain associated protein (ZAP-70) tyrosine kinase in the human T cell line, Jurkat. Incubation of various glutathione S-transferase fusion proteins with a lysate of activated Jurkat cells resulted in selective association of ZAP-70 with Crk, but not Grb2 or Nck, adapter proteins. In addition, tyrosine-phosphorylated ZAP-70 co-immunoprecipitated with Crk from a lysate of activated Jurkat cells, and ZAP-70 association with GST-Crk was observed in a lysate of activated human peripheral blood T cells. Association between the two molecules was mediated by direct physical interaction and involved the Crk-SH2 domain and phosphotyrosyl-containing sequences on ZAP-70. The association required intact Lck, considered to be an upstream regulator of ZAP-70, because it could not take place in activated JCaM1 cells, which express normal levels of ZAP-70 but are devoid of Lck. Finally, glutathione S-transferase-Crk fusion proteins were found to interact predominantly with membrane-residing tyrosine-phosphorylated ZAP-70 that exhibited autophosphorylation activity as well as phosphorylation of an exogenous substrate, CFB3. These findings suggest that Crk adapter proteins play a role in the early activation events of T lymphocytes, apparently, by direct interaction with, and regulation of, the membrane-residing ZAP-70 protein tyrosine kinase.
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Affiliation(s)
- S Gelkop
- Department of Microbiology and Immunology, Faculty of Health Sciences, Cancer Research Center, Ben Gurion University of the Negev, Beer Sheva 84105, Israel
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31
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Ogata M, Takada T, Mori Y, Uchida Y, Miki T, Okuyama A, Kosugi A, Sawada M, Oh-hora M, Hamaoka T. Regulation of phosphorylation level and distribution of PTP36, a putative protein tyrosine phosphatase, by cell-substrate adhesion. J Biol Chem 1999; 274:20717-24. [PMID: 10400706 DOI: 10.1074/jbc.274.29.20717] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Recently we have cloned a putative protein tyrosine phosphatase, PTP36/PTPD2/pez, which possesses a domain homologous to the N-terminal half of band 4.1 protein. In mouse fibroblasts adhered to substrates, PTP36 was phosphorylated on serine residues. PTP36 was found to make complexes with serine/threonine kinase(s), which phosphorylated PTP36 in vitro. PTP36 was dephosphorylated rapidly when the cell-substrate adhesion was disrupted and it was phosphorylated again along with the reattachment of the cells to fibronectin. Rephosphorylation of PTP36 seemed to depend on actin polymerization since it was inhibited by cytochalasin D. The cell detachment also induced the translocation of PTP36 into the membrane-associated cytoskeletal fraction. Staurosporine and ML-9, which inhibited the phosphorylation of PTP36 in vivo, induced the translocation of PTP36 too. On the contrary, when the dephosphorylation of PTP36 was inhibited by okadaic acid, no translocation of PTP36 was induced by the cell detachment. These results demonstrate that the cell-substrate adhesion and cell spreading regulates the intracellular localization of PTP36 most likely through its phosphorylation and therefore, PTP36 may play important roles in the signal transduction pathway of cell-adhesion.
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Affiliation(s)
- M Ogata
- Department of Oncology, Biomedical Research Center, Osaka University Medical School, Suita, Osaka 565-0871, Japan.
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Hegedûs Z, Chitu V, Tóth GK, Finta C, Váradi G, Andó I, Monostori E. Contribution of kinases and the CD45 phosphatase to the generation of tyrosine phosphorylation patterns in the T-cell receptor complex zeta chain. Immunol Lett 1999; 67:31-9. [PMID: 10217203 DOI: 10.1016/s0165-2478(98)00138-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The zeta subunit of the T-cell receptor complex plays a crucial role in coupling the antigen binding alphabeta and gammadelta heterodimers to the downstream activation pathways. Three tandem amino acid sequence motifs containing pairs of exactly spaced Tyr-X-X-Leu/Ile sequences, designated as Immunoreceptor Tyrosine-based Activation Motifs (ITAMs), control this function. The phosphorylated forms of ITAMs serve as docking sites for several src homology 2 (SH2) domain containing signaling proteins. The composition of the assembled signaling complex and the outcome of cell activation depends on the tyrosine phosphorylation pattern of the zeta polypeptide. The mechanism that conducts the generation of various phosphorylated forms has not yet been well established. In this study we have analyzed the ability of src family tyrosine kinases and the CD45 tyrosine phosphatase in determining the phosphorylation state of the different ITAMs and the individual tyrosine residues of the TCR zeta chain. The intracellular part of the zeta chain was phosphorylated by src family tyrosine kinases, p56lck and p59fyn in vitro. Synthetic oligopeptides representing full-length or half-sized ITAMs with a single tyrosine residue were also phosphorylated by both p56lck and p59fyn. In contrast, an additional membrane proximal tyrosine residue in the human zeta chain, located outside of the ITAMs, was not phosphorylated. We also examined the activity of the CD45 phosphatase, using a panel of ITAM derivatives, in which one or both tyrosines were phosphorylated. The efficiency of ITAM dephosphorylation by CD45 was dependent on the primary sequence of the oligopeptides and the position of the phosphotyrosine residues. The in vitro data suggest that the CD45 phosphatase rather than the tyrosine kinase(s) may control the generation of specific phosphorylation patterns of the zeta chain during cell activation.
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Affiliation(s)
- Z Hegedûs
- Institute of Genetics, Biological Research Center of Hungarian Academy of Sciences, Szeged
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Lee KM, Chuang E, Griffin M, Khattri R, Hong DK, Zhang W, Straus D, Samelson LE, Thompson CB, Bluestone JA. Molecular basis of T cell inactivation by CTLA-4. Science 1998; 282:2263-6. [PMID: 9856951 DOI: 10.1126/science.282.5397.2263] [Citation(s) in RCA: 484] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
CTLA-4, a negative regulator of T cell function, was found to associate with the T cell receptor (TCR) complex zeta chain in primary T cells. The association of TCRzeta with CTLA-4, reconstituted in 293 transfectants, was enhanced by p56(lck)-induced tyrosine phosphorylation. Coexpression of the CTLA-4-associated tyrosine phosphatase, SHP-2, resulted in dephosphorylation of TCRzeta bound to CTLA-4 and abolished the p56(lck)-inducible TCRzeta-CTLA-4 interaction. Thus, CTLA-4 inhibits TCR signal transduction by binding to TCRzeta and inhibiting tyrosine phosphorylation after T cell activation. These findings have broad implications for the negative regulation of T cell function and T cell tolerance.
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Affiliation(s)
- K M Lee
- Ben May Institute for Cancer Research, and Committee on Immunology, University of Chicago, Chicago, IL 60637, USA
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Abstract
Activation of T lymphocytes is a key event for an efficient response of the immune system. It requires the involvement of the T cell receptor antigen as well as costimulatory molecules such as CD28. Engagement of these receptors through the interaction with a foreign antigen associated with major histocompatibility complex molecules and CD28 counter-receptors B7.1/B7.2, respectively, results in a series of signaling cascades acting in synergy and which culminate in activation of interleukin-2 gene transcription and eventually cell proliferation. Many studies aimed at characterizing these specific effector pathways have been published; however, the actual signaling molecules that transduce activation signals from the cell membrane to the nucleus and that directly regulate interleukin-2 gene transcription are not yet completely defined and remain a matter of debate. In this commentary, we have attempted to analyze the results, which are sometimes diverging if not totally contradictory, characterizing effector pathways that possibly are triggered during T cell activation.
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Affiliation(s)
- J Favero
- INSERM U 431, Microbiologie et Pathologie Cellulaire Infectieuse, Universite de Montpellier II, France.
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35
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Xavier R, Brennan T, Li Q, McCormack C, Seed B. Membrane compartmentation is required for efficient T cell activation. Immunity 1998; 8:723-32. [PMID: 9655486 DOI: 10.1016/s1074-7613(00)80577-4] [Citation(s) in RCA: 765] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The plasma membrane of mammalian cells contains detergent-resistant membrane rafts enriched in glycosphingolipids and cholesterol. Although several important signaling molecules have been found in such rafts, evidence documenting a functional role for their localization has been scarce. Using a fractionation scheme that preserves tyrosine phosphorylation, we show that T cell activation leads to a striking compartmentation in the rafts of activated T cell receptor and associated signal-transducing molecules. Conditions that reversibly disrupt raft structure either by dispersing their contents or by forcing their internalization reversibly disrupt the earliest steps of T cell activation. Thus, raft integrity is a prerequisite for efficient T cell receptor signal transduction.
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Affiliation(s)
- R Xavier
- Department of Molecular Biology, Massachusetts General Hospital, Boston 02114, USA
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36
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Rellahan BL, Jensen JP, Howcroft TK, Singer DS, Bonvini E, Weissman AM. Elf-1 Regulates Basal Expression from the T Cell Antigen Receptor ζ-Chain Gene Promoter. THE JOURNAL OF IMMUNOLOGY 1998. [DOI: 10.4049/jimmunol.160.6.2794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
In mature T cells, limited synthesis of the TCR-ζ subunit is primarily responsible for regulating surface expression of TCRs. Transcription of ζ is directed by a complex promoter that includes two potential binding sites for the Ets family of transcription factors at −52 (zEBS1) and −135 (zEBS2). Mutation of these two sites results in a marked reduction of transcription from this promoter. Using electrophoretic mobility shift analysis, Elf-1 was demonstrated to be the Ets family member that binds to these sites. One site, zEBS1, matches the optimal Elf-1 consensus sequence in eight of nine bases, making it the best match of any known mammalian Elf-1 binding site. A role for Elf-1 in TCR-ζ trans-activation was confirmed by ectopic expression of Elf-1 in COS-7 cells. This resulted in an increase in TCR-ζ promoter activity that mapped to zEBS1 and zEBS2. Additional support for the involvement of Elf-1 in TCR-ζ trans-activation derives from the finding that a GAL4-Elf-1 fusion protein trans-activated TCR-ζ promoter constructs that had been modified to contain GAL4 DNA binding sites. These results demonstrate that Elf-1 plays an essential role in the trans-activation of a constitutively expressed T cell-specific gene, and that trans-activation occurs in the context of the native promoter in both lymphoid and nonlymphoid cells. Taken together with the existing literature, these data also suggest that the requirement for inducible factors in Elf-1-mediated trans-activation may decrease as the affinity and number of Elf-1 sites increase.
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Affiliation(s)
- Barbara L. Rellahan
- *Laboratory of Immunobiology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892; and
| | - Jane P. Jensen
- †Laboratory of Immune Cell Biology, National Cancer Institute, and
| | - Thomas K. Howcroft
- ‡Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Dinah S. Singer
- ‡Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Ezio Bonvini
- *Laboratory of Immunobiology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892; and
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Role of Immunoreceptor Tyrosine-Based Activation Motif in Signal Transduction from Antigen and Fc Receptors**Received for publication October 7, 1997. Adv Immunol 1998. [DOI: 10.1016/s0065-2776(08)60608-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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38
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de Aós I, Metzger MH, Exley M, Dahl CE, Misra S, Zheng D, Varticovski L, Terhorst C, Sancho J. Tyrosine phosphorylation of the CD3-epsilon subunit of the T cell antigen receptor mediates enhanced association with phosphatidylinositol 3-kinase in Jurkat T cells. J Biol Chem 1997; 272:25310-8. [PMID: 9312149 DOI: 10.1074/jbc.272.40.25310] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
T cell receptor signaling results both in T cell proliferation and apoptosis. A key enzyme at the intersection of these downstream pathways is phosphatidylinositol 3'-kinase (PI 3-kinase). In a previous report, we showed that the p85alpha subunit of the PI 3-kinase preferentially associated with the CD3-zeta membrane-proximal immunoreceptor tyrosine-based activation motif of the zeta chain (zetaA-ITAM) (Exley, M., Varticovski, L., Peter, M., Sancho, J., and Terhorst, C. (1994) J. Biol. Chem. 269, 15140-15146). Here, we demonstrate that tyrosine phosphorylation of CD3-epsilon can recruit the PI 3-kinase enzyme in a T cell activation-dependent manner. In vivo studies with Jurkat cells stably transfected with a CD8-CD3-epsilon chimera (termed CD8-epsilon) shows that ligation of endogenous CD3-epsilon or CD8-epsilon by specific antibodies induces tyrosine phosphorylation of CD3-epsilon or CD8-epsilon, respectively. Increased tyrosine phosphorylation correlates with increased binding of p85alpha PI 3-kinase and recruitment of PI 3-kinase enzymatic activity to CD3-epsilon or CD8-epsilon proteins. Mutagenesis studies in COS-7 cells, transiently transfected with CD8-epsilon, p85alpha, and Fyn cDNAs in various combinations, show that both Tyr170 and Tyr181 within the CD3-epsilon-ITAM are required for efficient binding of p85alpha PI 3-kinase. Thus, replacement of Tyr170 by Phe (Y170F), or Tyr181 by Phe (Y181F) significantly reduces binding of p85alpha PI 3-kinase, whereas it does not affect binding of Fyn. Further in vitro experiments suggest that a direct binding of the tandem SH2 domains of p85alpha PI 3-kinase to the two phosphorylated tyrosines in a single CD3-epsilon-ITAM may occur. The data also support a model in which a single CD3 subunit can recruit distinct effector molecules by means of TCR-mediated differential ITAM phosphorylation.
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Affiliation(s)
- I de Aós
- Instituto de Parasitología y Biomedicina, Consejo Superior de Investigaciones Científicas, Ventanilla 11, 18001 Granada, Spain
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Huby RD, Iwashima M, Weiss A, Ley SC. ZAP-70 protein tyrosine kinase is constitutively targeted to the T cell cortex independently of its SH2 domains. J Cell Biol 1997; 137:1639-49. [PMID: 9199177 PMCID: PMC2137816 DOI: 10.1083/jcb.137.7.1639] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
ZAP-70 is a nonreceptor protein tyrosine kinase that is essential for signaling via the T cell antigen receptor (TCR). ZAP-70 becomes phosphorylated and activated by LCK protein tyrosine kinase after interaction of its two NH2-terminal SH2 domains with tyrosine-phosphorylated subunits of the activated TCR. In this study, the localization of ZAP-70 was investigated by immunofluorescence and confocal microscopy. ZAP-70 was found to be localized to the cell cortex in a diffuse band under the plasma membrane in unstimulated T cells, and this localization was not detectably altered by TCR stimulation. Analysis of mutants indicated that ZAP-70 targeting was independent of its SH2 domains but required its active kinase domain. The specific compartmentalization of ZAP-70 suggests that it may interact with an anchoring protein in the cell cortex via its hinge or kinase domains. It is likely that the maintenance of high concentrations of ZAP-70 at the cell cortex, that only has to move a short distance to interact with phophorylated TCR subunits, facilitates rapid initiation of signaling by the TCR. In addition, as the major increase in tyrosine phosphorylation induced by the TCR also occurs at the cell cortex (Ley, S.C., M. Marsh, C.R. Bebbington, K. Proudfoot, and P. Jordan. 1994. J. Cell. Biol. 125:639-649), ZAP-70 may be localized close to its downstream targets.
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Affiliation(s)
- R D Huby
- Division of Cellular Immunology, National Institute for Medical Research, London NW7 1AA, United Kingdom
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40
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Luo X, Sando JJ. Deficient tyrosine phosphorylation of c-Cbl and associated proteins in phorbol ester-resistant EL4 mouse thymoma cells. J Biol Chem 1997; 272:12221-8. [PMID: 9115297 DOI: 10.1074/jbc.272.18.12221] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Two tyrosine phosphoproteins in phorbol ester-sensitive EL4 (S-EL4) mouse thymoma cells have been identified as the p120 c-Cbl protooncogene product and the p85 subunit of phosphatidylinositol 3-kinase. Tyrosine phosphorylation of p120 and p85 increased rapidly after phorbol ester stimulation. Phorbol ester-resistant EL4 (R-EL4) cells expressed comparable amounts of c-Cbl and phosphatidylinositol 3-kinase protein but greatly diminished tyrosine phosphorylation. Co-immunoprecipitation experiments revealed complexes of c-Cbl with p85, and of p85 with the tyrosine kinase Lck in phorbol ester-stimulated S-EL4 but not in unstimulated S-EL4 or in R-EL4 cells. In vitro binding of c-Cbl with Lck SH2 or SH3 domains was detected in both S-EL4 and R-EL4 cells, suggesting that c-Cbl, p85, and Lck may form a ternary complex. In vitro kinase assays revealed phosphorylation of p85 by Lck only in phorbol ester-stimulated S-EL4 cells. Collectively, these results suggest that Cbl-p85 and Lck-p85 complexes may form in unstimulated S-EL4 and R-EL4 cells but were not detected due to absence of tyrosine phosphorylation of p85. Greatly decreased tyrosine phosphorylation of c-Cbl and p85 in the complexes may contribute to the failure of R-EL4 cells to respond to phorbol ester.
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Affiliation(s)
- X Luo
- Department of Pharmacology and Cancer Center, University of Virginia, Charlottesville, Virginia 22908, USA
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41
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Isakov N. ITIMs and ITAMs. The Yin and Yang of antigen and Fc receptor-linked signaling machinery. Immunol Res 1997; 16:85-100. [PMID: 9048210 DOI: 10.1007/bf02786325] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The initial stages of an immune response are regulated at the level of the cell-surface antigen and Fc receptors. The extracellular portions of these receptors provide immune specificity and determine the nature of the responding effector cells, whereas the intracellular portion transduces signals into the cell and determines the intensity and duration of the immune response. Recent studies led to the identification of two types of modules within the cytoplasmic region of receptor subunits that are critical for the activation and termination of signal transduction pathways. Phosphorylation of the conserved tyrosine residues within the two modules, the immunoreceptor tyrosine-based activation motif (ITAM) and the immunoreceptor tyrosine-based inhibition motif (ITIM), is followed by the recruitment of different sets of SH2-containing molecules to the receptor site. These proteins regulate the receptor-linked signal transduction pathways in a positive or a negative fashion, which is a reminiscent of the ancestral Yin-Yang principle.
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Affiliation(s)
- N Isakov
- Department of Microbiology and Immunology, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel
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42
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Caplan S, Baniyash M. Normal T cells express two T cell antigen receptor populations, one of which is linked to the cytoskeleton via zeta chain and displays a unique activation-dependent phosphorylation pattern. J Biol Chem 1996; 271:20705-12. [PMID: 8702821 DOI: 10.1074/jbc.271.34.20705] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The TCR couples antigen recognition and the transmission of activation signals. We report the expression of two TCR populations on the surface of T lymphocytes, one of which is linked to the cytoskeleton via the zeta chain. We also demonstrate that assembly of the CD3 subunits with cytoskeleton-associated zeta is necessary for their maximal localization to the cytoskeleton. The potential significance of these two receptor forms is underscored by differences observed in non-activated T cells; while detergent-soluble phosphorylated zeta appears as a 21-kDa protein, phosphorylated cytoskeleton-associated zeta appears as a 16-kDa form. This dichotomous phosphorylation pattern is rigidly maintained following activation, although each of the receptor populations undergoes different activation-dependent modifications: 1) levels of soluble phosphorylated 21-kDa zeta are enhanced, while phosphorylated 16-kDa cytoskeleton-associated zeta exhibits little change; 2) soluble non-phosphorylated 16-kDa zeta translocates to the cytoskeleton; 3) activation-dependent ubiquitinated zeta forms localize to both fractions, albeit with different kinetics. We also show that the protein tyrosine kinase Lck undergoes activation-dependent modifications and translocates to the cytoskeleton. The phosphorylation profiles of the dichotomous TCR populations in both non-activated and activated lymphocytes suggest that each population could regulate distinct cellular functions, possibly by select intermolecular associations.
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Affiliation(s)
- S Caplan
- The Lautenberg Center for General and Tumor Immunology, Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
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Frearson JA, Yi T, Alexander DR. A tyrosine-phosphorylated 110-120-kDa protein associates with the C-terminal SH2 domain of phosphotyrosine phosphatase-1D in T cell receptor-stimulated T cells. Eur J Immunol 1996; 26:1539-43. [PMID: 8766558 DOI: 10.1002/eji.1830260720] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The role of cytosolic phosphotyrosine phosphatases (PTPase) in T cell receptor (TCR)-mediated signaling was investigated. PTPase activity was detected in a purified immunocomplex comprising aggregated TCR from the cell surface of Jurkat T cells. Since TCR aggregation results in phosphorylation of critical immunoreceptor tyrosine-based activation motifs (ITAM) in the TCR zeta chain, a doubly tyrosine-phosphorylated synthetic peptide containing the membrane-proximal zeta chain ITAM (zeta p ITAM) was used to characterize TCR zeta-associated PTPases. PTPase activity was detected in stable association with zeta p ITAM and the SH2 domain-containing PTPase PTP-1D (Syp, SH-PTP2) was identified in this complex. TCR stimulation resulted in increased total PTPase activity and PTP-1D protein in zeta p ITAM precipitates. TCR stimulation did not result in the tyrosine phosphorylation of PTP-1D but caused the rapid and transient tyrosine phosphorylation of a 110-120-kDa protein which associated selectively with the C-terminal SH2 domain of PTP-1D. This currently unidentified phosphotyrosine protein may be involved in localizing PTP-1D to the TCR following receptor stimulation.
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Affiliation(s)
- J A Frearson
- Department of Immunology, The Babraham Institute, Cambridge, GB
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44
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Isakov N, Wange RL, Watts JD, Aebersold R, Samelson LE. Purification and characterization of human ZAP-70 protein-tyrosine kinase from a baculovirus expression system. J Biol Chem 1996; 271:15753-61. [PMID: 8663155 DOI: 10.1074/jbc.271.26.15753] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The ZAP-70 protein tyrosine kinase is essential for T cell antigen receptor (TCR)-mediated signaling. The absence of ZAP-70 results in impaired differentiation of T cells and a lack of responsiveness to antigenic stimulation. In order to study the characteristics of ZAP-70 in vitro, we overexpressed an epitopically tagged human ZAP-70 in a recombinant baculovirus expression system and purified it by column chromatography. The kinase activity of purified, recombinant ZAP-70 required cation and exhibited a strong preference for Mn2+ over Mg2+. The apparent Km of ZAP-70 for ATP was approximately 3.0 microM. The activity of the recombinant ZAP-70, unlike that of the homologous protein tyrosine kinase, Syk, was not affected by binding of TCR-derived tyrosine phosphorylated immunoreceptor tyrosine-based activation motif peptides. Several proteins were tested as potential in vitro substrates of ZAP-70. Only alpha-tubulin and the cytoplasmic fragment of human erythrocyte band 3 (cfb3), which have a region of sequence identity at the phosphorylation site, proved to be good substrates, exhibiting Kmvalues of approximately 3.3 and approximately 2.5 microM, respectively ([ATP] = 50 microM). alpha- and beta-Casein were poor substrates for ZAP-70, and no activity toward enolase, myelin basic protein, calmodulin, histone proteins, or angiotensin could be detected. In contrast to the T cell protein tyrosine kinase, Lck, ZAP-70 did not phosphorylate the cytoplasmic portion of the TCRzeta chain or short peptides corresponding to the CD3epsilon or the TCRzeta immunoreceptor tyrosine-based activation motifs. Our studies suggest that ZAP-70 exhibits a high degree of substrate specificity.
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Affiliation(s)
- N Isakov
- Cell Biology and Metabolism Branch, NICHD, National Institutes of Health, Bethesda, Maryland, 20892, USA
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Cenciarelli C, Wilhelm KG, Guo A, Weissman AM. T cell antigen receptor ubiquitination is a consequence of receptor-mediated tyrosine kinase activation. J Biol Chem 1996; 271:8709-13. [PMID: 8621503 DOI: 10.1074/jbc.271.15.8709] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Engagement of the T cell antigen receptor results in both its phosphorylation and its ubiquitination. T cell antigen receptor ubiquitination was evaluated in Jurkat, a well characterized human T leukemia cell line. Treatment of cells with the tyrosine kinase inhibitor herbimycin A resulted in an inhibition of receptor ubiquitination. Consistent with this, pervanadate, which increases cellular tyrosine phosphorylation, enhanced receptor ubiquitination. A requirement for receptor-mediated tyrosine kinase activity for ubiquitination was confirmed in cells lacking the tyrosine kinase p56lck and also in cells that are defective in expression of CD45, a tyrosine phosphatase that regulates the activity of p56lck. The need for tyrosine kinase activation for ubiquitination was not bypassed by directly activating protein kinase C and stimulating endocytosis of receptors. These observations establish ubiquitination of the T cell antigen receptor as a tyrosine kinase-dependent manifestation of transmembrane signaling and suggest a role for tyrosine phosphorylation in the ligand-dependent ubiquitination of mammalian transmembrane receptors.
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Affiliation(s)
- C Cenciarelli
- Laboratory of Immune Cell Biology, Division of Basic Sciences, NCI, National Institutes of Health, Bethesda, Maryland 20892-1152, USA
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Samelson LE, Donovan JA, Isakov N, Ota Y, Wange RL. Signal transduction mediated by the T-cell antigen receptor. Ann N Y Acad Sci 1995; 766:157-72. [PMID: 7486652 DOI: 10.1111/j.1749-6632.1995.tb26659.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- L E Samelson
- Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-5430, USA
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47
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Wange RL, Isakov N, Burke TR, Otaka A, Roller PP, Watts JD, Aebersold R, Samelson LE. F2(Pmp)2-TAM zeta 3, a novel competitive inhibitor of the binding of ZAP-70 to the T cell antigen receptor, blocks early T cell signaling. J Biol Chem 1995; 270:944-8. [PMID: 7822334 DOI: 10.1074/jbc.270.2.944] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Signaling by the T cell antigen receptor (TCR) is mediated by 17-residue tyrosine-based activation motifs (TAM) present in the cytoplasmic tails of the TCR zeta and CD3 chains. TAMs become tyrosine-phosphorylated upon TCR stimulation, creating a high affinity binding site for the tandem SH2 domains of ZAP-70. In permeabilized T cells, the association of TCR and ZAP-70 was inhibited by a protein tyrosine phosphatase (PTPase)-resistant TAM peptide analog, in which difluorophosphonomethyl phenylalanyl (F2Pmp) residues replaced phosphotyrosine. Inhibition of this association prevented TCR-stimulated tyrosine phosphorylation of ZAP-70 and reduced ZAP-70 kinase activity to basal levels. The reduction in ZAP-70 activity coincided with reduced tyrosine phosphorylation of a number of substrates. Such PTPase-resistant peptides, capable of disrupting SH2 domain-mediated protein-protein interactions, should prove useful in further dissection of multiple signaling pathways and may serve as models for rationally designed chemotherapeutic agents for the treatment of autoimmune and neoplastic disorders.
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Affiliation(s)
- R L Wange
- Cell Biology and Metabolism Branch, NICHD, National Institutes of Health, Bethesda, Maryland 20892
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48
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Activation-dependent ubiquitination of a T cell antigen receptor subunit on multiple intracellular lysines. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)36780-7] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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49
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Association of phosphatidylinositol 3-kinase with a specific sequence of the T cell receptor zeta chain is dependent on T cell activation. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)36584-5] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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50
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Biochemical characterization of valosin-containing protein, a protein tyrosine kinase substrate in hematopoietic cells. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(19)78142-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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