1
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Wang H, Huang Y, Xu C. Charging CAR by electrostatic power. Immunol Rev 2023; 320:138-146. [PMID: 37366589 DOI: 10.1111/imr.13232] [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: 05/25/2023] [Accepted: 06/13/2023] [Indexed: 06/28/2023]
Abstract
Chimeric antigen receptor (CAR)-T cell therapy has emerged as a promising approach for cancer treatment. CAR is a synthetic immune receptor that recognizes tumor antigen and activates T cells through multiple signaling pathways. However, the current CAR design is not as robust as T cell receptor (TCR), a natural antigen receptor with high sensitivity and efficiency. TCR signaling relies on specific molecular interactions, and thus electrostatic force, the major force of molecular interactions, play critical roles. Understanding how electrostatic charge regulates TCR/CAR signaling events will facilitate the development of next-generation T cell therapies. This review summarizes recent findings on the roles of electrostatic interactions in both natural and synthetic immune receptor signaling, specifically that in CAR clustering and effector molecule recruitments, and highlights potential strategies for engineering CAR-T cell therapy by leveraging charge-based interactions.
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Affiliation(s)
- Haopeng Wang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- Shanghai Clinical Research and Trial Center, Shanghai, China
| | - Yuwei Huang
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- Lingang Laboratory, Shanghai, China
| | - Chenqi Xu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
- School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China
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2
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Smid AI, Garforth SJ, Obaid MS, Bollons HR, James JR. Pre-T cell receptor localization and trafficking are independent of its signaling. J Cell Biol 2023; 222:e202212106. [PMID: 37516909 PMCID: PMC10373305 DOI: 10.1083/jcb.202212106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 06/08/2023] [Accepted: 07/06/2023] [Indexed: 07/31/2023] Open
Abstract
Expression of the pre-T cell receptor (preTCR) is an important checkpoint during the development of T cells, an essential cell type of our adaptive immune system. The preTCR complex is only transiently expressed and rapidly internalized in developing T cells and is thought to signal in a ligand-independent manner. However, identifying a mechanistic basis for these unique features of the preTCR compared with the final TCR complex has been confounded by the concomitant signaling that is normally present. Thus, we have reconstituted preTCR expression in non-immune cells to uncouple receptor trafficking dynamics from its associated signaling. We find that all the defining features of the preTCR are intrinsic properties of the receptor itself, driven by exposure of an extracellular hydrophobic region, and are not the consequence of receptor activation. Finally, we show that transitory preTCR cell surface expression can sustain tonic signaling in the absence of ligand binding, suggesting how the preTCR can nonetheless drive αβTCR lineage commitment.
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Affiliation(s)
- Andrei I Smid
- Molecular Immunity Unit, Department of Medicine, Medical Research Council-Laboratory of Molecular Biology, University of Cambridge, Cambridge, UK
| | - Sam J Garforth
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Maryam S Obaid
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Hannah R Bollons
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - John R James
- Molecular Immunity Unit, Department of Medicine, Medical Research Council-Laboratory of Molecular Biology, University of Cambridge, Cambridge, UK
- Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
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3
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Charnley M, Allam AH, Newton LM, Humbert PO, Russell SM. E-cadherin in developing murine T cells controls spindle alignment and progression through β-selection. SCIENCE ADVANCES 2023; 9:eade5348. [PMID: 36652509 DOI: 10.1126/sciadv.ade5348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 12/21/2022] [Indexed: 06/17/2023]
Abstract
A critical stage of T cell development is β-selection; at this stage, the T cell receptor β (TCRβ) chain is generated, and the developing T cell starts to acquire antigenic specificity. Progression through β-selection is assisted by low-affinity interactions between the nascent TCRβ chain and peptide presented on stromal major histocompatibility complex and cues provided by the niche. In this study, we identify a cue within the developing T cell niche that is critical for T cell development. E-cadherin mediates cell-cell interactions and influences cell fate in many developmental systems. In developing T cells, E-cadherin contributed to the formation of an immunological synapse and the alignment of the mitotic spindle with the polarity axis during division, which facilitated subsequent T cell development. Collectively, these data suggest that E-cadherin facilitates interactions with the thymic niche to coordinate the β-selection stage of T cell development.
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Affiliation(s)
- Mirren Charnley
- Optical Sciences Centre, School of Science, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia
- Immune Signalling Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia
| | - Amr H Allam
- Optical Sciences Centre, School of Science, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia
- Immune Signalling Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia
| | - Lucas M Newton
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
- Research Centre for Molecular Cancer Prevention, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Patrick O Humbert
- Department of Biochemistry and Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
- Research Centre for Molecular Cancer Prevention, La Trobe University, Melbourne, Victoria 3086, Australia
- Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne, Victoria 3010, Australia
- Department of Clinical Pathology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Sarah M Russell
- Optical Sciences Centre, School of Science, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia
- Immune Signalling Laboratory, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Victoria 3010, Australia
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4
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Muro R, Narita T, Nitta T, Takayanagi H. Spleen tyrosine kinase mediates the γδTCR signaling required for γδT cell commitment and γδT17 differentiation. Front Immunol 2023; 13:1045881. [PMID: 36713401 PMCID: PMC9878111 DOI: 10.3389/fimmu.2022.1045881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 12/23/2022] [Indexed: 01/13/2023] Open
Abstract
The γδT cells that produce IL-17 (γδT17 cells) play a key role in various pathophysiologic processes in host defense and homeostasis. The development of γδT cells in the thymus requires γδT cell receptor (γδTCR) signaling mediated by the spleen tyrosine kinase (Syk) family proteins, Syk and Zap70. Here, we show a critical role of Syk in the early phase of γδT cell development using mice deficient for Syk specifically in lymphoid lineage cells (Syk-conditional knockout (cKO) mice). The development of γδT cells in the Syk-cKO mice was arrested at the precursor stage where the expression of Rag genes and αβT-lineage-associated genes were retained, indicating that Syk is required for γδT-cell lineage commitment. Loss of Syk in γδT cells weakened TCR signal-induced phosphorylation of Erk and Akt, which is mandatory for the thymic development of γδT17 cells. Syk-cKO mice exhibited a loss of γδT17 cells in the thymus as well as throughout the body, and thereby are protected from γδT17-dependent psoriasis-like skin inflammation. Collectively, our results indicate that Syk is a key player in the lineage commitment of γδT cells and the priming of γδT17 cell differentiation.
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Affiliation(s)
- Ryunosuke Muro
- Department of Immunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan
| | - Tomoya Narita
- Department of Pharmacotherapeutics, Research Institute of Pharmaceutical Sciences and Faculty of Pharmacy, Musashino University, Tokyo, Japan
| | - Takeshi Nitta
- Department of Immunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan,*Correspondence: Takeshi Nitta,
| | - Hiroshi Takayanagi
- Department of Immunology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, Japan
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5
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This S, Rogers D, Mallet Gauthier È, Mandl JN, Melichar HJ. What's self got to do with it: Sources of heterogeneity among naive T cells. Semin Immunol 2023; 65:101702. [PMID: 36463711 DOI: 10.1016/j.smim.2022.101702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 11/23/2022] [Accepted: 11/25/2022] [Indexed: 12/04/2022]
Abstract
There is a long-standing assumption that naive CD4+ and CD8+ T cells are largely homogeneous populations despite the extraordinary diversity of their T cell receptors (TCR). The self-immunopeptidome plays a key role in the selection of the naive T cell repertoire in the thymus, and self-peptides are also an important driver of differences between individual naive T cells with regard to their subsequent functional contributions to an immune response. Accumulating evidence suggests that as early as the β-selection stage of T cell development, when only one of the recombined chains of the mature TCR is expressed, signaling thresholds may be established for positive selection of immature thymocytes. Stochastic encounters subsequently made with self-ligands during positive selection in the thymus imprint functional biases that a T cell will carry with it throughout its lifetime, although ongoing interactions with self in the periphery ensure a level of plasticity in the gene expression wiring of naive T cells. Identifying the sources of heterogeneity in the naive T cell population and which functional attributes of T cells can be modulated through post-thymic interventions versus those that are fixed during T cell development, could enable us to better select or generate T cells with particular traits to improve the efficacy of T cell therapies.
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Affiliation(s)
- Sébastien This
- Department of Microbiology, Infectious Disease, and Immunology, Université de Montréal, Montreal, Canada; Immunology-Oncology Unit, Maisonneuve-Rosemont Hospital Research Center, Montreal, Canada
| | - Dakota Rogers
- Department of Physiology and McGill Research Centre on Complex Traits, McGill University, Montreal, Canada
| | - Ève Mallet Gauthier
- Department of Microbiology, Infectious Disease, and Immunology, Université de Montréal, Montreal, Canada; Immunology-Oncology Unit, Maisonneuve-Rosemont Hospital Research Center, Montreal, Canada
| | - Judith N Mandl
- Department of Physiology and McGill Research Centre on Complex Traits, McGill University, Montreal, Canada.
| | - Heather J Melichar
- Immunology-Oncology Unit, Maisonneuve-Rosemont Hospital Research Center, Montreal, Canada; Department of Medicine, Université de Montréal, Montreal, Canada.
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6
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Pre-T cell receptor self-MHC sampling restricts thymocyte dedifferentiation. Nature 2023; 613:565-574. [PMID: 36410718 PMCID: PMC9851994 DOI: 10.1038/s41586-022-05555-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 11/11/2022] [Indexed: 11/22/2022]
Abstract
Programming T cells to distinguish self from non-self is a vital, multi-step process that occurs in the thymus1-4. Signalling through the pre-T cell receptor (preTCR), a CD3-associated heterodimer comprising an invariant pTα chain and a clone-specific β chain, is a critical early checkpoint in thymocyte development within the αβ T cell lineage5,6. PreTCRs arrayed on CD4-CD8- double-negative thymocytes ligate peptides bound to major histocompatibility complex molecules (pMHC) on thymic stroma, similar to αβ T cell receptors that appear on CD4+CD8+ double-positive thymocytes, but via a different molecular docking strategy7-10. Here we show the consequences of these distinct interactions for thymocyte progression using synchronized fetal thymic progenitor cultures that differ in the presence or absence of pMHC on support stroma, and single-cell transcriptomes at key thymocyte developmental transitions. Although major histocompatibility complex (MHC)-negative stroma fosters αβ T cell differentiation, the absence of preTCR-pMHC interactions leads to deviant thymocyte transcriptional programming associated with dedifferentiation. Highly proliferative double-negative and double-positive thymocyte subsets emerge, with antecedent characteristics of T cell lymphoblastic and myeloid malignancies. Compensatory upregulation of diverse MHC class Ib proteins in B2m/H2-Ab1 MHC-knockout mice partially safeguards in vivo thymocyte progression, although disseminated double-positive thymic tumours may develop with ageing. Thus, as well as promoting β chain repertoire broadening for subsequent αβ T cell receptor utilization, preTCR-pMHC interactions limit cellular plasticity to facilitate normal thymocyte differentiation and proliferation that, if absent, introduce developmental vulnerabilities.
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7
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Ohigashi I, Matsuda-Lennikov M, Takahama Y. Peptides for T cell selection in the thymus. Peptides 2021; 146:170671. [PMID: 34624431 DOI: 10.1016/j.peptides.2021.170671] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 09/29/2021] [Accepted: 09/30/2021] [Indexed: 12/15/2022]
Abstract
Major histocompatibility complex (MHC)-associated peptides generated and displayed by antigen-presenting cells in the thymus are essential for the generation of functional and self-tolerant T cells that protect our body from various pathogens. The peptides displayed by cortical thymic epithelial cells (cTECs) are generated by unique enzymatic machineries including the thymoproteasomes, and are involved in the positive selection of self-protective T cells. On the other hand, the peptides displayed by medullary thymic epithelial cells (mTECs) and thymic dendritic cells (DCs) are involved in further selection to establish self-tolerance in T cells. Although the biochemical nature of the peptide repertoire displayed in the thymus remains unclear, many studies have suggested a thymus-specific mechanism for the generation of MHC-associated peptides in the thymus. In this review, we summarize basic knowledge and recent advances in MHC-associated thymic peptides, focusing on the generation and function of thymoproteasome-dependent peptides specifically displayed by cTECs.
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Affiliation(s)
- Izumi Ohigashi
- Division of Experimental Immunology, Institute of Advanced Medical Sciences, University of Tokushima, Tokushima, 770-8503, Japan.
| | - Mami Matsuda-Lennikov
- Thymus Biology Section, Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Yousuke Takahama
- Thymus Biology Section, Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892, USA
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8
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Allam AH, Charnley M, Pham K, Russell SM. Developing T cells form an immunological synapse for passage through the β-selection checkpoint. J Cell Biol 2021; 220:e201908108. [PMID: 33464309 PMCID: PMC7814350 DOI: 10.1083/jcb.201908108] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 10/22/2020] [Accepted: 12/10/2020] [Indexed: 02/07/2023] Open
Abstract
The β-selection checkpoint of T cell development tests whether the cell has recombined its genomic DNA to produce a functional T cell receptor β (TCRβ). Passage through the β-selection checkpoint requires the nascent TCRβ protein to mediate signaling through a pre-TCR complex. In this study, we show that developing T cells at the β-selection checkpoint establish an immunological synapse in in vitro and in situ, resembling that of the mature T cell. The immunological synapse is dependent on two key signaling pathways known to be critical for the transition beyond the β-selection checkpoint, Notch and CXCR4 signaling. In vitro and in situ analyses indicate that the immunological synapse promotes passage through the β-selection checkpoint. Collectively, these data indicate that developing T cells regulate pre-TCR signaling through the formation of an immunological synapse. This signaling platform integrates cues from Notch, CXCR4, and MHC on the thymic stromal cell to allow transition beyond the β-selection checkpoint.
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Affiliation(s)
- Amr H. Allam
- Optical Sciences Centre, Faculty of Science, Engineering & Technology, Swinburne University of Technology, Hawthorn, Victoria, Australia
- Immune Signalling Laboratory, Peter MacCallum Cancer Centre, Parkville, Victoria, Australia
| | - Mirren Charnley
- Optical Sciences Centre, Faculty of Science, Engineering & Technology, Swinburne University of Technology, Hawthorn, Victoria, Australia
- Immune Signalling Laboratory, Peter MacCallum Cancer Centre, Parkville, Victoria, Australia
| | - Kim Pham
- Optical Sciences Centre, Faculty of Science, Engineering & Technology, Swinburne University of Technology, Hawthorn, Victoria, Australia
- Immune Signalling Laboratory, Peter MacCallum Cancer Centre, Parkville, Victoria, Australia
- Department of Pathology, The University of Melbourne, Australia
| | - Sarah M. Russell
- Optical Sciences Centre, Faculty of Science, Engineering & Technology, Swinburne University of Technology, Hawthorn, Victoria, Australia
- Immune Signalling Laboratory, Peter MacCallum Cancer Centre, Parkville, Victoria, Australia
- Department of Pathology, The University of Melbourne, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Australia
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9
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Li X, Mizsei R, Tan K, Mallis RJ, Duke-Cohan JS, Akitsu A, Tetteh PW, Dubey A, Hwang W, Wagner G, Lang MJ, Arthanari H, Wang JH, Reinherz EL. Pre-T cell receptors topologically sample self-ligands during thymocyte β-selection. Science 2020; 371:181-185. [PMID: 33335016 DOI: 10.1126/science.abe0918] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 12/03/2020] [Indexed: 11/02/2022]
Abstract
Self-discrimination, a critical but ill-defined molecular process programmed during thymocyte development, requires myriad pre-T cell receptors (preTCRs) and αβTCRs. Using x-ray crystallography, we show how a preTCR applies the concave β-sheet surface of its single variable domain (Vβ) to "horizontally" grab the protruding MHC α2-helix. By contrast, αβTCRs purpose all six complementarity-determining region (CDR) loops of their paired VαVβ module to recognize peptides bound to major histocompatibility complex molecules (pMHCs) in "vertical" head-to-head binding. The preTCR topological fit ensures that CDR3β reaches the peptide's featured C-terminal segment for pMHC sampling, establishing the subsequent αβTCR canonical docking mode. "Horizontal" docking precludes germline CDR1β- and CDR2β-MHC binding to broaden β-chain repertoire diversification before αβTCR-mediated selection refinement. Thus, one subunit successively attunes the recognition logic of related multicomponent receptors.
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Affiliation(s)
- Xiaolong Li
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, USA. .,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Réka Mizsei
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, USA.
| | - Kemin Tan
- Structural Biology Center, X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL, USA
| | - Robert J Mallis
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Dermatology, Harvard Medical School, Boston, MA, USA.,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Jonathan S Duke-Cohan
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Aoi Akitsu
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Paul W Tetteh
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Abhinav Dubey
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.,Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Wonmuk Hwang
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA.,Department of Materials Science & Engineering, Texas A&M University, College Station, TX, USA.,Department of Physics & Astronomy, Texas A&M University, College Station, TX, USA.,School of Computational Sciences, Korea Institute for Advanced Study, Seoul, Republic of Korea
| | - Gerhard Wagner
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Matthew J Lang
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Haribabu Arthanari
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.,Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Jia-Huai Wang
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, USA. .,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.,Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Ellis L Reinherz
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, USA. .,Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Medicine, Harvard Medical School, Boston, MA, USA
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10
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Abstract
Nonclonal innate immune responses mediated by germ line-encoded receptors, such as Toll-like receptors or natural killer receptors, are commonly contrasted with diverse, clonotypic adaptive responses of lymphocyte antigen receptors generated by somatic recombination. However, the Variable (V) regions of antigen receptors include germ line-encoded motifs unaltered by somatic recombination, and theoretically available to mediate nonclonal, innate responses, that are independent of or largely override clonotypic responses. Recent evidence demonstrates that such responses exist, underpinning the associations of particular γδ T cell receptors (TCRs) with specific anatomical sites. Thus, TCRγδ can make innate and adaptive responses with distinct functional outcomes. Given that αβ T cells and B cells can also make nonclonal responses, we consider that innate responses of antigen receptor V-regions may be more widespread, for example, inducing states of preparedness from which adaptive clones are better selected. We likewise consider that potent, nonclonal T cell responses to microbial superantigens may reflect subversion of physiologic innate responses of TCRα/β chains.
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Affiliation(s)
- Adrian C Hayday
- Peter Gorer Department of Immunobiology, King's College, London, SE1 9RT, United Kingdom; .,Immunosurveillance Laboratory, Francis Crick Institute, London, NW1 1AT, United Kingdom
| | - Pierre Vantourout
- Peter Gorer Department of Immunobiology, King's College, London, SE1 9RT, United Kingdom; .,Immunosurveillance Laboratory, Francis Crick Institute, London, NW1 1AT, United Kingdom
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11
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Rushdi M, Li K, Yuan Z, Travaglino S, Grakoui A, Zhu C. Mechanotransduction in T Cell Development, Differentiation and Function. Cells 2020; 9:E364. [PMID: 32033255 PMCID: PMC7072571 DOI: 10.3390/cells9020364] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 01/16/2020] [Accepted: 01/17/2020] [Indexed: 02/07/2023] Open
Abstract
Cells in the body are actively engaging with their environments that include both biochemical and biophysical aspects. The process by which cells convert mechanical stimuli from their environment to intracellular biochemical signals is known as mechanotransduction. Exemplifying the reliance on mechanotransduction for their development, differentiation and function are T cells, which are central to adaptive immune responses. T cell mechanoimmunology is an emerging field that studies how T cells sense, respond and adapt to the mechanical cues that they encounter throughout their life cycle. Here we review different stages of the T cell's life cycle where existing studies have shown important effects of mechanical force or matrix stiffness on a T cell as sensed through its surface molecules, including modulating receptor-ligand interactions, inducing protein conformational changes, triggering signal transduction, amplifying antigen discrimination and ensuring directed targeted cell killing. We suggest that including mechanical considerations in the immunological studies of T cells would inform a more holistic understanding of their development, differentiation and function.
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Affiliation(s)
- Muaz Rushdi
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; (M.R.); (K.L.); (S.T.)
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA;
| | - Kaitao Li
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; (M.R.); (K.L.); (S.T.)
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA;
| | - Zhou Yuan
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA;
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30313, USA
| | - Stefano Travaglino
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; (M.R.); (K.L.); (S.T.)
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA;
| | - Arash Grakoui
- Emory Vaccine Center, Division of Microbiology and Immunology, Yerkes Research Primate Center, Emory University School of Medicine, Atlanta, GA 30329, USA;
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Cheng Zhu
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; (M.R.); (K.L.); (S.T.)
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA;
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30313, USA
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12
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Mallis RJ, Brazin KN, Duke-Cohan JS, Hwang W, Wang JH, Wagner G, Arthanari H, Lang MJ, Reinherz EL. NMR: an essential structural tool for integrative studies of T cell development, pMHC ligand recognition and TCR mechanobiology. JOURNAL OF BIOMOLECULAR NMR 2019; 73:319-332. [PMID: 30815789 PMCID: PMC6693947 DOI: 10.1007/s10858-019-00234-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 02/06/2019] [Indexed: 05/05/2023]
Abstract
Early studies of T cell structural biology using X-ray crystallography, surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC) focused on a picture of the αβT cell receptor (αβTCR) component domains and their cognate ligands (peptides bound to MHC molecules, i.e. pMHCs) as static interaction partners. Moving forward requires integrating this corpus of data with dynamic technologies such as NMR, molecular dynamics (MD) simulations and real-time single molecule (SM) studies exemplified by optical tweezers (OT). NMR bridges relevant timescales and provides the potential for an all-atom dynamic description of αβTCR components prior to and during interactions with binding partners. SM techniques have opened up vistas in understanding the non-equilibrium nature of T cell signaling through the introduction of force-mediated binding measurements into the paradigm for T cell function. In this regard, bioforces consequent to T-lineage cell motility are now perceived as placing piconewton (pN)-level loads on single receptor-pMHC bonds to impact structural change and αβT-lineage biology, including peptide discrimination, cellular activation, and developmental progression. We discuss herein essential NMR technologies in illuminating the role of ligand binding in the preT cell receptor (preTCR), the αβTCR developmental precursor, and convergence of NMR, SM and MD data in advancing our comprehension of T cell development. More broadly we review the central hypothesis that the αβTCR is a mechanosensor, fostered by breakthrough NMR-based structural insights. Collectively, elucidating dynamic aspects through the integrative use of NMR, SM, and MD shall advance fundamental appreciation of the mechanism of T cell signaling as well as inform translational efforts in αβTCR and chimeric T cell (CAR-T) immunotherapies and T cell vaccinology.
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Affiliation(s)
- Robert J Mallis
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA
- Department of Dermatology, Harvard Medical School, Boston, MA, 02115, USA
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
| | - Kristine N Brazin
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
- Department of Medicine, Harvard Medical School, Boston, MA, 02115, USA
| | - Jonathan S Duke-Cohan
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
- Department of Medicine, Harvard Medical School, Boston, MA, 02115, USA
| | - Wonmuk Hwang
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, 77843, USA
- Department of Materials Science & Engineering, Texas A&M University, College Station, TX, 77843, USA
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul, 02455, Republic of Korea
| | - Jia-Huai Wang
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
| | - Gerhard Wagner
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA
| | - Haribabu Arthanari
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA.
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA.
| | - Matthew J Lang
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, 37235, USA.
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN, 37235, USA.
| | - Ellis L Reinherz
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA.
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA.
- Department of Medicine, Harvard Medical School, Boston, MA, 02115, USA.
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13
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Glynn RA, Bassing CH. From RAG2 to T Cell Riches and Future Fortunes. THE JOURNAL OF IMMUNOLOGY 2019; 202:1315-1316. [PMID: 30782849 DOI: 10.4049/jimmunol.1900010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Rebecca A Glynn
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; and Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Craig H Bassing
- Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104; and Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
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14
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Klein F, Mitrovic M, Roux J, Engdahl C, von Muenchow L, Alberti-Servera L, Fehling HJ, Pelczar P, Rolink A, Tsapogas P. The transcription factor Duxbl mediates elimination of pre-T cells that fail β-selection. J Exp Med 2019; 216:638-655. [PMID: 30765463 PMCID: PMC6400535 DOI: 10.1084/jem.20181444] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 12/13/2018] [Accepted: 01/22/2019] [Indexed: 12/13/2022] Open
Abstract
During β-selection, T cells without productive TCRβ rearrangements are eliminated. Klein et al. show that the transcription factor Duxbl regulates this process by inducing apoptosis through activation of the Oas/RNaseL pathway. Successful TCRβ rearrangement rescues cells by pre-TCR–mediated Duxbl suppression. T cell development is critically dependent on successful rearrangement of antigen-receptor chains. At the β-selection checkpoint, only cells with a functional rearrangement continue in development. However, how nonselected T cells proceed in their dead-end fate is not clear. We identified low CD27 expression to mark pre-T cells that have failed to rearrange their β-chain. Expression profiling and single-cell transcriptome clustering identified a developmental trajectory through β-selection and revealed specific expression of the transcription factor Duxbl at a stage of high recombination activity before β-selection. Conditional transgenic expression of Duxbl resulted in a developmental block at the DN3-to-DN4 transition due to reduced proliferation and enhanced apoptosis, whereas RNA silencing of Duxbl led to a decrease in apoptosis. Transcriptome analysis linked Duxbl to elevated expression of the apoptosis-inducing Oas/RNaseL pathway. RNaseL deficiency or sustained Bcl2 expression led to a partial rescue of cells in Duxbl transgenic mice. These findings identify Duxbl as a regulator of β-selection by inducing apoptosis in cells with a nonfunctional rearrangement.
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Affiliation(s)
- Fabian Klein
- Developmental and Molecular Immunology, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Mladen Mitrovic
- Immune Regulation, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Julien Roux
- Bioinformatics Core Facility, Department of Biomedicine, University of Basel, Basel, Switzerland.,Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Corinne Engdahl
- Developmental and Molecular Immunology, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Lilly von Muenchow
- Developmental and Molecular Immunology, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Llucia Alberti-Servera
- Developmental and Molecular Immunology, Department of Biomedicine, University of Basel, Basel, Switzerland
| | | | - Pawel Pelczar
- Center for Transgenic Models, University of Basel, Basel, Switzerland
| | - Antonius Rolink
- Developmental and Molecular Immunology, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Panagiotis Tsapogas
- Developmental and Molecular Immunology, Department of Biomedicine, University of Basel, Basel, Switzerland
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15
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Structural Conservation and Effects of Alterations in T Cell Receptor Transmembrane Interfaces. Biophys J 2018; 114:1030-1035. [PMID: 29395047 DOI: 10.1016/j.bpj.2018.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 12/21/2017] [Accepted: 01/05/2018] [Indexed: 11/20/2022] Open
Abstract
T cell receptors (TCRs) are octameric assemblies of type-I membrane proteins in which a receptor heterodimer (αβ, δγ, or pre-Tαβ) is associated with three dimeric signaling modules (CD3δε, CD3γε, and ζζ) at the T cell or pre-T cell surface. In the human αβTCR, the α and β transmembrane (TM) domains form a specific structure that acts as a hub for assembly with the signaling modules inside the lipid bilayer. Conservation of key polar contacts across the C-terminal half of this TM interface suggests that the structure is a common feature of all TCR types. In this study, using molecular dynamics simulations in explicit lipid bilayers, we show that human δγ and pre-Tαβ TM domains also adopt stable αβ-like interfaces, yet each displays unique features that modulate the stability of the interaction and are related to sequences that are conserved within TCR types, but are distinct from the αβ sequences. We also performed simulations probing effects of previously reported mutations in the human αβ TM interface, and observed that the most disruptive mutations caused substantial departures from the wild-type TM structure and increased dynamics. These simulations show a strong correlation between structural instability, increased conformational variation, and the severity of structural defects in whole-TCR complexes measured in our previous biochemical assays. These results thus support the view that the stability of the core TM structure is a key determinant of TCR structural integrity and suggest that the interface has been evolutionarily optimized for different forms of TCRs.
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16
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Das DK, Mallis RJ, Duke-Cohan JS, Hussey RE, Tetteh PW, Hilton M, Wagner G, Lang MJ, Reinherz EL. Pre-T Cell Receptors (Pre-TCRs) Leverage Vβ Complementarity Determining Regions (CDRs) and Hydrophobic Patch in Mechanosensing Thymic Self-ligands. J Biol Chem 2016; 291:25292-25305. [PMID: 27707880 DOI: 10.1074/jbc.m116.752865] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 09/28/2016] [Indexed: 11/06/2022] Open
Abstract
The pre-T cell receptor (pre-TCR) is a pTα-β heterodimer functioning in early αβ T cell development. Although once thought to be ligand-autonomous, recent studies show that pre-TCRs participate in thymic repertoire formation through recognition of peptides bound to major histocompatibility molecules (pMHC). Using optical tweezers, we probe pre-TCR bonding with pMHC at the single molecule level. Like the αβTCR, the pre-TCR is a mechanosensor undergoing force-based structural transitions that dynamically enhance bond lifetimes and exploiting allosteric control regulated via the Cβ FG loop region. The pre-TCR structural transitions exhibit greater reversibility than TCRαβ and ordered force-bond lifetime curves. Higher piconewton force requires binding through both complementarity determining region loops and hydrophobic Vβ patch apposition. This patch functions in the pre-TCR as a surrogate Vα domain, fostering ligand promiscuity to favor development of β chains with self-reactivity but is occluded by α subunit replacement of pTα upon αβTCR formation. At the double negative 3 thymocyte stage where the pre-TCR is first expressed, pre-TCR interaction with self-pMHC ligands imparts growth and survival advantages as revealed in thymic stromal cultures, imprinting fundamental self-reactivity in the T cell repertoire. Collectively, our data imply the existence of sequential mechanosensor αβTCR repertoire tuning via the pre-TCR.
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Affiliation(s)
- Dibyendu Kumar Das
- From the Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee 37235
| | - Robert J Mallis
- the Departments of Biological Chemistry and Molecular Pharmacology and
| | - Jonathan S Duke-Cohan
- the Department of Medical Oncology, Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, and.,Medicine, Harvard Medical School, and
| | - Rebecca E Hussey
- the Department of Medical Oncology, Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, and
| | - Paul W Tetteh
- the Department of Medical Oncology, Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, and.,Medicine, Harvard Medical School, and
| | - Mark Hilton
- From the Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee 37235
| | - Gerhard Wagner
- the Departments of Biological Chemistry and Molecular Pharmacology and
| | - Matthew J Lang
- From the Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee 37235, .,the Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37235
| | - Ellis L Reinherz
- the Department of Medical Oncology, Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, and .,Medicine, Harvard Medical School, and
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17
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Chang VT, Fernandes RA, Ganzinger KA, Lee SF, Siebold C, McColl J, Jönsson P, Palayret M, Harlos K, Coles CH, Jones EY, Lui Y, Huang E, Gilbert RJC, Klenerman D, Aricescu AR, Davis SJ. Initiation of T cell signaling by CD45 segregation at 'close contacts'. Nat Immunol 2016; 17:574-582. [PMID: 26998761 PMCID: PMC4839504 DOI: 10.1038/ni.3392] [Citation(s) in RCA: 196] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 12/29/2015] [Indexed: 12/14/2022]
Abstract
It has been proposed that the local segregation of kinases and the tyrosine phosphatase CD45 underpins T cell antigen receptor (TCR) triggering, but how such segregation occurs and whether it can initiate signaling is unclear. Using structural and biophysical analysis, we show that the extracellular region of CD45 is rigid and extends beyond the distance spanned by TCR-ligand complexes, implying that sites of TCR-ligand engagement would sterically exclude CD45. We also show that the formation of 'close contacts', new structures characterized by spontaneous CD45 and kinase segregation at the submicron-scale, initiates signaling even when TCR ligands are absent. Our work reveals the structural basis for, and the potent signaling effects of, local CD45 and kinase segregation. TCR ligands have the potential to heighten signaling simply by holding receptors in close contacts.
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Affiliation(s)
- Veronica T Chang
- Radcliffe Department of Medicine and MRC Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Ricardo A Fernandes
- Radcliffe Department of Medicine and MRC Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, United Kingdom
| | | | - Steven F Lee
- Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW
| | - Christian Siebold
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN
| | - James McColl
- Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW
| | - Peter Jönsson
- Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW
| | - Matthieu Palayret
- Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW
| | - Karl Harlos
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN
| | - Charlotte H Coles
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN
| | - E Yvonne Jones
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN
| | - Yuan Lui
- Radcliffe Department of Medicine and MRC Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Elizabeth Huang
- Radcliffe Department of Medicine and MRC Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, United Kingdom
| | - Robert J C Gilbert
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN
| | - David Klenerman
- Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW
| | - A Radu Aricescu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN
| | - Simon J Davis
- Radcliffe Department of Medicine and MRC Human Immunology Unit, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DS, United Kingdom
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18
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Iguchi T, Aoki K, Ikawa T, Taoka M, Taya C, Yoshitani H, Toma-Hirano M, Koiwai O, Isobe T, Kawamoto H, Masai H, Miyatake S. BTB-ZF Protein Znf131 Regulates Cell Growth of Developing and Mature T Cells. THE JOURNAL OF IMMUNOLOGY 2015; 195:982-93. [PMID: 26136427 DOI: 10.4049/jimmunol.1500602] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 05/31/2015] [Indexed: 02/01/2023]
Abstract
Many members of the BTB-ZF family have been shown to play important roles in lymphocyte development and function. The role of zinc finger Znf131 (also known as Zbtb35) in T cell lineage was elucidated through the production of mice with floxed allele to disrupt at different stages of development. In this article, we present that Znf131 is critical for T cell development during double-negative to double-positive stage, with which significant cell expansion triggered by the pre-TCR signal is coupled. In mature T cells, Znf131 is required for the activation of effector genes, as well as robust proliferation induced upon TCR signal. One of the cyclin-dependent kinase inhibitors, p21(Cip1) encoded by cdkn1a gene, is one of the targets of Znf131. The regulation of T cell proliferation by Znf131 is in part attributed to its suppression on the expression of p21(Cip1).
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Affiliation(s)
- Tomohiro Iguchi
- Laboratory of Self Defense Gene Regulation, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
| | - Kazuhisa Aoki
- Laboratory of Self Defense Gene Regulation, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Tomokatsu Ikawa
- Young Chief Investigators Laboratory for Immune Regeneration, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan
| | - Masato Taoka
- Laboratory of Biochemistry, Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan
| | - Choji Taya
- Animal Research Division, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Hiroshi Yoshitani
- Laboratory of Self Defense Gene Regulation, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Makiko Toma-Hirano
- Department of Otolaryngology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Osamu Koiwai
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda 278-8510, Japan
| | - Toshiaki Isobe
- Laboratory of Biochemistry, Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan
| | - Hiroshi Kawamoto
- Department of Immunology, Field of Regeneration Control, Institute of Frontier Medical Sciences, Kyoto University, Kyoto 606-8507, Japan; and
| | - Hisao Masai
- Genome Dynamics Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Shoichiro Miyatake
- Laboratory of Self Defense Gene Regulation, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan;
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19
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Pre-T-cell receptor binds MHC: Implications for thymocyte signaling and selection. Proc Natl Acad Sci U S A 2015; 112:8166-7. [PMID: 26134398 DOI: 10.1073/pnas.1510127112] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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20
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Pre-TCR ligand binding impacts thymocyte development before αβTCR expression. Proc Natl Acad Sci U S A 2015; 112:8373-8. [PMID: 26056289 DOI: 10.1073/pnas.1504971112] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Adaptive cellular immunity requires accurate self- vs. nonself-discrimination to protect against infections and tumorous transformations while at the same time excluding autoimmunity. This vital capability is programmed in the thymus through selection of αβT-cell receptors (αβTCRs) recognizing peptides bound to MHC molecules (pMHC). Here, we show that the pre-TCR (preTCR), a pTα-β heterodimer appearing before αβTCR expression, directs a previously unappreciated initial phase of repertoire selection. Contrasting with the ligand-independent model of preTCR function, we reveal through NMR and bioforce-probe analyses that the β-subunit binds pMHC using Vβ complementarity-determining regions as well as an exposed hydrophobic Vβ patch characteristic of the preTCR. Force-regulated single bonds akin to those of αβTCRs but with more promiscuous ligand specificity trigger calcium flux. Thus, thymic development involves sequential β- and then, αβ-repertoire tuning, whereby preTCR interactions with self pMHC modulate early thymocyte expansion, with implications for β-selection, immunodominant peptide recognition, and germ line-encoded MHC interaction.
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21
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Tan YX, Zikherman J, Weiss A. Novel tools to dissect the dynamic regulation of TCR signaling by the kinase Csk and the phosphatase CD45. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2013; 78:131-139. [PMID: 24100586 DOI: 10.1101/sqb.2013.78.020347] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Although the biochemical events induced by T-cell receptor (TCR) triggering have been well studied, both the mediators and function of basal signaling in T cells remain poorly understood. Furthermore, the precise mechanisms by which MHC-peptide interaction with the TCR disrupt the basal equilibrium to induce downstream signaling are also unclear. Here we describe novel approaches to understand the basal state of T cells and the mechanisms of TCR triggering by perturbing regulation of the Src family kinases (SFKs). The SFKs are critical proximal mediators of TCR signaling that are in turn tightly regulated by the tyrosine kinase Csk and the receptor-like tyrosine phosphatase CD45. We have developed a small-molecule analog-sensitive allele of Csk and an allelic series of mice in which expression of CD45 is varied across a broad range. Our studies have unmasked contributions of Csk and CD45 to maintain the basal state of T cells and also suggest that dynamic regulation of Csk may be involved in TCR triggering.
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Affiliation(s)
- Ying Xim Tan
- Division of Rheumatology, Rosalind Russell Medical Research Center for Arthritis, Department of Medicine, UCSF, San Francisco, CA, 94143, USA
| | - Julie Zikherman
- Division of Rheumatology, Rosalind Russell Medical Research Center for Arthritis, Department of Medicine, UCSF, San Francisco, CA, 94143, USA
| | - Arthur Weiss
- Division of Rheumatology, Rosalind Russell Medical Research Center for Arthritis, Department of Medicine, UCSF, San Francisco, CA, 94143, USA.,Howard Hughes Medical Institute, UCSF, San Francisco, CA, 94143, USA
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22
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Kuhns MS, Badgandi HB. Piecing together the family portrait of TCR-CD3 complexes. Immunol Rev 2013; 250:120-43. [PMID: 23046126 DOI: 10.1111/imr.12000] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The pre-T-cell receptor (TCR)-, αβTCR-, and γδTCR-CD3 complexes are members of a family of modular biosensors that are responsible for driving T-cell development, activation, and effector functions. They inform essential checkpoint decisions by relaying key information from their ligand-binding modules (TCRs) to their signaling modules (CD3γε + CD3δε and CD3ζζ) and on to the intracellular signaling apparatus. Their actions shape the T-cell repertoire, as well as T-cell-mediated immunity; yet, the mechanisms that underlie their activity remain an enigma. As with any molecular machine, understanding how they function depends upon understanding how their parts fit and work together. In the 30 years since the initial biochemical and genetic characterizations of the αβTCR, the structure and function of the individual components of these family members have been extensively characterized. Cumulatively, this information has allowed us to piece together a portrait of the αβTCR-CD3 complex and outline the form of the remaining family members. Here we review the known structural and functional characteristics of the components of these TCR-CD3 complex family members. We then discuss how these data have informed our understanding of the architecture of the αβTCR-CD3 complex as well as their implications for the other family members. The intent is to provide a framework for considering: (i) how these thematically similar complexes diverge to execute their specific functions and (ii) how our knowledge of the form and function of these distinct family members can cross-inform our understanding of the other family members.
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Affiliation(s)
- Michael S Kuhns
- Department of Immunobiology, The University of Arizona College of Medicine, Tucson, USA.
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23
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How the TCR balances sensitivity and specificity for the recognition of self and pathogens. Nat Immunol 2012; 13:121-8. [PMID: 22261968 DOI: 10.1038/ni.2190] [Citation(s) in RCA: 142] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The T cell repertoire is generated during thymic development in preparation for the response to antigens from pathogens. The T cell repertoire is shaped by positive selection, which requires recognition by the T cell antigen receptor (TCR) of complexes of self peptide and major histocompatibility complex proteins (self-pMHC) with low affinity, and negative selection, which eliminates T cells with TCRs that recognize self-pMHC with high affinity. This generates a repertoire with low affinity for self-pMHC but high affinity for foreign antigens. The TCR must successfully engage both of these ligands for development, homeostasis and immune responses. This review discusses mechanisms underlying the interaction of the TCR with peptide-major histocompatibility complex ligands of varying affinity and highlights signaling mechanisms that enable the TCR to generate different responses to very distinct ligands.
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24
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T cell receptor signalling in γδ cell development: strength isn't everything. Trends Immunol 2011; 32:567-73. [PMID: 22056207 DOI: 10.1016/j.it.2011.09.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 09/07/2011] [Accepted: 09/09/2011] [Indexed: 10/15/2022]
Abstract
γδ cells have been conserved across ∼450 million years of evolution, from which they share the distinction, alongside αβ T cells and B cells, of forming antigen receptors by somatic gene recombination. However, much about these cells remains unclear. Indeed, although γδ cells display 'innate-like' characteristics exemplified by rapid tissue-localised responses to stress-associated stimuli, their huge capacity for T cell receptor (TCR)γδ diversity also suggests 'adaptive-like' potential. Clarity requires a better understanding of TCRγδ itself, not only through identification of TCR ligands, but also by correlating thymic TCRγδ signalling with commitment to γδ effector fates. Here, we propose that thymic TCRγδ-ligand engagement versus ligand-independent signalling differentially imprints innate-like versus adaptive-like characteristics on developing γδ cells, which fundamentally dictate their peripheral effector properties.
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25
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Mahtani-Patching J, Neves JF, Pang DJ, Stoenchev KV, Aguirre-Blanco AM, Silva-Santos B, Pennington DJ. PreTCR and TCRγδ signal initiation in thymocyte progenitors does not require domains implicated in receptor oligomerization. Sci Signal 2011; 4:ra47. [PMID: 21775286 PMCID: PMC3475409 DOI: 10.1126/scisignal.2001765] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Whether thymocytes adopt an αβ or a γδ T cell fate in the thymus is determined at the β selection checkpoint by the relatively weak or strong signals that are delivered by either the pre-T cell receptor (preTCR) or the γδ TCR, respectively. Signal initiation at the β selection checkpoint is thought to be independent of ligand engagement of these receptors. Some reports have suggested that receptor oligomerization, which is thought to be mediated by either the immunoglobulin (Ig)-like domain of the preTCRα (pTα) chain or the variable domain of TCRδ, is a unifying mechanism that initiates signaling in early CD4(-)CD8(-) double-negative (DN) thymocyte progenitors. Here, we demonstrate that the extracellular regions of pTα and TCRδ that are implicated in mediating receptor oligomerization were not required for signal initiation from the preTCR or TCRγδ. Indeed, a truncated TCRγδ that lacked all of its extracellular Ig-like domains still formed a signaling-competent TCR that drove cells through the β selection checkpoint. These observations suggest that signal initiation in DN thymocytes is simply a consequence of the surface-pairing of TCR chains, with signal strength being a function of the abundances of surface TCRs. Thus, processes that regulate the surface abundances of TCR complexes in DN cells, such as oligomerization-induced endocytosis, would be predicted to have a major influence in determining whether cells adopt an αβ versus γδ T cell fate.
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Affiliation(s)
- Juliet Mahtani-Patching
- Blizard Institute of Cell and Molecular Science, Barts and The London School of Medicine, Queen Mary University of London, 4 Newark Street, London, E1 2AT, United Kingdom
| | - Joana F. Neves
- Blizard Institute of Cell and Molecular Science, Barts and The London School of Medicine, Queen Mary University of London, 4 Newark Street, London, E1 2AT, United Kingdom
- Programa Doutoral de Biologia Experimental e Biomedicina, Centro de Neurociências e Biologia Celular, Universidade de Coimbra, Coimbra, Portugal
| | - Dick John Pang
- Blizard Institute of Cell and Molecular Science, Barts and The London School of Medicine, Queen Mary University of London, 4 Newark Street, London, E1 2AT, United Kingdom
| | - Kostadin V. Stoenchev
- Blizard Institute of Cell and Molecular Science, Barts and The London School of Medicine, Queen Mary University of London, 4 Newark Street, London, E1 2AT, United Kingdom
| | - Ana M. Aguirre-Blanco
- Blizard Institute of Cell and Molecular Science, Barts and The London School of Medicine, Queen Mary University of London, 4 Newark Street, London, E1 2AT, United Kingdom
| | - Bruno Silva-Santos
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Portugal
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Daniel J. Pennington
- Blizard Institute of Cell and Molecular Science, Barts and The London School of Medicine, Queen Mary University of London, 4 Newark Street, London, E1 2AT, United Kingdom
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26
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Abstract
The negative selection of self-reactive thymocytes depends on the expression of tissue-specific antigens by medullary thymic epithelial cells. The autoimmune regulator (Aire) protein plays an important role in turning on these antigens, and the absence of even one Aire-induced tissue-specific antigen in the thymus can lead to autoimmunity in the antigen-expressing target organ. Recently, Aire protein has been detected in peripheral lymphoid organs, suggesting that peripheral Aire plays a complementary role here. In these peripheral sites, Aire was found to regulate the expression of a group of tissue-specific antigens that is distinct from those expressed in the thymus. Furthermore, transgenic antigen expression in extrathymic Aire-expressing cells (eTACs) can mediate deletional tolerance, but the immunological relevance of Aire-dependent, endogenous tissue-specific antigens remains to be determined.
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Affiliation(s)
- Todd C Metzger
- Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA
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27
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Orlando L, Accomasso L, Circosta P, Turinetto V, Lantelme E, Porcedda P, Minieri V, Pautasso M, Willemsen RA, Cignetti A, Giachino C. TCR transfer induces TCR-mediated tonic inhibition of RAG genes in human T cells. Mol Immunol 2011; 48:1369-76. [PMID: 21481940 DOI: 10.1016/j.molimm.2011.02.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 02/22/2011] [Accepted: 02/24/2011] [Indexed: 11/24/2022]
Abstract
Induction of the TCR signaling pathway terminates the expression of RAG genes, and a link between this pathway and their transcriptional control is evident from the recent demonstration of their re-expression if the TCR is subsequently lost or down-regulated. Since unstimulated T cells display a steady-state level of "tonic" TCR signaling, i.e. in the absence of any antigenic stimulus, it was uncertain whether this control was exerted through ligand-dependent or ligand-independent TCR signaling. Here we demonstrate for the first time that exogenous TCR α and β chains transferred into the human immature RAG(+) T cell line Sup-T1 by lentiviral transduction inhibit RAG expression through tonic signaling, and that this inhibition could itself be reverted by pharmacological tonic pathway inhibitors. We also suggest that mature T cells already expressing an endogenous TCR on their surface maintain some levels of plasticity at the RAG locus when their basal TCR signaling is interfered with. Lastly, we show that the TCR constructs employed in TCR gene therapy do not possess the same basal signaling transduction capability, a feature that may have therapeutic implications.
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Affiliation(s)
- Luca Orlando
- Department of Clinical and Biological Sciences, University of Turin, Orbassano, Italy.
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28
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Berry R, Chen Z, McCluskey J, Rossjohn J. Insight into the basis of autonomous immunoreceptor activation. Trends Immunol 2011; 32:165-70. [PMID: 21354859 DOI: 10.1016/j.it.2011.01.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2010] [Revised: 01/25/2011] [Accepted: 01/27/2011] [Indexed: 12/16/2022]
Abstract
Expression of the pre-T cell receptor (pTCR) by immature thymocytes is crucial for T cell development. The pTCR comprises an invariant pre-Tα chain that pairs with a newly rearranged TCRβ chain and CD3 signaling components. Despite its similarity to the mature αβTCR, which binds to specific peptide-loaded major histocompatibility molecules, the pTCR functions in a ligand-independent manner. Precisely how pTCR functions autonomously has remained a source of intense debate. Recently, the structure of the extracellular domain of the pTCR has been determined, providing insight into the mechanism of pTCR autonomous signaling. In this review, we reflect on the current understanding of pTCR function and draw comparisons to the mechanisms employed by the mature αβTCR and the related pre-B cell receptor.
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Affiliation(s)
- Richard Berry
- The Protein Crystallography Unit, Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Monash University, Clayton, Victoria 3800, Australia
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29
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Germ-line elimination of electric charge on pre-T-cell receptor (TCR) impairs autonomous signaling for beta-selection and TCR repertoire formation. Proc Natl Acad Sci U S A 2010; 107:19979-84. [PMID: 21030681 DOI: 10.1073/pnas.1011228107] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The pre-T-cell receptor (TCR) is crucial for the early T-cell development, but the ligand for pre-TCR remains unidentified. We recently proposed a model that pre-TCR complexes oligomerize spontaneously through interactions of the pre-TCRα chain. To investigate the mechanism underlying this ligand-independent signaling in vivo, we established knock-in mice that express a pre-TCRα mutant lacking charged amino acids (D(22)R(24)R(102)R(117) to A(22)A(24)A(102)A(117); 4A). CD4(+)CD8(+) thymocyte number was significantly reduced in invariant pre-TCRα (pTα(4A/4A)) mice, whereas CD4(-)CD8(-) thymocytes were unaffected. The percentages of double-negative 3 (DN3) cells and γδ T cells were increased in the pTα(4A/4A) thymus, indicating that β-selection is impaired in pTα(4A/4A) mice. Pre-TCR-mediated tyrosine phosphorylation and clonal expansion into double-positive thymocytes were also defective in the knock-in mice. Pre-TCR was expressed at higher levels on pTα(4A/4A) cell surfaces than on those of the wild type, suggesting that the charged residues in pTα are critical for autonomous engagement and subsequent internalization of pre-TCR. Pre-TCR-mediated allelic exclusion of the TCRβ gene was also inhibited in pTα(4A/4A) mice, and thereby, dual TCRβs were expressed on pTα(4A/4A) T cells. Furthermore, the TCRβ chain variable region (Vβ) repertoire of mature T cells was significantly altered in pTα(4A/4A) mice. These results suggest that charged residues of pTα are critical for β-selection, allelic exclusion, and TCRβ repertoire formation.
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30
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Abstract
The thymus produces several types of functionally distinct T cell subsets. However, at a more fundamental level only two genetically distinct T cell lineages exist: the γδ and αß T cell lineages. Precisely how these two T cell lineages are generated from common thymocyte progenitor cells remains to be fully elucidated and is under intense investigation. Here, we highlight recent findings that have helped to provide important clues to the mechanisms that underpin the generation of γδ T cells in the mouse thymus.
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31
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Lee SY, Stadanlick J, Kappes DJ, Wiest DL. Towards a molecular understanding of the differential signals regulating alphabeta/gammadelta T lineage choice. Semin Immunol 2010; 22:237-46. [PMID: 20471282 PMCID: PMC2906684 DOI: 10.1016/j.smim.2010.04.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Accepted: 04/14/2010] [Indexed: 10/19/2022]
Abstract
While insights into the molecular processes that specify adoption of the alphabeta and gammadelta fates are beginning to emerge, the basis for control of specification remains highly controversial. This review highlights the current models attempting to explain T lineage commitment. Recent observations support the hypothesis that the T cell receptor (TCR) provides instructive cues through differences in TCR signaling intensity and/or longevity. Accordingly, we review evidence addressing the importance of differences in signal strength/longevity, how signals differing in intensity/longevity may be generated, and finally how such signals modulate the activity of downstream effectors to promote the opposing developmental fates.
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MESH Headings
- Animals
- Cell Lineage
- Humans
- Models, Immunological
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
- Receptors, Antigen, T-Cell, gamma-delta/immunology
- Receptors, Antigen, T-Cell, gamma-delta/metabolism
- Signal Transduction
- T-Lymphocytes/cytology
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
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Affiliation(s)
- Sang-Yun Lee
- Immune Cell Development and Host Defense Program, Blood Cell Development and Cancer Keystone, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111
| | - Jason Stadanlick
- Immune Cell Development and Host Defense Program, Blood Cell Development and Cancer Keystone, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111
| | - Dietmar J. Kappes
- Immune Cell Development and Host Defense Program, Blood Cell Development and Cancer Keystone, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111
| | - David L. Wiest
- Immune Cell Development and Host Defense Program, Blood Cell Development and Cancer Keystone, Fox Chase Cancer Center, 333 Cottman Avenue, Philadelphia, PA 19111
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32
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Abstract
The development of T cells in the thymus involves several differentiation and proliferation events, during which hematopoietic precursors give rise to T cells ready to respond to antigen stimulation and undergo effector differentiation. This review addresses signaling and transcriptional checkpoints that control the intrathymic journey of T cell precursors. We focus on the divergence of alphabeta and gammadelta lineage cells and the elaboration of the alphabeta T cell repertoire, with special emphasis on the emergence of transcriptional programs that direct lineage decisions.
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MESH Headings
- Animals
- Cell Differentiation/genetics
- Cell Differentiation/immunology
- Cell Lineage
- Gene Expression Regulation/immunology
- Humans
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Receptors, Antigen, T-Cell, gamma-delta/genetics
- Receptors, Antigen, T-Cell, gamma-delta/immunology
- Signal Transduction/genetics
- Signal Transduction/immunology
- T-Lymphocytes/cytology
- T-Lymphocytes/immunology
- Thymus Gland/cytology
- Thymus Gland/immunology
- Transcription, Genetic/genetics
- Transcription, Genetic/immunology
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Affiliation(s)
- Andrea C Carpenter
- Laboratory of Immune Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
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33
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Tremblay M, Tremblay CS, Herblot S, Aplan PD, Hébert J, Perreault C, Hoang T. Modeling T-cell acute lymphoblastic leukemia induced by the SCL and LMO1 oncogenes. Genes Dev 2010; 24:1093-105. [PMID: 20516195 PMCID: PMC2878648 DOI: 10.1101/gad.1897910] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 04/12/2010] [Indexed: 11/25/2022]
Abstract
Deciphering molecular events required for full transformation of normal cells into cancer cells remains a challenge. In T-cell acute lymphoblastic leukemia (T-ALL), the genes encoding the TAL1/SCL and LMO1/2 transcription factors are recurring targets of chromosomal translocations, whereas NOTCH1 is activated in >50% of samples. Here we show that the SCL and LMO1 oncogenes collaborate to expand primitive thymocyte progenitors and inhibit later stages of differentiation. Together with pre-T-cell antigen receptor (pre-TCR) signaling, these oncogenes provide a favorable context for the acquisition of activating Notch1 mutations and the emergence of self-renewing leukemia-initiating cells in T-ALL. All tumor cells harness identical and specific Notch1 mutations and Tcrbeta clonal signature, indicative of clonal dominance and concurring with the observation that Notch1 gain of function confers a selective advantage to SCL-LMO1 transgenic thymocytes. Accordingly, a hyperactive Notch1 allele accelerates leukemia onset induced by SCL-LMO1 and bypasses the requirement for pre-TCR signaling. Finally, the time to leukemia induced by the three transgenes corresponds to the time required for clonal expansion from a single leukemic stem cell, suggesting that SCL, LMO1, and Notch1 gain of function, together with an active pre-TCR, might represent the minimum set of complementing events for the transformation of susceptible thymocytes.
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Affiliation(s)
- Mathieu Tremblay
- Institute of Research in Immunology and Cancer, University of Montreal, Montréal, Québec H3C 3J7, Canada
| | - Cédric S. Tremblay
- Institute of Research in Immunology and Cancer, University of Montreal, Montréal, Québec H3C 3J7, Canada
| | - Sabine Herblot
- Institute of Research in Immunology and Cancer, University of Montreal, Montréal, Québec H3C 3J7, Canada
| | - Peter D. Aplan
- Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892, USA
| | - Josée Hébert
- Banque de Cellules Leucémiques du Québec, Maisonneuve-Rosemont Hospital, Montréal, Québec H1T 2M4, Canada
| | - Claude Perreault
- Institute of Research in Immunology and Cancer, University of Montreal, Montréal, Québec H3C 3J7, Canada
| | - Trang Hoang
- Institute of Research in Immunology and Cancer, University of Montreal, Montréal, Québec H3C 3J7, Canada
- Department of Pharmacology, Faculty of Medicine, University of Montréal, Montréal, Québec H3C 3J7, Canada
- Department of Biochemistry, Faculty of Medicine, University of Montréal, Montréal, Québec H3C 3J7, Canada
- Department of Molecular Biology, Faculty of Medicine, University of Montréal, Montréal, Québec H3C 3J7, Canada
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34
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Zikherman J, Jenne C, Watson S, Doan K, Raschke W, Goodnow CC, Weiss A. CD45-Csk phosphatase-kinase titration uncouples basal and inducible T cell receptor signaling during thymic development. Immunity 2010; 32:342-54. [PMID: 20346773 DOI: 10.1016/j.immuni.2010.03.006] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Revised: 11/23/2009] [Accepted: 12/29/2009] [Indexed: 12/18/2022]
Abstract
The kinase-phosphatase pair Csk and CD45 reciprocally regulate phosphorylation of the inhibitory tyrosine of the Src family kinases Lck and Fyn. T cell receptor (TCR) signaling and thymic development require CD45 expression but proceed constitutively in the absence of Csk. Here, we show that relative titration of CD45 and Csk expression reveals distinct regulation of basal and inducible TCR signaling during thymic development. Low CD45 expression is sufficient to rescue inducible TCR signaling and positive selection, whereas high expression is required to reconstitute basal TCR signaling and beta selection. CD45 has a dual positive and negative regulatory role during inducible but not basal TCR signaling. By contrast, Csk titration regulates basal but not inducible signaling. High physiologic expression of CD45 is thus required for two reasons-to downmodulate inducible TCR signaling during positive selection and to counteract Csk during basal TCR signaling.
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Affiliation(s)
- Julie Zikherman
- Division of Rheumatology, University of California San Francisco, San Francisco, CA 94143, USA
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35
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Differential subcellular localization regulates c-Cbl E3 ligase activity upon Notch3 protein in T-cell leukemia. Oncogene 2009; 29:1463-74. [PMID: 19966856 DOI: 10.1038/onc.2009.446] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Notch3 and pTalpha signaling events are essential for T-cell leukemogenesis and characterize murine and human T-cell acute lymphoblastic leukemia. Genetic ablation of pTalpha expression in Notch3 transgenic mice abrogates tumor development, indicating that pTalpha signaling is crucial to the Notch3-mediated leukemogenesis. Here we report a novel direct interaction between Notch3 and pTalpha. This interaction leads to the recruitment and persistence of the E3 ligase protein c-Cbl to the lipid rafts in Notch3-IC transgenic thymocytes. Conversely, deletion of pTalpha in Notch3 transgenic mice leads to cytoplasmic retention of c-Cbl that targets Notch3 protein to the proteasomal-degradative pathway. It appears that protein kinase C theta (PKCtheta), by regulating tyrosine and serine phosphorylation of Cbl, is able to control its function. We report here that the increased Notch3-IC degradation correlates with higher levels of c-Cbl tyrosine phosphorylation in Notch3-IC/pTalpha(-/-) double-mutant thymocytes, which also display a decreased PKCtheta activity. Our data indicate that pTalpha/pre-T-cell receptor is able to regulate the different subcellular localization of c-Cbl and, by regulating PKCtheta activity, is also able to influence its ubiquitin ligase activity upon Notch3 protein.
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36
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Bezman NA, Baker RG, Lenox LE, Jordan MS, Koretzky GA. Cutting edge: rescue of pre-TCR but not mature TCR signaling in mice expressing membrane-targeted SLP-76. THE JOURNAL OF IMMUNOLOGY 2009; 182:5183-7. [PMID: 19380761 DOI: 10.4049/jimmunol.0802176] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
SLP-76 (Src homology 2 domain-containing leukocyte phosphoprotein of 76 kDa) organizes signaling from immunoreceptors, including the platelet collagen receptor, the pre-TCR, and the TCR, and is required for T cell development. In this study we examine a mouse in which wild-type SLP-76 is replaced with a mutant constitutively targeted to the cell membrane. Membrane-targeted SLP-76 (MTS) supports ITAM signaling in platelets and from the pre-TCR. Signaling from the mature TCR, however, is defective in MTS thymocytes, resulting in failed T cell differentiation. Defective thymic selection by MTS is not rescued by a SLP-76 mutant whose localization is restricted to the cytosol. Thus, fixed localization of SLP-76 reveals differential requirements for the subcellular localization of signaling complexes downstream of the pre-TCR vs mature TCR.
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Affiliation(s)
- Natalie A Bezman
- Abramson Family Cancer Research Institute, Philadelphia, PA 19104, USA
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37
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Wiest DL. Identification of the last cog in a ligand-independent signaling machine? THE JOURNAL OF IMMUNOLOGY 2009; 182:5163-4. [PMID: 19380757 DOI: 10.4049/jimmunol.0990028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- David L Wiest
- Blood Cell Development and Cancer Program, Fox Chase Cancer Center, Room 390, Reimann Building, 333 Cottman Avenue, Philadelphia, PA 19111-2497, USA.
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38
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Melenhorst JJ, Lay MDH, Price DA, Adams SD, Zeilah J, Sosa E, Hensel NF, Follmann D, Douek DC, Davenport MP, Barrett AJ. Contribution of TCR-beta locus and HLA to the shape of the mature human Vbeta repertoire. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2008; 180:6484-9. [PMID: 18453566 DOI: 10.4049/jimmunol.180.10.6484] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
T cells that survive thymic selection express a diverse array of unique heterodimeric alphabeta TCRs that mediate peptide-MHC Ag recognition. The proportion of the total T cell repertoire that expresses a particular Vbeta protein may be determined by a variety of factors: 1) germline preference for use of particular Vbeta genes; 2) allelic effects on the expression of different Vbeta genes; and 3) HLA effects on the expression of different Vbeta genes (acting via thymic selection and/or peripheral mechanisms). In this study, we show that Vbeta usage by human CD4(+) and CD8(+) T cells in neonatal and adult donors is highly correlated between unrelated individuals, suggesting that a large proportion of the observed pattern of Vbeta expression is determined by factors intrinsic to the TCR-beta locus. The presence of identical TCR alleles (within an individual) leads to a significantly better correlation between CD4(+) and CD8(+) T cells with respect to Vbeta expression; these effects are, however, relatively minor. The sharing of HLA alleles between individuals also leads to an increased correlation between their Vbeta expression patterns, although this did not reach statistical significance. We therefore conclude that the correlation in Vbeta expression patterns between CD4(+) and CD8(+) T cells can be explained predominantly by germline TCR-beta locus factors and not TCR-beta allelic or HLA effects.
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Affiliation(s)
- J Joseph Melenhorst
- Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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39
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Croxford AL, Akilli-Ozturk O, Rieux-Laucat F, Förster I, Waisman A, Buch T. MHC-restricted T cell receptor signaling is required for alpha beta TCR replacement of the pre T cell receptor. Eur J Immunol 2008; 38:391-9. [PMID: 18203137 DOI: 10.1002/eji.200737054] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A developmental block is imposed on CD25(+)CD44(-) thymocytes at the beta-selection checkpoint in the absence of the pre T cell receptor (preTCR) alpha-chain, pTalpha. Early surface expression of a transgenic alphabeta TCR has been shown to partially circumvent this block, such that thymocytes progress to the CD4(+)CD8(+) double-positive stage. We wanted to analyze whether a restricting MHC element is required for alphabeta TCR-expressing double-negative (DN) thymocytes to overcome the developmental block in pTalpha-deficient animals. We used the HY-I knock-in model that endows thymocytes with alphabeta TCR expression in the DN compartment but has the advantage of physiological expression levels, in contrast to conventional TCR transgenes. On a pTalpha-deficient background, this HY-I TCR transgene 'rescued' CD25(+)CD44(-) thymocytes from apoptosis and enabled progression to later differentiation stages. On a non-selecting MHC background, however, pTalpha-deficient HY-I mice presented a pronounced reduction in numbers of splenocytes and thymocytes when compared to animals of selecting MHC genotype, showing that MHC restriction is necessary to drive HY-TCR-mediated rescue of pTalpha-deficient thymocytes.
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MESH Headings
- Animals
- Female
- H-2 Antigens/genetics
- H-2 Antigens/immunology
- H-Y Antigen/genetics
- H-Y Antigen/immunology
- Histocompatibility Antigen H-2D
- Lymphopoiesis/genetics
- Lymphopoiesis/immunology
- Male
- Membrane Glycoproteins/deficiency
- Membrane Glycoproteins/genetics
- Membrane Glycoproteins/metabolism
- Mice
- Mice, Inbred BALB C
- Mice, Knockout
- Mice, Transgenic
- Models, Immunological
- Receptors, Antigen, T-Cell, alpha-beta/deficiency
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
- Signal Transduction/genetics
- Signal Transduction/immunology
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
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40
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Ferrera D, Panigada M, Porcellini S, Grassi F. Recombinase-deficient T cell development by selective accumulation of CD3 into lipid rafts. Eur J Immunol 2008; 38:1148-56. [DOI: 10.1002/eji.200737917] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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41
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Abstract
Like all hematopoietic cells, T lymphocytes are derived from bone-marrow-resident stem cells. However, whereas most blood lineages are generated within the marrow, the majority of T cell development occurs in a specialized organ, the thymus. This distinction underscores the unique capacity of the thymic microenvironment to support T lineage restriction and differentiation. Although the identity of many of the contributing thymus-derived signals is well established and rooted in highly conserved pathways involving Notch, morphogenetic, and protein tyrosine kinase signals, the manner in which the ensuing cascades are integrated to orchestrate the underlying processes of T cell development remains under investigation. This review focuses on the current definition of the early stages of T cell lymphopoiesis, with an emphasis on the nature of thymus-derived signals delivered to T cell progenitors that support the commitment and differentiation of T cells toward the alphabeta and gammadelta T cell lineages.
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Affiliation(s)
- Maria Ciofani
- Molecular Pathogenesis Program, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, USA.
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42
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Grande SM, Bannish G, Fuentes-Panana EM, Katz E, Monroe JG. Tonic B-cell and viral ITAM signaling: context is everything. Immunol Rev 2007; 218:214-34. [PMID: 17624955 DOI: 10.1111/j.1600-065x.2007.00535.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The presence of an immunoreceptor tyrosine-based activation motif (ITAM) makes immunoreceptors different from other signaling receptors, like integrins, G-coupled protein receptors, chemokine receptors, and growth factor receptors. This unique motif has the canonical sequence D/Ex(0-2)YxxL/Ix(6-8)YxxL/I, where x represents any amino acid and is present at least once in all immunoreceptor complexes. Immunoreceptors can promote survival, activation, and differentiation by transducing signals through these highly conserved motifs. Traditionally, ITAM signaling is thought to occur in response to ligand-induced aggregation, although evidence indicates that ligand-independent tonic signaling also provides functionally relevant signals. The majority of proteins containing ITAMs are transmembrane proteins that exist as part of immunoreceptor complexes. However, oncogenic viruses also have ITAM-containing proteins. In this review, we discuss what is known about tonic signaling by both cellular and viral ITAM-containing proteins and speculate what we might learn from each context.
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Affiliation(s)
- Shannon M Grande
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
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43
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Navarro MN, Nusspaumer G, Fuentes P, González-García S, Alcain J, Toribio ML. Identification of CMS as a cytosolic adaptor of the human pTalpha chain involved in pre-TCR function. Blood 2007; 110:4331-40. [PMID: 17823309 DOI: 10.1182/blood-2007-06-094938] [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: 02/06/2023] Open
Abstract
The T-cell receptor beta (TCRbeta)/pre-TCRalpha (pTalpha) pre-TCR complex (pre-TCR) signals the expansion and differentiation of de-veloping thymocytes. Functional pro-perties of the pre-TCR rely on its unique pTalpha chain, which suggests the participation of specific intracellular adaptors. However, pTalpha-interacting molecules remain unknown. Here, we identified a polyproline-arginine sequence in the human pTalpha cytoplasmic tail that interacted in vitro with SH3 domains of the CIN85/CMS family of adaptors, and mediated the recruitment of multiprotein complexes involving all (CMS, CIN85, and CD2BP3) members. Supporting the physiologic relevance of this interaction, we found that 1 such adaptor, CMS, interacted in vivo with human pTalpha, and its expression was selectively up-regulated during human thymopoiesis in pre-TCR-activated thymocytes. Upon activation, pre-TCR clustering was induced, and CMS and polymerized actin were simultaneously recruited to the pre-TCR activation site. CMS also associated via its C-terminal region to the actin cytoskeleton in the endocytic compartment, where it colocalized with internalized pTalpha in traffic to lysosomal degradation. Notably, deletion of the pTalpha CIN85/CMS-binding motif impaired pre-TCR-mediated Ca(2+) mobilization and NFAT transcriptional activity, and precluded activation induced by overexpression of a CMS-SH3 N-terminal mutant. These results provide the first molecular evidence for a pTalpha intracellular adaptor involved in pre-TCR function.
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Affiliation(s)
- María N Navarro
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain
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44
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Abstract
The spleen tyrosine kinase (Syk) and ζ-associated protein of 70 kD (ZAP-70) tyrosine kinases are both expressed during early thymocyte development, but their unique thymic functions have remained obscure. No specific role for Syk during β-selection has been established, and no role has been described for ZAP-70 before positive selection. We show that Syk and ZAP-70 provide thymocytes with unique and separable fitness advantages during early development. Syk-deficient, but not ZAP-70–deficient, thymocytes are specifically impaired in initial pre-TCR signaling at the double-negative (DN) 3 β selection stage and show reduced cell-cycle entry. Surprisingly, and despite overlapping expression of both kinases, only ZAP-70 appears to promote sustained pre-TCR/TCR signaling during the DN4, immature single-positive, and double-positive stages of development before thymic selection occurs. ZAP-70 promotes survival and cell-cycle progression of developing thymocytes before positive selection, as also shown by in vivo anti-CD3 treatment of recombinase-activating gene 1–deficient mice. Our results establish a temporal separation of Syk family kinase function during early thymocyte development and a novel role for ZAP-70. We propose that pre-TCR signaling continues during DN4 and later stages, with ZAP-70 dynamically replacing Syk for continued pre-TCR signaling.
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Affiliation(s)
- Emil H Palacios
- Department of Medicine, the Rosalind Russell Medical Research Center for Arthritis, University of California-San Francisco, San Francisco, CA 94143, USA
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Petrie HT, Zúñiga-Pflücker JC. Zoned out: functional mapping of stromal signaling microenvironments in the thymus. Annu Rev Immunol 2007; 25:649-79. [PMID: 17291187 DOI: 10.1146/annurev.immunol.23.021704.115715] [Citation(s) in RCA: 339] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
All hematopoietic cells, including T lymphocytes, originate from stem cells that reside in the bone marrow. Most hematopoietic lineages also mature in the bone marrow, but in this respect, T lymphocytes differ. Under normal circumstances, most T lymphocytes are produced in the thymus from marrow-derived progenitors that circulate in the blood. Cells that home to the thymus from the marrow possess the potential to generate multiple T and non-T lineages. However, there is little evidence to suggest that, once inside the thymus, they give rise to anything other than T cells. Thus, signals unique to the thymic microenvironment compel multipotent progenitors to commit to the T lineage, at the expense of other potential lineages. Summarizing what is known about the signals the thymus delivers to uncommitted progenitors, or to immature T-committed progenitors, to produce functional T cells is the focus of this review.
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Affiliation(s)
- Howard T Petrie
- Scripps Florida Research Institute, Jupiter, Florida 33458, USA.
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Miosge L, Zamoyska R. Signalling in T-cell development: is it all location, location, location? Curr Opin Immunol 2007; 19:194-9. [PMID: 17306519 DOI: 10.1016/j.coi.2007.02.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2006] [Accepted: 02/02/2007] [Indexed: 12/31/2022]
Abstract
During thymocyte development, signals through the pre-T-cell receptor induce proliferation and differentiation at early stages of maturation; thereafter, signals through the alphabeta T-cell receptor complex mediate positive and negative selection and commitment to the CD4 or CD8 lineage. How these signals are initiated, the transduction pathways involved, and ultimately how gene transcription is regulated are current active areas of research. Recent literature highlights the importance of geography to thymocyte differentiation: first, in relation to the ability of the developing thymocyte to traffic to localities within the thymus in which particular selection events occur and which are crucial for successful T-cell maturation; and, second, in respect to the subcellular localisation of intracellular signalling molecules, which might provide the key to understanding how similar signals can be translated into dramatically distinct fates, such as positive selection, lineage commitment and negative selection.
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Affiliation(s)
- Lisa Miosge
- Molecular Immunology, MRC National Institute for Medical Research, The Ridgeway, London NW71AA, United Kingdom
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Falahati R, Leitenberg D. Changes in the Role of the CD45 Protein Tyrosine Phosphatase in Regulating Lck Tyrosine Phosphorylation during Thymic Development. THE JOURNAL OF IMMUNOLOGY 2007; 178:2056-64. [PMID: 17277109 DOI: 10.4049/jimmunol.178.4.2056] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
CD45-dependent dephosphorylation of the negative regulatory C-terminal tyrosine of the Src family kinase Lck, promotes efficient TCR signal transduction. However, despite the role of CD45 in positively regulating Lck activity, the distinct phenotypes of CD45 and Lck/Fyn-deficient mice suggest that the role of CD45 in promoting Lck activity may be differentially regulated during thymocyte development. In this study, we have found that the C-terminal tyrosine of Lck (Y505) is markedly hyperphosphorylated in total thymocytes from CD45-deficient mice compared with control animals. In contrast, regulation of the Lck Y505 phosphorylation in purified, double-negative thymocytes is relatively unaffected in CD45-deficient cells. These changes in the role of CD45 in regulating Lck phosphorylation during thymocyte development correlate with changes in coreceptor expression and the presence of coreceptor-associated Lck. Biochemical analysis of coreceptor-associated and nonassociated Lck in thymocytes, and in cell lines varying in CD4 and CD45 expression, indicate that CD45-dependent regulation of Lck Y505 phosphorylation is most evident within the fraction of Lck that is coreceptor associated. In contrast, Lck Y505 phosphorylation that is not coreceptor associated is less affected by the absence of CD45. These data define distinct pools of Lck that are differentially regulated by CD45 during T cell development.
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Affiliation(s)
- Rustom Falahati
- Department of Microbiology, Immunology, and Tropical Medicine, George Washington University, Washington, DC 20037
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48
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Yamasaki S, Saito T. Molecular basis for pre-TCR-mediated autonomous signaling. Trends Immunol 2007; 28:39-43. [PMID: 17126602 DOI: 10.1016/j.it.2006.11.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Revised: 10/27/2006] [Accepted: 11/16/2006] [Indexed: 02/05/2023]
Abstract
The pre-T-cell receptor (pre-TCR) is a multimeric complex composed of a nascent TCRbeta chain, an invariant pre-TCRalpha (pTalpha) chain and CD3 molecules, and is crucial for early T-cell development. Despite its structural similarity to the mature alphabetaTCR, which requires MHC-antigen for receptor triggering, the pre-TCR is proposed to initiate signals in a ligand-independent manner. However, the molecular mechanism underlying the autonomous signaling is still unclear. Recent studies have revealed that pTalpha possesses unique characteristics that promote autonomous signaling. In this review, we summarize current data relating to the molecular mechanism underlying the initiation of pre-TCR-mediated autonomous signaling.
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Affiliation(s)
- Sho Yamasaki
- Laboratory for Cell Signaling, RIKEN Research Center for Allergy and Immunology, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.
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49
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Abstract
Rap1 (Ras-proximity 1), a member of the Ras family of small guanine triphosphatases (GTPases), is activated by diverse extracellular stimuli. While Rap1 has been discovered originally as a potential Ras antagonist, accumulating evidence indicates that Rap1 per se mediates unique signals and exerts biological functions distinctly different from Ras. Rap1 plays a dominant role in the control of cell-cell and cell-matrix interactions by regulating the function of integrins and other adhesion molecules in various cell types. Rap1 also regulates MAP kinase (MAPK) activity in a manner highly dependent on the context of cell types. Recent studies (including gene-targeting analysis) have uncovered that the Rap1 signal is integrated crucially and unpredictably in the diverse aspects of comprehensive biological systems. This review summarizes the role of the Rap1 signal in developments and functions of the immune and hematopoietic systems as well as in malignancy. Importantly, Rap1 activation is tightly regulated in tissue cells, and dysregulations of the Rap1 signal in specific tissues result in certain disorders, including myeloproliferative disorders and leukemia, platelet dysfunction with defective hemostasis, leukocyte adhesion-deficiency syndrome, lupus-like systemic autoimmune disease, and T cell anergy. Many of these disorders resemble human diseases, and the Rap1 signal with its regulators may provide rational molecular targets for controlling certain human diseases including malignancy.
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Affiliation(s)
- Nagahiro Minato
- Department of Immunology and Cell Biology, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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Lauritsen JPH, Haks MC, Lefebvre JM, Kappes DJ, Wiest DL. Recent insights into the signals that control alphabeta/gammadelta-lineage fate. Immunol Rev 2006; 209:176-90. [PMID: 16448543 DOI: 10.1111/j.0105-2896.2006.00349.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
During thymopoiesis, two major types of mature T cells are generated that can be distinguished by the clonotypic subunits contained within their T-cell receptor (TCR) complexes: alphabeta T cells and gammadelta T cells. Although there is no consensus as to the exact developmental stage where alphabeta and gammadelta T-cell lineages diverge, gammadelta T cells and precursors to the alphabeta T-cell lineage (bearing the pre-TCR) are thought to be derived from a common CD4- CD8- double-negative precursor. The role of the TCR in alphabeta/gammadelta lineage commitment has been controversial, in particular whether different TCR isotypes intrinsically favor adoption of the corresponding lineage. Recent evidence supports a signal strength model of lineage commitment, whereby stronger signals promote gammadelta development and weaker signals promote adoption of the alphabeta fate, irrespective of the TCR isotype from which the signals originate. Moreover, differences in the amplitude of activation of the extracellular signal-regulated kinase- mitogen-activated protein kinase-early growth response pathway appear to play a critical role. These findings will be placed in context of previous analyses in an effort to more precisely define the signals that control T-lineage fate during thymocyte development.
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Affiliation(s)
- Jens Peter H Lauritsen
- Fox Chase Cancer Center, Division of Basic Sciences, Immunobiology Working Group, Philadelphia, PA 19111, USA
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