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Rogers J, Bajur AT, Salaita K, Spillane KM. Mechanical control of antigen detection and discrimination by T and B cell receptors. Biophys J 2024; 123:2234-2255. [PMID: 38794795 PMCID: PMC11331051 DOI: 10.1016/j.bpj.2024.05.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 05/10/2024] [Accepted: 05/21/2024] [Indexed: 05/26/2024] Open
Abstract
The adaptive immune response is orchestrated by just two cell types, T cells and B cells. Both cells possess the remarkable ability to recognize virtually any antigen through their respective antigen receptors-the T cell receptor (TCR) and B cell receptor (BCR). Despite extensive investigations into the biochemical signaling events triggered by antigen recognition in these cells, our ability to predict or control the outcome of T and B cell activation remains elusive. This challenge is compounded by the sensitivity of T and B cells to the biophysical properties of antigens and the cells presenting them-a phenomenon we are just beginning to understand. Recent insights underscore the central role of mechanical forces in this process, governing the conformation, signaling activity, and spatial organization of TCRs and BCRs within the cell membrane, ultimately eliciting distinct cellular responses. Traditionally, T cells and B cells have been studied independently, with researchers working in parallel to decipher the mechanisms of activation. While these investigations have unveiled many overlaps in how these cell types sense and respond to antigens, notable differences exist. To fully grasp their biology and harness it for therapeutic purposes, these distinctions must be considered. This review compares and contrasts the TCR and BCR, placing emphasis on the role of mechanical force in regulating the activity of both receptors to shape cellular and humoral adaptive immune responses.
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Affiliation(s)
- Jhordan Rogers
- Department of Chemistry, Emory University, Atlanta, Georgia
| | - Anna T Bajur
- Department of Physics, King's College London, London, United Kingdom; Randall Centre for Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Khalid Salaita
- Department of Chemistry, Emory University, Atlanta, Georgia; Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia.
| | - Katelyn M Spillane
- Department of Physics, King's College London, London, United Kingdom; Randall Centre for Cell and Molecular Biophysics, King's College London, London, United Kingdom; Department of Life Sciences, Imperial College London, London, United Kingdom.
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2
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Wilhelm KB, Vissa A, Groves JT. Differential Roles of Kinetic On- and Off-Rates in T-Cell Receptor Signal Integration Revealed with a Modified Fab'-DNA Ligand. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.01.587588. [PMID: 38617215 PMCID: PMC11014569 DOI: 10.1101/2024.04.01.587588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
Antibody-derived T-cell receptor (TCR) agonists are commonly used to activate T cells. While antibodies can trigger TCRs regardless of clonotype, they bypass native T cell signal integration mechanisms that rely on monovalent, membrane-associated, and relatively weakly-binding ligand in the context of cellular adhesion. Commonly used antibodies and their derivatives bind much more strongly than native peptide-MHC (pMHC) ligands bind their cognate TCRs. Because ligand dwell time is a critical parameter that tightly correlates with physiological function of the TCR signaling system, there is a general need, both in research and therapeutics, for universal TCR ligands with controlled kinetic binding parameters. To this end, we have introduced point mutations into recombinantly expressed α-TCRβ H57 Fab to modulate the dwell time of monovalent Fab binding to TCR. When tethered to a supported lipid bilayer via DNA complementation, these monovalent Fab'-DNA ligands activate T cells with potencies well-correlated with their TCR binding dwell time. Single-molecule tracking studies in live T cells reveal that individual binding events between Fab'-DNA ligands and TCRs elicit local signaling responses closely resembling native pMHC. The unique combination of high on- and off-rate of the H57 R97L mutant enables direct observations of cooperative interplay between ligand binding and TCR-proximal condensation of the linker for activation of T cells (LAT), which is not readily visualized with pMHC. This work provides insights into how T cells integrate kinetic information from synthetic ligands and introduces a method to develop affinity panels for polyclonal T cells, such as cells from a human patient.
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Affiliation(s)
- Kiera B Wilhelm
- Department of Chemistry, University of California-Berkeley, Berkeley, CA, 93720
| | - Anand Vissa
- Department of Chemistry, University of California-Berkeley, Berkeley, CA, 93720
| | - Jay T Groves
- Department of Chemistry, University of California-Berkeley, Berkeley, CA, 93720
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3
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Giguère S, Wang X, Huber S, Xu L, Warner J, Weldon SR, Hu J, Phan QA, Tumang K, Prum T, Ma D, Kirsch KH, Nair U, Dedon P, Batista FD. Antibody production relies on the tRNA inosine wobble modification to meet biased codon demand. Science 2024; 383:205-211. [PMID: 38207021 PMCID: PMC10954030 DOI: 10.1126/science.adi1763] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 11/27/2023] [Indexed: 01/13/2024]
Abstract
Antibodies are produced at high rates to provide immunoprotection, which puts pressure on the B cell translational machinery. Here, we identified a pattern of codon usage conserved across antibody genes. One feature thereof is the hyperutilization of codons that lack genome-encoded Watson-Crick transfer RNAs (tRNAs), instead relying on the posttranscriptional tRNA modification inosine (I34), which expands the decoding capacity of specific tRNAs through wobbling. Antibody-secreting cells had increased I34 levels and were more reliant on I34 for protein production than naïve B cells. Furthermore, antibody I34-dependent codon usage may influence B cell passage through regulatory checkpoints. Our work elucidates the interface between the tRNA pool and protein production in the immune system and has implications for the design and selection of antibodies for vaccines and therapeutics.
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Affiliation(s)
- Sophie Giguère
- The Ragon Institute of Mass General, MIT, and Harvard, Cambridge, MA 02139, USA
| | - Xuesong Wang
- The Ragon Institute of Mass General, MIT, and Harvard, Cambridge, MA 02139, USA
| | - Sabrina Huber
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Liling Xu
- The Ragon Institute of Mass General, MIT, and Harvard, Cambridge, MA 02139, USA
| | - John Warner
- The Ragon Institute of Mass General, MIT, and Harvard, Cambridge, MA 02139, USA
| | - Stephanie R. Weldon
- The Ragon Institute of Mass General, MIT, and Harvard, Cambridge, MA 02139, USA
| | - Jennifer Hu
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Quynh Anh Phan
- The Ragon Institute of Mass General, MIT, and Harvard, Cambridge, MA 02139, USA
| | - Katie Tumang
- The Ragon Institute of Mass General, MIT, and Harvard, Cambridge, MA 02139, USA
| | - Thavaleak Prum
- The Ragon Institute of Mass General, MIT, and Harvard, Cambridge, MA 02139, USA
| | - Duanduan Ma
- BioMicro Center, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Kathrin H. Kirsch
- The Ragon Institute of Mass General, MIT, and Harvard, Cambridge, MA 02139, USA
| | - Usha Nair
- The Ragon Institute of Mass General, MIT, and Harvard, Cambridge, MA 02139, USA
| | - Peter Dedon
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Singapore-MIT Alliance for Research and Technology, Singapore 138602
| | - Facundo D. Batista
- The Ragon Institute of Mass General, MIT, and Harvard, Cambridge, MA 02139, USA
- Department of Immunology, Harvard Medical School, Boston, MA 02115, USA
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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4
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Yao M, Liu X, Qian Z, Fan D, Sun X, Zhong L, Wu P. Research progress of nanovaccine in anti-tumor immunotherapy. Front Oncol 2023; 13:1211262. [PMID: 37692854 PMCID: PMC10484753 DOI: 10.3389/fonc.2023.1211262] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 08/07/2023] [Indexed: 09/12/2023] Open
Abstract
Tumor vaccines aim to activate dormant or unresponsive tumor-specific T lymphocytes by using tumor-specific or tumor-associated antigens, thus enhancing the body's natural defense against cancer. However, the effectiveness of tumor vaccines is limited by the presence of tumor heterogeneity, low immunogenicity, and immune evasion mechanisms. Fortunately, multifunctional nanoparticles offer a unique chance to address these issues. With the advantages of their small size, high stability, efficient drug delivery, and controlled surface chemistry, nanomaterials can precisely target tumor sites, improve the delivery of tumor antigens and immune adjuvants, reshape the immunosuppressive tumor microenvironment, and enhance the body's anti-tumor immune response, resulting in improved efficacy and reduced side effects. Nanovaccine, a type of vaccine that uses nanotechnology to deliver antigens and adjuvants to immune cells, has emerged as a promising strategy for cancer immunotherapy due to its ability to stimulate immune responses and induce tumor-specific immunity. In this review, we discussed the compositions and types of nanovaccine, and the mechanisms behind their anti-tumor effects based on the latest research. We hope that this will provide a more scientific basis for designing tumor vaccines and enhancing the effectiveness of tumor immunotherapy.
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Affiliation(s)
- Min Yao
- State Key Laboratory of Targeting Oncology, National Center for International Research of Bio-targeting Theranostics, Guangxi Key Laboratory of Bio-targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, Guangxi, China
| | - Xiyu Liu
- State Key Laboratory of Targeting Oncology, National Center for International Research of Bio-targeting Theranostics, Guangxi Key Laboratory of Bio-targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, Guangxi, China
| | - Zhangbo Qian
- State Key Laboratory of Targeting Oncology, National Center for International Research of Bio-targeting Theranostics, Guangxi Key Laboratory of Bio-targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, Guangxi, China
| | - Dianfa Fan
- State Key Laboratory of Targeting Oncology, National Center for International Research of Bio-targeting Theranostics, Guangxi Key Laboratory of Bio-targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, Guangxi, China
| | - Xinjun Sun
- State Key Laboratory of Targeting Oncology, National Center for International Research of Bio-targeting Theranostics, Guangxi Key Laboratory of Bio-targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, Guangxi, China
| | - Liping Zhong
- State Key Laboratory of Targeting Oncology, National Center for International Research of Bio-targeting Theranostics, Guangxi Key Laboratory of Bio-targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, Guangxi, China
| | - Pan Wu
- State Key Laboratory of Targeting Oncology, National Center for International Research of Bio-targeting Theranostics, Guangxi Key Laboratory of Bio-targeting Theranostics, Collaborative Innovation Center for Targeting Tumor Diagnosis and Therapy, Guangxi Medical University, Nanning, Guangxi, China
- Pharmaceutical College, Guangxi Medical University, Nanning, Guangxi, China
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Feng L, Gao YY, Sun M, Li ZB, Zhang Q, Yang J, Qiao C, Jin H, Feng HS, Xian YH, Qi J, Gao GF, Liu WJ, Gao FS. The Parallel Presentation of Two Functional CTL Epitopes Derived from the O and Asia 1 Serotypes of Foot-and-Mouth Disease Virus and Swine SLA-2*HB01: Implications for Universal Vaccine Development. Cells 2022; 11:cells11244017. [PMID: 36552780 PMCID: PMC9777387 DOI: 10.3390/cells11244017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 12/06/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022] Open
Abstract
Foot-and-mouth disease virus (FMDV) poses a significant threat to the livestock industry. Through their recognition of the conserved epitopes presented by the swine leukocyte antigen (SLA), T cells play a pivotal role in the antiviral immunity of pigs. Herein, based on the peptide binding motif of SLA-2*HB01, from an original SLA-2 allele, a series of functional T-cell epitopes derived from the dominant antigen VP1 of FMDV with high binding capacity to SLA-2 were identified. Two parallel peptides, Hu64 and As64, from the O and Asia I serotypes, respectively, were both crystallized with SLA-2*HB01. Compared to SLA-1 and SLA-3, the SLA-2 structures showed the flexibility of residues in the P4, P6, and P8 positions and in their potential interface with TCR. Notably, the peptides Hu64 and As64 adopted quite similar overall conformation when bound to SLA-2*HB01. Hu64 has two different conformations, a more stable 'chair' conformation and an unstable 'boat' conformation observed in the two molecules of one asymmetric unit, whereas only a single 'chair' conformation was observed for As64. Both Hu64 and As64 could induce similar dominant T-cell activities. Our interdisciplinary study establishes a basis for the in-depth interpretation of the peptide presentation of SLA-I, which can be used toward the development of universal vaccines.
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Affiliation(s)
- Lei Feng
- Department of Bioengineering, College of Life and Health, Dalian University, Dalian 116622, China
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing 100101, China
| | - Yong-Yu Gao
- Department of Bioengineering, College of Life and Health, Dalian University, Dalian 116622, China
- College of Animal Medicine, Jilin Agricultural University, Changchun 130118, China
| | - Mingwei Sun
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing 100101, China
| | - Zi-Bin Li
- Department of Bioengineering, College of Life and Health, Dalian University, Dalian 116622, China
- Department of Microbiology and Immunology, College of Veterinary Medicine, China Agricultural University, Beijing 100094, China
| | - Qiang Zhang
- State Key Laboratory of Veterinary Etiological Biology, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730046, China
| | - Jie Yang
- Department of Bioengineering, College of Life and Health, Dalian University, Dalian 116622, China
- NHC Key Laboratory of Biosafety, Research Unit of Adaptive Evolution and Control of Emerging Viruses, Chinese Academy of Medical Sciences, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
| | - Cui Qiao
- Department of Bioengineering, College of Life and Health, Dalian University, Dalian 116622, China
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing 100101, China
| | - Hang Jin
- Department of Bioengineering, College of Life and Health, Dalian University, Dalian 116622, China
| | - Hong-Sheng Feng
- Department of Bioengineering, College of Life and Health, Dalian University, Dalian 116622, China
| | - Yu-Han Xian
- Department of Bioengineering, College of Life and Health, Dalian University, Dalian 116622, China
| | - Jianxun Qi
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing 100101, China
| | - George F. Gao
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing 100101, China
- NHC Key Laboratory of Biosafety, Research Unit of Adaptive Evolution and Control of Emerging Viruses, Chinese Academy of Medical Sciences, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
- Correspondence: (G.F.G.); (W.J.L.); (F.-S.G.)
| | - William J. Liu
- NHC Key Laboratory of Biosafety, Research Unit of Adaptive Evolution and Control of Emerging Viruses, Chinese Academy of Medical Sciences, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China
- Correspondence: (G.F.G.); (W.J.L.); (F.-S.G.)
| | - Feng-Shan Gao
- Department of Bioengineering, College of Life and Health, Dalian University, Dalian 116622, China
- Correspondence: (G.F.G.); (W.J.L.); (F.-S.G.)
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6
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Wilhelm KB, Morita S, McAffee DB, Kim S, O'Dair MK, Groves JT. Height, but not binding epitope, affects the potency of synthetic TCR agonists. Biophys J 2021; 120:3869-3880. [PMID: 34453921 PMCID: PMC8511163 DOI: 10.1016/j.bpj.2021.08.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/16/2021] [Accepted: 08/20/2021] [Indexed: 12/27/2022] Open
Abstract
Under physiological conditions, peptide-major histocompatibility complex (pMHC) molecules can trigger T cell receptors (TCRs) as monovalent ligands that are sparsely distributed on the plasma membrane of an antigen-presenting cell. TCRs can also be triggered by artificial clustering, such as with pMHC tetramers or antibodies; however, these strategies circumvent many of the natural ligand discrimination mechanisms of the T cell and can elicit nonphysiological signaling activity. We have recently introduced a synthetic TCR agonist composed of an anti-TCRβ Fab′ antibody fragment covalently bound to a DNA oligonucleotide, which serves as a membrane anchor. This Fab′-DNA ligand efficiently triggers TCR as a monomer when membrane associated and exhibits a potency and activation profile resembling agonist pMHC. In this report, we explore the geometric requirements for efficient TCR triggering and cellular activation by Fab′-DNA ligands. We find that T cells are insensitive to the ligand binding epitope on the TCR complex but that length of the DNA tether is important. Increasing, the intermembrane distance spanned by Fab′-DNA:TCR complexes decreases TCR triggering efficiency and T cell activation potency, consistent with the kinetic-segregation model of TCR triggering. These results establish design parameters for constructing synthetic TCR agonists that are able to activate polyclonal T cell populations, such as T cells from a human patient, in a similar manner as the native pMHC ligand.
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Affiliation(s)
- Kiera B Wilhelm
- Department of Chemistry, University of California, Berkeley, California
| | - Shumpei Morita
- Department of Chemistry, University of California, Berkeley, California
| | - Darren B McAffee
- Department of Chemistry, University of California, Berkeley, California
| | - Sungi Kim
- Department of Chemistry, University of California, Berkeley, California
| | - Mark K O'Dair
- Department of Chemistry, University of California, Berkeley, California
| | - Jay T Groves
- Department of Chemistry, University of California, Berkeley, California.
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7
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Characterization and modulation of anti-αβTCR antibodies and their respective binding sites at the βTCR chain to enrich engineered T cells. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2021; 22:388-400. [PMID: 34514030 PMCID: PMC8411211 DOI: 10.1016/j.omtm.2021.06.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 06/10/2021] [Indexed: 12/14/2022]
Abstract
T cell engineering strategies offer cures to patients and have entered clinical practice with chimeric antibody-based receptors; αβT cell receptor (αβTCR)-based strategies are, however, lagging behind. To allow a more rapid and successful translation to successful concepts also using αβTCRs for engineering, incorporating a method for the purification of genetically modified T cells, as well as engineered T cell deletion after transfer into patients, could be beneficial. This would allow increased efficacy, reduced potential side effects, and improved safety of newly to-be-tested lead structures. By characterizing the antigen-binding interface of a good manufacturing process (GMP)-grade anti-αβTCR antibody, usually used for depletion of αβT cells from stem cell transplantation products, we developed a strategy that allows for the purification of untouched αβTCR-engineered immune cells by changing 2 amino acids only in the TCRβ chain constant domain of introduced TCR chains. Alternatively, we engineered an antibody that targets an extended mutated interface of 9 amino acids in the TCRβ chain constant domain and provides the opportunity to further develop depletion strategies of engineered immune cells.
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Pandey PR, Różycki B, Lipowsky R, Weikl TR. Structural variability and concerted motions of the T cell receptor - CD3 complex. eLife 2021; 10:e67195. [PMID: 34490842 PMCID: PMC8504971 DOI: 10.7554/elife.67195] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 09/06/2021] [Indexed: 11/28/2022] Open
Abstract
We investigate the structural and orientational variability of the membrane-embedded T cell receptor (TCR) - CD3 complex in extensive atomistic molecular dynamics simulations based on the recent cryo-EM structure determined by Dong et al., 2019. We find that the TCR extracellular (EC) domain is highly variable in its orientation by attaining tilt angles relative to the membrane normal that range from 15° to 55°. The tilt angle of the TCR EC domain is both coupled to a rotation of the domain and to characteristic changes throughout the TCR - CD3 complex, in particular in the EC interactions of the Cβ FG loop of the TCR, as well as in the orientation of transmembrane helices. The concerted motions of the membrane-embedded TCR - CD3 complex revealed in our simulations provide atomistic insights on conformational changes of the complex in response to tilt-inducing forces on antigen-bound TCRs.
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MESH Headings
- CD3 Complex/metabolism
- CD3 Complex/ultrastructure
- Cell Membrane/metabolism
- Cell Membrane/ultrastructure
- Cryoelectron Microscopy
- Humans
- Molecular Dynamics Simulation
- Protein Binding
- Protein Conformation, alpha-Helical
- Receptor-CD3 Complex, Antigen, T-Cell/metabolism
- Receptor-CD3 Complex, Antigen, T-Cell/ultrastructure
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
- Receptors, Antigen, T-Cell, alpha-beta/ultrastructure
- Structure-Activity Relationship
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- T-Lymphocytes/ultrastructure
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Affiliation(s)
- Prithvi R Pandey
- Max Planck Institute of Colloids and Interfaces, Department of Theory and Bio-SystemsPotsdamGermany
| | - Bartosz Różycki
- Institute of Physics, Polish Academy of SciencesWarsawPoland
| | - Reinhard Lipowsky
- Max Planck Institute of Colloids and Interfaces, Department of Theory and Bio-SystemsPotsdamGermany
| | - Thomas R Weikl
- Max Planck Institute of Colloids and Interfaces, Department of Theory and Bio-SystemsPotsdamGermany
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Molecular design of the γδT cell receptor ectodomain encodes biologically fit ligand recognition in the absence of mechanosensing. Proc Natl Acad Sci U S A 2021; 118:2023050118. [PMID: 34172580 PMCID: PMC8256041 DOI: 10.1073/pnas.2023050118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
TCR mechanosensing is thought necessary for digital sensitivity of αβT cell response to scant pMHC antigens. We use bioinformatic analysis, molecular dynamics, single-molecule optical tweezers techniques, cellular activation, and RNA-seq analysis to explore this paradigm in the γδT cell lineage. We find that, in keeping with its role in recognizing abundant cell-surface ligands, the γδTCR lacks force-dependent hallmarks of mechanosensing in αβT cells. High-acuity αβT cell receptor (TCR) recognition of peptides bound to major histocompatibility complex molecules (pMHCs) requires mechanosensing, a process whereby piconewton (pN) bioforces exert physical load on αβTCR–pMHC bonds to dynamically alter their lifetimes and foster digital sensitivity cellular signaling. While mechanotransduction is operative for both αβTCRs and pre-TCRs within the αβT lineage, its role in γδT cells is unknown. Here, we show that the human DP10.7 γδTCR specific for the sulfoglycolipid sulfatide bound to CD1d only sustains a significant load and undergoes force-induced structural transitions when the binding interface-distal γδ constant domain (C) module is replaced with that of αβ. The chimeric γδ–αβTCR also signals more robustly than does the wild-type (WT) γδTCR, as revealed by RNA-sequencing (RNA-seq) analysis of TCR-transduced Rag2−/− thymocytes, consistent with structural, single-molecule, and molecular dynamics studies reflective of γδTCRs as mediating recognition via a more canonical immunoglobulin-like receptor interaction. Absence of robust, force-related catch bonds, as well as γδTCR structural transitions, implies that γδT cells do not use mechanosensing for ligand recognition. This distinction is consonant with the fact that their innate-type ligands, including markers of cellular stress, are expressed at a high copy number relative to the sparse pMHC ligands of αβT cells arrayed on activating target cells. We posit that mechanosensing emerged over ∼200 million years of vertebrate evolution to fulfill indispensable adaptive immune recognition requirements for pMHC in the αβT cell lineage that are unnecessary for the γδT cell lineage mechanism of non-pMHC ligand detection.
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10
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The αβTCR mechanosensor exploits dynamic ectodomain allostery to optimize its ligand recognition site. Proc Natl Acad Sci U S A 2020; 117:21336-21345. [PMID: 32796106 DOI: 10.1073/pnas.2005899117] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Each [Formula: see text]T cell receptor (TCR) functions as a mechanosensor. The TCR is comprised of a clonotypic TCR[Formula: see text] ligand-binding heterodimer and the noncovalently associated CD3 signaling subunits. When bound by ligand, an antigenic peptide arrayed by a major histocompatibility complex molecule (pMHC), the TCR[Formula: see text] has a longer bond lifetime under piconewton-level loads. The atomistic mechanism of this "catch bond" behavior is unknown. Here, we perform molecular dynamics simulation of a TCR[Formula: see text]-pMHC complex and its variants under physiologic loads to identify this mechanism and any attendant TCR[Formula: see text] domain allostery. The TCR[Formula: see text]-pMHC interface is dynamically maintained by contacts with a spectrum of occupancies, introducing a level of control via relative motion between Vα and Vβ variable domains containing the pMHC-binding complementarity-determining region (CDR) loops. Without adequate load, the interfacial contacts are unstable, whereas applying sufficient load suppresses Vα-Vβ motion, stabilizing the interface. A second level of control is exerted by Cα and Cβ constant domains, especially Cβ and its protruding FG-loop, that create mismatching interfaces among the four TCR[Formula: see text] domains and with a pMHC ligand. Applied load enhances fit through deformation of the TCR[Formula: see text] molecule. Thus, the catch bond involves the entire TCR[Formula: see text] conformation, interdomain motion, and interfacial contact dynamics, collectively. This multilayered architecture of the machinery fosters fine-tuning of cellular response to load and pMHC recognition. Since the germline-derived TCR[Formula: see text] ectodomain is structurally conserved, the proposed mechanism can be universally adopted to operate under load during immune surveillance by diverse [Formula: see text]TCRs constituting the T cell repertoire.
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11
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Wang JH. T cell receptors, mechanosensors, catch bonds and immunotherapy. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2020; 153:23-27. [DOI: 10.1016/j.pbiomolbio.2020.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 01/15/2020] [Indexed: 12/28/2022]
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12
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Lin JJ, O'Donoghue GP, Wilhelm KB, Coyle MP, Low-Nam ST, Fay NC, Alfieri KN, Groves JT. Membrane Association Transforms an Inert Anti-TCRβ Fab' Ligand into a Potent T Cell Receptor Agonist. Biophys J 2020; 118:2879-2893. [PMID: 32407684 DOI: 10.1016/j.bpj.2020.04.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 03/09/2020] [Accepted: 04/13/2020] [Indexed: 12/27/2022] Open
Abstract
The natural peptide-major histocompatibility complex (pMHC) ligand for T cell receptors (TCRs) is inactive from solution yet capable of activating T cells at single-molecule levels when membrane-associated. This distinctive feature stems from the mechanism of TCR activation, which is thought to involve steric phosphatase exclusion as well as direct mechanical forces. It is possible to defeat this mechanism and activate T cells with solution ligands by cross-linking pMHC or using multivalent antibodies to TCR. However, these widely used strategies activate TCRs through a nonphysiological mechanism and can produce different activation profiles than natural, monovalent, membrane-associated pMHC. Here, we introduce a strictly monovalent anti-TCRβ H57 Fab' ligand that, when coupled to a supported lipid bilayer via DNA complementation, triggers TCRs and activates nuclear translocation of the transcription factor nuclear factor of activated T cells (NFAT) with a similar potency to pMHC in primary murine T cells. Importantly, like monovalent pMHC and unlike bivalent antibodies, monovalent Fab'-DNA triggers TCRs only when physically coupled to the membrane, and only around 100 individual Fab':TCR interactions are necessary to stimulate early T cell activation.
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Affiliation(s)
- Jenny J Lin
- Department of Chemistry, University of California, Berkeley, Berkeley, California
| | - Geoff P O'Donoghue
- Department of Chemistry, University of California, Berkeley, Berkeley, California.
| | - Kiera B Wilhelm
- Department of Chemistry, University of California, Berkeley, Berkeley, California
| | - Michael P Coyle
- Department of Chemistry, University of California, Berkeley, Berkeley, California.
| | - Shalini T Low-Nam
- Department of Chemistry, University of California, Berkeley, Berkeley, California
| | - Nicole C Fay
- Department of Molecular and Cellular Biology, University of California, Berkeley, Berkeley, California
| | - Katherine N Alfieri
- Department of Chemistry, University of California, Berkeley, Berkeley, California
| | - Jay T Groves
- Department of Chemistry, University of California, Berkeley, Berkeley, California.
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13
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Xu X, Li H, Xu C. Structural understanding of T cell receptor triggering. Cell Mol Immunol 2020; 17:193-202. [PMID: 32047259 PMCID: PMC7052162 DOI: 10.1038/s41423-020-0367-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 01/08/2020] [Indexed: 11/09/2022] Open
Abstract
The T cell receptor (TCR) is one of the most complicated receptors in mammalian cells, and its triggering mechanism remains mysterious. As an octamer complex, TCR comprises an antigen-binding subunit (TCRαβ) and three CD3 signaling subunits (CD3ζζ, CD3δε, and CD3γε). Engagement of TCRαβ with an antigen peptide presented on the MHC leads to tyrosine phosphorylation of the immunoreceptor tyrosine-based activation motif (ITAM) in CD3 cytoplasmic domains (CDs), thus translating extracellular binding kinetics to intracellular signaling events. Whether conformational change plays an important role in the transmembrane signal transduction of TCR is under debate. Attracted by the complexity and functional importance of TCR, many groups have been studying TCR structure and triggering for decades using diverse biochemical and biophysical tools. Here, we synthesize these structural studies and discuss the relevance of the conformational change model in TCR triggering.
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Affiliation(s)
- Xinyi Xu
- State Key Laboratory of Molecular Biology, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, 200031, Shanghai, China
| | - Hua Li
- State Key Laboratory of Molecular Biology, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, 200031, Shanghai, China
| | - Chenqi Xu
- State Key Laboratory of Molecular Biology, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, 320 Yueyang Road, 200031, Shanghai, China.
- School of Life Science and Technology, ShanghaiTech University, 100 Haike Road, 201210, Shanghai, China.
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14
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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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15
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Miller ML, McIntosh CM, Williams JB, Wang Y, Hollinger MK, Isaad NJ, Moon JJ, Gajewski TF, Chong AS, Alegre ML. Distinct Graft-Specific TCR Avidity Profiles during Acute Rejection and Tolerance. Cell Rep 2018; 24:2112-2126. [PMID: 30134172 PMCID: PMC6142813 DOI: 10.1016/j.celrep.2018.07.067] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 06/19/2018] [Accepted: 07/18/2018] [Indexed: 11/17/2022] Open
Abstract
Mechanisms implicated in robust transplantation tolerance at the cellular level can be broadly categorized into those that inhibit alloreactive T cells intrinsically (clonal deletion and dysfunction) or extrinsically through regulation. Here, we investigated whether additional population-level mechanisms control T cells by examining whether therapeutically induced peripheral transplantation tolerance could influence T cell populations' avidity for alloantigens. Whereas T cells with high avidity preferentially accumulated during acute rejection of allografts, the alloreactive T cells in tolerant recipients retained a low-avidity profile, comparable to naive mice despite evidence of activation. These contrasting avidity profiles upon productive versus tolerogenic stimulation were durable and persisted upon alloantigen re-encounter in the absence of any immunosuppression. Thus, peripheral transplantation tolerance involves control of alloreactive T cells at the population level, in addition to the individual cell level. Controlling expansion or eliminating high-affinity, donor-specific T cells long term may be desirable to achieve robust transplantation tolerance in the clinic.
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Affiliation(s)
- Michelle L Miller
- Department of Medicine, Section of Rheumatology, The University of Chicago, Chicago, IL 60637, USA
| | - Christine M McIntosh
- Department of Medicine, Section of Rheumatology, The University of Chicago, Chicago, IL 60637, USA
| | - Jason B Williams
- Department of Pathology, The University of Chicago, Chicago, IL 60637, USA
| | - Ying Wang
- Department of Medicine, Section of Rheumatology, The University of Chicago, Chicago, IL 60637, USA
| | - Maile K Hollinger
- Department of Medicine, Section of Rheumatology, The University of Chicago, Chicago, IL 60637, USA
| | - Noel J Isaad
- Department of Medicine, Section of Rheumatology, The University of Chicago, Chicago, IL 60637, USA
| | - James J Moon
- Center for Immunology and Inflammatory Diseases and Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Charlestown, MA 02129, USA; Harvard Medical School, Charlestown, MA 02129, USA
| | - Thomas F Gajewski
- Department of Pathology, The University of Chicago, Chicago, IL 60637, USA
| | - Anita S Chong
- Department of Surgery, Section of Transplantation, The University of Chicago, Chicago, IL 60637, USA
| | - Maria-Luisa Alegre
- Department of Medicine, Section of Rheumatology, The University of Chicago, Chicago, IL 60637, USA.
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16
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Feng Y, Reinherz EL, Lang MJ. αβ T Cell Receptor Mechanosensing Forces out Serial Engagement. Trends Immunol 2018; 39:596-609. [PMID: 30060805 PMCID: PMC6154790 DOI: 10.1016/j.it.2018.05.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 05/15/2018] [Accepted: 05/31/2018] [Indexed: 11/08/2022]
Abstract
T lymphocytes use αβ T cell receptors (TCRs) to recognize
sparse antigenic peptides bound to MHC molecules (pMHCs) arrayed on
antigen-presenting cells (APCs). Contrary to conventional receptor–ligand
associations exemplified by antigen-antibody interactions, forces play a crucial
role in nonequilibrium mechanosensor-based T cell activation. Both T cell
motility and local cytoskeleton machinery exert forces (i.e., generate loads) on
TCR–pMHC bonds. We review biological features of the load-dependent
activation process as revealed by optical tweezers single molecule/single cell
and other biophysical measurements. The findings link pMHC-triggered TCRs to
single cytoskeletal motors; define the importance of energized anisotropic
(i.e., force direction dependent) activation; and characterize immunological
synapse formation as digital, revealing no serial requirement. The emerging
picture suggests new approaches for the monitoring and design of cytotoxic T
lymphocyte (CTL)-based immunotherapy.
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Affiliation(s)
- Yinnian Feng
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235, USA
| | - Ellis L Reinherz
- Laboratory of Immunobiology and Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA; Department of Medicine, Harvard Medical School, 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.
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17
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Mallis RJ, Arthanari H, Lang MJ, Reinherz EL, Wagner G. NMR-directed design of pre-TCRβ and pMHC molecules implies a distinct geometry for pre-TCR relative to αβTCR recognition of pMHC. J Biol Chem 2017; 293:754-766. [PMID: 29101227 DOI: 10.1074/jbc.m117.813493] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 10/20/2017] [Indexed: 11/06/2022] Open
Abstract
The pre-T cell receptor (pre-TCR) guides early thymocytes through maturation processes within the thymus via interaction with self-ligands displayed on thymic epithelial cells. The pre-TCR is a disulfide-linked heterodimer composed of an invariant pre-TCR α (pTα) subunit and a variable β subunit, the latter of which is incorporated into the mature TCR in subsequent developmental progression. This interaction of pre-TCR with peptide-major histocompatibility complex (pMHC) molecules has recently been shown to drive robust pre-TCR signaling and thymocyte maturation. Although the native sequences of β are properly folded and suitable for NMR studies in isolation, a tendency to self-associate rendered binding studies with physiological ligands difficult to interpret. Consequently, to structurally define this critical interaction, we have re-engineered the extracellular regions of β, designated as β-c1, for prokaryotic production to be used in NMR spectroscopy. Given the large size of the full extracellular domain of class I MHC molecules such as H-Kb, we produced a truncated form termed Kb-t harboring properties favorable for NMR measurements. This system has enabled robust measurement of a pre-TCR-pMHC interaction directly analogous to that of TCRαβ-pMHC. Binding surface analysis identified a contact surface comparable in size to that of the TCRαβ-pMHC but potentially with a rather distinct binding orientation. A tilting of the pre-TCRβ when bound to the pMHC ligand recognition surface versus the upright orientation of TCRαβ would alter the direction of force application between pre-TCR and TCR mechanosensors, impacting signal initiation.
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Affiliation(s)
- Robert J Mallis
- From the Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115
| | - Haribabu Arthanari
- From the Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115.,Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115
| | - Matthew J Lang
- Department of Chemical and Biomolecular Engineering, Vanderbilt University and Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37235, and
| | - Ellis L Reinherz
- Department of Medical Oncology, Laboratory of Immunobiology, Dana-Farber Cancer Institute and Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115
| | - Gerhard Wagner
- From the Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115,
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18
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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: 47] [Impact Index Per Article: 5.9] [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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19
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García-Guerrero E, Pérez-Simón JA, Sánchez-Abarca LI, Díaz-Moreno I, De la Rosa MA, Díaz-Quintana A. The Dynamics of the Human Leukocyte Antigen Head Domain Modulates Its Recognition by the T-Cell Receptor. PLoS One 2016; 11:e0154219. [PMID: 27124285 PMCID: PMC4849770 DOI: 10.1371/journal.pone.0154219] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 04/11/2016] [Indexed: 01/13/2023] Open
Abstract
Generating the immune response requires the discrimination of peptides presented by the human leukocyte antigen complex (HLA) through the T-cell receptor (TCR). However, how a single amino acid substitution in the antigen bonded to HLA affects the response of T cells remains uncertain. Hence, we used molecular dynamics computations to analyze the molecular interactions between peptides, HLA and TCR. We compared immunologically reactive complexes with non-reactive and weakly reactive complexes. MD trajectories were produced to simulate the behavior of isolated components of the various p-HLA-TCR complexes. Analysis of the fluctuations showed that p-HLA binding barely restrains TCR motions, and mainly affects the CDR3 loops. Conversely, inactive p-HLA complexes displayed significant drop in their dynamics when compared with its free versus ternary forms (p-HLA-TCR). In agreement, the free non-reactive p-HLA complexes showed a lower amount of salt bridges than the responsive ones. This resulted in differences between the electrostatic potentials of reactive and inactive p-HLA species and larger vibrational entropies in non-elicitor complexes. Analysis of the ternary p-HLA-TCR complexes also revealed a larger number of salt bridges in the responsive complexes. To summarize, our computations indicate that the affinity of each p-HLA complex towards TCR is intimately linked to both, the dynamics of its free species and its ability to form specific intermolecular salt-bridges in the ternary complexes. Of outstanding interest is the emerging concept of antigen reactivity involving its interplay with the HLA head sidechain dynamics by rearranging its salt-bridges.
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Affiliation(s)
- Estefanía García-Guerrero
- Instituto de Biomedicina de Sevilla (IBIS)/Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
| | - José Antonio Pérez-Simón
- Instituto de Biomedicina de Sevilla (IBIS)/Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
- * E-mail: (ADQ); (JAPS)
| | | | - Irene Díaz-Moreno
- Instituto de Bioquímica Vegetal y Fotosíntesis, cicCartuja, Universidad de Sevilla—CSIC, Seville, Spain
| | - Miguel A. De la Rosa
- Instituto de Bioquímica Vegetal y Fotosíntesis, cicCartuja, Universidad de Sevilla—CSIC, Seville, Spain
| | - Antonio Díaz-Quintana
- Instituto de Bioquímica Vegetal y Fotosíntesis, cicCartuja, Universidad de Sevilla—CSIC, Seville, Spain
- * E-mail: (ADQ); (JAPS)
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20
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Mallis RJ, Reinherz EL, Wagner G, Arthanari H. Backbone resonance assignment of N15, N30 and D10 T cell receptor β subunits. BIOMOLECULAR NMR ASSIGNMENTS 2016; 10:35-9. [PMID: 26275917 PMCID: PMC4767692 DOI: 10.1007/s12104-015-9632-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 08/11/2015] [Indexed: 05/21/2023]
Abstract
The αβT Cell receptor (TCR) governs T cell immunity through its interaction with peptide bound to major histocompatibility complex molecules (pMHC). Previously, soluble ectodomain constructs have been used to elucidate the binding mode of the TCR for the MHC. However, the full heterodimeric αβTCR has proven difficult to produce reproducibly in recombinant systems to the extent seen in the routine production of novel antibodies. Particularly, the route of production in E. coli, which is most convenient for isotopic labeling of proteins, is challenging for a wide range of αβTCR, including N15αβ, N30αβ, but not D10αβ. With the aim of understanding the TCR-pMHC interaction through the use of dynamic binding measurements, we set out to produce TCRβ subunits with which we could investigate binding with pMHC. The TCRβ constructs are more readily produced and refolded than their αβ counterparts and have proven to be an effective model of preTCR in pMHC binding studies. As a first step towards characterizing potential interactions with protein ligands, we have assigned the backbone resonances of three TCRβ subunits, N15β, N30β and D10β.
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Affiliation(s)
- Robert J Mallis
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA
| | - Ellis L Reinherz
- Laboratory of Immunobiology, Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, 02115, USA
- Department of Medicine, 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.
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21
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Suzuki Y, Schmitt MJ. Redox diversity in ERAD-mediated protein retrotranslocation from the endoplasmic reticulum: a complex puzzle. Biol Chem 2016; 396:539-54. [PMID: 25741737 DOI: 10.1515/hsz-2014-0299] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 02/23/2015] [Indexed: 11/15/2022]
Abstract
Misfolded and incorrectly assembled proteins in the secretory pathway are eliminated by ubiquitylation and proteasomal degradation in a process known as ER-associated degradation (ERAD). Retrotranslocation of diverse substrates including misfolded proteins and viruses occurs through channels in the ER membrane, which are also utilized for host cell penetration by A/B class protein toxins such as cholera toxin, ricin or K28. According to the current view, disulfide-bonded proteins must either be reduced or rearranged to ensure translocation competence and entry into the cytosol from the ER. As the underlying mechanisms are still largely mysterious, we here focus on the redox status and disulfide isomerization of ERAD substrates and the role of oxidoreductases in the essential process of ER-to-cytosol retrotranslocation.
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22
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Brazin KN, Mallis RJ, Das DK, Feng Y, Hwang W, Wang JH, Wagner G, Lang MJ, Reinherz EL. Structural Features of the αβTCR Mechanotransduction Apparatus That Promote pMHC Discrimination. Front Immunol 2015; 6:441. [PMID: 26388869 PMCID: PMC4558533 DOI: 10.3389/fimmu.2015.00441] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 08/14/2015] [Indexed: 12/20/2022] Open
Abstract
The αβTCR was recently revealed to function as a mechanoreceptor. That is, it leverages mechanical energy generated during immune surveillance and at the immunological synapse to drive biochemical signaling following ligation by a specific foreign peptide-MHC complex (pMHC). Here, we review the structural features that optimize this transmembrane (TM) receptor for mechanotransduction. Specialized adaptations include (1) the CβFG loop region positioned between Vβ and Cβ domains that allosterically gates both dynamic T cell receptor (TCR)-pMHC bond formation and lifetime; (2) the rigid super β-sheet amalgams of heterodimeric CD3εγ and CD3εδ ectodomain components of the αβTCR complex; (3) the αβTCR subunit connecting peptides linking the extracellular and TM segments, particularly the oxidized CxxC motif in each CD3 heterodimeric subunit that facilitates force transfer through the TM segments and surrounding lipid, impacting cytoplasmic tail conformation; and (4) quaternary changes in the αβTCR complex that accompany pMHC ligation under load. How bioforces foster specific αβTCR-based pMHC discrimination and why dynamic bond formation is a primary basis for kinetic proofreading are discussed. We suggest that the details of the molecular rearrangements of individual αβTCR subunit components can be analyzed utilizing a combination of structural biology, single-molecule FRET, optical tweezers, and nanobiology, guided by insightful atomistic molecular dynamic studies. Finally, we review very recent data showing that the pre-TCR complex employs a similar mechanobiology to that of the αβTCR to interact with self-pMHC ligands, impacting early thymic repertoire selection prior to the CD4(+)CD8(+) double positive thymocyte stage of development.
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Affiliation(s)
- Kristine N. Brazin
- Laboratory of Immunobiology, Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Robert J. Mallis
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Dibyendu Kumar Das
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA
| | - Yinnian Feng
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN, USA
| | - Wonmuk Hwang
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
- Department of Materials Science and Engineering, Texas A&M University, College Station, TX, USA
- School of Computational Sciences, Korea Institute for Advanced Study, Seoul, South Korea
| | - Jia-huai Wang
- Laboratory of Immunobiology, Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - 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
| | - Ellis L. Reinherz
- Laboratory of Immunobiology, Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
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23
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Abstract
The structure and amino acid diversity of the T-cell receptor (TCR), similar in nature to that of Fab portions of antibodies, would suggest that these proteins have a nearly infinite capacity to recognize antigen. Yet all currently defined native T cells expressing an α and β chain in their TCR can only sense antigen when presented in the context of a major histocompatibility complex (MHC) molecule. This MHC molecule can be one of many that exist in vertebrates, presenting small peptide fragments, lipid molecules, or small molecule metabolites. Here we review the pattern of TCR recognition of MHC molecules throughout a broad sampling of species and T-cell lineages and also touch upon T cells that do not appear to require MHC presentation for their surveillance function. We review the diversity of MHC molecules and information on the corresponding T-cell lineages identified in divergent species. We also discuss TCRs with structural domains unlike that of conventional TCRs of mouse and human. By presenting this broad view of TCR sequence, structure, domain organization, and function, we seek to explore how this receptor has evolved across time and been selected for alternative antigen-recognition capabilities in divergent lineages.
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Affiliation(s)
- Caitlin C. Castro
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
- Committee on Immunology, University of Chicago, Chicago, IL, USA
| | - Adrienne M. Luoma
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
- Committee on Immunology, University of Chicago, Chicago, IL, USA
| | - Erin J. Adams
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
- Committee on Immunology, University of Chicago, Chicago, IL, USA
- Committee on Cancer Biology, University of Chicago, Chicago, IL, USA
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24
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Assembly, organization and regulation of cell-surface receptors by lectin–glycan complexes. Biochem J 2015; 469:1-16. [DOI: 10.1042/bj20150461] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Galectins are a family of β-galactoside-binding lectins carrying at least one consensus sequence in the carbohydrate-recognition domain. Properties of glycosylated ligands, such as N- and O-glycan branching, LacNAc (N-acetyl-lactosamine) content and the balance of α2,3- and α2,6-linked sialic acid dramatically influence galectin binding to a preferential set of counter-receptors. The presentation of specific glycans in galectin-binding partners is also critical, as proper orientation and clustering of oligosaccharide ligands on multiple carbohydrate side chains increase the binding avidity of galectins for particular glycosylated receptors. When galectins are released from the cells, they typically concentrate on the cell surface and the local matrix, raising their local concentration. Thus galectins can form their own multimers in the extracellular milieu, which in turn cross-link glycoconjugates on the cell surface generating galectin–glycan complexes that modulate intracellular signalling pathways, thus regulating cellular processes such as apoptosis, proliferation, migration and angiogenesis. Subtle changes in receptor expression, rates of protein synthesis, activities of Golgi enzymes, metabolite concentrations supporting glycan biosynthesis, density of glycans, strength of protein–protein interactions at the plasma membrane and stoichiometry may modify galectin–glycan complexes. Although galectins are key contributors to the formation of these extended glycan complexes leading to promotion of receptor segregation/clustering, and inhibition of receptor internalization by surface retention, when these complexes are disrupted, some galectins, particularly galectin-3 and -4, showed the ability to drive clathrin-independent mechanisms of endocytosis. In the present review, we summarize the data available on the assembly, hierarchical organization and regulation of conspicuous galectin–glycan complexes, and their implications in health and disease.
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25
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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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26
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Force-dependent transition in the T-cell receptor β-subunit allosterically regulates peptide discrimination and pMHC bond lifetime. Proc Natl Acad Sci U S A 2015; 112:1517-22. [PMID: 25605925 DOI: 10.1073/pnas.1424829112] [Citation(s) in RCA: 184] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The αβ T-cell receptor (TCR) on each T lymphocyte mediates exquisite specificity for a particular foreign peptide bound to a major histocompatibility complex molecule (pMHC) displayed on the surface of altered cells. This recognition stimulates protection in the mammalian host against intracellular pathogens, including viruses, and involves piconewton forces that accompany pMHC ligation. Physical forces are generated by T-lymphocyte movement during immune surveillance as well as by cytoskeletal rearrangements at the immunological synapse following cessation of cell migration. The mechanistic explanation for how TCRs distinguish between foreign and self-peptides bound to a given MHC molecule is unclear: peptide residues themselves comprise few of the TCR contacts on the pMHC, and pathogen-derived peptides are scant among myriad self-peptides bound to the same MHC class arrayed on infected cells. Using optical tweezers and DNA tether spacer technology that permit piconewton force application and nanometer scale precision, we have determined how bioforces relate to self versus nonself discrimination. Single-molecule analyses involving isolated αβ-heterodimers as well as complete TCR complexes on T lymphocytes reveal that the FG loop in the β-subunit constant domain allosterically controls both the variable domain module's catch bond lifetime and peptide discrimination via force-driven conformational transition. In contrast to integrins, the TCR interrogates its ligand via a strong force-loaded state with release through a weakened, extended state. Our work defines a key element of TCR mechanotransduction, explaining why the FG loop structure evolved for adaptive immunity in αβ but not γδTCRs or immunoglobulins.
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27
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The immunology connection--my first T cell receptor structure projects. Protein Cell 2014; 5:649-52. [PMID: 25087847 PMCID: PMC4145086 DOI: 10.1007/s13238-014-0091-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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28
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Abstract
Molecular interactions at the interface between helper T cells and antigen-presenting B cells govern the ability to produce specific antibodies, which is a central event in protective immunity generated by natural infection or man-made vaccines. In order for a T cell to deliver effective help to a B cell and guide affinity maturation, it needs to provide feedback that is proportional to the amount of antigen the B cell collects with its surface antibody. This review focuses on mechanisms by which T and B cells manage to count the products of antigen capture and encourage B cells with the best receptors to dominate the response and make antibody-producing plasma cells. We discuss what is known about the proportionality of T cells responses to presented antigens and consider the mechanisms that B cells may use to keep count of positive feedback from T cells.
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Affiliation(s)
- Michael L Dustin
- Kennedy Institute of Rheumatology, Nuffield Department of Orthopedics, Rheumatology, and Musculoskeletal Sciences, The University of Oxford, Roosevelt Drive, Headington OX3 7FY, UK; Skirball Institute of Biomolecular Medicine, Department of Pathology, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA.
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29
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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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30
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Wang JH, Reinherz EL. Revisiting the putative TCR Cα dimerization model through structural analysis. Front Immunol 2013; 4:16. [PMID: 23386853 PMCID: PMC3558723 DOI: 10.3389/fimmu.2013.00016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 01/08/2013] [Indexed: 12/18/2022] Open
Abstract
Despite major advances in T cell receptor (TCR) biology and structure, how peptide-MHC complex (pMHC) ligands trigger αβ TCR activation remains unresolved. Two views exist. One model postulates that monomeric TCR-pMHC ligation events are sufficient while a second proposes that TCR-TCR dimerization in cis via Cα domain interaction plus pMHC binding is critical. We scrutinized 22 known TCR/pMHC complex crystal structures, and did not find any predicted molecular Cα-Cα contacts in these crystals that would allow for physiological TCR dimerization. Moreover, the presence of conserved glycan adducts on the outer face of the Cα domain preclude the hypothesized TCR dimerization through the Cα domain. Observed functional consequences of Cα mutations are likely indirect, with TCR microclusters at the immunological synapse driven by TCR transmembrane/cytoplasmic interactions via signaling molecules, scaffold proteins, and/or cytoskeletal elements.
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Affiliation(s)
- Jia-Huai Wang
- Laboratory of Immunobiology, Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical SchoolBoston, MA, USA
- Department of Pediatrics, Harvard Medical SchoolBoston, MA, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical SchoolBoston, MA, USA
| | - Ellis L. Reinherz
- Laboratory of Immunobiology, Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical SchoolBoston, MA, USA
- Department of Medicine, Harvard Medical SchoolBoston, MA, USA
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31
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Rossy J, Williamson DJ, Benzing C, Gaus K. The integration of signaling and the spatial organization of the T cell synapse. Front Immunol 2012. [PMID: 23189081 PMCID: PMC3504718 DOI: 10.3389/fimmu.2012.00352] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Engagement of the T cell antigen receptor (TCR) triggers signaling pathways that lead to T cell selection, differentiation and clonal expansion. Superimposed onto the biochemical network is a spatial organization that describes individual receptor molecules, dimers, oligomers and higher order structures. Here we discuss recent findings and new concepts that may regulate TCR organization in naïve and memory T cells. A key question that has emerged is how antigen-TCR interactions encode spatial information to direct T cell activation and differentiation. Single molecule super-resolution microscopy may become an important tool in decoding receptor organization at the molecular level.
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Affiliation(s)
- Jérémie Rossy
- Centre for Vascular Research and Australian Centre for Nanomedicine, University of New South Wales Sydney, NSW, Australia
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32
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Wang JH, Reinherz EL. The structural basis of αβ T-lineage immune recognition: TCR docking topologies, mechanotransduction, and co-receptor function. Immunol Rev 2012; 250:102-19. [PMID: 23046125 PMCID: PMC3694212 DOI: 10.1111/j.1600-065x.2012.01161.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Self versus non-self discrimination is at the core of T-lymphocyte recognition. To this end, αβ T-cell receptors (TCRs) ligate 'foreign' peptides bound to major histocompatibility complex (MHC) class I or class II molecules (pMHC) arrayed on the surface of antigen-presenting cells (APCs). Since the discovery of TCRs approximately 30 years ago, considerable structural and functional data have detailed the molecular basis of their extraordinary ligand specificity and sensitivity in mediating adaptive T-cell immunity. This review focuses on the structural biology of the Fab-like TCRαβ clonotypic heterodimer and its unique features in conjunction with those of the associated CD3εγ and CD3εδ heterodimeric molecules, which, along with CD3ζζ homodimer, comprise the TCR complex in a stoichiometry of 1:1:1:1. The basis of optimized TCRαβ docking geometry on the pMHC linked to TCR mechanotransduction and required for T-cell signaling as well as CD4 and CD8 co-receptor function is detailed. A model of the TCR ectodomain complex including its connecting peptides suggests how force generated during T-cell immune surveillance and at the immunological synapse results in dynamic TCR quaternary change involving its heterodimeric components. Potential insights from the structural biology relevant to immunity and immunosuppression are revealed.
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MESH Headings
- Animals
- Antigen-Presenting Cells/cytology
- Antigen-Presenting Cells/immunology
- Antigen-Presenting Cells/metabolism
- Antigens/chemistry
- Antigens/immunology
- Antigens/metabolism
- CD3 Complex/chemistry
- CD3 Complex/immunology
- CD3 Complex/metabolism
- CD4-Positive T-Lymphocytes/cytology
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- CD8-Positive T-Lymphocytes/cytology
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/metabolism
- Humans
- Major Histocompatibility Complex/immunology
- Mechanotransduction, Cellular
- Mice
- Models, Molecular
- Peptides/chemistry
- Peptides/immunology
- Peptides/metabolism
- Protein Conformation
- Protein Multimerization
- Receptors, Antigen, T-Cell, alpha-beta/chemistry
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
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Affiliation(s)
- Jia-huai Wang
- Laboratory of Immunobiology and Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
- Department of Biological Chemistry & Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Ellis L. Reinherz
- Laboratory of Immunobiology and Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
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33
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Bulek AM, Madura F, Fuller A, Holland CJ, Schauenburg AJ, Sewell AK, Rizkallah PJ, Cole DK. TCR/pMHC Optimized Protein crystallization Screen. J Immunol Methods 2012; 382:203-10. [PMID: 22705983 PMCID: PMC3404460 DOI: 10.1016/j.jim.2012.06.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 06/07/2012] [Accepted: 06/07/2012] [Indexed: 11/24/2022]
Abstract
The interaction between the clonotypic αβ T cell receptor (TCR), expressed on the T cell surface, and peptide-major histocompatibility complex (pMHC) molecules, expressed on the target cell surface, governs T cell mediated autoimmunity and immunity against pathogens and cancer. Structural investigations of this interaction have been limited because of the challenges inherent in the production of good quality TCR/pMHC protein crystals. Here, we report the development of an 'intelligently designed' crystallization screen that reproducibly generates high quality TCR/pMHC complex crystals suitable for X-ray crystallographic studies, thereby reducing protein consumption. Over the last 2 years, we have implemented this screen to produce 32 T cell related protein structures at high resolution, substantially contributing to the current immune protein database. Protein crystallography, used to study this interaction, has already extended our understanding of the molecular rules that govern T cell immunity. Subsequently, these data may help to guide the intelligent design of T cell based therapies that target human diseases, underlining the importance of developing optimized approaches for crystallizing novel TCR/pMHC complexes.
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34
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Ozawa T, Horii M, Kobayashi E, Jin A, Kishi H, Muraguchi A. The binding affinity of a soluble TCR-Fc fusion protein is significantly improved by crosslinkage with an anti-Cβ antibody. Biochem Biophys Res Commun 2012; 422:245-9. [PMID: 22575452 DOI: 10.1016/j.bbrc.2012.04.134] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 04/24/2012] [Indexed: 11/24/2022]
Abstract
The identification and cloning of tumor antigen-specific T cell receptors (TCRs) and the production of the soluble form of the TCR (sTCR) contributed to the development of diagnostic and therapeutic tools for cancer. Recently, several groups have reported the development of technologies for the production of sTCRs. The native sTCR has a very low binding affinity for the antigenic peptide/MHC (p/MHC) complex. In this study, we established a technology to produce high affinity, functional sTCRs. We generated a novel sTCR-Fc fusion protein composed of the TCR V and C regions of the TCR linked to the immunoglobulin (Ig) Fc region. A Western blot analysis revealed that the molecular weight of the fusion protein was approximately 60 kDa under reducing conditions and approximately 100-200 kDa under non-reducing conditions. ELISAs using various antibodies showed that the structure of each domain of the TCR-Fc protein was intact. The TCR-Fc protein immobilized by an anti-Cβ antibody effectively bound to a p/MHC tetramer. An SPR analysis showed that the TCR-Fc protein had a low binding affinity (KD; 1.1 × 10(-5)M) to the p/MHC monomer. Interestingly, when the TCR-Fc protein was pre-incubated with an anti-Cβ antibody, its binding affinity for p/MHC increased by 5-fold (2.2 × 10(-6)M). We demonstrated a novel method for constructing a functional soluble TCR using the Ig Fc region and showed that the binding affinity of the functional sTCR-Fc was markedly increased by an anti-Cβ antibody, which is probably due to the stabilization of the Vα/Vβ region of the TCR. These findings provide new insights into the binding of sTCRs to p/MHCs and will hopefully be instrumental in establishing functional sTCR as a diagnostic and therapeutic tool for cancer.
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Affiliation(s)
- Tatsuhiko Ozawa
- Department of Immunology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan
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35
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Kim ST, Shin Y, Brazin K, Mallis RJ, Sun ZYJ, Wagner G, Lang MJ, Reinherz EL. TCR Mechanobiology: Torques and Tunable Structures Linked to Early T Cell Signaling. Front Immunol 2012; 3:76. [PMID: 22566957 PMCID: PMC3342345 DOI: 10.3389/fimmu.2012.00076] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Accepted: 03/27/2012] [Indexed: 11/16/2022] Open
Abstract
Mechanotransduction is a basis for receptor signaling in many biological systems. Recent data based upon optical tweezer experiments suggest that the TCR is an anisotropic mechanosensor, converting mechanical energy into biochemical signals upon specific peptide-MHC complex (pMHC) ligation. Tangential force applied along the pseudo-twofold symmetry axis of the TCR complex post-ligation results in the αβ heterodimer exerting torque on the CD3 heterodimers as a consequence of molecular movement at the T cell-APC interface. Accompanying TCR quaternary change likely fosters signaling via the lipid bilayer predicated on the magnitude and direction of the TCR-pMHC force. TCR glycans may modulate quaternary change, thereby altering signaling outcome as might the redox state of the CxxC motifs located proximal to the TM segments in the heterodimeric CD3 subunits. Predicted alterations in TCR TM segments and surrounding lipid will convert ectodomain ligation into the earliest intracellular signaling events.
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Affiliation(s)
- Sun Taek Kim
- Laboratory of Immunobiology and Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical SchoolBoston, MA, USA
- Department of Medicine, Harvard Medical SchoolBoston, MA, USA
| | - Yongdae Shin
- Department of Mechanical Engineering, Massachusetts Institute of Technology, CambridgeMA, USA
| | - Kristine Brazin
- Laboratory of Immunobiology and Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical SchoolBoston, MA, USA
- Department of Medicine, Harvard Medical SchoolBoston, MA, USA
| | - Robert J. Mallis
- Laboratory of Immunobiology and Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical SchoolBoston, MA, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical SchoolBoston, MA, USA
| | - Zhen-Yu J. Sun
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical SchoolBoston, MA, USA
| | - Gerhard Wagner
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical SchoolBoston, MA, USA
| | - Matthew J. Lang
- Department of Chemical and Biomolecular Engineering, Vanderbilt UniversityNashville, TN, USA
| | - Ellis L. Reinherz
- Laboratory of Immunobiology and Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical SchoolBoston, MA, USA
- Department of Medicine, Harvard Medical SchoolBoston, MA, USA
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36
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Abstract
Functional cognate T cell recognition is mediated via the interaction of a T cell receptor complex with its pMHC ligand. Adams et al. (2011) in this issue of Immunity provide evidence that docking geometry may impact 2D binding and T cell activation.
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Affiliation(s)
- Jia-huai Wang
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
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37
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Leimgruber A, Ferber M, Irving M, Hussain-Kahn H, Wieckowski S, Derré L, Rufer N, Zoete V, Michielin O. TCRep 3D: an automated in silico approach to study the structural properties of TCR repertoires. PLoS One 2011; 6:e26301. [PMID: 22053188 PMCID: PMC3203878 DOI: 10.1371/journal.pone.0026301] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 09/23/2011] [Indexed: 11/18/2022] Open
Abstract
TCRep 3D is an automated systematic approach for TCR-peptide-MHC class I structure prediction, based on homology and ab initio modeling. It has been considerably generalized from former studies to be applicable to large repertoires of TCR. First, the location of the complementary determining regions of the target sequences are automatically identified by a sequence alignment strategy against a database of TCR Vα and Vβ chains. A structure-based alignment ensures automated identification of CDR3 loops. The CDR are then modeled in the environment of the complex, in an ab initio approach based on a simulated annealing protocol. During this step, dihedral restraints are applied to drive the CDR1 and CDR2 loops towards their canonical conformations, described by Al-Lazikani et. al. We developed a new automated algorithm that determines additional restraints to iteratively converge towards TCR conformations making frequent hydrogen bonds with the pMHC. We demonstrated that our approach outperforms popular scoring methods (Anolea, Dope and Modeller) in predicting relevant CDR conformations. Finally, this modeling approach has been successfully applied to experimentally determined sequences of TCR that recognize the NY-ESO-1 cancer testis antigen. This analysis revealed a mechanism of selection of TCR through the presence of a single conserved amino acid in all CDR3β sequences. The important structural modifications predicted in silico and the associated dramatic loss of experimental binding affinity upon mutation of this amino acid show the good correspondence between the predicted structures and their biological activities. To our knowledge, this is the first systematic approach that was developed for large TCR repertoire structural modeling.
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Affiliation(s)
- Antoine Leimgruber
- Multidisciplinary Oncology Center, Lausanne University Hospital (CHUV), Lausanne, Switzerland
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38
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Schrum AG, Gil D, Turka LA, Palmer E. Physical and functional bivalency observed among TCR/CD3 complexes isolated from primary T cells. THE JOURNAL OF IMMUNOLOGY 2011; 187:870-8. [PMID: 21666056 DOI: 10.4049/jimmunol.1100538] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Unlike BCR and secreted Ig, TCR expression is not thought to occur in a bivalent form. The conventional monovalent model of TCR/CD3 is supported by published studies of complexes solubilized in the detergent digitonin, in which bivalency was not observed. We revisited the issue of TCR valency by examining complexes isolated from primary αβ T cells after solubilization in digitonin. Using immunoprecipitation followed by flow cytometry, we unexpectedly observed TCR/CD3 complexes that contained two TCRs per complex. Standard anti-TCR Abs, being bivalent themselves, tended to bind with double occupancy to bivalent TCRs; this property masked the presence of the second TCR per complex in certain Ab binding assays, which may partially explain why previous data did not reveal these bivalent complexes. We also found that the prevalence of bivalency among fully assembled, mature TCR/CD3 complexes was sufficient to impact the functional performance of immunoprecipitated TCRs in binding antigenic peptide/MHC-Ig fusion proteins. Both TCR positions per bivalent complex required an Ag-specific TCR to effect optimal binding to these soluble ligands. Therefore, we conclude that in primary T cells, TCR/CD3 complexes can be found that are physically and functionally bivalent. The expression of bivalent TCR/CD3 complexes has implications regarding potential mechanisms by which Ag may trigger signaling. It also suggests the possibility that the potential for bivalent expression could represent a general feature of Ag receptors.
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Affiliation(s)
- Adam G Schrum
- Department of Immunology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
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39
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Zhou B, Chen Q, Mallis RJ, Zhang H, Liu JH, Reinherz EL, Wang JH. A conserved hydrophobic patch on Vβ domains revealed by TCRβ chain crystal structures: Implications for pre-TCR dimerization. Front Immunol 2011; 2:5. [PMID: 22566796 PMCID: PMC3341985 DOI: 10.3389/fimmu.2011.00005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Accepted: 02/15/2011] [Indexed: 01/21/2023] Open
Abstract
The αβ T cell receptor (TCR) is a multimeric complex whose β chain plays a crucial role in thymocyte development as well as antigen recognition by mature T lymphocytes. We report here crystal structures of individual β subunits, termed N15β (Vβ5.2Dβ2Jβ2.6Cβ2) and N30β (Vβ13Dβ1Jβ1.1Cβ2), derived from two αβ TCRs specific for the immunodominant vesicular stomatitis virus octapeptide (VSV-8) bound to the murine H-2Kb MHC class I molecule. The crystal packing of the N15β structure reveals a homodimer formed through two Vβ domains. The Vβ/Vβ module is topologically very similar to the Vα/Vβ module in the N15αβ heterodimer. By contrast, in the N30β structure, the Vβ domain’s external hydrophobic CFG face is covered by the neighboring molecule’s Cβ domain. In conjunction with systematic investigation of previously published TCR single-subunit structures, we identified several conserved residues forming a concave hydrophobic patch at the center of the CFG outer face of the Vβ and other V-type Ig-like domains. This hydrophobic patch is shielded from solvent exposure in the crystal packing, implying that it is unlikely to be thermodynamically stable if exposed on the thymocyte surface. Accordingly, we propose a dimeric pre-TCR model distinct from those suggested previously by others and discuss its functional and structural implications.
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Affiliation(s)
- Bo Zhou
- Laboratory of Immunobiology, Dana-Farber Cancer Institute, Harvard Medical School Boston, MA, USA
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Arechaga I, Swamy M, Abia D, Schamel WA, Alarcón B, Valpuesta JM. Structural characterization of the TCR complex by electron microscopy. Int Immunol 2010; 22:897-903. [PMID: 21059766 DOI: 10.1093/intimm/dxq443] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Structural information on how the TCR transmits signals upon binding of its antigen peptide MHC molecule ligand is still lacking. The ectodomains of the TCRα/β, CD3εγ and CD3εδ dimers, as well as the transmembrane domain of CD3ζ, have been characterized by X-ray crystallography and nuclear magnetic resonance (NMR). However, no structural data have been obtained for the entire TCR complex. In this study, we have purified the TCR from T cells under native conditions and used electron microscopy to derive a three-dimensional structure. The TCR complex appears as a pear-shaped structure of 180 × 120 × 65 . Furthermore, the use of mAbs has allowed to determine the orientation of the TCRα/β and CD3 subunits and to suggest a model of interactions. Interestingly, the reconstructed TCR is larger than expected for a complex with a αβγεδεζζ stoichiometry. The accommodation of a second TCRαβ to fill in the extra volume is discussed.
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Affiliation(s)
- Ignacio Arechaga
- Departamento de Biología Molecular, Universidad de Cantabria (UC) and Instituto de Biomedicina y Biotecnología de Cantabria, IBBTEC (CSIC-UC-IDICAN), c/Herrera Oria s/n, 39011 Santander, Spain
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41
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Soetandyo N, Wang Q, Ye Y, Li L. Role of intramembrane charged residues in the quality control of unassembled T-cell receptor alpha-chains at the endoplasmic reticulum. J Cell Sci 2010; 123:1031-8. [PMID: 20332119 DOI: 10.1242/jcs.059758] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Endoplasmic reticulum (ER)-associated degradation (ERAD) of unassembled T-cell receptor alpha-chain (TCRalpha) is reliant on the presence of two basic residues in the transmembrane (TM) segment of TCRalpha. The precise role of these residues in ER quality control is unclear. Here, we show that a TCRalpha mutant lacking these intramembrane charged residues has a tendency to form homooligomers through an interchain disulfide bond that involves a specific pair of cysteine residues. Covalent oligomerization of TCRalpha appears to stabilize it at the ER membrane. The presence of a single lysine residue at specific positions within the TCRalpha TM domain abolishes its oligomerization and causes its rapid degradation. Conversely, when TCRalpha oligomerization is induced by a bivalent compound, the degradation of TCRalpha is inhibited. Together, these results suggest that the intramembrane charged residues in TCRalpha do not function as a signal for substrate recognition in ERAD. Instead, their primary role is to reduce TCRalpha oligomerization, maintaining it in a retrotranslocation-competent state. Our results also suggest that the ERAD machinery is inefficient when coping with oligomerized substrates, indicating a requirement for chaperone-mediated protein disassembly in the ER lumen prior to retrotranslocation.
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Affiliation(s)
- Nia Soetandyo
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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42
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Kim ST, Touma M, Takeuchi K, Sun ZYJ, Dave VP, Kappes DJ, Wagner G, Reinherz EL. Distinctive CD3 heterodimeric ectodomain topologies maximize antigen-triggered activation of alpha beta T cell receptors. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2010; 185:2951-9. [PMID: 20660709 PMCID: PMC2936104 DOI: 10.4049/jimmunol.1000732] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The alphabeta TCR has recently been suggested to function as an anisotropic mechanosensor during immune surveillance, converting mechanical energy into a biochemical signal upon specific peptide/MHC ligation of the alphabeta clonotype. The heterodimeric CD3epsilongamma and CD3epsilondelta subunits, each composed of two Ig-like ectodomains, form unique side-to-side hydrophobic interfaces involving their paired G-strands, rigid connectors to their respective transmembrane segments. Those dimers are laterally disposed relative to the alphabeta heterodimer within the TCR complex. In this paper, using structure-guided mutational analysis, we investigate the functional consequences of a striking asymmetry in CD3gamma and CD3delta G-strand geometries impacting ectodomain shape. The uniquely kinked conformation of the CD3gamma G-strand is crucial for maximizing Ag-triggered TCR activation and surface TCR assembly/expression, offering a geometry to accommodate juxtaposition of CD3gamma and TCR beta ectodomains and foster quaternary change that cannot be replaced by the isologous CD3delta subunit's extracellular region. TCRbeta and CD3 subunit protein sequence analyses among Gnathostomata species show that the Cbeta FG loop and CD3gamma subunit coevolved, consistent with this notion. Furthermore, restoration of T cell activation and development in CD3gamma(-/-) mouse T lineage cells by interspecies replacement can be rationalized from structural insights on the topology of chimeric mouse/human CD3epsilondelta dimers. Most importantly, our findings imply that CD3gamma and CD3delta evolved from a common precursor gene to optimize peptide/MHC-triggered alphabeta TCR activation.
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MESH Headings
- Amino Acid Sequence
- Animals
- CD3 Complex/chemistry
- CD3 Complex/genetics
- CD3 Complex/physiology
- Evolution, Molecular
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Molecular Sequence Data
- Organ Culture Techniques
- Protein Multimerization
- Protein Structure, Quaternary
- Protein Structure, Tertiary
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
- Receptors, Antigen, T-Cell, alpha-beta/physiology
- Sheep
- Signal Transduction/genetics
- Signal Transduction/immunology
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Affiliation(s)
- Sun Taek Kim
- Laboratory of Immunobiology and Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
- Department of Medicine, Harvard Medical School, Boston, MA 02115
| | - Maki Touma
- Laboratory of Immunobiology and Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
- Department of Medicine, Harvard Medical School, Boston, MA 02115
| | - Koh Takeuchi
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115
| | - Zhen-Yu J. Sun
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115
| | - Vibhuti P. Dave
- Lymphocyte Development Laboratory, Clinical Research Institute of Montreal, Montreal, Quebec, Canada
| | - Dietmar J. Kappes
- Blood Cell Development and Cancer Program, Fox Chase Cancer Center, Philadelphia, PA 19111
| | - Gerhard Wagner
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115
| | - Ellis L. Reinherz
- Laboratory of Immunobiology and Department of Medical Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115
- Department of Medicine, Harvard Medical School, Boston, MA 02115
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43
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van Boxel GI, Holmes S, Fugger L, Jones EY. An alternative conformation of the T-cell receptor alpha constant region. J Mol Biol 2010; 400:828-37. [PMID: 20630474 PMCID: PMC2930249 DOI: 10.1016/j.jmb.2010.05.053] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Revised: 05/20/2010] [Accepted: 05/24/2010] [Indexed: 11/10/2022]
Abstract
αβ T-cell receptors (TcRs) play a central role in cellular immune response. They are members of the Ig superfamily, with extracellular regions of the α and β chains each comprising a V-type domain and a C-type domain. We have determined the ectodomain structure of an αβ TcR, which recognizes the autoantigen myelin basic protein. The 2.0-Å-resolution structure reveals canonical main-chain conformations for the Vα, Vβ, and Cβ domains, but the Cα domain exhibits a main-chain conformation remarkably different from those previously reported for TcR crystal structures. The global IgC-like fold is maintained, but a piston-like rearrangement between BC and DE β-turns results in β-strand slippage. This substantial conformational change may represent a signaling intermediate. Our structure is the first example for the Ig fold of the increasingly recognized concept of “metamorphic proteins.”
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Affiliation(s)
- Gijs I van Boxel
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, The University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
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44
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Huppa JB, Axmann M, Mörtelmaier MA, Lillemeier BF, Newell EW, Brameshuber M, Klein LO, Schütz GJ, Davis MM. TCR-peptide-MHC interactions in situ show accelerated kinetics and increased affinity. Nature 2010; 463:963-7. [PMID: 20164930 PMCID: PMC3273423 DOI: 10.1038/nature08746] [Citation(s) in RCA: 369] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Accepted: 12/07/2009] [Indexed: 11/09/2022]
Abstract
The recognition of foreign antigens by T lymphocytes is essential to most adaptive immune responses. It is driven by specific T-cell antigen receptors (TCRs) binding to antigenic peptide-major histocompatibility complex (pMHC) molecules on other cells. If productive, these interactions promote the formation of an immunological synapse. Here we show that synaptic TCR-pMHC binding dynamics differ significantly from TCR-pMHC binding in solution. We used single-molecule microscopy and fluorescence resonance energy transfer (FRET) between fluorescently tagged TCRs and their cognate pMHC ligands to measure the kinetics of TCR-pMHC binding in situ. When compared with solution measurements, the dissociation of this complex was increased significantly (4-12-fold). Disruption of actin polymers reversed this effect, indicating that cytoskeletal dynamics destabilize this interaction directly or indirectly. Nevertheless, TCR affinity for pMHC was significantly elevated as the result of a large (about 100-fold) increase in the association rate, a likely consequence of complementary molecular orientation and clustering. In helper T cells, the CD4 molecule has been proposed to bind cooperatively with the TCR to the same pMHC complex. However, CD4 blockade had no effect on the synaptic TCR affinity, nor did it destabilize TCR-pMHC complexes, indicating that the TCR binds pMHC independently of CD4.
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Affiliation(s)
- Johannes B Huppa
- Department of Microbiology and Immunology, Stanford School of Medicine, California 94305-5323, USA
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45
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Di Tommaso S, Antonacci R, Ciccarese S, Massari S. Extensive analysis of D-J-C arrangements allows the identification of different mechanisms enhancing the diversity in sheep T cell receptor beta-chain repertoire. BMC Genomics 2010; 11:3. [PMID: 20047680 PMCID: PMC2806336 DOI: 10.1186/1471-2164-11-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2009] [Accepted: 01/04/2010] [Indexed: 11/10/2022] Open
Abstract
Background In most species of mammals, the TRB locus has the common feature of a library of TRBV genes positioned at the 5'- end of two in tandem aligned D-J-C gene clusters, each composed of a single TRBD gene, 6-7 TRBJ genes and one TRBC gene. An enhancer located at the 3'end of the last TRBC and a well-defined promoter situated at the 5'end of the TRBD gene and/or a undefined promoter situated at the 5'end of the TRBD2 are sufficient to generate the full recombinase accessibility at the locus. In ruminant species, the 3'end of the TRB locus is characterized by the presence of three D-J-C clusters, each constituted by a single TRBD, 5-7 TRBJ and one TRBC genes with the center cluster showing a structure combined with the clusters upstream and downstream, suggesting that a unequal crossover occurred in the duplication. An enhancer downstream the last TRBC, and a promoter at the 5'-end of each TRBD gene are also present. Results In this paper we focused our attention on the analysis of a large number of sheep TR β-chain transcripts derived from four different lymphoid tissues of three diverse sheep breed animals to certify the use and frequency of the three gene clusters in the β-chain repertoire. As the sheep TRB locus genomic organization is known, the exact interpretation of the V-D-J rearrangements was fully determined. Our results clearly demonstrate that sheep β-chain constitutes a level of variability that is substantially larger than that described in other mammalian species. This is due not only to the increase of the number of D and J genes available to the somatic recombination, but also to the presence of the trans-rearrangement process. Moreover, the functional complexity of β-chain repertoire is resolved by other mechanisms such as alternative cis- and trans-splicing and recombinational diversification that seems to affect the variety of the constant region. Conclusion All together our data demonstrate that a disparate set of molecular mechanisms operate to perform a diversified repertoire in the sheep β-chain and this could confer some special biological properties to the corresponding αβ T cells in the ruminant lineage.
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Affiliation(s)
- Silvia Di Tommaso
- Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Universita' del Salento, Lecce, Italy.
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46
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Kim ST, Takeuchi K, Sun ZYJ, Touma M, Castro CE, Fahmy A, Lang MJ, Wagner G, Reinherz EL. The alphabeta T cell receptor is an anisotropic mechanosensor. J Biol Chem 2009; 284:31028-37. [PMID: 19755427 PMCID: PMC2781503 DOI: 10.1074/jbc.m109.052712] [Citation(s) in RCA: 309] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Revised: 09/12/2009] [Indexed: 01/06/2023] Open
Abstract
Thymus-derived lymphocytes protect mammalian hosts against virus- or cancer-related cellular alterations through immune surveillance, eliminating diseased cells. In this process, T cell receptors (TCRs) mediate both recognition and T cell activation via their dimeric alphabeta, CD3 epsilon gamma, CD3 epsilon delta, and CD3 zeta zeta subunits using an unknown structural mechanism. Here, site-specific binding topology of anti-CD3 monoclonal antibodies (mAbs) and dynamic TCR quaternary change provide key clues. Agonist mAbs footprint to the membrane distal CD3 epsilon lobe that they approach diagonally, adjacent to the lever-like C beta FG loop that facilitates antigen (pMHC)-triggered activation. In contrast, a non-agonist mAb binds to the cleft between CD3 epsilon and CD3 gamma in a perpendicular mode and is stimulatory only subsequent to an external tangential but not a normal force ( approximately 50 piconewtons) applied via optical tweezers. Specific pMHC but not irrelevant pMHC activates a T cell upon application of a similar force. These findings suggest that the TCR is an anisotropic mechanosensor, converting mechanical energy into a biochemical signal upon specific pMHC ligation during immune surveillance. Activating anti-CD3 mAbs mimic this force via their intrinsic binding mode. A common TCR quaternary change rather than conformational alterations can better facilitate structural signal initiation, given the vast array of TCRs and their specific pMHC ligands.
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MESH Headings
- Animals
- Antibodies, Monoclonal/immunology
- CD3 Complex/immunology
- Cell Line
- Mechanotransduction, Cellular
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Molecular Conformation
- Protein Binding
- Receptors, Antigen, T-Cell, alpha-beta/chemistry
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
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Affiliation(s)
- Sun Taek Kim
- From the Department of Medical Oncology, Laboratory of Immunobiology, Dana-Farber Cancer Institute and
- Departments of Medicine and
| | - Koh Takeuchi
- Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115 and
| | - Zhen-Yu J. Sun
- Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115 and
| | - Maki Touma
- From the Department of Medical Oncology, Laboratory of Immunobiology, Dana-Farber Cancer Institute and
- Departments of Medicine and
| | | | - Amr Fahmy
- Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115 and
| | - Matthew J. Lang
- the Departments of Mechanical Engineering and
- **Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Gerhard Wagner
- Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115 and
| | - Ellis L. Reinherz
- From the Department of Medical Oncology, Laboratory of Immunobiology, Dana-Farber Cancer Institute and
- Departments of Medicine and
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47
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van Boxel GI, Stewart-Jones G, Holmes S, Sainsbury S, Shepherd D, Gillespie GMA, Harlos K, Stuart DI, Owens R, Jones EY. Some lessons from the systematic production and structural analysis of soluble (alpha)(beta) T-cell receptors. J Immunol Methods 2009; 350:14-21. [PMID: 19715696 DOI: 10.1016/j.jim.2009.08.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2009] [Revised: 07/29/2009] [Accepted: 08/17/2009] [Indexed: 01/20/2023]
Abstract
T-cell receptors (TCRs) are membrane proteins which recognize antigens with high specificity forming the basis of the cellular immune response. The study of these receptors has been limited by the challenges in expressing sufficient quantities of stable soluble protein. Here we report our systematic approach for generating soluble, (alpha)(beta)-TCRs, for X-ray crystallographic studies. By using small-scale expression screens, novel standardized quality control mechanisms and crystallization and imaging robots we were able to add significantly to the current TCR structural database. Our success in crystallizing both isolated TCRs and Major histocompatibility complex (MHC):TCR complexes has provided us with sufficient data to develop focused crystallization screens, which have proved generically useful for the crystallization of this family of proteins and complexes.
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MESH Headings
- Animals
- Crystallography, X-Ray/methods
- Histocompatibility Antigens/chemistry
- Histocompatibility Antigens/immunology
- Histocompatibility Antigens/metabolism
- Humans
- Protein Structure, Quaternary/physiology
- Receptors, Antigen, T-Cell, alpha-beta/chemistry
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
- Solubility
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Affiliation(s)
- Gijs I van Boxel
- Cancer Research UK Receptor Structure Research Group, Division of Structural Biology, The Henry Wellcome Building for Genomic Medicine, Roosevelt Drive, Headington, Oxford OX3 7BN, UK
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48
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Beddoe T, Chen Z, Clements CS, Ely LK, Bushell SR, Vivian JP, Kjer-Nielsen L, Pang SS, Dunstone MA, Liu YC, Macdonald WA, Perugini MA, Wilce MC, Burrows SR, Purcell AW, Tiganis T, Bottomley SP, McCluskey J, Rossjohn J. Antigen Ligation Triggers a Conformational Change within the Constant Domain of the αβ T Cell Receptor. Immunity 2009; 30:777-88. [DOI: 10.1016/j.immuni.2009.03.018] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2007] [Revised: 02/16/2009] [Accepted: 03/17/2009] [Indexed: 10/20/2022]
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49
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Du X, Cheng J, Song J. Identifying protein-protein interaction sites using covering algorithm. Int J Mol Sci 2009; 10:2190-2202. [PMID: 19564948 PMCID: PMC2695276 DOI: 10.3390/ijms10052190] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Revised: 04/30/2009] [Accepted: 05/13/2009] [Indexed: 12/03/2022] Open
Abstract
Identification of protein-protein interface residues is crucial for structural biology. This paper proposes a covering algorithm for predicting protein-protein interface residues with features including protein sequence profile and residue accessible area. This method adequately utilizes the characters of a covering algorithm which have simple, lower complexity and high accuracy for high dimension data. The covering algorithm can achieve a comparable performance (69.62%, Complete dataset; 60.86%, Trim dataset with overall accuracy) to a support vector machine and maximum entropy on our dataset, a correlation coefficient (CC) of 0.2893, 58.83% specificity, 56.12% sensitivity on the Complete dataset and 0.2144 (CC), 53.34% (specificity), 65.59% (sensitivity) on the Trim dataset in identifying interface residues by 5-fold cross-validation on 61 protein chains. This result indicates that the covering algorithm is a powerful and robust protein-protein interaction site prediction method that can guide biologists to make specific experiments on proteins. Examination of the predictions in the context of the 3-dimensional structures of proteins demonstrates the effectiveness of this method.
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Affiliation(s)
- Xiuquan Du
- The Key Laboratory of Intelligent Computing and Signal Processing, Ministry of Education, Anhui University, Anhui, China; E-Mails:
(J.-X.C.);
(J.S.)
| | - Jiaxing Cheng
- The Key Laboratory of Intelligent Computing and Signal Processing, Ministry of Education, Anhui University, Anhui, China; E-Mails:
(J.-X.C.);
(J.S.)
| | - Jie Song
- The Key Laboratory of Intelligent Computing and Signal Processing, Ministry of Education, Anhui University, Anhui, China; E-Mails:
(J.-X.C.);
(J.S.)
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50
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Collins EJ, Riddle DS. TCR-MHC docking orientation: natural selection, or thymic selection? Immunol Res 2009; 41:267-94. [PMID: 18726714 DOI: 10.1007/s12026-008-8040-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
T cell receptors (TCR) dock on their peptide-major histocompatibility complex (pMHC) targets in a conserved orientation. Since amino acid sidechains are the foundation of specific protein-protein interactions, a simple explanation for the conserved docking orientation is that key amino acids encoded by the TCR and MHC genes have been selected and maintained through evolution in order to preserve TCR/pMHC binding. Expectations that follow from the hypothesis that TCR and MHC evolved to interact are discussed in light of the data that both support and refute them. Finally, an alternative and equally simple explanation for the driving force behind the conserved docking orientation is described.
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Affiliation(s)
- Edward J Collins
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, 804 Mary Ellen Jones Building, Chapel Hill, NC 27510, USA.
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