1
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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. Proc Natl Acad Sci U S A 2024; 121:e2406680121. [PMID: 39298491 DOI: 10.1073/pnas.2406680121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 08/05/2024] [Indexed: 09/21/2024] Open
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 major histocompatibility complex (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-rates 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, which is not readily visualized with pMHC. This work provides insights into how T cells integrate kinetic information from TCR ligands and introduces a method to develop affinity panels for polyclonal T cells, such as cells from a human patient.
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MESH Headings
- Humans
- Kinetics
- Ligands
- Signal Transduction
- Immunoglobulin Fab Fragments/metabolism
- Immunoglobulin Fab Fragments/immunology
- Immunoglobulin Fab Fragments/chemistry
- Immunoglobulin Fab Fragments/genetics
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- DNA/metabolism
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Antigen, T-Cell/immunology
- Protein Binding
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Lymphocyte Activation
- Point Mutation
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Affiliation(s)
- Kiera B Wilhelm
- Department of Chemistry, University of California-Berkeley, Berkeley, CA 94720
| | - Anand Vissa
- Department of Chemistry, University of California-Berkeley, Berkeley, CA 94720
| | - Jay T Groves
- Department of Chemistry, University of California-Berkeley, Berkeley, CA 94720
- Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
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2
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Mohammad Taheri M, Javan F, Poudineh M, Athari SS. Beyond CAR-T: The rise of CAR-NK cell therapy in asthma immunotherapy. J Transl Med 2024; 22:736. [PMID: 39103889 PMCID: PMC11302387 DOI: 10.1186/s12967-024-05534-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2024] [Accepted: 07/23/2024] [Indexed: 08/07/2024] Open
Abstract
Asthma poses a major public health burden. While existing asthma drugs manage symptoms for many, some patients remain resistant. The lack of a cure, especially for severe asthma, compels exploration of novel therapies. Cancer immunotherapy successes with CAR-T cells suggest its potential for asthma treatment. Researchers are exploring various approaches for allergic diseases including membrane-bound IgE, IL-5, PD-L2, and CTLA-4 for asthma, and Dectin-1 for fungal asthma. NK cells offer several advantages over T cells for CAR-based immunotherapy. They offer key benefits: (1) HLA compatibility, meaning they can be used in a wider range of patients without the need for matching tissue types. (2) Minimal side effects (CRS and GVHD) due to their limited persistence and cytokine profile. (3) Scalability for "off-the-shelf" production from various sources. Several strategies have been introduced that highlight the superiority and challenges of CAR-NK cell therapy for asthma treatment including IL-10, IFN-γ, ADCC, perforin-granzyme, FASL, KIR, NCRs (NKP46), DAP, DNAM-1, TGF-β, TNF-α, CCL, NKG2A, TF, and EGFR. Furthermore, we advocate for incorporating AI for CAR design optimization and CRISPR-Cas9 gene editing technology for precise gene manipulation to generate highly effective CAR constructs. This review will delve into the evolution and production of CAR designs, explore pre-clinical and clinical studies of CAR-based therapies in asthma, analyze strategies to optimize CAR-NK cell function, conduct a comparative analysis of CAR-T and CAR-NK cell therapy with their respective challenges, and finally present established novel CAR designs with promising potential for asthma treatment.
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Affiliation(s)
| | - Fatemeh Javan
- Student Research Committee, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Mohadeseh Poudineh
- Student Research Committee, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Seyed Shamseddin Athari
- Cancer Gene Therapy Research Center, Zanjan University of Medical Sciences, Zanjan, Iran.
- Department of Immunology, Zanjan School of Medicine, Zanjan University of Medical Sciences, 12th Street, Shahrake Karmandan, Zanjan, 45139-561111, Iran.
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3
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Zhang S, Ma Z. trans-Interacting Plasma Membrane Proteins and Binding Partner Identification. J Proteome Res 2024; 23:3322-3331. [PMID: 38937710 DOI: 10.1021/acs.jproteome.4c00289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2024]
Abstract
Plasma membrane proteins (PMPs) play critical roles in a myriad of physiological and disease conditions. A unique subset of PMPs functions through interacting with each other in trans at the interface between two contacting cells. These trans-interacting PMPs (tiPMPs) include adhesion molecules and ligands/receptors that facilitate cell-cell contact and direct communication between cells. Among the tiPMPs, a significant number have apparent extracellular binding domains but remain orphans with no known binding partners. Identification of their potential binding partners is therefore important for the understanding of processes such as organismal development and immune cell activation. While a number of methods have been developed for the identification of protein binding partners in general, very few are applicable to tiPMPs, which interact in a two-dimensional fashion with low intrinsic binding affinities. In this review, we present the significance of tiPMP interactions, the challenges of identifying binding partners for tiPMPs, and the landscape of method development. We describe current avidity-based screening approaches for identifying novel tiPMP binding partners and discuss their advantages and limitations. We conclude by highlighting the importance of developing novel methods of identifying new tiPMP interactions for deciphering the complex protein interactome and developing targeted therapeutics for diseases.
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Affiliation(s)
- Shenyu Zhang
- Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, United States
| | - Zhengyu Ma
- Nemours Children's Hospital, Wilmington, Delaware 19803, United States
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4
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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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5
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Rogers J, Ma R, Foote A, Hu Y, Salaita K. Force-Induced Site-Specific Enzymatic Cleavage Probes Reveal That Serial Mechanical Engagement Boosts T Cell Activation. J Am Chem Soc 2024; 146:7233-7242. [PMID: 38451498 PMCID: PMC10958510 DOI: 10.1021/jacs.3c08137] [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: 07/28/2023] [Revised: 01/11/2024] [Accepted: 01/12/2024] [Indexed: 03/08/2024]
Abstract
The T cell membrane is studded with >104 T cell receptors (TCRs) that are used to scan target cells to identify short peptide fragments associated with viral infection or cancerous mutation. These peptides are presented as peptide-major-histocompatibility complexes (pMHCs) on the surface of virtually all nucleated cells. The TCR-pMHC complex forms at cell-cell junctions, is highly transient, and experiences mechanical forces. An important question in this area pertains to the role of the force duration in immune activation. Herein, we report the development of force probes that autonomously terminate tension within a time window following mechanical triggering. Force-induced site-specific enzymatic cleavage (FUSE) probes tune the tension duration by controlling the rate of a force-triggered endonuclease hydrolysis reaction. This new capability provides a method to study how the accumulated force duration contributes to T cell activation. We screened DNA sequences and identified FUSE probes that disrupt mechanical interactions with F > 7.1 piconewtons (pN) between TCRs and pMHCs. This rate of disruption, or force lifetime (τF), is tunable from tens of minutes down to 1.9 min. T cells challenged with FUSE probes with F > 7.1 pN presenting cognate antigens showed up to a 23% decrease in markers of early activation. FUSE probes with F > 17.0 pN showed weaker influence on T cell triggering further showing that TCR-pMHC with F > 17.0 pN are less frequent compared to F > 7.1 pN. Taken together, FUSE probes allow a new strategy to investigate the role of force dynamics in mechanotransduction broadly and specifically suggest a model of serial mechanical engagement boosting TCR activation.
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Affiliation(s)
- Jhordan Rogers
- Department
of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
| | - Rong Ma
- Department
of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
| | - Alexander Foote
- Department
of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
| | - Yuesong Hu
- Department
of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
| | - Khalid Salaita
- Department
of Chemistry, Emory University, 1515 Dickey Drive, Atlanta, Georgia 30322, United States
- Wallace
H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, United States
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6
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Finnigan JP, Newman JH, Patskovsky Y, Patskovska L, Ishizuka AS, Lynn GM, Seder RA, Krogsgaard M, Bhardwaj N. Structural basis for self-discrimination by neoantigen-specific TCRs. Nat Commun 2024; 15:2140. [PMID: 38459027 PMCID: PMC10924104 DOI: 10.1038/s41467-024-46367-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 02/26/2024] [Indexed: 03/10/2024] Open
Abstract
T cell receptors (TCR) are pivotal in mediating tumour cell cytolysis via recognition of mutation-derived tumour neoantigens (neoAgs) presented by major histocompatibility class-I (MHC-I). Understanding the factors governing the emergence of neoAg from somatic mutations is a major focus of current research. However, the structural and cellular determinants controlling TCR recognition of neoAgs remain poorly understood. This study describes the multi-level analysis of a model neoAg from the B16F10 murine melanoma, H2-Db/Hsf2 p.K72N68-76, as well as its cognate TCR 47BE7. Through cellular, molecular and structural studies we demonstrate that the p.K72N mutation enhances H2-Db binding, thereby improving cell surface presentation and stabilizing the TCR 47BE7 epitope. Furthermore, TCR 47BE7 exhibited high functional avidity and selectivity, attributable to a broad, stringent, binding interface enabling recognition of native B16F10 despite low antigen density. Our findings provide insight into the generation of anchor-residue modified neoAg, and emphasize the value of molecular and structural investigations of neoAg in diverse MHC-I contexts for advancing the understanding of neoAg immunogenicity.
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Affiliation(s)
- John P Finnigan
- Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Pl., New York, NY, USA
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, 1470 Madison Ave., New York, NY, USA
- Department of Medicine, Division of Hematology and Medical Oncology, Mount Sinai Hospital, New York, NY, USA
- Department of Surgery, Division of Thoracic and Cardiac Surgery, Brigham and Women's Hospital, 75 Francis St., Boston, MA, USA
| | - Jenna H Newman
- Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Pl., New York, NY, USA
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, 1470 Madison Ave., New York, NY, USA
- Department of Medicine, Division of Hematology and Medical Oncology, Mount Sinai Hospital, New York, NY, USA
| | - Yury Patskovsky
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
- Laura and Isaac Perlmutter Cancer Center at NYU Langone Health, New York, NY, USA
| | - Larysa Patskovska
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
- Laura and Isaac Perlmutter Cancer Center at NYU Langone Health, New York, NY, USA
| | - Andrew S Ishizuka
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
- Barinthus Biotherapeutics, Germantown, MD, USA
| | - Geoffrey M Lynn
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
- Barinthus Biotherapeutics, Germantown, MD, USA
| | - Robert A Seder
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Michelle Krogsgaard
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA.
- Laura and Isaac Perlmutter Cancer Center at NYU Langone Health, New York, NY, USA.
| | - Nina Bhardwaj
- Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Pl., New York, NY, USA.
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, 1470 Madison Ave., New York, NY, USA.
- Department of Medicine, Division of Hematology and Medical Oncology, Mount Sinai Hospital, New York, NY, USA.
- Parker Institute for Cancer Immunotherapy, Francisco, CA, USA.
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7
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Patskovsky Y, Natarajan A, Patskovska L, Nyovanie S, Joshi B, Morin B, Brittsan C, Huber O, Gordon S, Michelet X, Schmitzberger F, Stein RB, Findeis MA, Hurwitz A, Van Dijk M, Chantzoura E, Yague AS, Pollack Smith D, Buell JS, Underwood D, Krogsgaard M. Molecular mechanism of phosphopeptide neoantigen immunogenicity. Nat Commun 2023; 14:3763. [PMID: 37353482 PMCID: PMC10290117 DOI: 10.1038/s41467-023-39425-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 06/12/2023] [Indexed: 06/25/2023] Open
Abstract
Altered protein phosphorylation in cancer cells often leads to surface presentation of phosphopeptide neoantigens. However, their role in cancer immunogenicity remains unclear. Here we describe a mechanism by which an HLA-B*0702-specific acute myeloid leukemia phosphoneoantigen, pMLL747-755 (EPR(pS)PSHSM), is recognized by a cognate T cell receptor named TCR27, a candidate for cancer immunotherapy. We show that the replacement of phosphoserine P4 with serine or phosphomimetics does not affect pMHC conformation or peptide-MHC affinity but abrogates TCR27-dependent T cell activation and weakens binding between TCR27 and pMHC. Here we describe the crystal structures for TCR27 and cognate pMHC, map of the interface produced by nuclear magnetic resonance, and a ternary complex generated using information-driven protein docking. Our data show that non-covalent interactions between the epitope phosphate group and TCR27 are crucial for TCR specificity. This study supports development of new treatment options for cancer patients through target expansion and TCR optimization.
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Grants
- P30 GM133893 NIGMS NIH HHS
- P30 CA016087 NCI NIH HHS
- U01 CA214354 NCI NIH HHS
- P50 CA225450 NCI NIH HHS
- R01 GM085586 NIGMS NIH HHS
- R01 GM124489 NIGMS NIH HHS
- R01 CA243486 NCI NIH HHS
- S10 OD016343 NIH HHS
- P41 GM118302 NIGMS NIH HHS
- U.S. Department of Health & Human Services | NIH | National Cancer Institute (NCI)
- This work was supported by the NIH grant NIGMS R01 GM124489 (to M.K.), NCI R01 CA243486 (to M.K) and a Sponsored Research Agreement from Agenus to M.K. Results shown in this report are partially derived from work performed at Argonne National Laboratory, Structural Biology Center at the Advanced Photon Source. SBC is operated by UChicago Argonne, LLC, for the U.S. Department of Energy, Office of Biological and Environmental Research under contract DE-AC02-06CH11357. Results in this report are partially derived from work performed at The Center for BioMolecular Structure (CBMS) primarily supported by the National Institutes of Health, National Institute of General Medical Sciences (NIGMS) through a Center Core P30 Grant (P30GM133893), and by the DOE Office of Biological and Environmental Research (KP1607011). As part of NSLS-II, a national user facility at Brookhaven National Laboratory, work performed at the CBMS is supported in part by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences Program under contract number and DE-SC0012704. The NMR spectrometers at the NYU Chemistry Shared Instrumentation Facility were supported by NYU and the NIH Grant 1S10-OD016343. The facilities at the NYSBC were supported by the NIH Grant P41GM118302.
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Affiliation(s)
- Yury Patskovsky
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
- Laura and Isaac Perlmutter Cancer Center at NYU Langone Health, New York, NY, USA
| | - Aswin Natarajan
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
- Laura and Isaac Perlmutter Cancer Center at NYU Langone Health, New York, NY, USA
| | - Larysa Patskovska
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
- Laura and Isaac Perlmutter Cancer Center at NYU Langone Health, New York, NY, USA
| | - Samantha Nyovanie
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
- Laura and Isaac Perlmutter Cancer Center at NYU Langone Health, New York, NY, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Michelle Krogsgaard
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA.
- Laura and Isaac Perlmutter Cancer Center at NYU Langone Health, New York, NY, USA.
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8
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Li L, Ji J, Song F, Hu J. Intercellular Receptor-ligand Binding: Effect of Protein-membrane Interaction. J Mol Biol 2023; 435:167787. [PMID: 35952805 DOI: 10.1016/j.jmb.2022.167787] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 08/03/2022] [Accepted: 08/04/2022] [Indexed: 02/04/2023]
Abstract
Gaining insights into the intercellular receptor-ligand binding is of great importance for understanding numerous physiological and pathological processes, and stimulating new strategies in drug design and discovery. In contrast to the in vitro protein interaction in solution, the anchored receptor and ligand molecules interact with membrane in situ, which affects the intercellular receptor-ligand binding. Here, we review theoretical, simulation and experimental works regarding the regulatory effects of protein-membrane interactions on intercellular receptor-ligand binding mainly from the following aspects: membrane fluctuations, membrane curvature, glycocalyx, and lipid raft. In addition, we discuss biomedical significances and possible research directions to advance the field and highlight the importance of understanding of coupling effects of these factors in pharmaceutical development.
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Affiliation(s)
- Long Li
- Kuang Yaming Honors School and Institute for Brain Sciences, Nanjing University, 210023 Nanjing, China; State Key Laboratory of Nonlinear Mechanics and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, 100190 Beijing, China
| | - Jing Ji
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education Beijing Advanced Innovation Center for Biomedical Engineering School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China.
| | - Fan Song
- State Key Laboratory of Nonlinear Mechanics and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, 100190 Beijing, China; School of Engineering Science, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Jinglei Hu
- Kuang Yaming Honors School and Institute for Brain Sciences, Nanjing University, 210023 Nanjing, China.
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9
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Hossain MA, Anasti K, Watts B, Cronin K, Derking R, Groschel B, Kane AP, Edwards R, Easterhoff D, Zhang J, Rountree W, Ortiz Y, Saunders K, Schief WR, Sanders RW, Verkoczy L, Reth M, Alam SM. B cells expressing IgM B cell receptors of HIV-1 neutralizing antibodies discriminate antigen affinities by sensing binding association rates. Cell Rep 2022; 39:111021. [PMID: 35767950 PMCID: PMC9837990 DOI: 10.1016/j.celrep.2022.111021] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 05/09/2022] [Accepted: 06/08/2022] [Indexed: 01/17/2023] Open
Abstract
HIV-1 envelope (Env) proteins designed to induce neutralizing antibody responses allow study of the role of affinities (equilibrium dissociation constant [KD]) and kinetic rates (association/dissociation rates) on B cell antigen recognition. It is unclear whether affinity discrimination during B cell activation is based solely on Env protein binding KD and whether B cells discriminate among proteins of similar affinities that bind with different kinetic rates. Here, we use a panel of Env proteins and Ramos B cell lines expressing immunoglobulin M (IgM) B cell receptors (BCRs) with specificity for CD4-binding-site broadly neutralizing antibodies to study the role of antigen binding kinetic rates on both early (proximal/distal signaling) and late events (BCR/antigen internalization) in B cell activation. Our results support a kinetic model for B cell activation in which Env protein affinity discrimination is based not on overall KD but on sensing of association rate and a threshold antigen-BCR half-life.
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Affiliation(s)
- Md. Alamgir Hossain
- Human Vaccine Institute, Duke University, Durham, NC, USA,These authors contributed equally
| | - Kara Anasti
- Human Vaccine Institute, Duke University, Durham, NC, USA,These authors contributed equally
| | - Brian Watts
- Human Vaccine Institute, Duke University, Durham, NC, USA
| | - Kenneth Cronin
- Human Vaccine Institute, Duke University, Durham, NC, USA
| | - Ronald Derking
- Human Vaccine Institute, Duke University, Durham, NC, USA
| | - Bettina Groschel
- Department of Immunology & Microbiology and Consortium for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA, USA,IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA, USA
| | | | - R.J. Edwards
- Human Vaccine Institute, Duke University, Durham, NC, USA
| | - David Easterhoff
- Human Vaccine Institute, Duke University, Durham, NC, USA,Present address: Moderna, Inc., Cambridge, MA, USA
| | - Jinsong Zhang
- Applied Biomedical Science Institute, San Diego, CA, USA
| | - Wes Rountree
- Human Vaccine Institute, Duke University, Durham, NC, USA
| | - Yaneth Ortiz
- Department of Molecular Immunology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Kevin Saunders
- Human Vaccine Institute, Duke University, Durham, NC, USA
| | - William R. Schief
- Department of Immunology & Microbiology and Consortium for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA, USA,IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA, USA
| | - Rogier W. Sanders
- Department of Medical Microbiology, Amsterdam UMC, University of Amsterdam, Amsterdam Infection & Immunity Institute, Amsterdam, the Netherlands
| | | | - Michael Reth
- Signaling Research Centers BIOSS and CIBSS, Freiburg, Germany,Department of Molecular Immunology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - S. Munir Alam
- Human Vaccine Institute, Duke University, Durham, NC, USA,Department of Medicine & Pathology, Duke University, Durham, NC, USA,Lead contact,Correspondence:
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10
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Hopkins JR, MacLachlan BJ, Harper S, Sewell AK, Cole DK. Unconventional modes of peptide-HLA-I presentation change the rules of TCR engagement. DISCOVERY IMMUNOLOGY 2022; 1:kyac001. [PMID: 38566908 PMCID: PMC10917088 DOI: 10.1093/discim/kyac001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/18/2022] [Accepted: 04/06/2022] [Indexed: 04/04/2024]
Abstract
The intracellular proteome of virtually every nucleated cell in the body is continuously presented at the cell surface via the human leukocyte antigen class I (HLA-I) antigen processing pathway. This pathway classically involves proteasomal degradation of intracellular proteins into short peptides that can be presented by HLA-I molecules for interrogation by T-cell receptors (TCRs) expressed on the surface of CD8+ T cells. During the initiation of a T-cell immune response, the TCR acts as the T cell's primary sensor, using flexible loops to mould around the surface of the pHLA-I molecule to identify foreign or dysregulated antigens. Recent findings demonstrate that pHLA-I molecules can also be highly flexible and dynamic, altering their shape according to minor polymorphisms between different HLA-I alleles, or interactions with different peptides. These flexible presentation modes have important biological consequences that can, for example, explain why some HLA-I alleles offer greater protection against HIV, or why some cancer vaccine approaches have been ineffective. This review explores how these recent findings redefine the rules for peptide presentation by HLA-I molecules and extend our understanding of the molecular mechanisms that govern TCR-mediated antigen discrimination.
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Affiliation(s)
- Jade R Hopkins
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University School of Medicine, Heath Park, Cardiff, UK
| | - Bruce J MacLachlan
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University School of Medicine, Heath Park, Cardiff, UK
| | | | - Andrew K Sewell
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University School of Medicine, Heath Park, Cardiff, UK
| | - David K Cole
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University School of Medicine, Heath Park, Cardiff, UK
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11
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Rollins ZA, Faller R, George SC. Using Molecular Dynamics Simulations to Interrogate T Cell Receptor Non-Equilibrium Kinetics. Comput Struct Biotechnol J 2022; 20:2124-2133. [PMID: 35832631 PMCID: PMC9092387 DOI: 10.1016/j.csbj.2022.04.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/13/2022] [Accepted: 04/13/2022] [Indexed: 11/30/2022] Open
Abstract
Insights into the atomic-scale interaction of the T Cell Receptor with the peptide Major Histocompatibility Complex. Investigation of the physiochemical features that correspond with T Cell Receptor recognition during dynamic dissociation. Implications of force-dependent non-equilibrium kinetics on T Cell Receptor mechanosensing.
An atomic-scale mechanism of T Cell Receptor (TCR) mechanosensing of peptides in the binding groove of the peptide-major histocompatibility complex (pMHC) may inform the design of novel TCRs for immunotherapies. Using steered molecular dynamics simulations, our study demonstrates that mutations to peptides in the binding groove of the pMHC – which are known to discretely alter the T cell response to an antigen – alter the MHC conformation at equilibrium. This subsequently impacts the overall strength (duration and length) of the TCR-pMHC bond under constant load. Moreover, physiochemical features of the TCR-pMHC dynamic bond strength, such as hydrogen bonds and Lennard-Jones contacts, correlate with the immunogenic response elicited by the specific peptide in the MHC groove. Thus, formation of transient TCR-pMHC bonds is characteristic of immunogenic peptides, and steered molecular dynamics simulations can be used in the overall design strategy of TCRs for immunotherapies.
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Affiliation(s)
- Zachary A. Rollins
- Department of Chemical Engineering, University of California, Davis, 1 Shields Ave, Bainer Hall, Davis, CA 95616, United States
| | - Roland Faller
- Department of Chemical Engineering, University of California, Davis, 1 Shields Ave, Bainer Hall, Davis, CA 95616, United States
| | - Steven C. George
- Department of Biomedical Engineering, University of California, Davis, 451 E. Health Sciences Dr., GBSF 2303, Davis, CA 95616, United States
- Corresponding author at: Department of Biomedical Engineering, 451 E. Health Sciences Drive, Room 2315, University of California, Davis, CA 95616, United States.
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12
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Pettmann J, Huhn A, Abu Shah E, Kutuzov MA, Wilson DB, Dustin ML, Davis SJ, van der Merwe PA, Dushek O. The discriminatory power of the T cell receptor. eLife 2021; 10:e67092. [PMID: 34030769 PMCID: PMC8219380 DOI: 10.7554/elife.67092] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 05/15/2021] [Indexed: 12/20/2022] Open
Abstract
T cells use their T cell receptors (TCRs) to discriminate between lower-affinity self and higher-affinity non-self peptides presented on major histocompatibility complex (pMHC) antigens. Although the discriminatory power of the TCR is widely believed to be near-perfect, technical difficulties have hampered efforts to precisely quantify it. Here, we describe a method for measuring very low TCR/pMHC affinities and use it to measure the discriminatory power of the TCR and the factors affecting it. We find that TCR discrimination, although enhanced compared with conventional cell-surface receptors, is imperfect: primary human T cells can respond to pMHC with affinities as low as KD ∼ 1 mM. The kinetic proofreading mechanism fit our data, providing the first estimates of both the time delay (2.8 s) and number of biochemical steps (2.67) that are consistent with the extraordinary sensitivity of antigen recognition. Our findings explain why self pMHC frequently induce autoimmune diseases and anti-tumour responses, and suggest ways to modify TCR discrimination.
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Affiliation(s)
- Johannes Pettmann
- Sir William Dunn School of Pathology, University of OxfordOxfordUnited Kingdom
- Radcliffe Department of Medicine, Medical Research Council Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of OxfordOxfordUnited Kingdom
| | - Anna Huhn
- Sir William Dunn School of Pathology, University of OxfordOxfordUnited Kingdom
| | - Enas Abu Shah
- Sir William Dunn School of Pathology, University of OxfordOxfordUnited Kingdom
- Kennedy Institute of Rheumatology, University of OxfordOxfordUnited Kingdom
| | - Mikhail A Kutuzov
- Sir William Dunn School of Pathology, University of OxfordOxfordUnited Kingdom
| | - Daniel B Wilson
- Sir William Dunn School of Pathology, University of OxfordOxfordUnited Kingdom
- Boston University, Department of Mathematics and StatisticsBostonUnited States
| | - Michael L Dustin
- Kennedy Institute of Rheumatology, University of OxfordOxfordUnited Kingdom
| | - Simon J Davis
- Radcliffe Department of Medicine, Medical Research Council Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of OxfordOxfordUnited Kingdom
| | | | - Omer Dushek
- Sir William Dunn School of Pathology, University of OxfordOxfordUnited Kingdom
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13
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Różycki B, Weikl TR. Cooperative Stabilization of Close-Contact Zones Leads to Sensitivity and Selectivity in T-Cell Recognition. Cells 2021; 10:1023. [PMID: 33926103 PMCID: PMC8145674 DOI: 10.3390/cells10051023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/19/2021] [Accepted: 04/20/2021] [Indexed: 11/30/2022] Open
Abstract
T cells are sensitive to 1 to 10 foreign-peptide-MHC complexes among a vast majority of self-peptide-MHC complexes, and discriminate selectively between peptide-MHC complexes that differ not much in their binding affinity to T-cell receptors (TCRs). Quantitative models that aim to explain this sensitivity and selectivity largely focus on single TCR/peptide-MHC complexes, but T cell adhesion involves a multitude of different complexes. In this article, we demonstrate in a three-dimensional computational model of T-cell adhesion that the cooperative stabilization of close-contact zones is sensitive to one to three foreign-peptide-MHC complexes and occurs at a rather sharp threshold affinity of these complexes, which implies selectivity. In these close-contact zones with lateral extensions of hundred to several hundred nanometers, few TCR/foreign-peptide-MHC complexes and many TCR/self-peptide-MHC complexes are segregated from LFA-1/ICAM-1 complexes that form at larger membrane separations. Previous high-resolution microscopy experiments indicate that the sensitivity and selectivity in the formation of closed-contact zones reported here are relevant for T-cell recognition, because the stabilization of close-contact zones by foreign, agonist peptide-MHC complexes precedes T-cell signaling and activation in the experiments.
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Affiliation(s)
- Bartosz Różycki
- Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw, Poland;
| | - Thomas R. Weikl
- Department of Theory and Bio-Systems, Max Planck Institut of Colloids and Interfaces, Am Mühlenberg 1, 14476 Potsdam, Germany
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14
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Johnson DK, Magoffin W, Myers SJ, Finnell JG, Hancock JC, Orton TS, Persaud SP, Christensen KA, Weber KS. CD4 Inhibits Helper T Cell Activation at Lower Affinity Threshold for Full-Length T Cell Receptors Than Single Chain Signaling Constructs. Front Immunol 2021; 11:561889. [PMID: 33542711 PMCID: PMC7851051 DOI: 10.3389/fimmu.2020.561889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 11/30/2020] [Indexed: 11/13/2022] Open
Abstract
CD4+ T cells are crucial for effective repression and elimination of cancer cells. Despite a paucity of CD4+ T cell receptor (TCR) clinical studies, CD4+ T cells are primed to become important therapeutics as they help circumvent tumor antigen escape and guide multifactorial immune responses. However, because CD8+ T cells directly kill tumor cells, most research has focused on the attributes of CD8+ TCRs. Less is known about how TCR affinity and CD4 expression affect CD4+ T cell activation in full length TCR (flTCR) and TCR single chain signaling (TCR-SCS) formats. Here, we generated an affinity panel of TCRs from CD4+ T cells and expressed them in flTCR and three TCR-SCS formats modeled after chimeric antigen receptors (CARs) to understand the contributions of TCR-pMHCII affinity, TCR format, and coreceptor CD4 interactions on CD4+ T cell activation. Strikingly, the coreceptor CD4 inhibited intermediate and high affinity TCR-construct activation by Lck-dependent and -independent mechanisms. These inhibition mechanisms had unique affinity thresholds dependent on the TCR format. Intracellular construct formats affected the tetramer staining for each TCR as well as IL-2 production. IL-2 production was promoted by increased TCR-pMHCII affinity and the flTCR format. Thus, CD4+ T cell therapy development should consider TCR affinity, CD4 expression, and construct format.
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Affiliation(s)
- Deborah K Johnson
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT, United States
| | - Wyatt Magoffin
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT, United States
| | - Sheldon J Myers
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT, United States
| | - Jordan G Finnell
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, United States
| | - John C Hancock
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT, United States
| | - Taylor S Orton
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT, United States
| | - Stephen P Persaud
- Division of Laboratory and Genomic Medicine, Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO, United States
| | - Kenneth A Christensen
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, United States
| | - K Scott Weber
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT, United States
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15
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A biomimetic five-module chimeric antigen receptor ( 5MCAR) designed to target and eliminate antigen-specific T cells. Proc Natl Acad Sci U S A 2020; 117:28950-28959. [PMID: 33139567 DOI: 10.1073/pnas.2012495117] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
T cells express clonotypic T cell receptors (TCRs) that recognize peptide antigens in the context of class I or II MHC molecules (pMHCI/II). These receptor modules associate with three signaling modules (CD3γε, δε, and ζζ) and work in concert with a coreceptor module (either CD8 or CD4) to drive T cell activation in response to pMHCI/II. Here, we describe a first-generation biomimetic five-module chimeric antigen receptor (5MCAR). We show that 1) chimeric receptor modules built with the ectodomains of pMHCII assemble with CD3 signaling modules into complexes that redirect cytotoxic T lymphocyte (CTL) specificity and function in response to the clonotypic TCRs of pMHCII-specific CD4+ T cells, and 2) surrogate coreceptor modules enhance the function of these complexes. Furthermore, we demonstrate that adoptively transferred 5MCAR-CTLs can mitigate type I diabetes by targeting autoimmune CD4+ T cells in NOD mice. This work provides a framework for the construction of biomimetic 5MCARs that can be used as tools to study the impact of particular antigen-specific T cells in immune responses, and may hold potential for ameliorating diseases mediated by pathogenic T cells.
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16
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Kolawole EM, Lamb TJ, Evavold BD. Relationship of 2D Affinity to T Cell Functional Outcomes. Int J Mol Sci 2020; 21:E7969. [PMID: 33120989 PMCID: PMC7662510 DOI: 10.3390/ijms21217969] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/14/2020] [Accepted: 10/23/2020] [Indexed: 12/11/2022] Open
Abstract
T cells are critical for a functioning adaptive immune response and a strong correlation exists between T cell responses and T cell receptor (TCR): peptide-loaded MHC (pMHC) binding. Studies that utilize pMHC tetramer, multimers, and assays of three-dimensional (3D) affinity have provided advancements in our understanding of T cell responses across different diseases. However, these technologies focus on higher affinity and avidity T cells while missing the lower affinity responders. Lower affinity TCRs in expanded polyclonal populations almost always constitute a significant proportion of the response with cells mediating different effector functions associated with variation in the proportion of high and low affinity T cells. Since lower affinity T cells expand and are functional, a fully inclusive view of T cell responses is required to accurately interpret the role of affinity for adaptive T cell immunity. For example, low affinity T cells are capable of inducing autoimmune disease and T cells with an intermediate affinity have been shown to exhibit an optimal anti-tumor response. Here, we focus on how affinity of the TCR may relate to T cell phenotype and provide examples where 2D affinity influences functional outcomes.
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Affiliation(s)
| | | | - Brian D. Evavold
- Department of Pathology, University of Utah, 15 N Medical Drive, Salt Lake City, UT 84112, USA; (E.M.K.); (T.J.L.)
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17
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Lee CH, Salio M, Napolitani G, Ogg G, Simmons A, Koohy H. Predicting Cross-Reactivity and Antigen Specificity of T Cell Receptors. Front Immunol 2020; 11:565096. [PMID: 33193332 PMCID: PMC7642207 DOI: 10.3389/fimmu.2020.565096] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Accepted: 09/07/2020] [Indexed: 12/13/2022] Open
Abstract
Adaptive immune recognition is mediated by specific interactions between heterodimeric T cell receptors (TCRs) and their cognate peptide-MHC (pMHC) ligands, and the methods to accurately predict TCR:pMHC interaction would have profound clinical, therapeutic and pharmaceutical applications. Herein, we review recent developments in predicting cross-reactivity and antigen specificity of TCR recognition. We discuss current experimental and computational approaches to investigate cross-reactivity and antigen-specificity of TCRs and highlight how integrating kinetic, biophysical and structural features may offer valuable insights in modeling immunogenicity. We further underscore the close inter-relationship of these two interconnected notions and the need to investigate each in the light of the other for a better understanding of T cell responsiveness for the effective clinical applications.
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Affiliation(s)
- Chloe H. Lee
- MRC Human Immunology Unit, Medical Research Council (MRC) Weatherall Institute of Molecular Medicine (WIMM), John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
- MRC WIMM Centre for Computational Biology, Medical Research Council (MRC) Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Mariolina Salio
- MRC Human Immunology Unit, Medical Research Council (MRC) Weatherall Institute of Molecular Medicine (WIMM), John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Giorgio Napolitani
- MRC Human Immunology Unit, Medical Research Council (MRC) Weatherall Institute of Molecular Medicine (WIMM), John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Graham Ogg
- MRC Human Immunology Unit, Medical Research Council (MRC) Weatherall Institute of Molecular Medicine (WIMM), John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Alison Simmons
- MRC Human Immunology Unit, Medical Research Council (MRC) Weatherall Institute of Molecular Medicine (WIMM), John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
- Translational Gastroenterology Unit, John Radcliffe Hospital, Oxford, United Kingdom
| | - Hashem Koohy
- MRC Human Immunology Unit, Medical Research Council (MRC) Weatherall Institute of Molecular Medicine (WIMM), John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
- MRC WIMM Centre for Computational Biology, Medical Research Council (MRC) Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
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18
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Teimouri H, Kolomeisky AB. Relaxation Times of Ligand-Receptor Complex Formation Control T Cell Activation. Biophys J 2020; 119:182-189. [PMID: 32562619 DOI: 10.1016/j.bpj.2020.06.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/20/2020] [Accepted: 06/01/2020] [Indexed: 11/18/2022] Open
Abstract
One of the most important functions of immune T cells is to recognize the presence of the pathogen-derived ligands and to quickly respond to them while at the same time not responding to its own ligands. This is known as absolute discrimination, and it is one of the most challenging phenomena to explain. The effectiveness of pathogen detection by T cell receptor is limited by chemical similarity of foreign and self-peptides and very low concentrations of foreign ligands. We propose a new mechanism of how absolute discrimination by T cells might function. It is suggested that the decision to activate or not to activate the immune response is controlled by the time to reach the stationary concentration of the T-cell-receptor-ligand-activated complex, which transfers the signal to downstream cellular biochemical networks. Our theoretical method models T cell receptor phosphorylation events as a sequence of stochastic transitions between discrete biochemical states, and this allows us to explicitly describe the dynamical properties of the system. It is found that the proposed criterion on the relaxation times is able to explain available experimental observations. In addition, we suggest that the level of stochastic noise might be an additional factor in the activation mechanisms. Furthermore, our theoretical approach explicitly analyzes the relationships between speed, sensitivity, and specificity of T cell functioning, which are the main characteristics of the process. Thus, it clarifies the molecular picture of T cell activation in immune response.
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Affiliation(s)
- Hamid Teimouri
- Department of Chemistry, Rice University, Houston, Texas; Center for Theoretical Biological Physics, Rice University, Houston, Texas
| | - Anatoly B Kolomeisky
- Department of Chemistry, Rice University, Houston, Texas; Center for Theoretical Biological Physics, Rice University, Houston, Texas; Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas; Department of Physics and Astronomy, Rice University, Houston, Texas.
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19
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Coles CH, McMurran C, Lloyd A, Hock M, Hibbert L, Raman MCC, Hayes C, Lupardus P, Cole DK, Harper S. T cell receptor interactions with human leukocyte antigen govern indirect peptide selectivity for the cancer testis antigen MAGE-A4. J Biol Chem 2020; 295:11486-11494. [PMID: 32532817 PMCID: PMC7450119 DOI: 10.1074/jbc.ra120.014016] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/11/2020] [Indexed: 12/18/2022] Open
Abstract
T cell-mediated immunity is governed primarily by T cell receptor (TCR) recognition of peptide-human leukocyte antigen (pHLA) complexes and is essential for immunosurveillance and disease control. This interaction is generally stabilized by interactions between the HLA surface and TCR germline-encoded complementarity-determining region (CDR) loops 1 and 2, whereas peptide selectivity is guided by direct interactions with the TCR CDR3 loops. Here, we solved the structure of a newly identified TCR in complex with a clinically relevant peptide derived from the cancer testis antigen melanoma antigen-A4 (MAGE-A4). The TCR bound pHLA in a position shifted toward the peptide's N terminus. This enabled the TCR to achieve peptide selectivity via an indirect mechanism, whereby the TCR sensed the first residue of the peptide through HLA residue Trp-167, which acted as a tunable gateway. Amino acid substitutions at peptide position 1 predicted to alter the HLA Trp-167 side-chain conformation abrogated TCR binding, indicating that this indirect binding mechanism is essential for peptide recognition. These findings extend our understanding of the molecular rules that underpin antigen recognition by TCRs and have important implications for the development of TCR-based therapies.
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Affiliation(s)
| | | | | | | | | | | | | | | | - David K Cole
- Immunocore Ltd., Abingdon, United Kingdom .,Cardiff University School of Medicine, Cardiff, United Kingdom
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20
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Hopkins JR, Crean RM, Catici DAM, Sewell AK, Arcus VL, Van der Kamp MW, Cole DK, Pudney CR. Peptide cargo tunes a network of correlated motions in human leucocyte antigens. FEBS J 2020; 287:3777-3793. [PMID: 32134551 PMCID: PMC8651013 DOI: 10.1111/febs.15278] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 02/20/2020] [Accepted: 03/03/2020] [Indexed: 11/28/2022]
Abstract
Most biomolecular interactions are typically thought to increase the (local) rigidity of a complex, for example, in drug‐target binding. However, detailed analysis of specific biomolecular complexes can reveal a more subtle interplay between binding and rigidity. Here, we focussed on the human leucocyte antigen (HLA), which plays a crucial role in the adaptive immune system by presenting peptides for recognition by the αβ T‐cell receptor (TCR). The role that the peptide plays in tuning HLA flexibility during TCR recognition is potentially crucial in determining the functional outcome of an immune response, with obvious relevance to the growing list of immunotherapies that target the T‐cell compartment. We have applied high‐pressure/temperature perturbation experiments, combined with molecular dynamics simulations, to explore the drivers that affect molecular flexibility for a series of different peptide–HLA complexes. We find that different peptide sequences affect peptide–HLA flexibility in different ways, with the peptide cargo tuning a network of correlated motions throughout the pHLA complex, including in areas remote from the peptide‐binding interface, in a manner that could influence T‐cell antigen discrimination.
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Affiliation(s)
- Jade R Hopkins
- Division of Infection and Immunity, School of Medicine, Cardiff University, UK
| | - Rory M Crean
- Department of Biology and Biochemistry, University of Bath, UK.,Doctoral Training Centre in Sustainable Chemical Technologies, University of Bath, UK
| | | | - Andrew K Sewell
- Division of Infection and Immunity, School of Medicine, Cardiff University, UK
| | - Vickery L Arcus
- School of Science, Faculty of Science and Engineering, University of Waikato, Hamilton, New Zealand
| | | | - David K Cole
- Division of Infection and Immunity, School of Medicine, Cardiff University, UK
| | - Christopher R Pudney
- Department of Biology and Biochemistry, University of Bath, UK.,Centre for Therapeutic Innovation, University of Bath, UK
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21
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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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22
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Rushdi M, Li K, Yuan Z, Travaglino S, Grakoui A, Zhu C. Mechanotransduction in T Cell Development, Differentiation and Function. Cells 2020; 9:E364. [PMID: 32033255 PMCID: PMC7072571 DOI: 10.3390/cells9020364] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Revised: 01/16/2020] [Accepted: 01/17/2020] [Indexed: 02/07/2023] Open
Abstract
Cells in the body are actively engaging with their environments that include both biochemical and biophysical aspects. The process by which cells convert mechanical stimuli from their environment to intracellular biochemical signals is known as mechanotransduction. Exemplifying the reliance on mechanotransduction for their development, differentiation and function are T cells, which are central to adaptive immune responses. T cell mechanoimmunology is an emerging field that studies how T cells sense, respond and adapt to the mechanical cues that they encounter throughout their life cycle. Here we review different stages of the T cell's life cycle where existing studies have shown important effects of mechanical force or matrix stiffness on a T cell as sensed through its surface molecules, including modulating receptor-ligand interactions, inducing protein conformational changes, triggering signal transduction, amplifying antigen discrimination and ensuring directed targeted cell killing. We suggest that including mechanical considerations in the immunological studies of T cells would inform a more holistic understanding of their development, differentiation and function.
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Affiliation(s)
- Muaz Rushdi
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; (M.R.); (K.L.); (S.T.)
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA;
| | - Kaitao Li
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; (M.R.); (K.L.); (S.T.)
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA;
| | - Zhou Yuan
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA;
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30313, USA
| | - Stefano Travaglino
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; (M.R.); (K.L.); (S.T.)
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA;
| | - Arash Grakoui
- Emory Vaccine Center, Division of Microbiology and Immunology, Yerkes Research Primate Center, Emory University School of Medicine, Atlanta, GA 30329, USA;
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Cheng Zhu
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; (M.R.); (K.L.); (S.T.)
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA;
- George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30313, USA
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23
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Abstract
The immune response is orchestrated by a variety of immune cells. The function of each cell is determined by the collective signals from various immunoreceptors, whose expression and activity depend on the developmental stages of the cell and its environmental context. Recent studies have highlighted the presence of mechanical force on several immunoreceptor-ligand pairs and the important role of force in regulating their interaction and function. In this Perspective, we use the T cell antigen receptor as an example with which to review the current understanding of the mechanosensing properties of immunoreceptors. We discuss the types of forces that immunoreceptors may encounter and the effects of force on ligand bonding, conformational change and the triggering of immunoreceptors, as well as the effects of force on the downstream signal transduction, cell-fate decisions and effector function of immune cells.
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24
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25
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Fodor J, Riley BT, Kass I, Buckle AM, Borg NA. The Role of Conformational Dynamics in Abacavir-Induced Hypersensitivity Syndrome. Sci Rep 2019; 9:10523. [PMID: 31324847 PMCID: PMC6642150 DOI: 10.1038/s41598-019-47001-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 07/04/2019] [Indexed: 02/06/2023] Open
Abstract
Abacavir is an antiretroviral drug used to reduce human immunodeficiency virus (HIV) replication and decrease the risk of developing acquired immune deficiency syndrome (AIDS). However, its therapeutic value is diminished by the fact that it is associated with drug hypersensitivity reactions in up to 8% of treated patients. This hypersensitivity is strongly associated with patients carrying human leukocyte antigen (HLA)-B*57:01, but not patients carrying closely related alleles. Abacavir’s specificity to HLA-B*57:01 is attributed to its binding site within the peptide-binding cleft and subsequent influence of the repertoire of peptides that can bind HLA-B*57:01. To further our understanding of abacavir-induced hypersensitivity we used molecular dynamics (MD) to analyze the dynamics of three different peptides bound to HLA-B*57:01 in the presence and absence of abacavir or abacavir analogues. We found that abacavir and associated peptides bind to HLA-B*57:01 in a highly diverse range of conformations that are not apparent from static crystallographic snapshots, but observed no difference in either the conformations, nor degree of flexibility when compared to abacavir-unbound systems. Our results support hypersensitivity models in which abacavir-binding alters the conformational ensemble of neopeptides, so as to favour exposed peptide surfaces that are no longer recognized as self by circulating CD8+ T cells, and are conducive to TCR binding. Our findings highlight the need to also consider the role of dynamics in understanding drug-induced hypersensitivities at the molecular and mechanistic level. This additional insight can help inform the chemical modification of abacavir to prevent hypersensitivity reactions in HLA-B*57:01+ HIV patients whilst retaining potent antiretroviral activity.
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Affiliation(s)
- James Fodor
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia
| | - Blake T Riley
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia
| | - Itamar Kass
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia.,The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Ashley M Buckle
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia.
| | - Natalie A Borg
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, 3800, Australia.
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26
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Xu J, Jo J. Broad cross-reactivity of the T-cell repertoire achieves specific and sufficiently rapid target searching. J Theor Biol 2019; 466:119-127. [PMID: 30699327 DOI: 10.1016/j.jtbi.2019.01.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 12/20/2018] [Accepted: 01/24/2019] [Indexed: 11/29/2022]
Abstract
The molecular recognition of T-cell receptors is the hallmark of the adaptive immunity. Given the finiteness of the T-cell repertoire, individual T-cell receptors are necessary to be cross-reactive to multiple antigenic peptides. In this study, we quantify the variability of the cross-reactivity by using a string model that estimates the binding affinity between two sequences of amino acids. We examine sequences of 10,000 human T-cell receptors and 10,000 antigenic peptides, and obtain a full spectrum of cross-reactivity of the receptor-peptide binding. Then, we find that the cross-reactivity spectrum is broad. Some T-cells are reactive to 1000 peptides, but some T-cells are reactive to only one or two peptides. Since the degree of cross-reactivity has a correlation with the (un)binding affinity of receptors, we further investigate how the broad cross-reactivity affects the target searching of T-cells. High cross-reactive T-cells may not require many trials for searching correct targets, but they may spend long time to unbind from incorrect targets. In contrast, low cross-reactive T-cells may not spend long time to ignore incorrect targets, but they require many trials for screening correct targets. We evaluate this hypothesis, and show that the broad cross-reactivity of the natural T-cell repertoire can balance the trade-off between the rapid screening and unbinding penalty.
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Affiliation(s)
- Jin Xu
- Asia Pacific Center for Theoretical Physics (APCTP), 67 Cheongam-ro, Pohang, 37673, South Korea; Department of Physics, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Pohang, 37673, South Korea
| | - Junghyo Jo
- Asia Pacific Center for Theoretical Physics (APCTP), 67 Cheongam-ro, Pohang, 37673, South Korea; Department of Physics, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Pohang, 37673, South Korea; School of Computational Sciences, Korea Institute for Advanced Study (KIAS), 85 Hoegiro, Seoul, 02455, South Korea; Department of Statistics, Keimyung University, 1095 Dalgubeol-daero, Daegu, 42601, South Korea.
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27
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Yousefi OS, Günther M, Hörner M, Chalupsky J, Wess M, Brandl SM, Smith RW, Fleck C, Kunkel T, Zurbriggen MD, Höfer T, Weber W, Schamel WW. Optogenetic control shows that kinetic proofreading regulates the activity of the T cell receptor. eLife 2019; 8:42475. [PMID: 30947807 PMCID: PMC6488296 DOI: 10.7554/elife.42475] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 03/05/2019] [Indexed: 12/18/2022] Open
Abstract
The immune system distinguishes between self and foreign antigens. The kinetic proofreading (KPR) model proposes that T cells discriminate self from foreign ligands by the different ligand binding half-lives to the T cell receptor (TCR). It is challenging to test KPR as the available experimental systems fall short of only altering the binding half-lives and keeping other parameters of the interaction unchanged. We engineered an optogenetic system using the plant photoreceptor phytochrome B (PhyB) as a ligand to selectively control the dynamics of ligand binding to the TCR by light. This opto-ligand-TCR system was combined with the unique property of PhyB to continuously cycle between the binding and non-binding states under red light, with the light intensity determining the cycling rate and thus the binding duration. Mathematical modeling of our experimental datasets showed that indeed the ligand-TCR interaction half-life is the decisive factor for activating downstream TCR signaling, substantiating KPR.
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Affiliation(s)
- O Sascha Yousefi
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany.,Spemann Graduate School of Biology and Medicine, University of Freiburg, Freiburg, Germany
| | - Matthias Günther
- Division of Theoretical Systems Biology, German Cancer Research Center, Heidelberg, Germany.,BioQuant Center, University of Heidelberg, Heidelberg, Germany
| | - Maximilian Hörner
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Julia Chalupsky
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany.,Center for Chronic Immunodeficiency, Medical Center Freiburg and Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Maximilian Wess
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Simon M Brandl
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Robert W Smith
- Laboratory of Systems and Synthetic Biology, Wageningen University and Research, Wageningen, Netherlands
| | - Christian Fleck
- Laboratory of Systems and Synthetic Biology, Wageningen University and Research, Wageningen, Netherlands
| | - Tim Kunkel
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Matias D Zurbriggen
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany.,Institute of Synthetic Biology and Cluster of Excellence on Plant Sciences, University of Düsseldorf, Düsseldorf, Germany
| | - Thomas Höfer
- Division of Theoretical Systems Biology, German Cancer Research Center, Heidelberg, Germany.,BioQuant Center, University of Heidelberg, Heidelberg, Germany
| | - Wilfried Weber
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Wolfgang Wa Schamel
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany.,Laboratory of Systems and Synthetic Biology, Wageningen University and Research, Wageningen, Netherlands
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28
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Harrison DL, Fang Y, Huang J. T-Cell Mechanobiology: Force Sensation, Potentiation, and Translation. FRONTIERS IN PHYSICS 2019; 7:45. [PMID: 32601597 PMCID: PMC7323161 DOI: 10.3389/fphy.2019.00045] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A T cell is a sensitive self-referential mechanical sensor. Mechanical forces influence the recognition, activation, differentiation, and function throughout the lifetime of a T cell. T cells constantly perceive and respond to physical stimuli through their surface receptors, cytoskeleton, and subcellular structures. Surface receptors receive physical cues in the form of forces generated through receptor-ligand binding events, which are dynamically regulated by contact tension, shear stress, and substrate rigidity. The resulting mechanotransduction not only influences T-cell recognition and signaling but also possibly modulates cell metabolism and gene expression. Moreover, forces also dynamically regulate the deformation, organization, and translocation of cytoskeleton and subcellular structures, leading to changes in T-cell mobility, migration, and infiltration. However, the roles and mechanisms of how mechanical forces modulate T-cell recognition, signaling, metabolism, and gene expression, are largely unknown and underappreciated. Here, we review recent technological and scientific advances in T-cell mechanobiology, discuss possible roles and mechanisms of T-cell mechanotransduction, and propose new research directions of this emerging field in health and disease.
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Affiliation(s)
- Devin L. Harrison
- The Graduate Program in Biophysical Sciences, The University of Chicago, Chicago, IL, United States
| | - Yun Fang
- The Graduate Program in Biophysical Sciences, The University of Chicago, Chicago, IL, United States
- Section of Pulmonary and Critical Care, Department of Medicine, The University of Chicago, Chicago, IL, United States
| | - Jun Huang
- The Graduate Program in Biophysical Sciences, The University of Chicago, Chicago, IL, United States
- Institute for Molecular Engineering, The University of Chicago, Chicago, IL, United States
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29
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Gupta PK, McIntosh CM, Chong AS, Alegre ML. The pursuit of transplantation tolerance: new mechanistic insights. Cell Mol Immunol 2019; 16:324-333. [PMID: 30760917 DOI: 10.1038/s41423-019-0203-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 01/17/2019] [Indexed: 12/11/2022] Open
Abstract
Donor-specific transplantation tolerance that enables weaning from immunosuppressive drugs but retains immune competence to non-graft antigens has been a lasting pursuit since the discovery of neonatal tolerance. More recently, efforts have been devoted not only to understanding how transplantation tolerance can be induced but also the mechanisms necessary to maintain it as well as how inflammatory exposure challenges its durability. This review focuses on recent advances regarding key peripheral mechanisms of T cell tolerance, with the underlying hypothesis that a combination of several of these mechanisms may afford a more robust and durable tolerance and that a better understanding of these individual pathways may permit longitudinal tracking of tolerance following clinical transplantation to serve as biomarkers. This review may enable a personalized assessment of the degree of tolerance in individual patients and the opportunity to strengthen the robustness of peripheral tolerance.
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Affiliation(s)
- Pawan K Gupta
- Department of Medicine, The University of Chicago, Chicago, IL, 60637, USA
| | | | - Anita S Chong
- Department of Surgery, The University of Chicago, Chicago, IL, 60637, USA
| | - Maria-Luisa Alegre
- Department of Medicine, The University of Chicago, Chicago, IL, 60637, USA.
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30
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Lin JJY, Low-Nam ST, Alfieri KN, McAffee DB, Fay NC, Groves JT. Mapping the stochastic sequence of individual ligand-receptor binding events to cellular activation: T cells act on the rare events. Sci Signal 2019; 12:12/564/eaat8715. [PMID: 30647147 DOI: 10.1126/scisignal.aat8715] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
T cell receptor (TCR) binding to agonist peptide major histocompatibility complex (pMHC) triggers signaling events that initiate T cell responses. This system is remarkably sensitive, requiring only a few binding events to successfully activate a cellular response. On average, activating pMHC ligands exhibit mean dwell times of at least a few seconds when bound to the TCR. However, a T cell accumulates pMHC-TCR interactions as a stochastic series of discrete, single-molecule binding events whose individual dwell times are broadly distributed. With activation occurring in response to only a handful of such binding events, individual cells are unlikely to experience the average binding time. Here, we mapped the ensemble of pMHC-TCR binding events in space and time while simultaneously monitoring cellular activation. Our findings revealed that T cell activation hinges on rare, long-dwell time binding events that are an order of magnitude longer than the average agonist pMHC-TCR dwell time. Furthermore, we observed that short pMHC-TCR binding events that were spatially correlated and temporally sequential led to cellular activation. These observations indicate that T cell antigen discrimination likely occurs by sensing the tail end of the pMHC-TCR binding dwell time distribution rather than its average properties.
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Affiliation(s)
- Jenny J Y Lin
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Shalini T Low-Nam
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Katherine N Alfieri
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Darren B McAffee
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Nicole C Fay
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Jay T Groves
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA.
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31
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Tu E, Chia CPZ, Chen W, Zhang D, Park SA, Jin W, Wang D, Alegre ML, Zhang YE, Sun L, Chen W. T Cell Receptor-Regulated TGF-β Type I Receptor Expression Determines T Cell Quiescence and Activation. Immunity 2019; 48:745-759.e6. [PMID: 29669252 DOI: 10.1016/j.immuni.2018.03.025] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 01/16/2018] [Accepted: 03/22/2018] [Indexed: 12/12/2022]
Abstract
It is unclear how quiescence is enforced in naive T cells, but activation by foreign antigens and self-antigens is allowed, despite the presence of inhibitory signals. We showed that active transforming growth factor β (TGF-β) signaling was present in naive T cells, and T cell receptor (TCR) engagement reduced TGF-β signaling during T cell activation by downregulating TGF-β type 1 receptor (TβRI) through activation of caspase recruitment domain-containing protein 11 (CARD11) and nuclear factor κB (NF-κB). TGF-β prevented TCR-mediated TβRI downregulation, but this was abrogated by interleukin-6 (IL-6). Mitigation of TCR-mediated TβRI downregulation through overexpression of TβRI in naive and activated T cells rendered T cells less responsive and suppressed autoimmunity. Naive T cells in autoimmune patients exhibited reduced TβRI expression and increased TCR-driven proliferation compared to healthy subjects. Thus, TCR-mediated regulation of TβRI-TGF-β signaling acts as a crucial criterion to determine T cell quiescence and activation.
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Affiliation(s)
- Eric Tu
- Mucosal Immunology Section, NIDCR, NIH, Bethesda, MD 20892, USA
| | - Cheryl P Z Chia
- Mucosal Immunology Section, NIDCR, NIH, Bethesda, MD 20892, USA
| | - Weiwei Chen
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Dunfang Zhang
- Mucosal Immunology Section, NIDCR, NIH, Bethesda, MD 20892, USA
| | - Sang A Park
- Mucosal Immunology Section, NIDCR, NIH, Bethesda, MD 20892, USA
| | - Wenwen Jin
- Mucosal Immunology Section, NIDCR, NIH, Bethesda, MD 20892, USA
| | - Dandan Wang
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | | | - Ying E Zhang
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, NIH, Bethesda, MD 20892, USA
| | - Lingyun Sun
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.
| | - WanJun Chen
- Mucosal Immunology Section, NIDCR, NIH, Bethesda, MD 20892, USA.
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32
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Riley TP, Baker BM. The intersection of affinity and specificity in the development and optimization of T cell receptor based therapeutics. Semin Cell Dev Biol 2018; 84:30-41. [DOI: 10.1016/j.semcdb.2017.10.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 10/07/2017] [Accepted: 10/17/2017] [Indexed: 12/29/2022]
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33
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Ward DE, Fay BL, Adejuwon A, Han H, Ma Z. Chimeric Antigen Receptors Based on Low Affinity Mutants of FcεRI Re-direct T Cell Specificity to Cells Expressing Membrane IgE. Front Immunol 2018; 9:2231. [PMID: 30364107 PMCID: PMC6191488 DOI: 10.3389/fimmu.2018.02231] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 09/07/2018] [Indexed: 12/31/2022] Open
Abstract
IgE is the key mediator of allergic responses. Omalizumab, an IgE-specific monoclonal antibody that depletes IgE, is effective for treating severe allergic asthma. The need for frequent administration of the expensive drug, however, limits its applications. Taking advantage of T cell memory, adoptive T cell therapy (ACT) targeting IgE-producing cells has the potential to achieve long-term suppression of IgE and relief of symptoms for severe allergic diseases. The transmembrane form of IgE (mIgE), which is present on all IgE-producing cells, serves as an excellent molecular target for ACT that employs chimeric antigen receptors (CARs). Here, we designed and tested CARs that use the extracellular domain of high affinity IgE receptor, FcεRIα, for mIgE recognition. When expressed on Jurkat T cells, FcεRIα-based CARs mediated robust responses in terms of CD69 upregulation to U266 myeloma cells expressing low levels of mIgE. FcεRIα-based CARs specifically recognized cells expressing mIgE, but not cells with secreted IgE captured through Fcε receptors. CAR+ Jurkat cells did not respond to LAD2 mast cells with secreted IgE bound through FcεRI or Ramos cells with secreted IgE bound through FcεRII. Co-culture of CAR+ Jurkat cells and LAD2 mast cells with IgE bound did not trigger LAD2 cell degranulation. The activity of CAR using wild type FcεRIα for mIgE binding was inhibited by the presence secreted IgE, which likely blocked CAR-mIgE interaction. The activities of CARs using low affinity mutants of FcεRIα, however, tolerated secreted IgE at relatively high concentrations. Moreover, primary human CD8+ T cells expressing a low affinity mutant CAR responded to U266 cells with INFγ production and cytotoxicity despite the presence of secreted IgE. The potency, specificity, and robustness of our CAR design, combined with repaid advances in the safety of ACT, hold promise for novel and highly effective cell-based therapies against severe allergic diseases.
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Affiliation(s)
- Dana E Ward
- Department of Biomedical Research, Nemours/A.I. duPont Hospital for Children, Wilmington, DE, United States
| | - Brittany L Fay
- Department of Biomedical Research, Nemours/A.I. duPont Hospital for Children, Wilmington, DE, United States
| | - Adebomi Adejuwon
- Department of Biological Sciences, University of Delaware, Newark, DE, United States
| | - Huihui Han
- Department of Biomedical Research, Nemours/A.I. duPont Hospital for Children, Wilmington, DE, United States
| | - Zhengyu Ma
- Department of Biomedical Research, Nemours/A.I. duPont Hospital for Children, Wilmington, DE, United States
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34
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Paul S, Karosiene E, Dhanda SK, Jurtz V, Edwards L, Nielsen M, Sette A, Peters B. Determination of a Predictive Cleavage Motif for Eluted Major Histocompatibility Complex Class II Ligands. Front Immunol 2018; 9:1795. [PMID: 30127785 PMCID: PMC6087742 DOI: 10.3389/fimmu.2018.01795] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 07/20/2018] [Indexed: 01/13/2023] Open
Abstract
CD4+ T cells have a major role in regulating immune responses. They are activated by recognition of peptides mostly generated from exogenous antigens through the major histocompatibility complex (MHC) class II pathway. Identification of epitopes is important and computational prediction of epitopes is used widely to save time and resources. Although there are algorithms to predict binding affinity of peptides to MHC II molecules, no accurate methods exist to predict which ligands are generated as a result of natural antigen processing. We utilized a dataset of around 14,000 naturally processed ligands identified by mass spectrometry of peptides eluted from MHC class II expressing cells to investigate the existence of sequence signatures potentially related to the cleavage mechanisms that liberate the presented peptides from their source antigens. This analysis revealed preferred amino acids surrounding both N- and C-terminuses of ligands, indicating sequence-specific cleavage preferences. We used these cleavage motifs to develop a method for predicting naturally processed MHC II ligands, and validated that it had predictive power to identify ligands from independent studies. We further confirmed that prediction of ligands based on cleavage motifs could be combined with predictions of MHC binding, and that the combined prediction had superior performance. However, when attempting to predict CD4+ T cell epitopes, either alone or in combination with MHC binding predictions, predictions based on the cleavage motifs did not show predictive power. Given that peptides identified as epitopes based on CD4+ T cell reactivity typically do not have well-defined termini, it is possible that motifs are present but outside of the mapped epitope. Our attempts to take that into account computationally did not show any sign of an increased presence of cleavage motifs around well-characterized CD4+ T cell epitopes. While it is possible that our attempts to translate the cleavage motifs in MHC II ligand elution data into T cell epitope predictions were suboptimal, other possible explanations are that the cleavage signal is too diluted to be detected, or that elution data are enriched for ligands generated through an antigen processing and presentation pathway that is less frequently utilized for T cell epitopes.
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Affiliation(s)
- Sinu Paul
- Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, United States
| | - Edita Karosiene
- Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, United States
| | - Sandeep Kumar Dhanda
- Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, United States
| | - Vanessa Jurtz
- Department of Bio and Health Informatics, Technical University of Denmark, Lyngby, Denmark
| | - Lindy Edwards
- Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, United States
| | - Morten Nielsen
- Department of Bio and Health Informatics, Technical University of Denmark, Lyngby, Denmark.,Instituto de Investigaciones Biotecnológicas, Universidad Nacional de San Martín, San Martín, Argentina
| | - Alessandro Sette
- Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, United States.,Department of Medicine, University of California San Diego, La Jolla, CA, United States
| | - Bjoern Peters
- Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology, La Jolla, CA, United States.,Department of Medicine, University of California San Diego, La Jolla, CA, United States
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35
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Sibener LV, Fernandes RA, Kolawole EM, Carbone CB, Liu F, McAffee D, Birnbaum ME, Yang X, Su LF, Yu W, Dong S, Gee MH, Jude KM, Davis MM, Groves JT, Goddard WA, Heath JR, Evavold BD, Vale RD, Garcia KC. Isolation of a Structural Mechanism for Uncoupling T Cell Receptor Signaling from Peptide-MHC Binding. Cell 2018; 174:672-687.e27. [PMID: 30053426 PMCID: PMC6140336 DOI: 10.1016/j.cell.2018.06.017] [Citation(s) in RCA: 194] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 03/13/2018] [Accepted: 06/07/2018] [Indexed: 12/21/2022]
Abstract
TCR-signaling strength generally correlates with peptide-MHC binding affinity; however, exceptions exist. We find high-affinity, yet non-stimulatory, interactions occur with high frequency in the human T cell repertoire. Here, we studied human TCRs that are refractory to activation by pMHC ligands despite robust binding. Analysis of 3D affinity, 2D dwell time, and crystal structures of stimulatory versus non-stimulatory TCR-pMHC interactions failed to account for their different signaling outcomes. Using yeast pMHC display, we identified peptide agonists of a formerly non-responsive TCR. Single-molecule force measurements demonstrated the emergence of catch bonds in the activating TCR-pMHC interactions, correlating with exclusion of CD45 from the TCR-APC contact site. Molecular dynamics simulations of TCR-pMHC disengagement distinguished agonist from non-agonist ligands based on the acquisition of catch bonds within the TCR-pMHC interface. The isolation of catch bonds as a parameter mediating the coupling of TCR binding and signaling has important implications for TCR and antigen engineering for immunotherapy.
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Affiliation(s)
- Leah V Sibener
- Departments of Molecular and Cellular Physiology and Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA; Immunology Graduate Program, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ricardo A Fernandes
- Departments of Molecular and Cellular Physiology and Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Elizabeth M Kolawole
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Catherine B Carbone
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Fan Liu
- Department of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Materials and Process Simulation Center, California Institute of Technology, Pasadena, CA 91125, USA; Institute for Systems Biology, Seattle, WA 98109, USA
| | - Darren McAffee
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Michael E Birnbaum
- Departments of Molecular and Cellular Physiology and Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA; Immunology Graduate Program, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Xinbo Yang
- Departments of Molecular and Cellular Physiology and Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Laura F Su
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Wong Yu
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Shen Dong
- Departments of Molecular and Cellular Physiology and Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Marvin H Gee
- Departments of Molecular and Cellular Physiology and Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA; Immunology Graduate Program, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Kevin M Jude
- Departments of Molecular and Cellular Physiology and Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Mark M Davis
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jay T Groves
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - William A Goddard
- Department of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Materials and Process Simulation Center, California Institute of Technology, Pasadena, CA 91125, USA
| | - James R Heath
- Institute for Systems Biology, Seattle, WA 98109, USA
| | - Brian D Evavold
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Ronald D Vale
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94143, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94143, USA
| | - K Christopher Garcia
- Departments of Molecular and Cellular Physiology and Structural Biology, Stanford University School of Medicine, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA.
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Holland CJ, MacLachlan BJ, Bianchi V, Hesketh SJ, Morgan R, Vickery O, Bulek AM, Fuller A, Godkin A, Sewell AK, Rizkallah PJ, Wells S, Cole DK. In Silico and Structural Analyses Demonstrate That Intrinsic Protein Motions Guide T Cell Receptor Complementarity Determining Region Loop Flexibility. Front Immunol 2018; 9:674. [PMID: 29696015 PMCID: PMC5904202 DOI: 10.3389/fimmu.2018.00674] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 03/19/2018] [Indexed: 11/13/2022] Open
Abstract
T-cell immunity is controlled by T cell receptor (TCR) binding to peptide major histocompatibility complexes (pMHCs). The nature of the interaction between these two proteins has been the subject of many investigations because of its central role in immunity against pathogens, cancer, in autoimmunity, and during organ transplant rejection. Crystal structures comparing unbound and pMHC-bound TCRs have revealed flexibility at the interaction interface, particularly from the perspective of the TCR. However, crystal structures represent only a snapshot of protein conformation that could be influenced through biologically irrelevant crystal lattice contacts and other factors. Here, we solved the structures of three unbound TCRs from multiple crystals. Superposition of identical TCR structures from different crystals revealed some conformation differences of up to 5 Å in individual complementarity determining region (CDR) loops that are similar to those that have previously been attributed to antigen engagement. We then used a combination of rigidity analysis and simulations of protein motion to reveal the theoretical potential of TCR CDR loop flexibility in unbound state. These simulations of protein motion support the notion that crystal structures may only offer an artifactual indication of TCR flexibility, influenced by crystallization conditions and crystal packing that is inconsistent with the theoretical potential of intrinsic TCR motions.
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Affiliation(s)
- Christopher J Holland
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom.,Immunocore, Abingdon, United Kingdom
| | - Bruce J MacLachlan
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Valentina Bianchi
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom.,Department of Oncology, University Hospital of Lausanne, Lausanne, Switzerland
| | - Sophie J Hesketh
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom.,Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Richard Morgan
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Owen Vickery
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Anna M Bulek
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Anna Fuller
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Andrew Godkin
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Andrew K Sewell
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Pierre J Rizkallah
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Stephen Wells
- Department of Chemistry, University of Bath, Bath, United Kingdom
| | - David K Cole
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom.,Immunocore, Abingdon, United Kingdom
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Ostrov DA, Alkanani A, McDaniel KA, Case S, Baschal EE, Pyle L, Ellis S, Pöllinger B, Seidl KJ, Shah VN, Garg SK, Atkinson MA, Gottlieb PA, Michels AW. Methyldopa blocks MHC class II binding to disease-specific antigens in autoimmune diabetes. J Clin Invest 2018; 128:1888-1902. [PMID: 29438107 DOI: 10.1172/jci97739] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 02/08/2018] [Indexed: 12/20/2022] Open
Abstract
Major histocompatibility (MHC) class II molecules are strongly associated with many autoimmune disorders. In type 1 diabetes (T1D), the DQ8 molecule is common, confers significant disease risk, and is involved in disease pathogenesis. We hypothesized that blocking DQ8 antigen presentation would provide therapeutic benefit by preventing recognition of self-peptides by pathogenic T cells. We used the crystal structure of DQ8 to select drug-like small molecules predicted to bind structural pockets in the MHC antigen-binding cleft. A limited number of the predicted compounds inhibited DQ8 antigen presentation in vitro, with 1 compound preventing insulin autoantibody production and delaying diabetes onset in an animal model of spontaneous autoimmune diabetes. An existing drug with a similar structure, methyldopa, specifically blocked DQ8 in patients with recent-onset T1D and reduced inflammatory T cell responses to insulin, highlighting the relevance of blocking disease-specific MHC class II antigen presentation to treat autoimmunity.
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Affiliation(s)
- David A Ostrov
- Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Aimon Alkanani
- Barbara Davis Center for Childhood Diabetes, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Kristen A McDaniel
- Barbara Davis Center for Childhood Diabetes, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Stephanie Case
- Barbara Davis Center for Childhood Diabetes, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Erin E Baschal
- Barbara Davis Center for Childhood Diabetes, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Laura Pyle
- Barbara Davis Center for Childhood Diabetes, University of Colorado School of Medicine, Aurora, Colorado, USA.,Department of Biostatistics and Informatics, University of Colorado School of Public Health, Aurora, Colorado, USA
| | - Sam Ellis
- Barbara Davis Center for Childhood Diabetes, University of Colorado School of Medicine, Aurora, Colorado, USA.,Department of Clinical Pharmacy, University of Colorado, Aurora, Colorado, USA
| | | | | | - Viral N Shah
- Barbara Davis Center for Childhood Diabetes, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Satish K Garg
- Barbara Davis Center for Childhood Diabetes, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Mark A Atkinson
- Department of Pathology, Immunology, and Laboratory Medicine, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Peter A Gottlieb
- Barbara Davis Center for Childhood Diabetes, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Aaron W Michels
- Barbara Davis Center for Childhood Diabetes, University of Colorado School of Medicine, Aurora, Colorado, USA
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Glassman CR, Parrish HL, Lee MS, Kuhns MS. Reciprocal TCR-CD3 and CD4 Engagement of a Nucleating pMHCII Stabilizes a Functional Receptor Macrocomplex. Cell Rep 2018; 22:1263-1275. [PMID: 29386113 PMCID: PMC5813697 DOI: 10.1016/j.celrep.2017.12.104] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 12/07/2017] [Accepted: 12/27/2017] [Indexed: 12/24/2022] Open
Abstract
CD4+ T cells convert the time that T cell receptors (TCRs) interact with peptides embedded within class II major histocompatibility complex molecules (pMHCII) into signals that direct cell-fate decisions. In principle, TCRs relay information to intracellular signaling motifs of the associated CD3 subunits, while CD4 recruits the kinase Lck to those motifs upon coincident detection of pMHCII. But the mechanics by which this occurs remain enigmatic. In one model, the TCR and CD4 bind pMHCII independently, while in another, CD4 interacts with a composite surface formed by the TCR-CD3 complex bound to pMHCII. Here, we report that the duration of TCR-pMHCII interactions impact CD4 binding to MHCII. In turn, CD4 increases TCR confinement to pMHCII via reciprocal interactions involving membrane distal and proximal CD4 ectodomains. The data suggest that a precisely assembled macrocomplex functions to reliably convert TCR-pMHCII confinement into reproducible signals that orchestrate adaptive immunity.
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Affiliation(s)
- Caleb R Glassman
- Department of Immunobiology, The University of Arizona College of Medicine, Tucson, AZ 85724, USA
| | - Heather L Parrish
- Department of Immunobiology, The University of Arizona College of Medicine, Tucson, AZ 85724, USA
| | - Mark S Lee
- Department of Immunobiology, The University of Arizona College of Medicine, Tucson, AZ 85724, USA
| | - Michael S Kuhns
- Department of Immunobiology, The University of Arizona College of Medicine, Tucson, AZ 85724, USA; The BIO-5 Institute, The University of Arizona College of Medicine, Tucson, AZ 85724, USA; The Arizona Center on Aging, The University of Arizona College of Medicine, Tucson, AZ 85724, USA; The University of Arizona Cancer Center, The University of Arizona College of Medicine, Tucson, AZ 85724, USA.
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40
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Tsuchiya Y, Namiuchi Y, Wako H, Tsurui H. A study of CDR3 loop dynamics reveals distinct mechanisms of peptide recognition by T-cell receptors exhibiting different levels of cross-reactivity. Immunology 2017; 153:466-478. [PMID: 28992359 DOI: 10.1111/imm.12849] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2017] [Revised: 10/04/2017] [Accepted: 10/05/2017] [Indexed: 01/09/2023] Open
Abstract
T-cell receptors (TCRs) can productively interact with many different peptides bound within the MHC binding groove. This property varies with the level of cross-reactivity of TCRs; some TCRs are particularly hyper cross-reactive while others exhibit greater specificity. To elucidate the mechanism behind these differences, we studied five TCRs in complex with the same class II MHC (1Ab )-peptide (3K), that are known to exhibit different levels of cross-reactivity. Although these complexes have similar binding affinities, the interface areas between the TCR and the peptide-MHC (pMHC) differ significantly. We investigated static and dynamic structural features of the TCR-pMHC complexes and of TCRs in a free state, as well as the relationship between binding affinity and interface area. It was found that the TCRs known to exhibit lower levels of cross-reactivity bound to pMHC using an induced-fitting mechanism, forming large and tight interfaces rich in specific hydrogen bonds. In contrast, TCRs known to exhibit high levels of cross-reactivity used a more rigid binding mechanism where non-specific π-interactions involving the bulky Trp residue in CDR3β dominated. As entropy loss upon binding in these highly degenerate and rigid TCRs is smaller than that in less degenerate TCRs, they can better tolerate changes in residues distal from the major contacts with MHC-bound peptide. Hence, our dynamics study revealed that differences in the peptide recognition mechanisms by TCRs appear to correlate with the levels of T-cell cross-reactivity.
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Affiliation(s)
- Yuko Tsuchiya
- Institute for Protein Research, Osaka University, Suita, Osaka, Japan
| | | | - Hiroshi Wako
- School of Social Sciences, Waseda University, Tokyo, Japan
| | - Hiromichi Tsurui
- Department of Pathology, Juntendo University School of Medicine, Tokyo, Japan
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The IRF4 Gene Regulatory Module Functions as a Read-Write Integrator to Dynamically Coordinate T Helper Cell Fate. Immunity 2017; 47:481-497.e7. [PMID: 28930660 DOI: 10.1016/j.immuni.2017.09.001] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 03/28/2017] [Accepted: 08/31/2017] [Indexed: 12/11/2022]
Abstract
Transcriptional regulation during CD4+ T cell fate decisions enables their differentiation into distinct states, guiding immune responses toward antibody production via Tfh cells or inflammation by Teff cells. Tfh-Teff cell fate commitment is regulated by mutual antagonism between the transcription factors Bcl6 and Blimp-1. Here we examined how T cell receptor (TCR) signals establish and arbitrate Bcl6-Blimp-1 counter-antagonism. We found that the TCR-signal-induced transcription factor Irf4 is essential for the differentiation of Bcl6-expressing Tfh and Blimp-1-expressing Teff cells. Increased TCR signaling raised Irf4 amounts and promoted Teff cell fates at the expense of Tfh ones. Importantly, orthogonal induction of Irf4 expression redirected Tfh cell fate trajectories toward those of Teff. Mechanistically, we linked greater Irf4 abundance with its recruitment toward low-affinity binding sites within Teff cell cis-regulatory elements, including those of Prdm1. We propose that the Irf4 locus functions as the "reader" of TCR signal strength, and in turn, concentration-dependent activity of Irf4 "writes" T helper fate choice.
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Highly functional T-cell receptor repertoires are abundant in stem memory T cells and highly shared among individuals. Sci Rep 2017. [PMID: 28623251 PMCID: PMC5473819 DOI: 10.1038/s41598-017-03855-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
To expand our knowledge of the ontogeny of the T-cell receptor (TCR) repertoire of antigen-specific T-cell subsets, we combined next-generation deep sequencing and single-cell multiplex clonotype analysis to evaluate the diversity and frequency of paired TCRs, their functions and whether clonotypic TCRs are shared among different individuals. Using an HLA-A*02-restricted cytomegalovirus (CMV) pp65-derived immunogenic peptide, we found that the more dominant pp65-specific TCR clonotypes in the blood of healthy donors have higher binding affinities for the CMV peptide and arise from clonotypes that are highly shared among individuals. Interestingly, these highly shared HLA-A*02-restricted CMV-specific TCRs were detected in a CMV-seronegative individual as well as in HLA-A*02-negative donors albeit at lower frequency. More intriguingly, these shared TCR clonotypes were abundant in the stem memory T-cell subset, and TCR diversity of the stem memory T-cell repertoire was significantly lower than in the central memory and effector memory T-cell repertoires. These results suggest that the stem memory T-cell subset may serve as a reservoir of highly shared and highly functional memory T-cells.
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43
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Differential utilization of binding loop flexibility in T cell receptor ligand selection and cross-reactivity. Sci Rep 2016; 6:25070. [PMID: 27118724 PMCID: PMC4846865 DOI: 10.1038/srep25070] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 04/11/2016] [Indexed: 12/27/2022] Open
Abstract
Complementarity determining region (CDR) loop flexibility has been suggested to play an important role in the selection and binding of ligands by T cell receptors (TCRs) of the cellular immune system. However, questions remain regarding the role of loop motion in TCR binding, and crystallographic structures have raised questions about the extent to which generalizations can be made. Here we studied the flexibility of two structurally well characterized αβ TCRs, A6 and DMF5. We found that the two receptors utilize loop motion very differently in ligand binding and cross-reactivity. While the loops of A6 move rapidly in an uncorrelated fashion, those of DMF5 are substantially less mobile. Accordingly, the mechanisms of binding and cross-reactivity are very different between the two TCRs: whereas A6 relies on conformational selection to select and bind different ligands, DMF5 uses a more rigid, permissive architecture with greater reliance on slower motions or induced-fit. In addition to binding site flexibility, we also explored whether ligand-binding resulted in common dynamical changes in A6 and DMF5 that could contribute to TCR triggering. Although binding-linked motional changes propagated throughout both receptors, no common features were observed, suggesting that changes in nanosecond-level TCR structural dynamics do not contribute to T cell signaling.
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44
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Natarajan A, Nadarajah V, Felsovalyi K, Wang W, Jeyachandran VR, Wasson RA, Cardozo T, Bracken C, Krogsgaard M. Structural Model of the Extracellular Assembly of the TCR-CD3 Complex. Cell Rep 2016; 14:2833-45. [PMID: 26997265 DOI: 10.1016/j.celrep.2016.02.081] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 12/24/2015] [Accepted: 02/21/2016] [Indexed: 11/29/2022] Open
Abstract
Antigen recognition of peptide-major histocompatibility complexes (pMHCs) by T cells, a key step in initiating adaptive immune responses, is performed by the T cell receptor (TCR) bound to CD3 heterodimers. However, the biophysical basis of the transmission of TCR-CD3 extracellular interaction into a productive intracellular signaling sequence remains incomplete. Here we used nuclear magnetic resonance (NMR) spectroscopy combined with mutational analysis and computational docking to derive a structural model of the extracellular TCR-CD3 assembly. In the inactivated state, CD3γε interacts with the helix 3 and helix 4-F strand regions of the TCR Cβ subunit, whereas CD3δε interacts with the F and C strand regions of the TCR Cα subunit in this model, placing the CD3 subunits on opposing sides of the TCR. This work identifies the molecular contacts between the TCR and CD3 subunits, identifying a physical basis for transmitting an activating signal through the complex.
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Affiliation(s)
- Aswin Natarajan
- Laura and Isaac Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016, USA
| | - Vidushan Nadarajah
- Laura and Isaac Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016, USA
| | - Klara Felsovalyi
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - Wenjuan Wang
- Laura and Isaac Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016, USA
| | - Vivian R Jeyachandran
- Laura and Isaac Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016, USA
| | - Riley A Wasson
- Laura and Isaac Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016, USA
| | - Timothy Cardozo
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA
| | - Clay Bracken
- Department of Biochemistry, Weill Cornell Medical College, New York, NY 10065, USA
| | - Michelle Krogsgaard
- Laura and Isaac Perlmutter Cancer Center, New York University School of Medicine, New York, NY 10016, USA; Interdiciplinary Cooperative Melanoma Group, New York University School of Medicine, New York, NY 10016, USA; Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.
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45
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Comrie WA, Burkhardt JK. Action and Traction: Cytoskeletal Control of Receptor Triggering at the Immunological Synapse. Front Immunol 2016; 7:68. [PMID: 27014258 PMCID: PMC4779853 DOI: 10.3389/fimmu.2016.00068] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 02/12/2016] [Indexed: 01/03/2023] Open
Abstract
It is well known that F-actin dynamics drive the micron-scale cell shape changes required for migration and immunological synapse (IS) formation. In addition, recent evidence points to a more intimate role for the actin cytoskeleton in promoting T cell activation. Mechanotransduction, the conversion of mechanical input into intracellular biochemical changes, is thought to play a critical role in several aspects of immunoreceptor triggering and downstream signal transduction. Multiple molecules associated with signaling events at the IS have been shown to respond to physical force, including the TCR, costimulatory molecules, adhesion molecules, and several downstream adapters. In at least some cases, it is clear that the relevant forces are exerted by dynamics of the T cell actomyosin cytoskeleton. Interestingly, there is evidence that the cytoskeleton of the antigen-presenting cell also plays an active role in T cell activation, by countering the molecular forces exerted by the T cell at the IS. Since actin polymerization is itself driven by TCR and costimulatory signaling pathways, a complex relationship exists between actin dynamics and receptor activation. This review will focus on recent advances in our understanding of the mechanosensitive aspects of T cell activation, paying specific attention to how F-actin-directed forces applied from both sides of the IS fit into current models of receptor triggering and activation.
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Affiliation(s)
- William A Comrie
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA , USA
| | - Janis K Burkhardt
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA , USA
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46
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Bello M, Correa-Basurto J. Energetic and flexibility properties captured by long molecular dynamics simulations of a membrane-embedded pMHCII-TCR complex. MOLECULAR BIOSYSTEMS 2016; 12:1350-66. [PMID: 26926952 DOI: 10.1039/c6mb00058d] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Although crystallographic data have provided important molecular insight into the interactions in the pMHC-TCR complex, the inherent features of this structural approach cause it to only provide a static picture of the interactions. While unbiased molecular dynamics simulations (UMDSs) have provided important information about the dynamic structural behavior of the pMHC-TCR complex, most of them have modeled the pMHC-TCR complex as soluble, when in physiological conditions, this complex is membrane bound; therefore, following this latter UMDS protocol might hamper important dynamic results. In this contribution, we performed three independent 300 ns-long UMDSs of the pMHCII-TCR complex anchored in two opposing membranes to explore the structural and energetic properties of the recognition of pMHCII by the TCR. The conformational ensemble generated through UMDSs was subjected to clustering and Cartesian principal component analyses (cPCA) to explore the dynamical behavior of the pMHCII-TCR association. Furthermore, based on the conformational population sampled through UMDSs, the effective binding free energy, per-residue free energy decomposition, and alanine scanning mutations were explored for the native pMHCII-TCR complex, as well as for 12 mutations (p1-p12MHCII-TCR) introduced in the native peptide. Clustering analyses and cPCA provide insight into the rocking motion of the TCR onto pMHCII, together with the presence of new electrostatic interactions not observed through crystallographic methods. Energetic results provide evidence of the main contributors to the pMHC-TCR complex formation as well as the key residues involved in this molecular recognition process.
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Affiliation(s)
- Martiniano Bello
- Laboratorio de Modelado Molecular, Bioinformática y Diseño de Fármacos de la Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis Y Diaz Mirón S/N, Col. Casco de Santo Tomas, Mexico City, CP: 11340, Mexico.
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47
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Hoffmann MM, Molina-Mendiola C, Nelson AD, Parks CA, Reyes EE, Hansen MJ, Rajagopalan G, Pease LR, Schrum AG, Gil D. Co-potentiation of antigen recognition: A mechanism to boost weak T cell responses and provide immunotherapy in vivo. SCIENCE ADVANCES 2015; 1:e1500415. [PMID: 26601285 PMCID: PMC4646799 DOI: 10.1126/sciadv.1500415] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 07/24/2015] [Indexed: 06/05/2023]
Abstract
Adaptive immunity is mediated by antigen receptors that can induce weak or strong immune responses depending on the nature of the antigen that is bound. In T lymphocytes, antigen recognition triggers signal transduction by clustering T cell receptor (TCR)/CD3 multiprotein complexes. In addition, it hypothesized that biophysical changes induced in TCR/CD3 that accompany receptor engagement may contribute to signal intensity. Nonclustering monovalent TCR/CD3 engagement is functionally inert despite the fact that it may induce changes in conformational arrangement or in the flexibility of receptor subunits. We report that the intrinsically inert monovalent engagement of TCR/CD3 can specifically enhance physiologic T cell responses to weak antigens in vitro and in vivo without stimulating antigen-unengaged T cells and without interrupting T cell responses to strong antigens, an effect that we term as "co-potentiation." We identified Mono-7D6-Fab, which biophysically altered TCR/CD3 when bound and functionally enhanced immune reactivity to several weak antigens in vitro, including a gp100-derived peptide associated with melanoma. In vivo, Mono-7D6-Fab induced T cell antigen-dependent therapeutic responses against melanoma lung metastases, an effect that synergized with other anti-melanoma immunotherapies to significantly improve outcome and survival. We conclude that Mono-7D6-Fab directly co-potentiated TCR/CD3 engagement by weak antigens and that such concept can be translated into an immunotherapeutic design. The co-potentiation principle may be applicable to other receptors that could be regulated by otherwise inert compounds whose latent potency is only invoked in concert with specific physiologic ligands.
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Affiliation(s)
- Michele M. Hoffmann
- Department of Immunology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | - Carlos Molina-Mendiola
- Department of Immunology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
- Department of Statistics, Polytechnic University of Catalonia, Barcelona 08034, Spain
| | - Alfreda D. Nelson
- Department of Immunology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | - Christopher A. Parks
- Department of Immunology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | - Edwin E. Reyes
- Department of Immunology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | - Michael J. Hansen
- Department of Immunology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | - Govindarajan Rajagopalan
- Department of Immunology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | - Larry R. Pease
- Department of Immunology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | - Adam G. Schrum
- Department of Immunology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
| | - Diana Gil
- Department of Immunology, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
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48
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Liu B, Chen W, Natarajan K, Li Z, Margulies DH, Zhu C. The cellular environment regulates in situ kinetics of T-cell receptor interaction with peptide major histocompatibility complex. Eur J Immunol 2015; 45:2099-110. [PMID: 25944482 DOI: 10.1002/eji.201445358] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 03/17/2015] [Accepted: 04/30/2015] [Indexed: 11/12/2022]
Abstract
T cells recognize antigens at the two-dimensional (2D) interface with antigen-presenting cells (APCs), which trigger T-cell effector functions. T-cell functional outcomes correlate with 2D kinetics of membrane-embedded T-cell receptors (TCRs) binding to surface-tethered peptide-major histocompatibility complex molecules (pMHCs). However, most studies have measured TCR-pMHC kinetics for recombinant TCRs in 3D by surface plasmon resonance, which differs drastically from 2D measurements. Here, we compared pMHC dissociation from native TCR on the T-cell surface to recombinant TCR immobilized on glass surface or in solution. Force on TCR-pMHC bonds regulated their lifetimes differently for native than recombinant TCRs. Perturbing the cellular environment suppressed 2D on-rates but had no effect on 2D off-rate regardless of whether force was applied. In contrast, for the TCR interacting with its monoclonal antibody, the 2D on-rate was insensitive to cellular perturbations and the force-dependent off-rates were indistinguishable for native and recombinant TCRs. These data present novel features of TCR-pMHC kinetics that are regulated by the cellular environment, underscoring the limitations of 3D kinetics in predicting T-cell functions and calling for further elucidation of the underlying molecular and cellular mechanisms that regulate 2D kinetics in physiological settings.
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Affiliation(s)
- Baoyu Liu
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Wei Chen
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Kannan Natarajan
- Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institute of Health, Bethesda, MD, USA
| | - Zhenhai Li
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - David H Margulies
- Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institute of Health, Bethesda, MD, USA
| | - Cheng Zhu
- Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, USA.,Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, USA.,Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, USA
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López CA, Sethi A, Goldstein B, Wilson BS, Gnanakaran S. Membrane-mediated regulation of the intrinsically disordered CD3ϵ cytoplasmic tail of the TCR. Biophys J 2015; 108:2481-2491. [PMID: 25992726 PMCID: PMC4457001 DOI: 10.1016/j.bpj.2015.03.059] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 01/27/2015] [Accepted: 03/02/2015] [Indexed: 10/23/2022] Open
Abstract
The regulation of T-cell-mediated immune responses depends on the phosphorylation of immunoreceptor tyrosine-based activation motifs (ITAMs) on T-cell receptors. Although many details of the signaling cascades are well understood, the initial mechanism and regulation of ITAM phosphorylation remains unknown. We used molecular dynamics simulations to study the influence of different compositions of lipid bilayers on the membrane association of the CD3ϵ cytoplasmic tails of the T-cell receptors. Our results show that binding of CD3ϵ to membranes is modulated by both the presence of negatively charged lipids and the lipid order of the membrane. Free-energy calculations reveal that the protein-membrane interaction is favored by the presence of nearby basic residues and the ITAM tyrosines. Phosphorylation minimizes membrane association, rendering the ITAM motif more accessible to binding partners. In systems mimicking biological membranes, the CD3ϵ chain localization is modulated by different facilitator lipids (e.g., gangliosides or phosphoinositols), revealing a plausible regulatory effect on activation through the regulation of lipid composition in cell membranes.
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Affiliation(s)
- Cesar A López
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico
| | - Anurag Sethi
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut
| | - Byron Goldstein
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico
| | - Bridget S Wilson
- Department of Pathology and Cancer Center, University of New Mexico Health Sciences Center, Albuquerque, New Mexico
| | - S Gnanakaran
- Theoretical Biology and Biophysics Group, Los Alamos National Laboratory, Los Alamos, New Mexico; New Mexico Consortium, Los Alamos, New Mexico.
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Løset GÅ, Berntzen G, Frigstad T, Pollmann S, Gunnarsen KS, Sandlie I. Phage Display Engineered T Cell Receptors as Tools for the Study of Tumor Peptide-MHC Interactions. Front Oncol 2015; 4:378. [PMID: 25629004 PMCID: PMC4290511 DOI: 10.3389/fonc.2014.00378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 12/17/2014] [Indexed: 11/13/2022] Open
Abstract
Cancer immunotherapy has finally come of age, demonstrated by recent progress in strategies that engage the endogenous adaptive immune response in tumor killing. Occasionally, significant and durable tumor regression has been achieved. A giant leap forward was the demonstration that the pre-existing polyclonal T cell repertoire could be re-directed by use of cloned T cell receptors (TCRs), to obtain a defined tumor-specific pool of T cells. However, the procedure must be performed with caution to avoid deleterious cross-reactivity. Here, the use of engineered soluble TCRs may represent a safer, yet powerful, alternative. There is also a need for deeper understanding of the processes that underlie antigen presentation in disease and homeostasis, how tumor-specific peptides are generated, and how epitope spreading evolves during tumor development. Due to its plasticity, the pivotal interaction where a TCR engages a peptide/MHC (pMHC) also requires closer attention. For this purpose, phage display as a tool to evolve cloned TCRs represents an attractive avenue to generate suitable reagents allowing the study of defined pMHC presentation, TCR engagement, as well as for the discovery of novel therapeutic leads. Here, we highlight important aspects of the current status in this field.
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Affiliation(s)
- Geir Åge Løset
- Nextera AS , Oslo , Norway ; Centre for Immune Regulation, Oslo University Hospital, University of Oslo , Oslo , Norway ; Department of Biosciences, University of Oslo , Oslo , Norway
| | | | | | | | - Kristin S Gunnarsen
- Centre for Immune Regulation, Oslo University Hospital, University of Oslo , Oslo , Norway
| | - Inger Sandlie
- Centre for Immune Regulation, Oslo University Hospital, University of Oslo , Oslo , Norway ; Department of Biosciences, University of Oslo , Oslo , Norway
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