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Mikhaylov V, Brambley CA, Keller GLJ, Arbuiso AG, Weiss LI, Baker BM, Levine AJ. Accurate modeling of peptide-MHC structures with AlphaFold. Structure 2024; 32:228-241.e4. [PMID: 38113889 PMCID: PMC10872456 DOI: 10.1016/j.str.2023.11.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 08/17/2023] [Accepted: 11/22/2023] [Indexed: 12/21/2023]
Abstract
Major histocompatibility complex (MHC) proteins present peptides on the cell surface for T cell surveillance. Reliable in silico prediction of which peptides would be presented and which T cell receptors would recognize them is an important problem in structural immunology. Here, we introduce an AlphaFold-based pipeline for predicting the three-dimensional structures of peptide-MHC complexes for class I and class II MHC molecules. Our method demonstrates high accuracy, outperforming existing tools in class I modeling accuracy and class II peptide register prediction. We validate its performance and utility with new experimental data on a recently described cancer neoantigen/wild-type peptide pair and explore applications toward improving peptide-MHC binding prediction.
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Affiliation(s)
- Victor Mikhaylov
- The Simons Center for Systems Biology, Institute for Advanced Study, 1 Einstein Drive, Princeton, NJ 08540, USA.
| | - Chad A Brambley
- Department of Chemistry and Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Grant L J Keller
- Department of Chemistry and Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Alyssa G Arbuiso
- Department of Chemistry and Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Laura I Weiss
- Department of Chemistry and Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Brian M Baker
- Department of Chemistry and Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Arnold J Levine
- The Simons Center for Systems Biology, Institute for Advanced Study, 1 Einstein Drive, Princeton, NJ 08540, USA
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2
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Klebanoff CA, Chandran SS, Baker BM, Quezada SA, Ribas A. T cell receptor therapeutics: immunological targeting of the intracellular cancer proteome. Nat Rev Drug Discov 2023; 22:996-1017. [PMID: 37891435 PMCID: PMC10947610 DOI: 10.1038/s41573-023-00809-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/08/2023] [Indexed: 10/29/2023]
Abstract
The T cell receptor (TCR) complex is a naturally occurring antigen sensor that detects, amplifies and coordinates cellular immune responses to epitopes derived from cell surface and intracellular proteins. Thus, TCRs enable the targeting of proteins selectively expressed by cancer cells, including neoantigens, cancer germline antigens and viral oncoproteins. As such, TCRs have provided the basis for an emerging class of oncology therapeutics. Herein, we review the current cancer treatment landscape using TCRs and TCR-like molecules. This includes adoptive cell transfer of T cells expressing endogenous or engineered TCRs, TCR bispecific engagers and antibodies specific for human leukocyte antigen (HLA)-bound peptides (TCR mimics). We discuss the unique complexities associated with the clinical development of these therapeutics, such as HLA restriction, TCR retrieval, potency assessment and the potential for cross-reactivity. In addition, we highlight emerging clinical data that establish the antitumour potential of TCR-based therapies, including tumour-infiltrating lymphocytes, for the treatment of diverse human malignancies. Finally, we explore the future of TCR therapeutics, including emerging genome editing methods to safely enhance potency and strategies to streamline patient identification.
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Affiliation(s)
- Christopher A Klebanoff
- Memorial Sloan Kettering Cancer Center (MSKCC), Human Oncology and Pathogenesis Program, New York, NY, USA.
| | - Smita S Chandran
- Memorial Sloan Kettering Cancer Center (MSKCC), Human Oncology and Pathogenesis Program, New York, NY, USA
- Parker Institute for Cancer Immunotherapy, New York, NY, USA
- Weill Cornell Medical College, Cornell University, New York, NY, USA
| | - Brian M Baker
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, ID, USA
- The Harper Cancer Research Institute, University of Notre Dame, Notre Dame, ID, USA
| | - Sergio A Quezada
- Cancer Immunology Unit, Research Department of Haematology, University College London Cancer Institute, London, UK
- Cancer Research UK Lung Cancer Centre of Excellence, University College London Cancer Institute, London, UK
- Achilles Therapeutics, London, UK
| | - Antoni Ribas
- Jonsson Comprehensive Cancer Center at the University of California, Los Angeles (UCLA), Los Angeles, CA, USA
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3
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Borowska MT, Boughter CT, Bunker JJ, Guthmiller JJ, Wilson PC, Roux B, Bendelac A, Adams EJ. Biochemical and biophysical characterization of natural polyreactivity in antibodies. Cell Rep 2023; 42:113190. [PMID: 37804505 PMCID: PMC10858392 DOI: 10.1016/j.celrep.2023.113190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 08/25/2023] [Accepted: 09/14/2023] [Indexed: 10/09/2023] Open
Abstract
To become specialized binders, antibodies undergo a process called affinity maturation to maximize their binding affinity. Despite this process, some antibodies retain low-affinity binding to diverse epitopes in a phenomenon called polyreactivity. Here we seek to understand the molecular basis of this polyreactivity in antibodies. Our results highlight that polyreactive antigen-binding fragments (Fabs) bind their targets with low affinities, comparable to T cell receptor recognition of autologous classical major histocompatibility complex. Extensive mutagenic studies find no singular amino acid residue or biochemical property responsible for polyreactive interaction, suggesting that polyreactive antibodies use multiple strategies for engagement. Finally, our crystal structures and all-atom molecular dynamics simulations of polyreactive Fabs show increased rigidity compared to their monoreactive relatives, forming a neutral and accessible platform for diverse antigens to bind. Together, these data support a cooperative strategy of rigid neutrality in establishing the polyreactive status of an antibody molecule.
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Affiliation(s)
- Marta T Borowska
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | | | - Jeffrey J Bunker
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA; Department of Pathology, University of Chicago, Chicago, IL 60637, USA
| | - Jenna J Guthmiller
- Department of Medicine, Section of Rheumatology, University of Chicago, Chicago, IL 60637, USA
| | - Patrick C Wilson
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA; Department of Medicine, Section of Rheumatology, University of Chicago, Chicago, IL 60637, USA
| | - Benoit Roux
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Albert Bendelac
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA; Department of Pathology, University of Chicago, Chicago, IL 60637, USA
| | - Erin J Adams
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA; Committee on Immunology, University of Chicago, Chicago, IL 60637, USA.
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4
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Tomasiak L, Karch R, Schreiner W. Conformational flexibility of a free and TCR-bound pMHC-I protein investigated by long-term molecular dynamics simulations. BMC Immunol 2022; 23:36. [PMID: 35902791 PMCID: PMC9335952 DOI: 10.1186/s12865-022-00510-7] [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: 07/04/2022] [Accepted: 07/13/2022] [Indexed: 11/10/2022] Open
Abstract
Background Major histocompatibility complexes (MHCs) play a crucial role in the cell-mediated adaptive immune response as they present antigenic peptides (p) which are recognized by host T cells through a complex formation of the T cell receptor (TCR) with pMHC. In the present study, we report on changes in conformational flexibility within a pMHC molecule upon TCR binding by looking at molecular dynamics (MD) simulations of the free and the TCR-bound pMHC-I protein of the LC13-HLA-B*44:05-pEEYLQAFTY complex. Results We performed long-term MD simulations with a total simulation time of 8 µs, employing 10 independent 400 ns replicas for the free and the TCR-bound pMHC system. Upon TCR ligation, we observed a reduced dynamic flexibility in the central residues of the peptide and the MHC α1-helix, altered occurrences of hydrogen bonds between the peptide and the MHC, a reduced conformational entropy of the peptide-binding groove, as well as a decreased solvent accessible surface area. Conclusions In summary, our results from 8 µs MD simulations indicate a restricted conformational space of the MHC peptide-binding groove upon TCR ligation and suggest a minimum simulation time of approximately 100 ns for biomolecules of comparable complexity to draw meaningful conclusions. Given the relatively long total simulation time, our results contribute to a more detailed view on conformational flexibility properties of the investigated free and TCR-bound pMHC-I system. Supplementary Information The online version contains supplementary material available at 10.1186/s12865-022-00510-7.
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Affiliation(s)
- Lisa Tomasiak
- Institute of Biosimulation and Bioinformatics, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria
| | - Rudolf Karch
- Institute of Biosimulation and Bioinformatics, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
| | - Wolfgang Schreiner
- Institute of Biosimulation and Bioinformatics, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria
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5
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Erausquin E, Serra P, Parras D, Santamaria P, López-Sagaseta J. Structural plasticity in I-Ag7 links autoreactivity to hybrid insulin peptides in type I diabetes. Front Immunol 2022; 13:924311. [PMID: 35967292 PMCID: PMC9365947 DOI: 10.3389/fimmu.2022.924311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 07/04/2022] [Indexed: 11/13/2022] Open
Abstract
We recently provided evidence for promiscuous recognition of several different hybrid insulin peptides (HIPs) by the highly diabetogenic, I-Ag7-restricted 4.1-T cell receptor (TCR). To understand the structural determinants of this phenomenon, we solved the structure of an agonistic HIP/I-Ag7 complex, both in isolation as well as bound to the 4.1-TCR. We find that HIP promiscuity of the 4.1-TCR is dictated, on the one hand, by an amino acid sequence pattern that ensures I-Ag7 binding and, on the other hand, by the presence of three acidic residues at positions P5, P7 and P8 that favor an optimal engagement by the 4.1-TCR’s complementary determining regions. Surprisingly, comparison of the TCR-bound and unbound HIP/I-Ag7 structures reveals that 4.1-TCR binding triggers several novel and unique structural motions in both the I-Ag7 molecule and the peptide that are essential for docking. This observation indicates that the type 1 diabetes-associated I-Ag7 molecule is structurally malleable and that this plasticity allows the recognition of multiple peptides by individual TCRs that would otherwise be unable to do so.
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Affiliation(s)
- Elena Erausquin
- Unit of Protein Crystallography and Structural Immunology, Navarrabiomed, Navarra, Spain
- Public University of Navarra (UPNA), Pamplona, Spain
- Navarra University Hospital, Pamplona, Spain
| | - Pau Serra
- Institut D’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Daniel Parras
- Institut D’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Pere Santamaria
- Institut D’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Julia McFarlane Diabetes Research Centre (JMDRC) and Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- *Correspondence: Jacinto López-Sagaseta, ; Pere Santamaria,
| | - Jacinto López-Sagaseta
- Unit of Protein Crystallography and Structural Immunology, Navarrabiomed, Navarra, Spain
- Public University of Navarra (UPNA), Pamplona, Spain
- Navarra University Hospital, Pamplona, Spain
- *Correspondence: Jacinto López-Sagaseta, ; Pere Santamaria,
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6
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Ayres CM, Baker BM. Peptide-dependent tuning of major histocompatibility complex motional properties and the consequences for cellular immunity. Curr Opin Immunol 2022; 76:102184. [PMID: 35550277 PMCID: PMC10052791 DOI: 10.1016/j.coi.2022.102184] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/15/2022] [Accepted: 04/05/2022] [Indexed: 12/22/2022]
Abstract
T cell receptors (TCRs) and other receptors of the immune system recognize peptides presented by class I or class II major histocompatibility complex (MHC) proteins. Although we generally distinguish between the MHC protein and its peptide, at an atomic level the two form a structural composite, which allows peptides to influence MHC properties and vice versa. One consequence is the peptide-dependent tuning of MHC structural dynamics, which contributes to protein structural adaptability and influences how receptors identify and bind targets. Peptide-dependent tuning of MHC protein dynamics can impact processes such as antigenicity, TCR cross-reactivity, and T cell repertoire selection. Motional tuning extends beyond the binding groove, influencing peptide selection and exchange, as well as interactions with other immune receptors. Here, we review recent findings showing how peptides can affect the dynamic and adaptable nature of MHC proteins. We highlight consequences for immunity and demonstrate how MHC proteins have evolved to be highly sensitive dynamic reporters, with broad immunological consequences.
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Affiliation(s)
- Cory M Ayres
- Department of Chemistry & Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN, USA
| | - Brian M Baker
- Department of Chemistry & Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN, USA.
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7
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Keller GLJ, Weiss LI, Baker BM. Physicochemical Heuristics for Identifying High Fidelity, Near-Native Structural Models of Peptide/MHC Complexes. Front Immunol 2022; 13:887759. [PMID: 35547730 PMCID: PMC9084917 DOI: 10.3389/fimmu.2022.887759] [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: 03/02/2022] [Accepted: 03/29/2022] [Indexed: 11/13/2022] Open
Abstract
There is long-standing interest in accurately modeling the structural features of peptides bound and presented by class I MHC proteins. This interest has grown with the advent of rapid genome sequencing and the prospect of personalized, peptide-based cancer vaccines, as well as the development of molecular and cellular therapeutics based on T cell receptor recognition of peptide-MHC. However, while the speed and accessibility of peptide-MHC modeling has improved substantially over the years, improvements in accuracy have been modest. Accuracy is crucial in peptide-MHC modeling, as T cell receptors are highly sensitive to peptide conformation and capturing fine details is therefore necessary for useful models. Studying nonameric peptides presented by the common class I MHC protein HLA-A*02:01, here we addressed a key question common to modern modeling efforts: from a set of models (or decoys) generated through conformational sampling, which is best? We found that the common strategy of decoy selection by lowest energy can lead to substantial errors in predicted structures. We therefore adopted a data-driven approach and trained functions capable of predicting near native decoys with exceptionally high accuracy. Although our implementation is limited to nonamer/HLA-A*02:01 complexes, our results serve as an important proof of concept from which improvements can be made and, given the significance of HLA-A*02:01 and its preference for nonameric peptides, should have immediate utility in select immunotherapeutic and other efforts for which structural information would be advantageous.
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Affiliation(s)
- Grant L J Keller
- Department of Chemistry & Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN, United States
| | - Laura I Weiss
- Department of Chemistry & Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN, United States
| | - Brian M Baker
- Department of Chemistry & Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN, United States
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8
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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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9
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Pishesha N, Harmand TJ, Ploegh HL. A guide to antigen processing and presentation. Nat Rev Immunol 2022; 22:751-764. [PMID: 35418563 DOI: 10.1038/s41577-022-00707-2] [Citation(s) in RCA: 164] [Impact Index Per Article: 82.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2022] [Indexed: 12/13/2022]
Abstract
Antigen processing and presentation are the cornerstones of adaptive immunity. B cells cannot generate high-affinity antibodies without T cell help. CD4+ T cells, which provide such help, use antigen-specific receptors that recognize major histocompatibility complex (MHC) molecules in complex with peptide cargo. Similarly, eradication of virus-infected cells often depends on cytotoxic CD8+ T cells, which rely on the recognition of peptide-MHC complexes for their action. The two major classes of glycoproteins entrusted with antigen presentation are the MHC class I and class II molecules, which present antigenic peptides to CD8+ T cells and CD4+ T cells, respectively. This Review describes the essentials of antigen processing and presentation. These pathways are divided into six discrete steps that allow a comparison of the various means by which antigens destined for presentation are acquired and how the source proteins for these antigens are tagged for degradation, destroyed and ultimately displayed as peptides in complex with MHC molecules for T cell recognition.
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Affiliation(s)
- Novalia Pishesha
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.,Society of Fellows, Harvard University, Cambridge, MA, USA.,Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Thibault J Harmand
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Hidde L Ploegh
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
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10
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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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11
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Truong HV, Sgourakis NG. Dynamics of MHC-I molecules in the antigen processing and presentation pathway. Curr Opin Immunol 2021; 70:122-128. [PMID: 34153556 PMCID: PMC8622473 DOI: 10.1016/j.coi.2021.04.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/20/2021] [Accepted: 04/30/2021] [Indexed: 01/07/2023]
Abstract
The endogenous antigen processing and presentation (APP) is a fundamental pathway found in jawed vertebrates, which allows for a set of epitope peptides sampled from the intracellular proteome to be assembled and displayed on class I proteins of the major histocompatibility complex (MHC-I). Peptide/MHC-I antigens enable different aspects of adaptive immunity to emerge, by providing a basis for recognition of self vs. non-self by T cells and Natural Killer (NK) cells. Pioneering studies of pMHC-I molecules and their higher-order protein complexes with molecular chaperones and membrane receptors have gleaned important insights into the peptide loading and antigen recognition mechanisms. While X-ray and cryoEM structures have provided us with static snapshots of different MHC-I assembly stages, complementary biophysical techniques have revealed that MHC-I molecules are highly mobile on a range of biologically relevant timescales, which bears importance for their assembly, peptide repertoire selection, membrane display and turnover. This review summarizes insights gained from experimental and simulation studies aimed at investigating MHC-I dynamics, and their functional implications.
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Affiliation(s)
- Hau V Truong
- Center for Computational and Genomic Medicine, Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA 19104, USA; Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, 3401 Civic Center Blvd., Philadelphia, PA 19104, USA
| | - Nikolaos G Sgourakis
- Center for Computational and Genomic Medicine, Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA 19104, USA; Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, 3401 Civic Center Blvd., Philadelphia, PA 19104, USA.
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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; 10:67092. [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] [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 Oxford, Oxford, United Kingdom.,Radcliffe Department of Medicine, Medical Research Council Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | - Anna Huhn
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Enas Abu Shah
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom.,Kennedy Institute of Rheumatology, University of Oxford, Oxford, United Kingdom
| | - Mikhail A Kutuzov
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Daniel B Wilson
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom.,Boston University, Department of Mathematics and Statistics, Boston, United States
| | - Michael L Dustin
- Kennedy Institute of Rheumatology, University of Oxford, Oxford, United Kingdom
| | - Simon J Davis
- Radcliffe Department of Medicine, Medical Research Council Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, United Kingdom
| | | | - Omer Dushek
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
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13
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Jantz-Naeem N, Springer S. Venus flytrap or pas de trois? The dynamics of MHC class I molecules. Curr Opin Immunol 2021; 70:82-89. [PMID: 33993034 DOI: 10.1016/j.coi.2021.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 04/05/2021] [Accepted: 04/08/2021] [Indexed: 11/25/2022]
Abstract
The peptide binding site of major histocompatibility complex (MHC) class I molecules is natively unfolded when devoid of peptides. Peptide binding stabilizes the structure and slows the dynamics, but peptide-specific and subtype-specific motions influence, and are influenced by, interaction with assembly chaperones, the T cell receptor, and other class I-binding proteins. The molecular mechanisms of cooperation between peptide, class I heavy chain, and beta-2 microglobulin are insufficiently known but are being elucidated by nuclear magnetic resonance and other modern methods. It appears that micropolymorphic clusters of charged amino acids, often hidden in the molecule interior, determine the dynamics and thus chaperone dependence, cellular fate, and disease association of class I.
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Affiliation(s)
- Nouria Jantz-Naeem
- Department of Life Sciences and Chemistry, Jacobs University, Bremen, Germany
| | - Sebastian Springer
- Department of Life Sciences and Chemistry, Jacobs University, Bremen, Germany.
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14
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Zhu Y, Huang C, Su M, Ge Z, Gao L, Shi Y, Wang X, Chen J. Characterization of amino acid residues of T-cell receptors interacting with HLA-A*02-restricted antigen peptides. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:495. [PMID: 33850892 PMCID: PMC8039679 DOI: 10.21037/atm-21-835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Background The present study aimed to explore residues’ properties interacting with HLA-A*02-restricted peptides on T-cell receptors (TCRs) and their effects on bond types of interaction and binding free energy. Methods We searched the crystal structures of HLA-A*02-restricted peptide-TCR complexes from the Protein Data Bank (PDB) database and subsequently collected relevant parameters. We then employed Schrodinger to analyze the bond types of interaction and Gromacs 2019 to evaluate the TCR-antigen peptide complex’s molecular dynamics simulation. Finally, we compared the changes of bond types of interaction and binding free energy before and after residue substitution to ensure consistency of the conditions before and after residue substitution. Results The main sites on the antigen peptides that formed the intermolecular interaction [hydrogen bond (HB) and pi stack] with TCRs were P4, P8, P2, and P6. The hydrophobicity of the amino acids inside or outside the disulfide bond of TCRs may be related to the intermolecular interaction and binding free energy between TCRs and peptides. Residues located outside the disulfide bond of TCR α or β chains and forming pi stack force played favorable roles in the complex intermolecular interaction and binding free energy. The residues of the TCR α or β chains that interacted with peptides were replaced by alanine (Ala) or glycine (Gly), and their intermolecular binding free energy of the complex had been improved. However, it had nothing to do with the formation of HB. Conclusions The findings of this study suggest that the hydrophobic nature of the amino acids inside or outside the disulfide bonds on the TCR may be associated with the intermolecular interaction and binding between the TCR and polypeptide. The residues located outside the TCR α or β single-chain disulfide bond and forming the pi-stack force showed a beneficial effect on the intermolecular interaction and binding of the complex. In addition, the part of the residues on the TCR α or β single chain that produced bond types of interaction with the polypeptide after being replaced by Ala or Gly, the intermolecular binding free energy of the complex was increased, regardless of whether HB was formed.
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Affiliation(s)
- Ying Zhu
- Department of Oncology, First Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China
| | - Changxin Huang
- Department of Oncology, Affiliated Hospital of Hangzhou Normal University, Hangzhou, China
| | - Meng Su
- Master Class, Zhejiang Chinese Medical University, Fourth School of Clinical Medicine, Hangzhou, China
| | - Zuanmin Ge
- Master Class, Hangzhou Normal University, School of Medicine, Hangzhou, China
| | - Lanlan Gao
- Master Class, Hangzhou Normal University, School of Medicine, Hangzhou, China
| | - Yanfei Shi
- Master Class, Hangzhou Normal University, School of Medicine, Hangzhou, China
| | - Xuechun Wang
- Master Class, Zhejiang Chinese Medical University, Fourth School of Clinical Medicine, Hangzhou, China
| | - Jianfeng Chen
- Department of Proctology, Affiliated Hospital of Hangzhou Normal University, Hangzhou, China
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15
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Smith AR, Alonso JA, Ayres CM, Singh NK, Hellman LM, Baker BM. Structurally silent peptide anchor modifications allosterically modulate T cell recognition in a receptor-dependent manner. Proc Natl Acad Sci U S A 2021; 118:e2018125118. [PMID: 33468649 PMCID: PMC7848747 DOI: 10.1073/pnas.2018125118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Presentation of peptides by class I MHC proteins underlies T cell immune responses to pathogens and cancer. The association between peptide binding affinity and immunogenicity has led to the engineering of modified peptides with improved MHC binding, with the hope that these peptides would be useful for eliciting cross-reactive immune responses directed toward their weak binding, unmodified counterparts. Increasing evidence, however, indicates that T cell receptors (TCRs) can perceive such anchor-modified peptides differently than wild-type (WT) peptides, although the scope of discrimination is unclear. We show here that even modifications at primary anchors that have no discernible structural impact can lead to substantially stronger or weaker T cell recognition depending on the TCR. Surprisingly, the effect of peptide anchor modification can be sensed by a TCR at regions distant from the site of modification, indicating a through-protein mechanism in which the anchor residue serves as an allosteric modulator for TCR binding. Our findings emphasize caution in the use and interpretation of results from anchor-modified peptides and have implications for how anchor modifications are accounted for in other circumstances, such as predicting the immunogenicity of tumor neoantigens. Our data also highlight an important need to better understand the highly tunable dynamic nature of class I MHC proteins and the impact this has on various forms of immune recognition.
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MESH Headings
- Allosteric Regulation
- Binding Sites
- Cloning, Molecular
- Crystallography, X-Ray
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Gene Expression
- Genetic Vectors/chemistry
- Genetic Vectors/metabolism
- HLA-A2 Antigen/chemistry
- HLA-A2 Antigen/genetics
- HLA-A2 Antigen/immunology
- Humans
- Jurkat Cells
- Kinetics
- Models, Molecular
- Peptides/chemistry
- Peptides/genetics
- Peptides/immunology
- Protein Binding
- Protein Conformation, alpha-Helical
- Protein Conformation, beta-Strand
- Protein Engineering
- Protein Interaction Domains and Motifs
- Receptors, Antigen, T-Cell, alpha-beta/chemistry
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Recombinant Proteins/immunology
- Th2 Cells/cytology
- Th2 Cells/immunology
- Thermodynamics
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Affiliation(s)
- Angela R Smith
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
- Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN 46556
| | - Jesus A Alonso
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
- Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN 46556
| | - Cory M Ayres
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
- Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN 46556
| | - Nishant K Singh
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
- Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN 46556
| | - Lance M Hellman
- Department of Physical and Life Sciences, Nevada State College, Henderson, NV 89002
| | - Brian M Baker
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556;
- Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN 46556
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16
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Borrman T, Pierce BG, Vreven T, Baker BM, Weng Z. High-throughput modeling and scoring of TCR-pMHC complexes to predict cross-reactive peptides. Bioinformatics 2020; 36:5377-5385. [PMID: 33355667 PMCID: PMC8016493 DOI: 10.1093/bioinformatics/btaa1050] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 11/23/2020] [Accepted: 12/08/2020] [Indexed: 01/14/2023] Open
Abstract
MOTIVATION The binding of T cell receptors (TCRs) to their target peptide MHC (pMHC) ligands initializes the cell-mediated immune response. In autoimmune diseases such as multiple sclerosis, the TCR erroneously recognizes self-peptides as foreign and activates an immune response against healthy cells. Such responses can be triggered by cross-recognition of the autoreactive TCR with foreign peptides. Hence, it would be desirable to identify such foreign-antigen triggers to provide a mechanistic understanding of autoimmune diseases. However, the large sequence space of foreign antigens presents an obstacle in the identification of cross-reactive peptides. RESULTS Here, we present an in silico modeling and scoring method which exploits the structural properties of TCR-pMHC complexes to predict the binding of cross-reactive peptides. We analyzed three mouse TCRs and one human TCR isolated from a patient with multiple sclerosis. Cross-reactive peptides for these TCRs were previously identified via yeast display coupled with deep sequencing, providing a robust dataset for evaluating our method. Modeling query peptides in their associated TCR-pMHC crystal structures, our method accurately selected the top binding peptides from sets containing more than a hundred thousand unique peptides. AVAILABILITY AND IMPLEMENTATION Analyses were performed using custom Python and R scripts available at https://github.com/tborrman/antigen-predict. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Tyler Borrman
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Brian G Pierce
- University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, MD, USA.,Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
| | - Thom Vreven
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Brian M Baker
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA.,Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN, USA
| | - Zhiping Weng
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA, USA
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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: 35] [Impact Index Per Article: 8.8] [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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Belz TF, Bremer PT, Zhou B, Ellis B, Eubanks LM, Janda KD. Enhancement of a Heroin Vaccine through Hapten Deuteration. J Am Chem Soc 2020; 142:13294-13298. [PMID: 32700530 DOI: 10.1021/jacs.0c05219] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The United States is in the midst of an unprecedented epidemic of opioid substance use disorder, and while pharmacotherapies including opioid agonists and antagonists have shown success, they can be inadequate and frequently result in high recidivism. With these challenges facing opioid use disorder treatments immunopharmacotherapy is being explored as an alternative therapy option and is based upon antibody-opioid sequestering to block brain entry. Development of a heroin vaccine has become a major research focal point; however, producing an efficient vaccine against heroin has been particularly challenging because of the need to generate not only a potent immune response but one against heroin and its multiple psychoactive molecules. In this study, we explored the consequence of regioselective deuteration of a heroin hapten and its impact upon the immune response against heroin and its psychoactive metabolites. Deuterium (HdAc) and cognate protium heroin (HAc) haptens were compared head to head in an inclusive vaccine study. Strikingly the HdAc vaccine granted greater efficacy in blunting heroin analgesia in murine behavioral models compared to the HAc vaccine. Binding studies confirmed that the HdAc vaccine elicited both greater quantities and equivalent or higher affinity antibodies toward heroin and 6-AM. Blood-brain biodistribution experiments corroborated these affinity tests. These findings suggest that regioselective hapten deuteration could be useful for the resurrection of previous drug of abuse vaccines that have met limited success in the past.
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Affiliation(s)
- Tyson F Belz
- Department of Chemistry, Department of Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The Worm Institute of Research and Medicine (WIRM), The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Paul T Bremer
- Department of Chemistry, Department of Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The Worm Institute of Research and Medicine (WIRM), The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States.,Cessation Therapeutics LLC, 3031 Tisch Way Ste 505, San Jose, California 95128, United States
| | - Bin Zhou
- Department of Chemistry, Department of Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The Worm Institute of Research and Medicine (WIRM), The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Beverly Ellis
- Department of Chemistry, Department of Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The Worm Institute of Research and Medicine (WIRM), The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Lisa M Eubanks
- Department of Chemistry, Department of Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The Worm Institute of Research and Medicine (WIRM), The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
| | - Kim D Janda
- Department of Chemistry, Department of Immunology and Microbial Science, The Skaggs Institute for Chemical Biology, The Worm Institute of Research and Medicine (WIRM), The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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19
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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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20
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Structures of peptide-free and partially loaded MHC class I molecules reveal mechanisms of peptide selection. Nat Commun 2020; 11:1314. [PMID: 32161266 PMCID: PMC7066147 DOI: 10.1038/s41467-020-14862-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 02/06/2020] [Indexed: 02/08/2023] Open
Abstract
Major Histocompatibility Complex (MHC) class I molecules selectively bind peptides for presentation to cytotoxic T cells. The peptide-free state of these molecules is not well understood. Here, we characterize a disulfide-stabilized version of the human class I molecule HLA-A*02:01 that is stable in the absence of peptide and can readily exchange cognate peptides. We present X-ray crystal structures of the peptide-free state of HLA-A*02:01, together with structures that have dipeptides bound in the A and F pockets. These structural snapshots reveal that the amino acid side chains lining the binding pockets switch in a coordinated fashion between a peptide-free unlocked state and a peptide-bound locked state. Molecular dynamics simulations suggest that the opening and closing of the F pocket affects peptide ligand conformations in adjacent binding pockets. We propose that peptide binding is co-determined by synergy between the binding pockets of the MHC molecule. Major Histocompatibility Complex (MHC) class I molecules present tightly binding peptides on the cell surface for recognition by cytotoxic T cells. Here, the authors present the crystal structures of a disulfide-stabilized human MHC class I molecule in the peptide-free state and bound with dipeptides, and find that peptide binding is accompanied by concerted conformational switches of the amino acid side chains in the binding pockets.
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21
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Trowitzsch S, Tampé R. Multifunctional Chaperone and Quality Control Complexes in Adaptive Immunity. Annu Rev Biophys 2020; 49:135-161. [PMID: 32004089 DOI: 10.1146/annurev-biophys-121219-081643] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The fundamental process of adaptive immunity relies on the differentiation of self from nonself. Nucleated cells are continuously monitored by effector cells of the immune system, which police the peptide status presented via cell surface molecules. Recent integrative structural approaches have provided insights toward our understanding of how sophisticated cellular machineries shape such hierarchical immune surveillance. Biophysical and structural achievements were invaluable for defining the interconnection of many key factors during antigen processing and presentation, and helped to solve several conundrums that persisted for many years. In this review, we illuminate the numerous quality control machineries involved in different steps during the maturation of major histocompatibility complex class I (MHC I) proteins, from their synthesis in the endoplasmic reticulum to folding and trafficking via the secretory pathway, optimization of antigenic cargo, final release to the cell surface, and engagement with their cognate receptors on cytotoxic T lymphocytes.
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Affiliation(s)
- Simon Trowitzsch
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany; ,
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany; ,
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22
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Sharma P, Harris DT, Stone JD, Kranz DM. T-cell Receptors Engineered De Novo for Peptide Specificity Can Mediate Optimal T-cell Activity without Self Cross-Reactivity. Cancer Immunol Res 2019; 7:2025-2035. [PMID: 31548259 DOI: 10.1158/2326-6066.cir-19-0035] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 06/04/2019] [Accepted: 09/17/2019] [Indexed: 12/17/2022]
Abstract
Despite progress in adoptive T-cell therapies, the identification of targets remains a challenge. Although chimeric antigen receptors recognize cell-surface antigens, T-cell receptors (TCR) have the advantage that they can target the array of intracellular proteins by binding to peptides associated with major histocompatibility complex (MHC) products (pepMHC). Although hundreds of cancer-associated peptides have been reported, it remains difficult to identify effective TCRs against each pepMHC complex. Conventional approaches require isolation of antigen-specific CD8+ T cells, followed by TCRαβ gene isolation and validation. To bypass this process, we used directed evolution to engineer TCRs with desired peptide specificity. Here, we compared the activity and cross-reactivity of two affinity-matured TCRs (T1 and RD1) with distinct origins. T1-TCR was isolated from a melanoma-reactive T-cell line specific for MART-1/HLA-A2, whereas RD1-TCR was derived de novo against MART-1/HLA-A2 by in vitro engineering. Despite their distinct origins, both TCRs exhibited similar peptide fine specificities, focused on the center of the MART-1 peptide. In CD4+ T cells, both TCRs mediated activity against MART-1 presented by HLA-A2. However, in CD8+ T cells, T1, but not RD1, demonstrated cross-reactivity with endogenous peptide/HLA-A2 complexes. Based on the fine specificity of these and other MART-1 binding TCRs, we conducted bioinformatics scans to identify structurally similar self-peptides in the human proteome. We showed that the T1-TCR cross-reacted with many of these self-peptides, whereas the RD1-TCR was rarely cross-reactive. Thus, TCRs such as RD1, generated de novo against cancer antigens, can serve as an alternative to TCRs generated from T-cell clones.
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Affiliation(s)
- Preeti Sharma
- Department of Biochemistry and Cancer Center at Illinois, University of Illinois, Urbana, Illinois.
| | - Daniel T Harris
- Department of Biochemistry and Cancer Center at Illinois, University of Illinois, Urbana, Illinois
| | - Jennifer D Stone
- Department of Biochemistry and Cancer Center at Illinois, University of Illinois, Urbana, Illinois
| | - David M Kranz
- Department of Biochemistry and Cancer Center at Illinois, University of Illinois, Urbana, Illinois.
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23
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Riley TP, Keller GLJ, Smith AR, Davancaze LM, Arbuiso AG, Devlin JR, Baker BM. Structure Based Prediction of Neoantigen Immunogenicity. Front Immunol 2019; 10:2047. [PMID: 31555277 PMCID: PMC6724579 DOI: 10.3389/fimmu.2019.02047] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 08/13/2019] [Indexed: 12/30/2022] Open
Abstract
The development of immunological therapies that incorporate peptide antigens presented to T cells by MHC proteins is a long sought-after goal, particularly for cancer, where mutated neoantigens are being explored as personalized cancer vaccines. Although neoantigens can be identified through sequencing, bioinformatics and mass spectrometry, identifying those which are immunogenic and able to promote tumor rejection remains a significant challenge. Here we examined the potential of high-resolution structural modeling followed by energetic scoring of structural features for predicting neoantigen immunogenicity. After developing a strategy to rapidly and accurately model nonameric peptides bound to the common class I MHC protein HLA-A2, we trained a neural network on structural features that influence T cell receptor (TCR) and peptide binding energies. The resulting structurally-parameterized neural network outperformed methods that do not incorporate explicit structural or energetic properties in predicting CD8+ T cell responses of HLA-A2 presented nonameric peptides, while also providing insight into the underlying structural and biophysical mechanisms governing immunogenicity. Our proof-of-concept study demonstrates the potential for structure-based immunogenicity predictions in the development of personalized peptide-based vaccines.
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Affiliation(s)
| | | | | | | | | | | | - Brian M. Baker
- Department of Chemistry and Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN, United States
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24
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Karch R, Stocsits C, Ilieva N, Schreiner W. Intramolecular Domain Movements of Free and Bound pMHC and TCR Proteins: A Molecular Dynamics Simulation Study. Cells 2019; 8:cells8070720. [PMID: 31337065 PMCID: PMC6678086 DOI: 10.3390/cells8070720] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/02/2019] [Accepted: 07/12/2019] [Indexed: 12/11/2022] Open
Abstract
The interaction of antigenic peptides (p) and major histocompatibility complexes (pMHC) with T-cell receptors (TCR) is one of the most important steps during the immune response. Here we present a molecular dynamics simulation study of bound and unbound TCR and pMHC proteins of the LC13-HLA-B*44:05-pEEYLQAFTY complex to monitor differences in relative orientations and movements of domains between bound and unbound states of TCR-pMHC. We generated local coordinate systems for MHC α1- and MHC α2-helices and the variable T-cell receptor regions TCR Vα and TCR Vβ and monitored changes in the distances and mutual orientations of these domains. In comparison to unbound states, we found decreased inter-domain movements in the simulations of bound states. Moreover, increased conformational flexibility was observed for the MHC α2-helix, the peptide, and for the complementary determining regions of the TCR in TCR-unbound states as compared to TCR-bound states.
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Affiliation(s)
- Rudolf Karch
- Section of Biosimulation and Bioinformatics, Center for Medical Statistics, Informatics and Intelligent Systems (CeMSIIS), Medical University of Vienna, Spitalgasse 23, A-1090 Vienna, Austria
| | - Claudia Stocsits
- Section of Biosimulation and Bioinformatics, Center for Medical Statistics, Informatics and Intelligent Systems (CeMSIIS), Medical University of Vienna, Spitalgasse 23, A-1090 Vienna, Austria
| | - Nevena Ilieva
- Institute of Information and Communication Technologies (IICT), Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Block 25A, 1113 Sofia, Bulgaria
- CERN-TH, Esplanade des Particules 1, 1211 Geneva, Switzerland
| | - Wolfgang Schreiner
- Section of Biosimulation and Bioinformatics, Center for Medical Statistics, Informatics and Intelligent Systems (CeMSIIS), Medical University of Vienna, Spitalgasse 23, A-1090 Vienna, Austria.
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25
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Ayres CM, Abualrous ET, Bailey A, Abraham C, Hellman LM, Corcelli SA, Noé F, Elliott T, Baker BM. Dynamically Driven Allostery in MHC Proteins: Peptide-Dependent Tuning of Class I MHC Global Flexibility. Front Immunol 2019; 10:966. [PMID: 31130956 PMCID: PMC6509175 DOI: 10.3389/fimmu.2019.00966] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Accepted: 04/15/2019] [Indexed: 11/21/2022] Open
Abstract
T cell receptor (TCR) recognition of antigenic peptides bound and presented by class I major histocompatibility complex (MHC) proteins underlies the cytotoxic immune response to diseased cells. Crystallographic structures of TCR-peptide/MHC complexes have demonstrated how TCRs simultaneously interact with both the peptide and the MHC protein. However, it is increasingly recognized that, beyond serving as a static platform for peptide presentation, the physical properties of class I MHC proteins are tuned by different peptides in ways that are not always structurally visible. These include MHC protein motions, or dynamics, which are believed to influence interactions with a variety of MHC-binding proteins, including not only TCRs, but other activating and inhibitory receptors as well as components of the peptide loading machinery. Here, we investigated the mechanisms by which peptides tune the dynamics of the common class I MHC protein HLA-A2. By examining more than 50 lengthy molecular dynamics simulations of HLA-A2 presenting different peptides, we identified regions susceptible to dynamic tuning, including regions in the peptide binding domain as well as the distal α3 domain. Further analyses of the simulations illuminated mechanisms by which the influences of different peptides are communicated throughout the protein, and involve regions of the peptide binding groove, the β2-microglobulin subunit, and the α3 domain. Overall, our results demonstrate that the class I MHC protein is a highly tunable peptide sensor whose physical properties vary considerably with bound peptide. Our data provides insight into the underlying principles and suggest a role for dynamically driven allostery in the immunological function of MHC proteins.
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Affiliation(s)
- Cory M Ayres
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States.,Harper Cancer Research Institute, University of Notre Dame, South Bend, IN, United States
| | - Esam T Abualrous
- Computational Molecular Biology Group, Institute for Mathematics, Freie Universität Berlin, Berlin, Germany
| | - Alistair Bailey
- Institute for Life Sciences and Centre for Cancer Immunology, University of Southampton, Southampton, United Kingdom
| | - Christian Abraham
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States.,Harper Cancer Research Institute, University of Notre Dame, South Bend, IN, United States
| | - Lance M Hellman
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States.,Harper Cancer Research Institute, University of Notre Dame, South Bend, IN, United States
| | - Steven A Corcelli
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States
| | - Frank Noé
- Computational Molecular Biology Group, Institute for Mathematics, Freie Universität Berlin, Berlin, Germany
| | - Tim Elliott
- Institute for Life Sciences and Centre for Cancer Immunology, University of Southampton, Southampton, United Kingdom
| | - Brian M Baker
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States.,Harper Cancer Research Institute, University of Notre Dame, South Bend, IN, United States
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26
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Buckle AM, Borg NA. Integrating Experiment and Theory to Understand TCR-pMHC Dynamics. Front Immunol 2018; 9:2898. [PMID: 30581442 PMCID: PMC6293202 DOI: 10.3389/fimmu.2018.02898] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 11/26/2018] [Indexed: 11/13/2022] Open
Abstract
The conformational dynamism of proteins is well established. Rather than having a single structure, proteins are more accurately described as a conformational ensemble that exists across a rugged energy landscape, where different conformational sub-states interconvert. The interaction between αβ T cell receptors (TCR) and cognate peptide-MHC (pMHC) is no exception, and is a dynamic process that involves substantial conformational change. This review focuses on technological advances that have begun to establish the role of conformational dynamics and dynamic allostery in TCR recognition of the pMHC and the early stages of signaling. We discuss how the marriage of molecular dynamics (MD) simulations with experimental techniques provides us with new ways to dissect and interpret the process of TCR ligation. Notably, application of simulation techniques lags behind other fields, but is predicted to make substantial contributions. Finally, we highlight integrated approaches that are being used to shed light on some of the key outstanding questions in the early events leading to TCR signaling.
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Affiliation(s)
- Ashley M Buckle
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | - Natalie A Borg
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
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27
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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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28
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Riley TP, Hellman LM, Gee MH, Mendoza JL, Alonso JA, Foley KC, Nishimura MI, Vander Kooi CW, Garcia KC, Baker BM. T cell receptor cross-reactivity expanded by dramatic peptide-MHC adaptability. Nat Chem Biol 2018; 14:934-942. [PMID: 30224695 PMCID: PMC6371774 DOI: 10.1038/s41589-018-0130-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 07/25/2018] [Indexed: 12/31/2022]
Abstract
T cell receptor cross-reactivity allows a fixed T cell repertoire to respond to a much larger universe of potential antigens. Recent work has emphasized the importance of peptide structural and chemical homology, as opposed to sequence similarity, in T cell receptor cross-reactivity. Surprisingly though, T cell receptors can also cross-react between ligands with little physiochemical commonalities. Studying the clinically relevant receptor DMF5, we demonstrate that cross-recognition of such divergent antigens can occur through mechanisms that involve heretofore unanticipated rearrangements in the peptide and presenting MHC protein, including binding-induced peptide register shifts and extensions from MHC peptide binding grooves. Moreover, cross-reactivity can proceed even when such dramatic rearrangements do not translate into structural or chemical molecular mimicry. Beyond demonstrating new principles of T cell receptor cross-reactivity, our results have implications for efforts to predict and control T cell specificity and cross-reactivity, and highlight challenges associated with predicting T cell reactivities.
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Affiliation(s)
- Timothy P Riley
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA.,Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN, USA
| | - Lance M Hellman
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA.,Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN, USA
| | - Marvin H Gee
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.,Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Juan L Mendoza
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.,Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Jesus A Alonso
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.,Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Kendra C Foley
- Department of Surgery, Cardinal Bernardin Cancer Center, Loyola University Chicago, Maywood, IL, USA
| | - Michael I Nishimura
- Department of Surgery, Cardinal Bernardin Cancer Center, Loyola University Chicago, Maywood, IL, USA
| | - Craig W Vander Kooi
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - K Christopher Garcia
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.,Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Brian M Baker
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, USA. .,Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN, USA.
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29
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Zhang L, Lin D, Yu S, Bai J, Jiang W, Su W, Huang Y, Yang S, Wu J. Polymorphism of duck MHC class molecules. Immunogenetics 2018; 71:49-59. [PMID: 30187087 DOI: 10.1007/s00251-018-1076-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 08/10/2018] [Indexed: 01/09/2023]
Abstract
Major histocompatibility complex class I (MHC I) molecules are critically involved in defense against pathogens, and their high polymorphism is advantageous to a range of immune responses, especially in duck displaying biased expression of one MHC I gene. Here, we examined MHC I polymorphism in two duck (Anas platyrhynchos) breeds from China: Shaoxing (SX) and Jinding (JD). Twenty-seven unique UAA alleles identified from the MHC I genes of these breeds were analyzed concerning amino acid composition, homology, and phylogenetic relationships. Based on amino acid sequence homology, allelic groups of Anas platyrhynchos MHC I (Anpl-MHC I) were established and their distribution was analyzed. Then, highly variable sites (HVSs) in peptide-binding domains (PBD) were estimated and located in the three-dimensional structure of Anpl-MHC I. The UAA alleles identified showed high polymorphism, based on full-length sequence homology. By adding the alleles found here to known Anpl-MHC I genes from domestic ducks, they could be divided into 17 groups and four novel groups were revealed for SX and JD ducks. The UAA alleles of the two breeds were not divergent from the MHC I of other duck breeds, and HVSs were mostly located in the peptide-binding groove (PBG), suggesting that they might determine peptide-binding characteristics and subsequently influence peptide presentation and recognition. The results from the present study enrich Anpl-MHC I polymorphism data and clarify the distribution of alleles with different peptide-binding specificities, which might also accelerate effective vaccine development and help control various infections in ducks.
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Affiliation(s)
- Lin Zhang
- Shandong Key Laboratory of Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Science, No. 8, Sangyuan Road, Jinan, Shandong, China.
| | - Dongmei Lin
- College of Life Sciences and Food Engineering, Hebei University of Engineering, 199, Guangming South Street, Handan, Hebei, China
| | - Sen Yu
- Shandong Key Laboratory of Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Science, No. 8, Sangyuan Road, Jinan, Shandong, China
| | - Junping Bai
- Shandong Key Laboratory of Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Science, No. 8, Sangyuan Road, Jinan, Shandong, China
- College of Life Sciences and Food Engineering, Hebei University of Engineering, 199, Guangming South Street, Handan, Hebei, China
| | - Wanchun Jiang
- College of Life Sciences and Food Engineering, Hebei University of Engineering, 199, Guangming South Street, Handan, Hebei, China
| | - Wenzheng Su
- Shandong Key Laboratory of Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Science, No. 8, Sangyuan Road, Jinan, Shandong, China
| | - Yanyan Huang
- Shandong Key Laboratory of Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Science, No. 8, Sangyuan Road, Jinan, Shandong, China
| | - Shaohua Yang
- Shandong Key Laboratory of Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Science, No. 8, Sangyuan Road, Jinan, Shandong, China
| | - Jiaqiang Wu
- Shandong Key Laboratory of Disease Control and Breeding, Institute of Animal Science and Veterinary Medicine, Shandong Academy of Agricultural Science, No. 8, Sangyuan Road, Jinan, Shandong, China.
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30
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Ahmed M, Lopez-Albaitero A, Pankov D, Santich BH, Liu H, Yan S, Xiang J, Wang P, Hasan AN, Selvakumar A, O'Reilly RJ, Liu C, Cheung NKV. TCR-mimic bispecific antibodies targeting LMP2A show potent activity against EBV malignancies. JCI Insight 2018; 3:97805. [PMID: 29467338 DOI: 10.1172/jci.insight.97805] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 01/10/2018] [Indexed: 12/14/2022] Open
Abstract
EBV infection is associated with a number of malignancies of clinical unmet need, including Hodgkin lymphoma, nasopharyngeal carcinoma, gastric cancer, and posttransplant lymphoproliferative disease (PTLD), all of which express the EBV protein latent membrane protein 2A (LMP2A), an antigen that is difficult to target by conventional antibody approaches. To overcome this, we utilized phage display technology and a structure-guided selection strategy to generate human T cell receptor-like (TCR-like) monoclonal antibodies with exquisite specificity for the LMP2A-derived nonamer peptide, C426LGGLLTMV434 (CLG), as presented on HLA-A*02:01. Our lead construct, clone 38, closely mimics the native binding mode of a TCR, recognizing residues at position P3-P8 of the CLG peptide. To enhance antitumor potency, we constructed dimeric T cell engaging bispecific antibodies (DiBsAb) of clone 38 and an affinity-matured version clone 38-2. Both DiBsAb showed potent antitumor properties in vitro and in immunodeficient mice implanted with EBV transformed B lymphoblastoid cell lines and human T cell effectors. Clone 38 DiBsAb showed a stronger safety profile compared with its affinity-matured variant, with no activity against EBV- tumor cell lines and a panel of normal tissues, and was less cross-reactive against HLA-A*02:01 cells pulsed with a panel of CLG-like peptides predicted from a proteomic analysis. Clone 38 was also shown to recognize the CLG peptide on other HLA-A*02 suballeles, including HLA-A*02:02, HLA-A*02:04, and HLA-A*02:06, allowing for its potential use in additional populations. Clone 38 DiBsAb is a lead candidate to treat EBV malignancies with one of the strongest safety profiles documented for TCR-like mAbs.
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Affiliation(s)
- Mahiuddin Ahmed
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Andres Lopez-Albaitero
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Dmitry Pankov
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Brian H Santich
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Hong Liu
- Eureka Therapeutics, Emeryville, California, USA
| | - Su Yan
- Eureka Therapeutics, Emeryville, California, USA
| | - Jingyi Xiang
- Eureka Therapeutics, Emeryville, California, USA
| | - Pei Wang
- Eureka Therapeutics, Emeryville, California, USA
| | - Aisha N Hasan
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Annamalai Selvakumar
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Richard J O'Reilly
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Cheng Liu
- Eureka Therapeutics, Emeryville, California, USA
| | - Nai-Kong V Cheung
- Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York, USA
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31
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Ayres CM, Corcelli SA, Baker BM. Peptide and Peptide-Dependent Motions in MHC Proteins: Immunological Implications and Biophysical Underpinnings. Front Immunol 2017; 8:935. [PMID: 28824655 PMCID: PMC5545744 DOI: 10.3389/fimmu.2017.00935] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 07/21/2017] [Indexed: 01/28/2023] Open
Abstract
Structural biology of peptides presented by class I and class II MHC proteins has transformed immunology, impacting our understanding of fundamental immune mechanisms and allowing researchers to rationalize immunogenicity and design novel vaccines. However, proteins are not static structures as often inferred from crystallographic structures. Their components move and breathe individually and collectively over a range of timescales. Peptides bound within MHC peptide-binding grooves are no exception and their motions have been shown to impact recognition by T cell and other receptors in ways that influence function. Furthermore, peptides tune the motions of MHC proteins themselves, which impacts recognition of peptide/MHC complexes by other proteins. Here, we review the motional properties of peptides in MHC binding grooves and discuss how peptide properties can influence MHC motions. We briefly review theoretical concepts about protein motion and highlight key data that illustrate immunological consequences. We focus primarily on class I systems due to greater availability of data, but segue into class II systems as the concepts and consequences overlap. We suggest that characterization of the dynamic “energy landscapes” of peptide/MHC complexes and the resulting functional consequences is one of the next frontiers in structural immunology.
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Affiliation(s)
- Cory M Ayres
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States.,Harper Cancer Research Institute, University of Notre Dame, South Bend, IN, United States
| | - Steven A Corcelli
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States
| | - Brian M Baker
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States.,Harper Cancer Research Institute, University of Notre Dame, South Bend, IN, United States
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32
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Structural Definition of Duck Major Histocompatibility Complex Class I Molecules That Might Explain Efficient Cytotoxic T Lymphocyte Immunity to Influenza A Virus. J Virol 2017; 91:JVI.02511-16. [PMID: 28490583 PMCID: PMC5487541 DOI: 10.1128/jvi.02511-16] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 04/26/2017] [Indexed: 01/16/2023] Open
Abstract
A single dominantly expressed allele of major histocompatibility complex class I (MHC I) may be responsible for the duck's high tolerance to highly pathogenic influenza A virus (HP-IAV) compared to the chicken's lower tolerance. In this study, the crystal structures of duck MHC I (Anpl-UAA*01) and duck β2-microglobulin (β2m) with two peptides from the H5N1 strains were determined. Two remarkable features were found to distinguish the Anpl-UAA*01 complex from other known MHC I structures. A disulfide bond formed by Cys95 and Cys112 and connecting the β5 and β6 sheets at the bottom of peptide binding groove (PBG) in Anpl-UAA*01 complex, which can enhance IAV peptide binding, was identified. Moreover, the interface area between duck MHC I and β2m was found to be larger than in other species. In addition, the two IAV peptides that display distinctive conformations in the PBG, B, and F pockets act as the primary anchor sites. Thirty-one IAV peptides were used to verify the peptide binding motif of Anpl-UAA*01, and the results confirmed that the peptide binding motif is similar to that of HLA-A*0201. Based on this motif, approximately 600 peptides from the IAV strains were partially verified as the candidate epitope peptides for Anpl-UAA*01, which is a far greater number than those for chicken BF2*2101 and BF2*0401 molecules. Extensive IAV peptide binding should allow for ducks with this Anpl-UAA*01 haplotype to resist IAV infection. IMPORTANCE Ducks are natural reservoirs of influenza A virus (IAV) and are more resistant to the IAV than chickens. Both ducks and chickens express only one dominant MHC I locus providing resistance to the virus. To investigate how MHC I provides IAV resistance, crystal structures of the dominantly expressed duck MHC class I (pAnpl-UAA*01) with two IAV peptides were determined. A disulfide bond was identified in the peptide binding groove that can facilitate Anpl-UAA*01 binding to IAV peptides. Anpl-UAA*01 has a much wider recognition spectrum of IAV epitope peptides than do chickens. The IAV peptides bound by Anpl-UAA*01 display distinctive conformations that can help induce an extensive cytotoxic T lymphocyte (CTL) response. In addition, the interface area between the duck MHC I and β2m is larger than in other species. These results indicate that HP-IAV resistance in ducks is due to extensive CTL responses induced by MHC I.
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33
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MacLachlan BJ, Greenshields-Watson A, Mason GH, Schauenburg AJ, Bianchi V, Rizkallah PJ, Sewell AK, Fuller A, Cole DK. Using X-ray Crystallography, Biophysics, and Functional Assays to Determine the Mechanisms Governing T-cell Receptor Recognition of Cancer Antigens. J Vis Exp 2017:54991. [PMID: 28287509 PMCID: PMC5408581 DOI: 10.3791/54991] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Human CD8+ cytotoxic T lymphocytes (CTLs) are known to play an important role in tumor control. In order to carry out this function, the cell surface-expressed T-cell receptor (TCR) must functionally recognize human leukocyte antigen (HLA)-restricted tumor-derived peptides (pHLA). However, we and others have shown that most TCRs bind sub-optimally to tumor antigens. Uncovering the molecular mechanisms that define this poor recognition could aid in the development of new targeted therapies that circumnavigate these shortcomings. Indeed, present therapies that lack this molecular understanding have not been universally effective. Here, we describe methods that we commonly employ in the laboratory to determine how the nature of the interaction between TCRs and pHLA governs T-cell functionality. These methods include the generation of soluble TCRs and pHLA and the use of these reagents for X-ray crystallography, biophysical analysis, and antigen-specific T-cell staining with pHLA multimers. Using these approaches and guided by structural analysis, it is possible to modify the interaction between TCRs and pHLA and to then test how these modifications impact T-cell antigen recognition. These findings have already helped to clarify the mechanism of T-cell recognition of a number of cancer antigens and could direct the development of altered peptides and modified TCRs for new cancer therapies.
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Affiliation(s)
- Bruce J MacLachlan
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University
| | | | - Georgina H Mason
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University
| | - Andrea J Schauenburg
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University
| | - Valentina Bianchi
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University; Department of Oncology, University Hospital of Lausanne (CHUV); Ludwig Insitutue for Cancer Research, Lausanne Branch, University of Lausanne
| | - Pierre J Rizkallah
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University
| | - Andrew K Sewell
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University
| | - Anna Fuller
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University
| | - David K Cole
- Division of Infection and Immunity and Systems Immunity Research Institute, Cardiff University;
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34
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Hoffmann T, Marion A, Antes I. DynaDom: structure-based prediction of T cell receptor inter-domain and T cell receptor-peptide-MHC (class I) association angles. BMC STRUCTURAL BIOLOGY 2017; 17:2. [PMID: 28148269 PMCID: PMC5289058 DOI: 10.1186/s12900-016-0071-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 12/29/2016] [Indexed: 11/22/2022]
Abstract
Background T cell receptor (TCR) molecules are involved in the adaptive immune response as they distinguish between self- and foreign-peptides, presented in major histocompatibility complex molecules (pMHC). Former studies showed that the association angles of the TCR variable domains (Vα/Vβ) can differ significantly and change upon binding to the pMHC complex. These changes can be described as a rotation of the domains around a general Center of Rotation, characterized by the interaction of two highly conserved glutamine residues. Methods We developed a computational method, DynaDom, for the prediction of TCR Vα/Vβ inter-domain and TCR/pMHC orientations in TCRpMHC complexes, which allows predicting the orientation of multiple protein-domains. In addition, we implemented a new approach to predict the correct orientation of the carboxamide endgroups in glutamine and asparagine residues, which can also be used as an external, independent tool. Results The approach was evaluated for the remodeling of 75 and 53 experimental structures of TCR and TCRpMHC (class I) complexes, respectively. We show that the DynaDom method predicts the correct orientation of the TCR Vα/Vβ angles in 96 and 89% of the cases, for the poses with the best RMSD and best interaction energy, respectively. For the concurrent prediction of the TCR Vα/Vβ and pMHC orientations, the respective rates reached 74 and 72%. Through an exhaustive analysis, we could show that the pMHC placement can be further improved by a straightforward, yet very time intensive extension of the current approach. Conclusions The results obtained in the present remodeling study prove the suitability of our approach for interdomain-angle optimization. In addition, the high prediction rate obtained specifically for the energetically highest ranked poses further demonstrates that our method is a powerful candidate for blind prediction. Therefore it should be well suited as part of any accurate atomistic modeling pipeline for TCRpMHC complexes and potentially other large molecular assemblies. Electronic supplementary material The online version of this article (doi:10.1186/s12900-016-0071-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Thomas Hoffmann
- Department of Biosciences and Center for Integrated Protein Science Munich, Technische Universität München, Emil-Erlenmeyer-Forum 8, 85354, Freising, Germany
| | - Antoine Marion
- Department of Biosciences and Center for Integrated Protein Science Munich, Technische Universität München, Emil-Erlenmeyer-Forum 8, 85354, Freising, Germany
| | - Iris Antes
- Department of Biosciences and Center for Integrated Protein Science Munich, Technische Universität München, Emil-Erlenmeyer-Forum 8, 85354, Freising, Germany.
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35
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Nakamura S, Ohmura R, Nakanishi I. An Interaction-based Approach for Affinity Prediction between Antigen Peptide and Human Leukocyte Antigen Using COMBINE Analysis. CHEM-BIO INFORMATICS JOURNAL 2017. [DOI: 10.1273/cbij.17.93] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
| | - Rie Ohmura
- Department of Pharmaceutical Sciences, Kindai University
| | - Isao Nakanishi
- Department of Pharmaceutical Sciences, Kindai University
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36
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Piepenbrink KH, Lillehoj E, Harding CM, Labonte JW, Zuo X, Rapp CA, Munson RS, Goldblum SE, Feldman MF, Gray JJ, Sundberg EJ. Structural Diversity in the Type IV Pili of Multidrug-resistant Acinetobacter. J Biol Chem 2016; 291:22924-22935. [PMID: 27634041 PMCID: PMC5087714 DOI: 10.1074/jbc.m116.751099] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Indexed: 11/06/2022] Open
Abstract
Acinetobacter baumannii is a Gram-negative coccobacillus found primarily in hospital settings that has recently emerged as a source of hospital-acquired infections. A. baumannii expresses a variety of virulence factors, including type IV pili, bacterial extracellular appendages often essential for attachment to host cells. Here, we report the high resolution structures of the major pilin subunit, PilA, from three Acinetobacter strains, demonstrating that A. baumannii subsets produce morphologically distinct type IV pilin glycoproteins. We examine the consequences of this heterogeneity for protein folding and assembly as well as host-cell adhesion by Acinetobacter Comparisons of genomic and structural data with pilin proteins from other species of soil gammaproteobacteria suggest that these structural differences stem from evolutionary pressure that has resulted in three distinct classes of type IVa pilins, each found in multiple species.
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Affiliation(s)
| | | | - Christian M Harding
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Jason W Labonte
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, The Johns Hopkins University, Baltimore, Maryland 21218
| | - Xiaotong Zuo
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, The Johns Hopkins University, Baltimore, Maryland 21218
| | | | - Robert S Munson
- The Center for Microbial Pathogenesis in the Research Institute at Nationwide Children's Hospital and Department of Pediatrics, The Ohio State University College of Medicine, Columbus, Ohio 43205, and
| | - Simeon E Goldblum
- Departments of Medicine.,Baltimore Veterans Affairs Medical Center, Baltimore, Maryland 21201.,Pathology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Mario F Feldman
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Jeffrey J Gray
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, The Johns Hopkins University, Baltimore, Maryland 21218
| | - Eric J Sundberg
- From the Institute of Human Virology and .,Departments of Medicine.,Microbiology and Immunology
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37
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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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38
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Differential scanning fluorimetry based assessments of the thermal and kinetic stability of peptide-MHC complexes. J Immunol Methods 2016; 432:95-101. [PMID: 26906089 DOI: 10.1016/j.jim.2016.02.016] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 02/17/2016] [Accepted: 02/17/2016] [Indexed: 11/20/2022]
Abstract
Measurements of thermal stability by circular dichroism (CD) spectroscopy have been widely used to assess the binding of peptides to MHC proteins, particularly within the structural immunology community. Although thermal stability assays offer advantages over other approaches such as IC50 measurements, CD-based stability measurements are hindered by large sample requirements and low throughput. Here we demonstrate that an alternative approach based on differential scanning fluorimetry (DSF) yields results comparable to those based on CD for both class I and class II complexes. As they require much less sample, DSF-based measurements reduce demands on protein production strategies and are amenable for high throughput studies. DSF can thus not only replace CD as a means to assess peptide/MHC thermal stability, but can complement other peptide-MHC binding assays used in screening, epitope discovery, and vaccine design. Due to the physical process probed, DSF can also uncover complexities not observed with other techniques. Lastly, we show that DSF can also be used to assess peptide/MHC kinetic stability, allowing for a single experimental setup to probe both binding equilibria and kinetics.
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39
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Ataie N, Xiang J, Cheng N, Brea EJ, Lu W, Scheinberg DA, Liu C, Ng HL. Structure of a TCR-Mimic Antibody with Target Predicts Pharmacogenetics. J Mol Biol 2016; 428:194-205. [PMID: 26688548 PMCID: PMC4738012 DOI: 10.1016/j.jmb.2015.12.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 11/25/2015] [Accepted: 12/03/2015] [Indexed: 11/21/2022]
Abstract
Antibody therapies currently target only extracellular antigens. A strategy to recognize intracellular antigens is to target peptides presented by immune HLA receptors. ESK1 is a human, T-cell receptor (TCR)-mimic antibody that binds with subnanomolar affinity to the RMF peptide from the intracellular Wilms tumor oncoprotein WT1 in complex with HLA-A*02:01. ESK1 is therapeutically effective in mouse models of WT1(+) human cancers. TCR-based therapies have been presumed to be restricted to one HLA subtype. The mechanism for the specificity and high affinity of ESK1 is unknown. We show in a crystal structure that ESK1 Fab binds to RMF/HLA-A*02:01 in a mode different from that of TCRs. From the structure, we predict and then experimentally confirm high-affinity binding with multiple other HLA-A*02 subtypes, broadening the potential patient pool for ESK1 therapy. Using the crystal structure, we also predict potential off-target binding that we experimentally confirm. Our results demonstrate how protein structure information can contribute to personalized immunotherapy.
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Affiliation(s)
- Niloufar Ataie
- University of Hawaii at Manoa, Department of Chemistry, 2545 McCarthy Mall, Honolulu, HI 96822-2275, USA
| | - Jingyi Xiang
- Eureka Therapeutics Inc., 5858 Horton Street, Emeryville, CA 94608, USA
| | - Neal Cheng
- Eureka Therapeutics Inc., 5858 Horton Street, Emeryville, CA 94608, USA
| | - Elliott J Brea
- Sloan Kettering Institute, 1275 York Avenue, New York, NY 10065, USA
| | - Wenjie Lu
- University of Hawaii at Manoa, Department of Chemistry, 2545 McCarthy Mall, Honolulu, HI 96822-2275, USA
| | - David A Scheinberg
- Sloan Kettering Institute, 1275 York Avenue, New York, NY 10065, USA; Weill Cornell Medical College, 1305 York Avenue, New York, NY 10021, USA
| | - Cheng Liu
- Eureka Therapeutics Inc., 5858 Horton Street, Emeryville, CA 94608, USA
| | - Ho Leung Ng
- University of Hawaii at Manoa, Department of Chemistry, 2545 McCarthy Mall, Honolulu, HI 96822-2275, USA; University of Hawaii Cancer Center, 2545 McCarthy Mall, Honolulu, HI 96822-2275, USA.
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40
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Rashin AA, Jernigan RL. Clusters of Structurally Similar MHC I HLA-A2 Molecules, Found with a New Method, Suggest Mechanisms of T-Cell Receptor Avidity. Biochemistry 2016; 55:167-85. [PMID: 26600404 DOI: 10.1021/acs.biochem.5b01077] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Only α1 and α2 domains of the α-chain of the major histocompatibility complex (MHC) directly bind peptide antigens (Ag-s) and the T-cell receptor (TCR). Significant plasticity was found in the TCR but only minor in (α1 + α2). The α3-domain position variation was noted only in connection to its binding the coreceptor CD8. We apply our methods for identifying functional conformational changes in proteins to a systematic study of similarities between 43 X-ray structures of the entire α chains of MHC-I HLA-A2. Out of 903 different αHLA-A2 pairs 203 show similarities within the earlier determined uncertainty threshold and unexpectedly form three similarity clusters (SCs) with all/most structures in a cluster similar within the uncertainty threshold. Pairs from different SCs always differ above the threshold, mainly due to variations in the α3 position/structure. All structures in SC3 cannot bind the CD8 coreceptor. Strong hydrogen bonds between (α1 + α2) and α3 differ between SC1 and SC2 but are nearly invariant within each SC. Small conformational changes in the (α1 + α2), caused by Ag-s differences, act as an α3 "allosteric switch" between SC2 and SC1. Binding of CD8 to SC2-HLA-A2 (Tax-type Ag-s) changes it to SC1-HLA-A2 (HuD-type Ag-s). HuD binding to HLA-A2 is much less stable than Tax binding. CD8-liganded HLA-A2 preference for binding HuD suggests that CD8-HLA-A2 may present a weakly binding peptide for TCR recognition, supporting the hypothesis that CD8 increases TCR avidity to weak Ag-s. Other HLA-A2 functions may involve α3. TCR-A6-liganded-Tax-type-HLA-A2s form two small clusters, similar to either A6-liganded-HuD or A6-liganded-native-Tax HLA-A2s.
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Affiliation(s)
- Alexander A Rashin
- BioChemComp Inc , 543 Sagamore Avenue, Teaneck, New Jersey 07666, United States
- LH Baker Center for Bioinformatics and Department of Biochemistry, Biophysics and Molecular Biology, 112 Office and Lab Building, Iowa State University , Ames, Iowa 50011-3020, United States
| | - Robert L Jernigan
- LH Baker Center for Bioinformatics and Department of Biochemistry, Biophysics and Molecular Biology, 112 Office and Lab Building, Iowa State University , Ames, Iowa 50011-3020, United States
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41
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Abstract
T-cell receptor (TCR) binding to peptide/MHC determines specificity and initiates signaling in antigen-specific cellular immune responses. Structures of TCR-pMHC complexes have provided enormous insight to cellular immune functions, permitted a rational understanding of processes such as pathogen escape, and led to the development of novel approaches for the design of vaccines and other therapeutics. As production, crystallization, and structure determination of TCR-pMHC complexes can be challenging, there is considerable interest in modeling new complexes. Here we describe a rapid approach to TCR-pMHC modeling that takes advantage of structural features conserved in known complexes, such as the restricted TCR binding site and the generally conserved diagonal docking mode. The approach relies on the powerful Rosetta suite and is implemented using the PyRosetta scripting environment. We show how the approach can recapitulate changes in TCR binding angles and other structural details, and highlight areas where careful evaluation of parameters is needed and alternative choices might be made. As TCRs are highly sensitive to subtle structural perturbations, there is room for improvement. Our method nonetheless generates high-quality models that can be foundational for structure-based hypotheses regarding TCR recognition.
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Affiliation(s)
- Timothy P Riley
- Department of Chemistry and Biochemistry, University of Notre Dame, 251 Nieuwland Science Hall, Notre Dame, IN, 46556, USA
- Harper Cancer Research Institute, University of Notre Dame, 251 Nieuwland Science Hall, Notre Dame, IN, 46556, USA
| | - Nishant K Singh
- Department of Chemistry and Biochemistry, University of Notre Dame, 251 Nieuwland Science Hall, Notre Dame, IN, 46556, USA
- Harper Cancer Research Institute, University of Notre Dame, 251 Nieuwland Science Hall, Notre Dame, IN, 46556, USA
| | - Brian G Pierce
- Institute for Bioscience and Biotechnology Research, University of Maryland, 9600 Gudelsky Drive, Rockville, MD, 20850, USA
| | - Zhiping Weng
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA, 01605, USA
| | - Brian M Baker
- Department of Chemistry and Biochemistry, University of Notre Dame, 251 Nieuwland Science Hall, Notre Dame, IN, 46556, USA.
- Harper Cancer Research Institute, University of Notre Dame, 251 Nieuwland Science Hall, Notre Dame, IN, 46556, USA.
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42
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Wan S, Knapp B, Wright DW, Deane CM, Coveney PV. Rapid, Precise, and Reproducible Prediction of Peptide-MHC Binding Affinities from Molecular Dynamics That Correlate Well with Experiment. J Chem Theory Comput 2015; 11:3346-56. [PMID: 26575768 DOI: 10.1021/acs.jctc.5b00179] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The presentation of potentially pathogenic peptides by major histocompatibility complex (MHC) molecules is one of the most important processes in adaptive immune defense. Prediction of peptide-MHC (pMHC) binding affinities is therefore a principal objective of theoretical immunology. Machine learning techniques achieve good results if substantial experimental training data are available. Approaches based on structural information become necessary if sufficiently similar training data are unavailable for a specific MHC allele, although they have often been deemed to lack accuracy. In this study, we use a free energy method to rank the binding affinities of 12 diverse peptides bound by a class I MHC molecule HLA-A*02:01. The method is based on enhanced sampling of molecular dynamics calculations in combination with a continuum solvent approximation and includes estimates of the configurational entropy based on either a one or a three trajectory protocol. It produces precise and reproducible free energy estimates which correlate well with experimental measurements. If the results are combined with an amino acid hydrophobicity scale, then an extremely good ranking of peptide binding affinities emerges. Our approach is rapid, robust, and applicable to a wide range of ligand-receptor interactions without further adjustment.
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Affiliation(s)
- Shunzhou Wan
- Centre for Computational Science, Department of Chemistry, University College London , London WC1H 0AJ, United Kingdom
| | - Bernhard Knapp
- Protein Informatics Group, Department of Statistics, University of Oxford , Oxford, OX1 3TG, United Kingdom
| | - David W Wright
- Institute of Structural and Molecular Biology, University College London , London WC1E 6BT, United Kingdom
| | - Charlotte M Deane
- Protein Informatics Group, Department of Statistics, University of Oxford , Oxford, OX1 3TG, United Kingdom
| | - Peter V Coveney
- Centre for Computational Science, Department of Chemistry, University College London , London WC1H 0AJ, United Kingdom
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43
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Murray JS. An old Twist in HLA-A: CDR3α Hook up at an R65-joint. Front Immunol 2015; 6:268. [PMID: 26074926 PMCID: PMC4445401 DOI: 10.3389/fimmu.2015.00268] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 05/14/2015] [Indexed: 11/30/2022] Open
Abstract
T-cell ontogeny optimizes the α/β T-cell receptor (TCR) repertoire for recognition of major histocompatibility complex (MHC) class-I/II genetic polymorphism, and co-evolution of TCR germline V-gene segments and the MHC must entail somatic diversity generated in the third complimentary determining regions (CDR3α/β); however, it is still not clear how. Herein, a conspicuous structural link between the V-Jα used by several different TCR [all in complex with the same MHC molecule (HLA-A2)], and a conserved MHC motif (a.a., R65-X-X-K-A-X-S-Q72) is described. We model this R65-joint in detail, and show that the same TCR’s CDR3α loop maintains its CDR2α loop at a distance of ~4 Å from polymorphic amino acid (a.a.) positions of the α-2 helix in all but one of the analyzed crystal structures. Indeed, the pitch of docked TCRs varies as their twist/tilt/sway maintains the R65-joint and peptide contacts. Thus, the R65-joint appears to have poised the HLA-A lineage toward alloreactivity.
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44
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Understanding the structural dynamics of TCR-pMHC interactions. Trends Immunol 2014; 35:604-612. [DOI: 10.1016/j.it.2014.10.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 10/20/2014] [Accepted: 10/20/2014] [Indexed: 12/23/2022]
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45
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Birnbaum ME, Mendoza JL, Sethi DK, Dong S, Glanville J, Dobbins J, Özkan E, Davis MM, Wucherpfennig KW, Garcia KC. Deconstructing the peptide-MHC specificity of T cell recognition. Cell 2014; 157:1073-87. [PMID: 24855945 PMCID: PMC4071348 DOI: 10.1016/j.cell.2014.03.047] [Citation(s) in RCA: 395] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 02/17/2014] [Accepted: 03/14/2014] [Indexed: 01/07/2023]
Abstract
In order to survey a universe of major histocompatibility complex (MHC)-presented peptide antigens whose numbers greatly exceed the diversity of the T cell repertoire, T cell receptors (TCRs) are thought to be cross-reactive. However, the nature and extent of TCR cross-reactivity has not been conclusively measured experimentally. We developed a system to identify MHC-presented peptide ligands by combining TCR selection of highly diverse yeast-displayed peptide-MHC libraries with deep sequencing. Although we identified hundreds of peptides reactive with each of five different mouse and human TCRs, the selected peptides possessed TCR recognition motifs that bore a close resemblance to their known antigens. This structural conservation of the TCR interaction surface allowed us to exploit deep-sequencing information to computationally identify activating microbial and self-ligands for human autoimmune TCRs. The mechanistic basis of TCR cross-reactivity described here enables effective surveillance of diverse self and foreign antigens without necessitating degenerate recognition of nonhomologous peptides.
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Affiliation(s)
- Michael E. Birnbaum
- Departments of Molecular and Cellular Physiology and Structural Biology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305,Program in Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305
| | - Juan L. Mendoza
- Departments of Molecular and Cellular Physiology and Structural Biology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305
| | - Dhruv K. Sethi
- Department of Cancer Immunology & AIDS, Dana-Farber Cancer Institute, Boston, MA 02115
| | - Shen Dong
- Departments of Molecular and Cellular Physiology and Structural Biology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305
| | - Jacob Glanville
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305,Program in Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305
| | - Jessica Dobbins
- Department of Cancer Immunology & AIDS, Dana-Farber Cancer Institute, Boston, MA 02115,Program in Immunology, Harvard Medical School, Boston, MA 02115
| | - Engin Özkan
- Departments of Molecular and Cellular Physiology and Structural Biology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305,The Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305
| | - Mark M. Davis
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305,Program in Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305,The Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305
| | - Kai W. Wucherpfennig
- Department of Cancer Immunology & AIDS, Dana-Farber Cancer Institute, Boston, MA 02115,Program in Immunology, Harvard Medical School, Boston, MA 02115
| | - K. Christopher Garcia
- Departments of Molecular and Cellular Physiology and Structural Biology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305,Program in Immunology, Stanford University School of Medicine, Stanford University, Stanford, CA 94305,The Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305
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46
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Hawse WF, De S, Greenwood AI, Nicholson LK, Zajicek J, Kovrigin EL, Kranz DM, Garcia KC, Baker BM. TCR scanning of peptide/MHC through complementary matching of receptor and ligand molecular flexibility. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2014; 192:2885-91. [PMID: 24523505 PMCID: PMC3992338 DOI: 10.4049/jimmunol.1302953] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Although conformational changes in TCRs and peptide Ags presented by MHC protein (pMHC) molecules often occur upon binding, their relationship to intrinsic flexibility and role in ligand selectivity are poorly understood. In this study, we used nuclear magnetic resonance to study TCR-pMHC binding, examining recognition of the QL9/H-2L(d) complex by the 2C TCR. Although the majority of the CDR loops of the 2C TCR rigidify upon binding, the CDR3β loop remains mobile within the TCR-pMHC interface. Remarkably, the region of the QL9 peptide that interfaces with CDR3β is also mobile in the free pMHC and in the TCR-pMHC complex. Determination of conformational exchange kinetics revealed that the motions of CDR3β and QL9 are closely matched. The matching of conformational exchange in the free proteins and its persistence in the complex enhances the thermodynamic and kinetic stability of the TCR-pMHC complex and provides a mechanism for facile binding. We thus propose that matching of structural fluctuations is a component of how TCRs scan among potential ligands for those that can bind with sufficient stability to enable T cell signaling.
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Affiliation(s)
- William F. Hawse
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46530, USA
| | - Soumya De
- Department of Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Alex I. Greenwood
- Department of Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Linda K. Nicholson
- Department of Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Jaroslav Zajicek
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46530, USA
| | | | - David M. Kranz
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana IL 61801, USA
| | - K. Christopher Garcia
- Departments of Molecular & Cellular Physiology and Structural Biology, Program in Immunology, and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Brian M. Baker
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46530, USA
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47
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The basis for limited specificity and MHC restriction in a T cell receptor interface. Nat Commun 2013; 4:1948. [PMID: 23736024 PMCID: PMC3708045 DOI: 10.1038/ncomms2948] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 04/30/2013] [Indexed: 02/03/2023] Open
Abstract
αβ T cell receptors (TCRs) recognize peptides presented by major histocompatibility complex (MHC) proteins using multiple complementarity determining region (CDR) loops. TCRs display an array of poorly understood recognition properties, including specificity, cross-reactivity, and MHC restriction. Here we report a comprehensive thermodynamic deconstruction of the interaction between the A6 TCR and the Tax peptide presented by the class I MHC HLA-A*0201, uncovering the physical basis for the receptor's recognition properties. Broadly, our findings are in conflict with widely-held generalities regarding TCR recognition, such as the relative contributions of central and peripheral peptide residues and the roles of the hypervariable and germline CDR loops in engaging peptide and MHC. Instead we find that the recognition properties of the receptor emerge from the need to engage the composite peptide/MHC surface, with the receptor utilizing its CDR loops in a cooperative fashion such that specificity, cross-reactivity, and MHC restriction are inextricably linked.
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48
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van der Most R, Van Mechelen M, Destexhe E, Wettendorff M, Hanon E. Narcolepsy and A(H1N1)pdm09 vaccination: shaping the research on the observed signal. Hum Vaccin Immunother 2013; 10:572-6. [PMID: 24342916 DOI: 10.4161/hv.27412] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Epidemiological data from several European countries suggested an increased risk of the chronic sleep disorder narcolepsy following vaccination with Pandemrix(™), an AS03-adjuvanted, pandemic A(H1N1)pdm09 influenza vaccine. Further research to investigate potential associations between Pandemrix™ vaccination, A(H1N1)pdm09 influenza infection and narcolepsy is required. Narcolepsy is most commonly caused by a reduction or absence of hypocretin produced by hypocretin-secreting neurons in the hypothalamus, and is tightly associated with HLA-II DQB1*06:02. Consequently, research focusing on CD4(+) T-cell responses, building on the hypothesis that for disease development, T cells specific for antigen(s) from hypocretin neurons must be activated or reactivated, is considered essential. Therefore, the following key areas of research can be identified, (1) characterization of hypothetical narcolepsy-specific auto-immune CD4(+) T cells, (2) mapping epitopes of such T cells, and (3) evaluating potential mechanisms that would enable such cells to gain access to the hypothalamus. Addressing these questions could further our understanding of the potential links between narcolepsy and A(H1N1)pdm09 vaccination and/or infection. Of particular interest is that any evidence of a mimicry-based mechanism could also explain the association between narcolepsy and A(H1N1)pdm09 influenza infection.
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49
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Shen ZT, Nguyen TT, Daniels KA, Welsh RM, Stern LJ. Disparate epitopes mediating protective heterologous immunity to unrelated viruses share peptide-MHC structural features recognized by cross-reactive T cells. THE JOURNAL OF IMMUNOLOGY 2013; 191:5139-52. [PMID: 24127554 DOI: 10.4049/jimmunol.1300852] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Closely related peptide epitopes can be recognized by the same T cells and contribute to the immune response against pathogens encoding those epitopes, but sometimes cross-reactive epitopes share little homology. The degree of structural homology required for such disparate ligands to be recognized by cross-reactive TCRs remains unclear. In this study, we examined the mechanistic basis for cross-reactive T cell responses between epitopes from unrelated and pathogenic viruses, lymphocytic choriomeningitis virus (LCMV) and vaccinia virus. Our results show that the LCMV cross-reactive T cell response toward vaccinia virus is dominated by a shared asparagine residue, together with other shared structural elements conserved in the crystal structures of K(b)-VV-A11R and K(b)-LCMV-gp34. Based on analysis of the crystal structures and the specificity determinants for the cross-reactive T cell response, we were able to manipulate the degree of cross-reactivity of the T cell response, and to predict and generate a LCMV cross-reactive response toward a variant of a null OVA-derived peptide. These results indicate that protective heterologous immune responses can occur for disparate epitopes from unrelated viruses.
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Affiliation(s)
- Zu T Shen
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA 01655
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50
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Hawse WF, Gloor BE, Ayres CM, Kho K, Nuter E, Baker BM. Peptide modulation of class I major histocompatibility complex protein molecular flexibility and the implications for immune recognition. J Biol Chem 2013; 288:24372-81. [PMID: 23836912 DOI: 10.1074/jbc.m113.490664] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
T cells use the αβ T cell receptor (TCR) to recognize antigenic peptides presented by class I major histocompatibility complex proteins (pMHCs) on the surfaces of antigen-presenting cells. Flexibility in both TCRs and peptides plays an important role in antigen recognition and discrimination. Less clear is the role of flexibility in the MHC protein; although recent observations have indicated that mobility in the MHC can impact TCR recognition in a peptide-dependent fashion, the extent of this behavior is unknown. Here, using hydrogen/deuterium exchange, fluorescence anisotropy, and structural analyses, we show that the flexibility of the peptide binding groove of the class I MHC protein HLA-A*0201 varies significantly with different peptides. The variations extend throughout the binding groove, impacting regions contacted by TCRs as well as other activating and inhibitory receptors of the immune system. Our results are consistent with statistical mechanical models of protein structure and dynamics, in which the binding of different peptides alters the populations and exchange kinetics of substates in the MHC conformational ensemble. Altered MHC flexibility will influence receptor engagement, impacting conformational adaptations, entropic penalties associated with receptor recognition, and the populations of binding-competent states. Our results highlight a previously unrecognized aspect of the "altered self" mechanism of immune recognition and have implications for specificity, cross-reactivity, and antigenicity in cellular immunity.
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Affiliation(s)
- William F Hawse
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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