1
|
Abualrous ET, Stolzenberg S, Sticht J, Wieczorek M, Roske Y, Günther M, Dähn S, Boesen BB, Calvo MM, Biese C, Kuppler F, Medina-García Á, Álvaro-Benito M, Höfer T, Noé F, Freund C. MHC-II dynamics are maintained in HLA-DR allotypes to ensure catalyzed peptide exchange. Nat Chem Biol 2023; 19:1196-1204. [PMID: 37142807 PMCID: PMC10522485 DOI: 10.1038/s41589-023-01316-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 03/17/2023] [Indexed: 05/06/2023]
Abstract
Presentation of antigenic peptides by major histocompatibility complex class II (MHC-II) proteins determines T helper cell reactivity. The MHC-II genetic locus displays a large degree of allelic polymorphism influencing the peptide repertoire presented by the resulting MHC-II protein allotypes. During antigen processing, the human leukocyte antigen (HLA) molecule HLA-DM (DM) encounters these distinct allotypes and catalyzes exchange of the placeholder peptide CLIP by exploiting dynamic features of MHC-II. Here, we investigate 12 highly abundant CLIP-bound HLA-DRB1 allotypes and correlate dynamics to catalysis by DM. Despite large differences in thermodynamic stability, peptide exchange rates fall into a target range that maintains DM responsiveness. A DM-susceptible conformation is conserved in MHC-II molecules, and allosteric coupling between polymorphic sites affects dynamic states that influence DM catalysis. As exemplified for rheumatoid arthritis, we postulate that intrinsic dynamic features of peptide-MHC-II complexes contribute to the association of individual MHC-II allotypes with autoimmune disease.
Collapse
Affiliation(s)
- Esam T Abualrous
- Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
- Department of Mathematics and Computer Science, Freie Universität Berlin, Berlin, Germany
- Department of Physics, Faculty of Science, Ain Shams University, Cairo, Egypt
| | - Sebastian Stolzenberg
- Department of Mathematics and Computer Science, Freie Universität Berlin, Berlin, Germany
| | - Jana Sticht
- Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
- Core Facility BioSupraMol, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Marek Wieczorek
- Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Yvette Roske
- Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Matthias Günther
- Theoretische Systembiologie (B086), Deutsches Krebsforschungszentrum, Heidelberg, Germany
| | - Steffen Dähn
- Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Benedikt B Boesen
- Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Marcos Martínez Calvo
- Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Charlotte Biese
- Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Frank Kuppler
- Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Álvaro Medina-García
- Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Miguel Álvaro-Benito
- Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Thomas Höfer
- Theoretische Systembiologie (B086), Deutsches Krebsforschungszentrum, Heidelberg, Germany
| | - Frank Noé
- Department of Mathematics and Computer Science, Freie Universität Berlin, Berlin, Germany.
- Microsoft Research AI4Science, Berlin, Germany.
- Department of Physics, Freie Universität Berlin, Berlin, Germany.
- Department of Chemistry, Rice University, Houston, TX, USA.
| | - Christian Freund
- Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany.
| |
Collapse
|
2
|
Landry SJ, Mettu RR, Kolls JK, Aberle JH, Norton E, Zwezdaryk K, Robinson J. Structural Framework for Analysis of CD4+ T-Cell Epitope Dominance in Viral Fusion Proteins. Biochemistry 2023; 62:2517-2529. [PMID: 37554055 PMCID: PMC10483696 DOI: 10.1021/acs.biochem.3c00335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 07/31/2023] [Indexed: 08/10/2023]
Abstract
Antigen conformation shapes CD4+ T-cell specificity through mechanisms of antigen processing, and the consequences for immunity may rival those from conformational effects on antibody specificity. CD4+ T cells initiate and control immunity to pathogens and cancer and are at least partly responsible for immunopathology associated with infection, autoimmunity, and allergy. The primary trigger for CD4+ T-cell maturation is the presentation of an epitope peptide in the MHC class II antigen-presenting protein (MHCII), most commonly on an activated dendritic cell, and then the T-cell responses are recalled by subsequent presentations of the epitope peptide by the same or other antigen-presenting cells. Peptide presentation depends on the proteolytic fragmentation of the antigen in an endosomal/lysosomal compartment and concomitant loading of the fragments into the MHCII, a multistep mechanism called antigen processing and presentation. Although the role of peptide affinity for MHCII has been well studied, the role of proteolytic fragmentation has received less attention. In this Perspective, we will briefly summarize evidence that antigen resistance to unfolding and proteolytic fragmentation shapes the specificity of the CD4+ T-cell response to selected viral envelope proteins, identify several remarkable examples in which the immunodominant CD4+ epitopes most likely depend on the interaction of processing machinery with antigen conformation, and outline how knowledge of antigen conformation can inform future efforts to design vaccines.
Collapse
Affiliation(s)
- Samuel J. Landry
- Department
of Biochemistry and Molecular Biology, Tulane
University School of Medicine, New Orleans, Louisiana 70112, United States
| | - Ramgopal R. Mettu
- Department
of Computer Science, Tulane University, New Orleans, Louisiana 70118, United States
| | - Jay K. Kolls
- John
W. Deming Department of Internal Medicine, Center for Translational
Research in Infection and Inflammation, Tulane University School of Medicine, New Orleans, Louisiana 70112, United States
| | - Judith H. Aberle
- Center
for Virology, Medical University of Vienna, 1090 Vienna, Austria
| | - Elizabeth Norton
- Department
of Microbiology & Immunology, Tulane
University School of Medicine, New Orleans, Louisiana 70112, United States
| | - Kevin Zwezdaryk
- Department
of Microbiology & Immunology, Tulane
University School of Medicine, New Orleans, Louisiana 70112, United States
| | - James Robinson
- Department
of Pediatrics, Tulane University School
of Medicine, New Orleans, Louisiana 70112, United States
| |
Collapse
|
3
|
Stražar M, Park J, Abelin JG, Taylor HB, Pedersen TK, Plichta DR, Brown EM, Eraslan B, Hung YM, Ortiz K, Clauser KR, Carr SA, Xavier RJ, Graham DB. HLA-II immunopeptidome profiling and deep learning reveal features of antigenicity to inform antigen discovery. Immunity 2023; 56:1681-1698.e13. [PMID: 37301199 PMCID: PMC10519123 DOI: 10.1016/j.immuni.2023.05.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 02/08/2023] [Accepted: 05/11/2023] [Indexed: 06/12/2023]
Abstract
CD4+ T cell responses are exquisitely antigen specific and directed toward peptide epitopes displayed by human leukocyte antigen class II (HLA-II) on antigen-presenting cells. Underrepresentation of diverse alleles in ligand databases and an incomplete understanding of factors affecting antigen presentation in vivo have limited progress in defining principles of peptide immunogenicity. Here, we employed monoallelic immunopeptidomics to identify 358,024 HLA-II binders, with a particular focus on HLA-DQ and HLA-DP. We uncovered peptide-binding patterns across a spectrum of binding affinities and enrichment of structural antigen features. These aspects underpinned the development of context-aware predictor of T cell antigens (CAPTAn), a deep learning model that predicts peptide antigens based on their affinity to HLA-II and full sequence of their source proteins. CAPTAn was instrumental in discovering prevalent T cell epitopes from bacteria in the human microbiome and a pan-variant epitope from SARS-CoV-2. Together CAPTAn and associated datasets present a resource for antigen discovery and the unraveling genetic associations of HLA alleles with immunopathologies.
Collapse
Affiliation(s)
- Martin Stražar
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Jihye Park
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | | | - Hannah B Taylor
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Thomas K Pedersen
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Technical University of Denmark, Kongens Lyngby, Denmark
| | | | - Eric M Brown
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Computational and Integrative Biology, Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Basak Eraslan
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Yuan-Mao Hung
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Computational and Integrative Biology, Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Kayla Ortiz
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Karl R Clauser
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Steven A Carr
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Ramnik J Xavier
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Computational and Integrative Biology, Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| | - Daniel B Graham
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Center for Computational and Integrative Biology, Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| |
Collapse
|
4
|
Drake LA, Hahn AB, Dixon AM, Drake JR. Differential pairing of transmembrane domain GxxxG dimerization motifs defines two HLA-DR MHC class II conformers. J Biol Chem 2023; 299:104869. [PMID: 37247758 PMCID: PMC10320510 DOI: 10.1016/j.jbc.2023.104869] [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: 02/10/2023] [Revised: 05/19/2023] [Accepted: 05/22/2023] [Indexed: 05/31/2023] Open
Abstract
MHC class II molecules function to present exogenous antigen-derived peptides to CD4 T cells to both drive T cell activation and to provide signals back into the class II antigen-presenting cell. Previous work established the presence of multiple GxxxG dimerization motifs within the transmembrane domains of MHC class II α and β chains across a wide range of species and revealed a role for differential GxxxG motif pairing in the formation of two discrete mouse class II conformers with distinct functional properties (i.e., M1-and M2-paired I-Ak class II). Biochemical and mutagenesis studies detailed herein extend this model to human class II by identifying an anti-HLA-DR mAb (Tü36) that selectively binds M1-paired HLA-DR molecules. Analysis of the HLA-DR allele reactivity of the Tü36 mAb helped define other HLA-DR residues involved in mAb binding. In silico modeling of both TM domain interactions and whole protein structure is consistent with the outcome of biochemical/mutagenesis studies and provides insight into the possible structural differences between the two HLA-DR conformers. Cholesterol depletion studies indicate a role for cholesterol-rich membrane domains in the formation/maintenance of Tü36 mAb reactive DR molecules. Finally, phylogenetic analysis of the amino acid sequences of Tü36-reactive HLA-DR β chains reveals a unique pattern of both Tü36 mAb reactivity and key amino acid polymorphisms. In total, these studies bring the paradigm M1/M2-paired MHC class II molecules to the human HLA-DR molecule and suggest that the functional differences between these conformers defined in mouse class II extend to the human immune system.
Collapse
Affiliation(s)
- Lisa A Drake
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, New York, USA
| | - Amy B Hahn
- Transplant Immunology Laboratory, Department of Surgery, Albany Medical College, Albany, New York, USA
| | - Ann M Dixon
- Department of Chemistry, University of Warwick, Coventry, United Kingdom
| | - James R Drake
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, New York, USA.
| |
Collapse
|
5
|
Lan BH, Becker M, Freund C. The mode of action of tapasin on major histocompatibility class I (MHC-I) molecules. J Biol Chem 2023; 299:102987. [PMID: 36758805 PMCID: PMC10040737 DOI: 10.1016/j.jbc.2023.102987] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 01/05/2023] [Accepted: 01/31/2023] [Indexed: 02/10/2023] Open
Abstract
Tapasin (Tsn) plays a critical role in antigen processing and presentation by major histocompatibility complex class I (MHC-I) molecules. The mechanism of Tsn-mediated peptide loading and exchange hinges on the conformational dynamics governing the interaction of Tsn and MHC-I with recent structural and functional studies pinpointing the critical sites of direct or allosteric regulation. In this review, we highlight these recent findings and relate them to the extensive molecular and cellular data that are available for these evolutionary interdependent proteins. Furthermore, allotypic differences of MHC-I with regard to the editing and chaperoning function of Tsn are reviewed and related to the mechanistic observations. Finally, evolutionary aspects of the mode of action of Tsn will be discussed, a short comparison with the Tsn-related molecule TAPBPR (Tsn-related protein) will be given, and the impact of Tsn on noncanonical MHC-I molecules will be described.
Collapse
Affiliation(s)
- By Huan Lan
- Institute of Chemistry & Biochemistry, Laboratory of Protein Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Moritz Becker
- Institute of Chemistry & Biochemistry, Laboratory of Protein Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Christian Freund
- Institute of Chemistry & Biochemistry, Laboratory of Protein Biochemistry, Freie Universität Berlin, Berlin, Germany.
| |
Collapse
|
6
|
Chan YW, Tan CH, Heh CH, Tan KY. An immunoinformatic approach to assessing the immunogenic capacity of alpha-neurotoxins in elapid snake venoms. Front Pharmacol 2023; 14:1143437. [PMID: 37153801 PMCID: PMC10155835 DOI: 10.3389/fphar.2023.1143437] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 03/27/2023] [Indexed: 05/10/2023] Open
Abstract
Introduction: Most elapid snakes produce venoms that contain alpha-neurotoxins (α-NTXs), which are proteins that cause post-synaptic blockade and paralysis in snakebite envenoming. However, existing elapid antivenoms are known for their low potency in neutralizing the neurotoxic activity of α-NTXs, while the immunological basis has not been elucidated. Methods: In this study, a structure-based major histocompatibility complex II (MHCII) epitope predictor of horse (Equus caballus), complemented with DM-editing determinant screening algorithm was adopted to assess the immunogenicity of α-NTXs in the venoms of major Asiatic elapids (Naja kaouthia, Ophiophagus hannah, Laticauda colubrina, Hydrophis schistosus, Hydrophis curtus). Results: The scoring metric M2R, representing the relative immunogenic performance of respective α-NTXs, showed all α-NTXs have an overall low M2R of <0.3, and most of the predicted binders feature non-optimal P1 anchor residues. The M2R scores correlate strongly (R2 = 0.82) with the potency scores (p-score) generated based on the relative abundances of α-NTXs and the neutralization potency of commercial antivenoms. Discussion: The immunoinformatic analysis indicates that the inferior antigenicity of α-NTXs is not only due to their small molecular size but also the subpar immunogenicity affected by their amino acid composition. Structural modification with conjugation and synthetic epitope as immunogen may potentially enhance the immunogenicity for improved antivenom potency against α-NTXs of elapid snakes.
Collapse
Affiliation(s)
- Yi Wei Chan
- Protein and Interactomics Laboratory, Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Choo Hock Tan
- Venom Research and Toxicology Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Choon Han Heh
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Malaya, Kuala Lumpur, Malaysia
| | - Kae Yi Tan
- Protein and Interactomics Laboratory, Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- *Correspondence: Kae Yi Tan,
| |
Collapse
|
7
|
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.
Collapse
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.
| |
Collapse
|
8
|
A previously unappreciated polymorphism in the beta chain of I-A s expressed in autoimmunity-prone SJL mice: Combined impact on antibody, CD4 T cell recognition and MHC class II dimer structural stability. Mol Immunol 2022; 143:17-26. [PMID: 34995990 PMCID: PMC9261112 DOI: 10.1016/j.molimm.2021.12.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/13/2021] [Accepted: 12/26/2021] [Indexed: 01/14/2023]
Abstract
In the process of structure-function studies on the MHC class II molecule expressed in autoimmunity prone SJL mice, I-As, we discovered a disparity from the reported sequence of the MHC class II beta chain. The variant is localized at a highly conserved site of the beta chain, at residue 58. Our studies revealed that this single amino acid substitution of Pro for Ala at this residue, found in I-As, changes the structure of the MHC class II molecule, as evidenced by a loss of recognition by two monoclonal antibodies, and elements of MHC class II conformational stability identified through molecular dynamics simulation. Two other rare polymorphisms in I-As involved in hydrogen bonding potential between the alpha chain and the peptide main chain are located at the same end of the MHC class II binding pocket, studied in parallel may impact the consequences of the β chain variant. Despite striking changes in MHC class II structure, CD4 T cell recognition of influenza-derived peptides was preserved. These disparate findings were reconciled by discovering, through monoclonal antibody blocking approaches, that CD4 T cell recognition by I-As restricted CD4 T cells focused more on the region of MHC class II at the peptide's amino terminus. These studies argue that the conformational variability or flexibility of the MHC class II molecule in that region of I-As select a CD4 T cell repertoire that deviates from the prototypical docking mode onto MHC class II peptide complexes. Overall, our results are consistent with the view that naturally occurring MHC class II molecules can possess polymorphisms that destabilize prototypical features of the MHC class II molecule but that can maintain T cell recognition of the MHC class II:peptide ligand via alternate docking modes.
Collapse
|
9
|
Regulation of the BCR signalosome by the class II peptide editor, H2-M, affects the development and repertoire of innate-like B cells. Cell Rep 2022; 38:110200. [DOI: 10.1016/j.celrep.2021.110200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 09/23/2021] [Accepted: 12/13/2021] [Indexed: 11/21/2022] Open
|
10
|
Yu M, Zhu Y, Li Y, Chen Z, Sha T, Li Z, Zhang F, Ding J. Design of a Novel Multi-Epitope Vaccine Against Echinococcus granulosus in Immunoinformatics. Front Immunol 2021; 12:668492. [PMID: 34456902 PMCID: PMC8388843 DOI: 10.3389/fimmu.2021.668492] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 07/15/2021] [Indexed: 12/18/2022] Open
Abstract
All the time, echinococcosis is a global zoonotic disease which seriously endangers public health all over the world. In order to speed up the development process of anti-Echinococcus granulosus vaccine, at the same time, it can also save economic cost. In this study, immunoinformatics tools and molecular docking methods were used to predict and screen the antigen epitopes of Echinococcus granulosus, to design a multi-epitope vaccine containing B- and T-cell epitopes. The multi-epitope vaccine could activate B lymphocytes to produce specific antibodies theoretically, which could protect the human body against Echinococcus granulosus infection. It also could activate T lymphocytes and clear the infected parasites in the body. In this study, four CD8+ T-cell epitopes, three CD4+ T-cell epitopes and four B-cell epitopes of Protein EgTeg were identified by immunoinformatics methods. Meanwhile, three CD8+ T-cell epitopes, two CD4+ T-cell epitopes and four B-cell epitopes of Protein EgFABP1 were identified. We constructed the multi-epitope vaccine using linker proteins. The study based on the traditional methods of antigen epitope prediction, further optimized the prediction results combined with molecular docking technology and improved the precision and accuracy of the results. Finally, in vivo and in vitro experiments had verified that the vaccine designed in this study had good antigenicity and immunogenicity.
Collapse
MESH Headings
- Adolescent
- Adult
- Animals
- Antibodies, Helminth/blood
- Antigens, Helminth/immunology
- Antigens, Helminth/pharmacology
- B-Lymphocytes/immunology
- B-Lymphocytes/parasitology
- Cells, Cultured
- Computer-Aided Design
- Disease Models, Animal
- Drug Design
- Echinococcosis/blood
- Echinococcosis/immunology
- Echinococcosis/parasitology
- Echinococcosis/prevention & control
- Echinococcus granulosus/immunology
- Epitopes, B-Lymphocyte/immunology
- Epitopes, T-Lymphocyte/immunology
- Fatty Acid-Binding Proteins/immunology
- Fatty Acid-Binding Proteins/pharmacology
- Humans
- Immunity, Humoral
- Immunogenicity, Vaccine
- Lymphocyte Activation
- Mice, Inbred BALB C
- Middle Aged
- Molecular Docking Simulation
- T-Lymphocytes/immunology
- T-Lymphocytes/parasitology
- Vaccines, DNA/immunology
- Vaccines, DNA/pharmacology
- Vaccines, Subunit/immunology
- Vaccines, Subunit/pharmacology
- Young Adult
- Mice
Collapse
Affiliation(s)
- Mingkai Yu
- Department of Immunology, School of Basic Medical Sciences, Xinjiang Medical University, Urumqi, China
| | - Yuejie Zhu
- Reproductive Medicine Center, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Yujiao Li
- Department of Blood Transfusion, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Zhiqiang Chen
- Department of Immunology, School of Basic Medical Sciences, Xinjiang Medical University, Urumqi, China
| | - Tong Sha
- Department of Immunology, School of Basic Medical Sciences, Xinjiang Medical University, Urumqi, China
| | - Zhiwei Li
- Clinical Laboratory Center, Xinjiang Uygur Autonomous Region People's Hospital, Urumqi, China
| | - Fengbo Zhang
- Department of Clinical Laboratory, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
- State Key Laboratory of Pathogenesis, Prevention, Treatment of Central Asian High Incidence Diseases, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Jianbing Ding
- Department of Immunology, School of Basic Medical Sciences, Xinjiang Medical University, Urumqi, China
- State Key Laboratory of Pathogenesis, Prevention, Treatment of Central Asian High Incidence Diseases, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| |
Collapse
|
11
|
Partnering for the major histocompatibility complex class II and antigenic determinant requires flexibility and chaperons. Curr Opin Immunol 2021; 70:112-121. [PMID: 34146954 DOI: 10.1016/j.coi.2021.05.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 05/12/2021] [Indexed: 11/22/2022]
Abstract
Cytotoxic, or helper T cells recognize antigen via T cell receptors (TCRs) that can see their target antigen as short sequences of peptides bound to the groove of proteins of major histocompatibility complex (MHC) class I, and class II respectively. For MHC class II epitope selection from exogenous pathogens or self-antigens, participation of several accessory proteins, molecular chaperons, processing enzymes within multiple vesicular compartments is necessary. A major contributing factor is the MHC class II structure itself that uniquely offers a dynamic and flexible groove essential for epitope selection. In this review, I have taken a historical perspective focusing on the flexibility of the MHC II molecules as the driving force in determinant selection and interactions with the accessory molecules in antigen processing, HLA-DM and HLA-DO.
Collapse
|
12
|
Abualrous ET, Sticht J, Freund C. Major histocompatibility complex (MHC) class I and class II proteins: impact of polymorphism on antigen presentation. Curr Opin Immunol 2021; 70:95-104. [PMID: 34052735 DOI: 10.1016/j.coi.2021.04.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 04/23/2021] [Accepted: 04/25/2021] [Indexed: 01/01/2023]
Abstract
The major histocompatibility complex (MHC) loci are amongst the most polymorphic regions in the genomes of vertebrates. In the human population, thousands of MHC gene variants (alleles) exist that translate into distinct allotypes equipped with overlapping but unique peptide binding profiles. Understanding the differential structural and dynamic properties of MHC alleles and their interaction with critical regulators of peptide exchange bears the potential for more personalized strategies of immune modulation in the context of HLA-associated diseases.
Collapse
Affiliation(s)
- Esam T Abualrous
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
| | - Jana Sticht
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
| | - Christian Freund
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany.
| |
Collapse
|
13
|
Gao J, Wu M, Wang F, Jiang L, Tian R, Zhu X, He S. CD74, a novel predictor for bronchopulmonary dysplasia in preterm infants. Medicine (Baltimore) 2020; 99:e23477. [PMID: 33235138 PMCID: PMC7710202 DOI: 10.1097/md.0000000000023477] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Bronchopulmonary dysplasia (BPD) remains a major complication and accounts for high morbidity and mortality of preterm infants. The present study aimed to identify the key genes in the development of BPD and to provide some new insights into the pathogenesis of BPD. The GSE108754 dataset was downloaded from Gene Expression Omnibus database containing 5 samples of BPD patients and 6 of non-BPD infants. The differentially expressed genes (DEGs) between BPD and non-BPD patients were identified by R software. The pathway and function enrichment analyses were performed through Database for Annotation Visualization and Integrated Discovery website. The protein-protein interaction network for DEGs was established by Cytoscape software and the most highly connected module was selected through MCODE plugin. Furthermore, the clinical sample verification among 25 BPD patients and 10 non-BPD infants was carried out in our center. Finally, based on the results above, the gene set enrichment analysis focusing on CD74 upregulated status was employed. Totally, 189 DEGs including 147 upregulated genes and 42 downregulated genes between BPD and non-BPD patients were screened out. The pathway and function enrichments revealed these DEGs were mainly enriched in asthma, intestinal immune network for IgA production, antigen processing and presentation and immune response. Thirteen DEGs (CD74, HLA-DMA, HLA-DRA, HLA-DMB, HLA-DOB, HLA-DQA1, HLA-DRB5, HLA-DPA1, HLA-DOA, HLA-DPB1, HLA-DQB2, HLA-DQA2, and HLA-DQB1) were determined as hub genes. The mRNA expression levels of the 13 hub genes were tested by quantitative real-time polymerase chain reaction among our clinical samples. Eventually, CD74 was confirmed to be the most significant highly expressed in BPD samples (P < .001) and its expression level was negatively correlated with gestational age (r = -0.653) and birth weight (r = -0.675). The gene set enrichment analysis results showed the gene sets associated with lupus erythematosus, viral myocarditis, immune network for IgA production, graft versus host disease, cell adhesion molecules and so no were differentially enriched with the phenotype of high-expression CD74. In conclusion, CD74 may serve to predict the BPD development and provide a new therapeutic target for BPD.
Collapse
Affiliation(s)
- Junyan Gao
- Department of Pediatrics, Affiliated Hospital of Yangzhou University, Yangzhou, Jiangsu
| | - Mingfu Wu
- Department of Pediatrics, Affiliated Hospital of Yangzhou University, Yangzhou, Jiangsu
| | - Fudong Wang
- Department of Pediatrics, Affiliated Hospital of Yangzhou University, Yangzhou, Jiangsu
| | - Lijun Jiang
- Department of Pediatrics, Affiliated Hospital of Yangzhou University, Yangzhou, Jiangsu
| | - Rui Tian
- Department of Pediatrics, The First People's Hospital of Kunming City, Kunming, Yunnan
| | - Xueping Zhu
- Department of Neonatology, Children's Hospital of Soochow University, Suzhou, Jiangsu
| | - Shan He
- Department of Neonatology, Children's Hospital of Soochow University, Suzhou, Jiangsu
- Department of Pediatrics, The First People's Hospital of Yunnan Province, Kunming, Yunnan, China
| |
Collapse
|
14
|
Szeto C, Bloom JI, Sloane H, Lobos CA, Fodor J, Jayasinghe D, Chatzileontiadou DSM, Grant EJ, Buckle AM, Gras S. Impact of HLA-DR Antigen Binding Cleft Rigidity on T Cell Recognition. Int J Mol Sci 2020; 21:ijms21197081. [PMID: 32992915 PMCID: PMC7582474 DOI: 10.3390/ijms21197081] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 09/22/2020] [Accepted: 09/23/2020] [Indexed: 01/22/2023] Open
Abstract
The interaction between T cell receptor (TCR) and peptide (p)-Human Leukocyte Antigen (HLA) complexes is the critical first step in determining T cell responses. X-ray crystallographic studies of pHLA in TCR-bound and free states provide a structural perspective that can help understand T cell activation. These structures represent a static “snapshot”, yet the nature of pHLAs and their interactions with TCRs are highly dynamic. This has been demonstrated for HLA class I molecules with in silico techniques showing that some interactions, thought to stabilise pHLA-I, are only transient and prone to high flexibility. Here, we investigated the dynamics of HLA class II molecules by focusing on three allomorphs (HLA-DR1, -DR11 and -DR15) that are able to present the same epitope and activate CD4+ T cells. A single TCR (F24) has been shown to recognise all three HLA-DR molecules, albeit with different affinities. Using molecular dynamics and crystallographic ensemble refinement, we investigate the molecular basis of these different affinities and uncover hidden roles for HLA polymorphic residues. These polymorphisms were responsible for the widening of the antigen binding cleft and disruption of pHLA-TCR interactions, underpinning the hierarchy of F24 TCR binding affinity, and ultimately T cell activation. We expanded this approach to all available pHLA-DR structures and discovered that all HLA-DR molecules were inherently rigid. Together with in vitro protein stability and peptide affinity measurements, our results suggest that HLA-DR1 possesses inherently high protein stability, and low HLA-DM susceptibility.
Collapse
Affiliation(s)
- Christopher Szeto
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
| | - Joseph I. Bloom
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
| | - Hannah Sloane
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
| | - Christian A. Lobos
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
| | - James Fodor
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT 0200, Australia
| | - Dhilshan Jayasinghe
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
| | - Demetra S. M. Chatzileontiadou
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
| | - Emma J. Grant
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
| | - Ashley M. Buckle
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
| | - Stephanie Gras
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (C.S.); (J.I.B.); (H.S.); (C.A.L.); (J.F.); (D.J.); (D.S.M.C.); (E.J.G.); (A.M.B.)
- Australian Research Council Centre of Excellence for Advanced Molecular Imaging, Monash University, Clayton, VIC 3800, Australia
- Correspondence:
| |
Collapse
|
15
|
Repertoire-scale determination of class II MHC peptide binding via yeast display improves antigen prediction. Nat Commun 2020; 11:4414. [PMID: 32887877 PMCID: PMC7473865 DOI: 10.1038/s41467-020-18204-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 08/12/2020] [Indexed: 02/03/2023] Open
Abstract
CD4+ helper T cells contribute important functions to the immune response during pathogen infection and tumor formation by recognizing antigenic peptides presented by class II major histocompatibility complexes (MHC-II). While many computational algorithms for predicting peptide binding to MHC-II proteins have been reported, their performance varies greatly. Here we present a yeast-display-based platform that allows the identification of over an order of magnitude more unique MHC-II binders than comparable approaches. These peptides contain previously identified motifs, but also reveal new motifs that are validated by in vitro binding assays. Training of prediction algorithms with yeast-display library data improves the prediction of peptide-binding affinity and the identification of pathogen-associated and tumor-associated peptides. In summary, our yeast-display-based platform yields high-quality MHC-II-binding peptide datasets that can be used to improve the accuracy of MHC-II binding prediction algorithms, and potentially enhance our understanding of CD4+ T cell recognition. Identifying peptides that can bind major histocompatibility complex II (MHC-II) is important for our understanding of T cell immunity and specificity. Here the authors present a yeast-display library screening approach that identifies more potential binders than various reported algorithms to help expand our understanding for antigen presentation.
Collapse
|
16
|
Álvaro-Benito M, Freund C. Revisiting nonclassical HLA II functions in antigen presentation: Peptide editing and its modulation. HLA 2020; 96:415-429. [PMID: 32767512 DOI: 10.1111/tan.14007] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 08/04/2020] [Indexed: 01/08/2023]
Abstract
The nonclassical major histocompatibility complex of class II molecules (ncMHCII) HLA-DM (DM) and HLA-DO (DO) feature essential functions for the selection of the peptides that are displayed by classical MHCII proteins (MHCII) for CD4+ Th cell surveillance. Thus, although the binding groove of classical MHCII dictates the main features of the peptides displayed, ncMHCII function defines the preferential loading of peptides from specific cellular compartments and the extent to which they are presented. DM acts as a chaperone for classical MHCII molecules facilitating peptide exchange and thereby favoring the binding of peptide-MHCII complexes of high kinetic stability mostly in late endosomal compartments. DO on the other hand binds to DM blocking its peptide-editing function in B cells and thymic epithelial cells, limiting DM activity in these cellular subsets. DM and DO distinct expression patterns therefore define specific antigen presentation profiles that select unique peptide pools for each set of antigen presenting cell. We have come a long way understanding the mechanistic underpinnings of such distinct editing profiles and start to grasp the implications for ncMHCII biological function. DM acts as filter for the selection of immunodominant, pathogen-derived epitopes while DO blocks DM activity under certain physiological conditions to promote tolerance to self. Interestingly, recent findings have shown that the unexplored and neglected ncMHCII genetic diversity modulates retroviral infection in mouse, and affects human ncMHCII function. This review aims at highlighting the importance of ncMHCII function for CD4+ Th cell responses while integrating and evaluating what could be the impact of distinct editing profiles because of natural genetic variations.
Collapse
Affiliation(s)
- Miguel Álvaro-Benito
- Laboratory of Protein Biochemistry, Institute für Chemie und Biochemie, Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Christian Freund
- Laboratory of Protein Biochemistry, Institute für Chemie und Biochemie, Department of Biology, Chemistry, Pharmacy, Freie Universität Berlin, Berlin, Germany
| |
Collapse
|
17
|
Welsh RA, Sadegh-Nasseri S. The love and hate relationship of HLA-DM/DO in the selection of immunodominant epitopes. Curr Opin Immunol 2020; 64:117-123. [PMID: 32599219 DOI: 10.1016/j.coi.2020.05.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 05/20/2020] [Indexed: 12/11/2022]
Abstract
Successful activation of CD4 T cells is centered around the ability of antigen presenting cells to successfully process, select Class II immunodominant epitopes from exogenous antigens and to present it to cognate T cells. To achieve this, newly synthesized MHC-II molecules are transferred to a specialized compartment which contain both exogenous antigens and the Class II processing machinery. Here in a process known as 'editing,' the Class II accessory molecule DM (HLA-DM human; murine H2-M) facilitates the loading and selection of exogenous peptides to MHC class II molecules thereby assuring proper selection of immunodominant epitopes. A second Class II accessory molecule, DO (HLA-DO human; murine H2-O), mainly present in B cells and thymic epithelium also contributes to the selection of immunodominant epitopes. Yet, despite a wealth of mechanistic insights into how DM functions, understanding the contributions of DO to epitope selection has proven to be highly challenging. In this review, we have attempted to discuss published in vitro and in vivo data during the past three years with insights into the biology of DO.
Collapse
Affiliation(s)
- Robin A Welsh
- Graduate Program in Immunology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Scheherazade Sadegh-Nasseri
- Graduate Program in Immunology, Johns Hopkins University School of Medicine, Baltimore, MD, United States; Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
| |
Collapse
|
18
|
Reyes-Vargas E, Barker AP, Zhou Z, He X, Jensen PE. HLA-DM catalytically enhances peptide dissociation by sensing peptide-MHC class II interactions throughout the peptide-binding cleft. J Biol Chem 2020; 295:2959-2973. [PMID: 31969393 PMCID: PMC7062162 DOI: 10.1074/jbc.ra119.010645] [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: 08/13/2019] [Revised: 01/13/2020] [Indexed: 11/06/2022] Open
Abstract
Human leukocyte antigen-DM (HLA-DM) is an integral component of the major histocompatibility complex class II (MHCII) antigen-processing and -presentation pathway. HLA-DM shapes the immune system by differentially catalyzing peptide exchange on MHCII molecules, thereby editing the peptide-MHCII (pMHCII) repertoire by imposing a bias on the foreign and self-derived peptide cargos that are presented on the cell surface for immune surveillance and tolerance induction by CD4+ T cells. To better understand DM selectivity, here we developed a real-time fluorescence anisotropy assay to delineate the pMHCII intrinsic stability, DM-binding affinity, and catalytic turnover, independent kinetic parameters of HLA-DM enzymatic activity. We analyzed prominent pMHCII contacts by differentiating the kinetic parameters in pMHCII homologs, observing that peptide interactions throughout the MHCII-binding cleft influence both the rate of peptide dissociation from the DM-pMHCII catalytic complex and the binding affinity of HLA-DM for a pMHCII. We show that the intrinsic stability of a pMHCII linearly correlates with DM catalytic turnover, but is nonlinearly correlated with its binding affinity. Surprisingly, interactions at the peptides N terminus up to and including MHCII position one (P1) anchor affected the catalytic turnover, suggesting that the active DM-pMHCII catalytic complex operates on pMHCII complexes with full peptide occupancy. Furthermore, interactions at the peptide C terminus modulated DM-binding affinity, suggesting distal communication between peptide interactions with the MHCII and the DM-pMHCII binding interface. Our results imply an intimate linkage between the DM-pMHCII interface and peptide-MHCII interactions throughout the peptide-binding cleft.
Collapse
Affiliation(s)
- Eduardo Reyes-Vargas
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112
| | - Adam P Barker
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112; Department of Pathology, ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories, Salt Lake City, Utah 84108
| | - Zemin Zhou
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112
| | - Xiao He
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112.
| | - Peter E Jensen
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah 84112; Department of Pathology, ARUP Institute for Clinical and Experimental Pathology, ARUP Laboratories, Salt Lake City, Utah 84108.
| |
Collapse
|
19
|
Mamedov A, Vorobyeva N, Filimonova I, Zakharova M, Kiselev I, Bashinskaya V, Baulina N, Boyko A, Favorov A, Kulakova O, Ziganshin R, Smirnov I, Poroshina A, Shilovskiy I, Khaitov M, Sykulev Y, Favorova O, Vlassov V, Gabibov A, Belogurov A. Protective Allele for Multiple Sclerosis HLA-DRB1*01:01 Provides Kinetic Discrimination of Myelin and Exogenous Antigenic Peptides. Front Immunol 2020; 10:3088. [PMID: 32010139 PMCID: PMC6978714 DOI: 10.3389/fimmu.2019.03088] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 12/17/2019] [Indexed: 12/15/2022] Open
Abstract
Risk of the development of multiple sclerosis (MS) is known to be increased in individuals bearing distinct class II human leukocyte antigen (HLA) variants, whereas some of them may have a protective effect. Here we analyzed distribution of a highly polymorphous HLA-DRB1 locus in more than one thousand relapsing-remitting MS patients and healthy individuals of Russian ethnicity. Carriage of HLA-DRB1*15 and HLA-DRB1*03 alleles was associated with MS risk, whereas carriage of HLA-DRB1*01 and HLA-DRB1*11 was found to be protective. Analysis of genotypes revealed the compensatory effect of risk and resistance alleles in trans. We have identified previously unknown MBP153-161 peptide located at the C-terminus of MBP protein and MBP90-98 peptide that bound to recombinant HLA-DRB1*01:01 protein with affinity comparable to that of classical antigenic peptide 306-318 from the hemagglutinin (HA) of the influenza virus demonstrating the ability of HLA-DRB1*01:01 to present newly identified MBP153-161 and MBP90-98 peptides. Measurements of kinetic parameters of MBP and HA peptides binding to HLA-DRB1*01:01 catalyzed by HLA-DM revealed a significantly lower rate of CLIP exchange for MBP153-161 and MBP90-98 peptides as opposed to HA peptide. Analysis of the binding of chimeric MBP-HA peptides demonstrated that the observed difference between MBP153-161, MBP90-98, and HA peptide epitopes is caused by the lack of anchor residues in the C-terminal part of the MBP peptides resulting in a moderate occupation of P6/7 and P9 pockets of HLA-DRB1*01:01 by MBP153-161 and MBP90-98 peptides in contrast to HA308-316 peptide. This leads to the P1 and P4 docking failure and rapid peptide dissociation and release of empty HLA-DM-HLA-DR complex. We would like to propose that protective properties of the HLA-DRB1*01 allele could be directly linked to the ability of HLA-DRB1*01:01 to kinetically discriminate between antigenic exogenous peptides and endogenous MBP derived peptides.
Collapse
Affiliation(s)
- Azad Mamedov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | | | - Ioanna Filimonova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Maria Zakharova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.,Pirogov Russian National Research Medical University, Moscow, Russia
| | - Ivan Kiselev
- Pirogov Russian National Research Medical University, Moscow, Russia
| | | | - Natalia Baulina
- Pirogov Russian National Research Medical University, Moscow, Russia
| | - Alexey Boyko
- Pirogov Russian National Research Medical University, Moscow, Russia.,Neuroimmunological Department of the Federal Center of Cerebrovascular Diseases and Stroke, Moscow, Russia
| | - Alexander Favorov
- Sidney Kimmel Comprehensive Cancer Center, The Johns Hopkins University, Baltimore, MD, United States.,Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
| | - Olga Kulakova
- Pirogov Russian National Research Medical University, Moscow, Russia
| | - Rustam Ziganshin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Ivan Smirnov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.,Institute of Fundamental Medicine and Biology, Kazan (Volga) Federal University, Kazan, Russia
| | - Alina Poroshina
- National Research Center Institute of Immunology FMBA of Russia, Moscow, Russia
| | - Igor Shilovskiy
- National Research Center Institute of Immunology FMBA of Russia, Moscow, Russia
| | - Musa Khaitov
- National Research Center Institute of Immunology FMBA of Russia, Moscow, Russia
| | - Yuri Sykulev
- Department of Microbiology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Olga Favorova
- Pirogov Russian National Research Medical University, Moscow, Russia
| | - Valentin Vlassov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
| | - Alexander Gabibov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.,Department of Fundamental Medicine, Lomonosov Moscow State University, Moscow, Russia
| | - Alexey Belogurov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.,Department of Fundamental Medicine, Lomonosov Moscow State University, Moscow, Russia
| |
Collapse
|
20
|
Synergy between B cell receptor/antigen uptake and MHCII peptide editing relies on HLA-DO tuning. Sci Rep 2019; 9:13877. [PMID: 31554902 PMCID: PMC6761166 DOI: 10.1038/s41598-019-50455-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 09/12/2019] [Indexed: 12/11/2022] Open
Abstract
B cell receptors and surface-displayed peptide/MHCII complexes constitute two key components of the B-cell machinery to sense signals and communicate with other cell types during antigen-triggered activation. However, critical pathways synergizing antigen-BCR interaction and antigenic peptide-MHCII presentation remain elusive. Here, we report the discovery of factors involved in establishing such synergy. We applied a single-cell measure coupled with super-resolution microscopy to investigate the integrated function of two lysosomal regulators for peptide loading, HLA-DM and HLA-DO. In model cell lines and human tonsillar B cells, we found that tunable DM/DO stoichiometry governs DMfree activity for exchange of placeholder CLIP peptides with high affinity MHCII ligands. Compared to their naïve counterparts, memory B cells with less DMfree concentrate a higher proportion of CLIP/MHCII in lysosomal compartments. Upon activation mediated by high affinity BCR, DO tuning is synchronized with antigen internalization and rapidly potentiates DMfree activity to optimize antigen presentation for T-cell recruitment.
Collapse
|
21
|
Salutari I, Martin R, Caflisch A. The 3A6-TCR/superagonist/HLA-DR2a complex shows similar interface and reduced flexibility compared to the complex with self-peptide. Proteins 2019; 88:31-46. [PMID: 31237711 DOI: 10.1002/prot.25764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 06/10/2019] [Accepted: 06/15/2019] [Indexed: 11/11/2022]
Abstract
T-cell receptor (TCR) recognition of the myelin basic protein (MBP) peptide presented by major histocompatibility complex (MHC) protein HLA-DR2a, one of the MHC class II alleles associated with multiple sclerosis, is highly variable. Interactions in the trimolecular complex between the TCR of the MBP83-99-specific T cell clone 3A6 with the MBP-peptide/HLA-DR2a (abbreviated TCR/pMHC) lead to substantially different proliferative responses when comparing the wild-type decapeptide MBP90-99 and a superagonist peptide, which differs mainly in the residues that point toward the TCR. Here, we investigate the influence of the peptide sequence on the interface and intrinsic plasticity of the TCR/pMHC trimolecular and pMHC bimolecular complexes by molecular dynamics simulations. The intermolecular contacts at the TCR/pMHC interface are similar for the complexes with the superagonist and the MBP self-peptide. The orientation angle between TCR and pMHC fluctuates less in the complex with the superagonist peptide. Thus, the higher structural stability of the TCR/pMHC tripartite complex with the superagonist peptide, rather than a major difference in binding mode with respect to the self-peptide, seems to be responsible for the stronger proliferative response.
Collapse
Affiliation(s)
- Ilaria Salutari
- Department of Biochemistry, University of Zürich, Zürich, Switzerland
| | - Roland Martin
- Department of Neurology, University Hospital Zürich, Zürich, Switzerland
| | - Amedeo Caflisch
- Department of Biochemistry, University of Zürich, Zürich, Switzerland
| |
Collapse
|
22
|
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.
Collapse
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
| |
Collapse
|
23
|
Nanaware PP, Jurewicz MM, Leszyk JD, Shaffer SA, Stern LJ. HLA-DO Modulates the Diversity of the MHC-II Self-peptidome. Mol Cell Proteomics 2019; 18:490-503. [PMID: 30573663 PMCID: PMC6398211 DOI: 10.1074/mcp.ra118.000956] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 11/26/2018] [Indexed: 12/30/2022] Open
Abstract
Presentation of antigenic peptides on MHC-II molecules is essential for tolerance to self and for initiation of immune responses against foreign antigens. DO (HLA-DO in humans, H2-O in mice) is a nonclassical MHC-II protein that has been implicated in control of autoimmunity and regulation of neutralizing antibody responses to viruses. These effects likely are related to a role of DO in selecting MHC-II epitopes, but previous studies examining the effect of DO on presentation of selected CD4 T cell epitopes have been contradictory. To understand how DO modulates MHC-II antigen presentation, we characterized the full spectrum of peptides presented by MHC-II molecules expressed by DO-sufficient and DO-deficient antigen-presenting cells in vivo and in vitro using quantitative mass spectrometry approaches. We found that DO controlled the diversity of the presented peptide repertoire, with a subset of peptides presented only when DO was expressed. Antigen-presenting cells express another nonclassical MHC-II protein, DM, which acts as a peptide editor by preferentially catalyzing the exchange of less stable MHC-II peptide complexes, and which is inhibited when bound to DO. Peptides presented uniquely in the presence of DO were sensitive to DM-mediated exchange, suggesting that decreased DM editing was responsible for the increased diversity. DO-deficient mice mounted CD4 T cell responses against wild-type antigen-presenting cells, but not vice versa, indicating that DO-dependent alterations in the MHC-II peptidome could be recognized by circulating T cells. These data suggest that cell-specific and regulated expression of HLA-DO serves to fine-tune MHC-II peptidomes, in order to enhance self-tolerance to a wide spectrum of epitopes while allowing focused presentation of immunodominant epitopes during an immune response.
Collapse
Affiliation(s)
- Padma P Nanaware
- From the ‡Department of Pathology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Mollie M Jurewicz
- From the ‡Department of Pathology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - John D Leszyk
- §Mass Spectrometry Facility, University of Massachusetts Medical School, Shrewsbury, Massachusetts 01545
| | - Scott A Shaffer
- §Mass Spectrometry Facility, University of Massachusetts Medical School, Shrewsbury, Massachusetts 01545
- ¶Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Lawrence J Stern
- From the ‡Department of Pathology, University of Massachusetts Medical School, Worcester, Massachusetts 01605;
- ¶Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| |
Collapse
|
24
|
Welsh R, Song N, Sadegh-Nasseri S. What to do with HLA-DO/H-2O two decades later? Immunogenetics 2019; 71:189-196. [PMID: 30683973 PMCID: PMC6377320 DOI: 10.1007/s00251-018-01097-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 11/20/2018] [Indexed: 10/27/2022]
Abstract
The main objective of antigen processing is to orchestrate the selection of immunodominant epitopes for recognition by CD4 T cells. To achieve this, MHC class II molecules have evolved with a flexible peptide-binding groove in need of a bound peptide. Newly synthesized MHC-II molecules bind a class II invariant chain (Ii) upon synthesis and are shuttled to a specialized compartment, where they encounter exogenous antigens. Ii serves multiple functions, one of which is to maintain the shape of the MHC-II groove so that it can readily bind exogenous antigens upon dissociation of the Ii peptide in MHC- II compartment. MIIC contains processing enzymes, one or both accessory molecules, HLA-DM/H2-M (DM) and HLA-DO/H2-O (DO), and optimal denaturing conditions. In a process known as "editing," DM facilitates the dissociation of the invariant chain peptide, CLIP, for exchange with exogenous antigens. Despite the availability of mechanistic insights into DM functions, understanding how DO contributes to epitope selection has proven to be more challenging. The current dogma assumes that DO inhibits DM, whereas an opposing model suggests that DO fine-tunes the epitope selection process. Understanding which of these, or potentially other models of DO function is important, as DO variants have been linked to autoimmunity, cancer, and the generation of broadly neutralizing antibodies to viruses. This review therefore attempts to evaluate experimental evidence in support of these hypotheses, with an emphasis on the less discussed model, and to explore intriguing questions about the importance of DO in biology.
Collapse
Affiliation(s)
- Robin Welsh
- Graduate Program in Immunology and Department of Pathology, Johns Hopkins University, Baltimore, MD, USA
| | - Nianbin Song
- Graduate Program in Immunology and Department of Pathology, Johns Hopkins University, Baltimore, MD, USA
| | - Scheherazade Sadegh-Nasseri
- Graduate Program in Immunology and Department of Pathology, Johns Hopkins University, Baltimore, MD, USA.
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
| |
Collapse
|
25
|
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.
Collapse
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
| |
Collapse
|
26
|
Class II MHC antigen processing in immune tolerance and inflammation. Immunogenetics 2018; 71:171-187. [PMID: 30421030 DOI: 10.1007/s00251-018-1095-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 10/31/2018] [Indexed: 01/22/2023]
Abstract
Presentation of peptide antigens by MHC-II proteins is prerequisite to effective CD4 T cell tolerance to self and to recognition of foreign antigens. Antigen uptake and processing pathways as well as expression of the peptide exchange factors HLA-DM and HLA-DO differ among the various professional and non-professional antigen-presenting cells and are modulated by cell developmental state and activation. Recent studies have highlighted the importance of these cell-specific factors in controlling the source and breadth of peptides presented by MHC-II under different conditions. During inflammation, increased presentation of selected self-peptides has implications for maintenance of peripheral tolerance and autoimmunity.
Collapse
|
27
|
Negroni MP, Stern LJ. The N-terminal region of photocleavable peptides that bind HLA-DR1 determines the kinetics of fragment release. PLoS One 2018; 13:e0199704. [PMID: 29965980 PMCID: PMC6028098 DOI: 10.1371/journal.pone.0199704] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 06/12/2018] [Indexed: 12/15/2022] Open
Abstract
Major Histocompatibility Complex class II (MHC-II) molecules bind peptides and present them to receptors on CD4+ T cells as part of the immune system's surveillance of pathogens and malignancy. In the absence of peptide, MHC-II equilibrates between peptide-receptive and peptide-averse conformations. The conversion between these forms has been postulated to be important in regulating cellular antigen presentation but has been difficult to study. In order to generate the MHC-II molecule HLA-DR1 in the peptide-receptive form, we designed and tested a series of photocleavable peptides that included the UV-sensitive 3-amino-3-(2-nitrophenyl)-propionate amino acid analog. They were intended to bind tightly to the HLA-DR1 MHC molecule, but to generate low-affinity fragments after UV exposure that would be released to yield HLA-DR1 in the peptide-receptive conformation. We were able to identify photocleavable peptides that bound tightly to HLA-DR1 and generated the peptide-receptive conformation after UV exposure. However, slow release of photocleaved peptide fragments from the binding site limited the rate of binding of an incoming labeled peptide and complicated kinetic measurements of the individual steps of the overall peptide binding reaction. Modification of the N-terminal region of the photocleavable peptide to reduce MHC-II pocket or H-bonding interactions allowed for generation of the peptide receptive form immediately after UV exposure with peptide fragments neither retained within the site nor interfering with binding of an incoming peptide. However this was achieved only at the expense of a substantial reduction in overall peptide binding affinity, and these peptides had such weak interaction with HLA-DR1 that they were easily exchanged by incoming peptide without UV exposure. These results show that photocleavable peptides can be used to generate peptide-receptive HLA-DR1 and to facilitate peptide exchange in generation of specific peptide-MHC-II complexes, but that usage of these peptides for kinetic studies can be constrained by slow fragment release.
Collapse
Affiliation(s)
- Maria Pia Negroni
- Program in Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Lawrence J. Stern
- Program in Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Department of Pathology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| |
Collapse
|
28
|
Fodor J, Riley BT, Borg NA, Buckle AM. Previously Hidden Dynamics at the TCR-Peptide-MHC Interface Revealed. THE JOURNAL OF IMMUNOLOGY 2018; 200:4134-4145. [PMID: 29728507 DOI: 10.4049/jimmunol.1800315] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 04/10/2018] [Indexed: 12/28/2022]
Abstract
A structural characterization of the interaction between αβ TCRs and cognate peptide-MHC (pMHC) is central to understanding adaptive T cell-mediated immunity. X-ray crystallography, although the source of much structural data, traditionally provides only a static snapshot of the protein. Given the emerging evidence for the important role of conformational dynamics in protein function, we interrogated 309 crystallographic structures of pMHC complexes using ensemble refinement, a technique that can extract dynamic information from the x-ray data. Focusing on a subset of human pMHC class I systems, we found that in many cases, ensemble methods were able to uncover previously hidden evidence of significant conformational plasticity, thereby revealing additional information that can build upon and significantly enhance functional interpretations that are based on a single static structure. Notable examples include the interpretation of differences in the disease association of HLA subtypes, the relationship between peptide prominence and TCR recognition, the role of conformational flexibility in vaccine design, and the discrimination between induced fit and conformational selection models of TCR binding. We show that the currently widespread practice of analyzing pMHC interactions via the study of a single crystallographic structure does not make use of pertinent and easily accessible information from x-ray data concerning alternative protein conformations. This new analysis therefore not only highlights the capacity for ensemble methods to significantly enrich the interpretation of decades of structural data but also provides previously missing information concerning the dynamics of existing characterized TCR-pMHC interactions.
Collapse
Affiliation(s)
- James Fodor
- Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia; and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Blake T Riley
- Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia; and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Natalie A Borg
- Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia; and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| | - Ashley M Buckle
- Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia; and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3800, Australia
| |
Collapse
|
29
|
Alvaro-Benito M, Morrison E, Wieczorek M, Sticht J, Freund C. Human leukocyte Antigen-DM polymorphisms in autoimmune diseases. Open Biol 2017; 6:rsob.160165. [PMID: 27534821 PMCID: PMC5008016 DOI: 10.1098/rsob.160165] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 07/19/2016] [Indexed: 12/20/2022] Open
Abstract
Classical MHC class II (MHCII) proteins present peptides for CD4+ T-cell surveillance and are by far the most prominent risk factor for a number of autoimmune disorders. To date, many studies have shown that this link between particular MHCII alleles and disease depends on the MHCII's particular ability to bind and present certain peptides in specific physiological contexts. However, less attention has been paid to the non-classical MHCII molecule human leucocyte antigen-DM, which catalyses peptide exchange on classical MHCII proteins acting as a peptide editor. DM function impacts the presentation of both antigenic peptides in the periphery and key self-peptides during T-cell development in the thymus. In this way, DM activity directly influences the response to pathogens, as well as mechanisms of self-tolerance acquisition. While decreased DM editing of particular MHCII proteins has been proposed to be related to autoimmune disorders, no experimental evidence for different DM catalytic properties had been reported until recently. Biochemical and structural investigations, together with new animal models of loss of DM activity, have provided an attractive foundation for identifying different catalytic efficiencies for DM allotypes. Here, we revisit the current knowledge of DM function and discuss how DM function may impart autoimmunity at the organism level.
Collapse
Affiliation(s)
- Miguel Alvaro-Benito
- Protein Biochemistry Group, Institute for Chemistry and Biochemistry, Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Eliot Morrison
- Protein Biochemistry Group, Institute for Chemistry and Biochemistry, Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Marek Wieczorek
- Protein Biochemistry Group, Institute for Chemistry and Biochemistry, Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Jana Sticht
- Protein Biochemistry Group, Institute for Chemistry and Biochemistry, Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Christian Freund
- Protein Biochemistry Group, Institute for Chemistry and Biochemistry, Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany
| |
Collapse
|
30
|
Wieczorek M, Abualrous ET, Sticht J, Álvaro-Benito M, Stolzenberg S, Noé F, Freund C. Major Histocompatibility Complex (MHC) Class I and MHC Class II Proteins: Conformational Plasticity in Antigen Presentation. Front Immunol 2017. [PMID: 28367149 DOI: 10.3389/fimmu.2017.00292.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Antigen presentation by major histocompatibility complex (MHC) proteins is essential for adaptive immunity. Prior to presentation, peptides need to be generated from proteins that are either produced by the cell's own translational machinery or that are funneled into the endo-lysosomal vesicular system. The prolonged interaction between a T cell receptor and specific pMHC complexes, after an extensive search process in secondary lymphatic organs, eventually triggers T cells to proliferate and to mount a specific cellular immune response. Once processed, the peptide repertoire presented by MHC proteins largely depends on structural features of the binding groove of each particular MHC allelic variant. Additionally, two peptide editors-tapasin for class I and HLA-DM for class II-contribute to the shaping of the presented peptidome by favoring the binding of high-affinity antigens. Although there is a vast amount of biochemical and structural information, the mechanism of the catalyzed peptide exchange for MHC class I and class II proteins still remains controversial, and it is not well understood why certain MHC allelic variants are more susceptible to peptide editing than others. Recent studies predict a high impact of protein intermediate states on MHC allele-specific peptide presentation, which implies a profound influence of MHC dynamics on the phenomenon of immunodominance and the development of autoimmune diseases. Here, we review the recent literature that describe MHC class I and II dynamics from a theoretical and experimental point of view and we highlight the similarities between MHC class I and class II dynamics despite the distinct functions they fulfill in adaptive immunity.
Collapse
Affiliation(s)
- Marek Wieczorek
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin , Berlin , Germany
| | - Esam T Abualrous
- Computational Molecular Biology Group, Institute for Mathematics , Berlin , Germany
| | - Jana Sticht
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin , Berlin , Germany
| | - Miguel Álvaro-Benito
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin , Berlin , Germany
| | | | - Frank Noé
- Computational Molecular Biology Group, Institute for Mathematics , Berlin , Germany
| | - Christian Freund
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin , Berlin , Germany
| |
Collapse
|
31
|
Nguyen TB, Jayaraman P, Bergseng E, Madhusudhan MS, Kim CY, Sollid LM. Unraveling the structural basis for the unusually rich association of human leukocyte antigen DQ2.5 with class-II-associated invariant chain peptides. J Biol Chem 2017; 292:9218-9228. [PMID: 28364043 DOI: 10.1074/jbc.m117.785139] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 03/28/2017] [Indexed: 11/06/2022] Open
Abstract
Human leukocyte antigen (HLA)-DQ2.5 (DQA1*05/DQB1*02) is a class-II major histocompatibility complex protein associated with both type 1 diabetes and celiac disease. One unusual feature of DQ2.5 is its high class-II-associated invariant chain peptide (CLIP) content. Moreover, HLA-DQ2.5 preferentially binds the non-canonical CLIP2 over the canonical CLIP1. To better understand the structural basis of HLA-DQ2.5's unusual CLIP association characteristics, better insight into the HLA-DQ2.5·CLIP complex structures is required. To this end, we determined the X-ray crystal structure of the HLA-DQ2.5· CLIP1 and HLA-DQ2.5·CLIP2 complexes at 2.73 and 2.20 Å, respectively. We found that HLA-DQ2.5 has an unusually large P4 pocket and a positively charged peptide-binding groove that together promote preferential binding of CLIP2 over CLIP1. An α9-α22-α24-α31-β86-β90 hydrogen bond network located at the bottom of the peptide-binding groove, spanning from the P1 to P4 pockets, renders the residues in this region relatively immobile. This hydrogen bond network, along with a deletion mutation at α53, may lead to HLA-DM insensitivity in HLA-DQ2.5. A molecular dynamics simulation experiment reported here and recent biochemical studies by others support this hypothesis. The diminished HLA-DM sensitivity is the likely reason for the CLIP-rich phenotype of HLA-DQ2.5.
Collapse
Affiliation(s)
- Thanh-Binh Nguyen
- the Bioinformatics Institute, Singapore 138671, Singapore.,the Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Priya Jayaraman
- the Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore
| | - Elin Bergseng
- the Centre for Immune Regulation and Department of Immunology, University of Oslo and Oslo University Hospital, N-0372 Oslo, Norway
| | - M S Madhusudhan
- the Bioinformatics Institute, Singapore 138671, Singapore.,the Indian Institute of Science Education and Research, Pune 411008, India, and
| | - Chu-Young Kim
- From the Department of Chemistry and .,School of Pharmacy, University of Texas at El Paso, El Paso, Texas 79968.,Synthetic Biology for Clinical and Technological Innovation, Life Sciences Institute, National University of Singapore, 117456 Singapore, Singapore
| | - Ludvig M Sollid
- the Centre for Immune Regulation and Department of Immunology, University of Oslo and Oslo University Hospital, N-0372 Oslo, Norway
| |
Collapse
|
32
|
Wieczorek M, Abualrous ET, Sticht J, Álvaro-Benito M, Stolzenberg S, Noé F, Freund C. Major Histocompatibility Complex (MHC) Class I and MHC Class II Proteins: Conformational Plasticity in Antigen Presentation. Front Immunol 2017; 8:292. [PMID: 28367149 PMCID: PMC5355494 DOI: 10.3389/fimmu.2017.00292] [Citation(s) in RCA: 566] [Impact Index Per Article: 80.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 02/28/2017] [Indexed: 11/21/2022] Open
Abstract
Antigen presentation by major histocompatibility complex (MHC) proteins is essential for adaptive immunity. Prior to presentation, peptides need to be generated from proteins that are either produced by the cell’s own translational machinery or that are funneled into the endo-lysosomal vesicular system. The prolonged interaction between a T cell receptor and specific pMHC complexes, after an extensive search process in secondary lymphatic organs, eventually triggers T cells to proliferate and to mount a specific cellular immune response. Once processed, the peptide repertoire presented by MHC proteins largely depends on structural features of the binding groove of each particular MHC allelic variant. Additionally, two peptide editors—tapasin for class I and HLA-DM for class II—contribute to the shaping of the presented peptidome by favoring the binding of high-affinity antigens. Although there is a vast amount of biochemical and structural information, the mechanism of the catalyzed peptide exchange for MHC class I and class II proteins still remains controversial, and it is not well understood why certain MHC allelic variants are more susceptible to peptide editing than others. Recent studies predict a high impact of protein intermediate states on MHC allele-specific peptide presentation, which implies a profound influence of MHC dynamics on the phenomenon of immunodominance and the development of autoimmune diseases. Here, we review the recent literature that describe MHC class I and II dynamics from a theoretical and experimental point of view and we highlight the similarities between MHC class I and class II dynamics despite the distinct functions they fulfill in adaptive immunity.
Collapse
Affiliation(s)
- Marek Wieczorek
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin , Berlin , Germany
| | - Esam T Abualrous
- Computational Molecular Biology Group, Institute for Mathematics , Berlin , Germany
| | - Jana Sticht
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin , Berlin , Germany
| | - Miguel Álvaro-Benito
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin , Berlin , Germany
| | | | - Frank Noé
- Computational Molecular Biology Group, Institute for Mathematics , Berlin , Germany
| | - Christian Freund
- Protein Biochemistry, Institute for Biochemistry, Freie Universität Berlin , Berlin , Germany
| |
Collapse
|
33
|
Zhou Z, Reyes-Vargas E, Escobar H, Chang KY, Barker AP, Rockwood AL, Delgado JC, He X, Jensen PE. Peptidomic analysis of type 1 diabetes associated HLA-DQ molecules and the impact of HLA-DM on peptide repertoire editing. Eur J Immunol 2016; 47:314-326. [PMID: 27861808 DOI: 10.1002/eji.201646656] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/21/2016] [Accepted: 11/10/2016] [Indexed: 11/08/2022]
Abstract
HLA-DM and class II associated invariant chain (Ii) are key cofactors in the MHC class II (MHCII) antigen processing pathway. We used tandem mass spectrometry sequencing to directly interrogate the global impact of DM and Ii on the repertoire of MHCII-bound peptides in human embryonic kidney 293T cells expressing HLA-DQ molecules in the absence or presence of these cofactors. We found that Ii and DM have a major impact on the repertoire of peptides presented by DQ1 and DQ6, with the caveat that this technology is not quantitative. The peptide repertoires of type 1 diabetes (T1D) associated DQ8, DQ2, and DQ8/2 are altered to a lesser degree by DM expression, and these molecules share overlapping features in their peptide binding motifs that are distinct from control DQ1 and DQ6 molecules. Peptides were categorized into DM-resistant, DM-dependent, or DM-sensitive groups based on the mass spectrometry data, and representative peptides were tested in competitive binding assays and peptide dissociation rate experiments with soluble DQ6. Our data support the conclusion that high intrinsic stability of DQ-peptide complexes is necessary but not sufficient to confer resistance to DM editing, and provide candidate parameters that may be useful in predicting the sensitivity of T-cell epitopes to DM editing.
Collapse
Affiliation(s)
- Zemin Zhou
- Department of Pathology, University of Utah, Salt Lake City, UT, USA
| | | | | | - Kuan Y Chang
- Department of Computer Science and Engineering, National Taiwan Ocean University, Keelung, Taiwan
| | - Adam P Barker
- Department of Pathology, University of Utah, Salt Lake City, UT, USA.,ARUP Laboratories, University of Utah, Salt Lake City, UT, USA
| | - Alan L Rockwood
- Department of Pathology, University of Utah, Salt Lake City, UT, USA.,ARUP Laboratories, University of Utah, Salt Lake City, UT, USA
| | - Julio C Delgado
- Department of Pathology, University of Utah, Salt Lake City, UT, USA.,ARUP Laboratories, University of Utah, Salt Lake City, UT, USA
| | - Xiao He
- Department of Pathology, University of Utah, Salt Lake City, UT, USA
| | - Peter E Jensen
- Department of Pathology, University of Utah, Salt Lake City, UT, USA
| |
Collapse
|
34
|
Wieczorek M, Sticht J, Stolzenberg S, Günther S, Wehmeyer C, El Habre Z, Álvaro-Benito M, Noé F, Freund C. MHC class II complexes sample intermediate states along the peptide exchange pathway. Nat Commun 2016; 7:13224. [PMID: 27827392 PMCID: PMC5105163 DOI: 10.1038/ncomms13224] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 09/13/2016] [Indexed: 01/07/2023] Open
Abstract
The presentation of peptide-MHCII complexes (pMHCIIs) for surveillance by T cells is a well-known immunological concept in vertebrates, yet the conformational dynamics of antigen exchange remain elusive. By combining NMR-detected H/D exchange with Markov modelling analysis of an aggregate of 275 microseconds molecular dynamics simulations, we reveal that a stable pMHCII spontaneously samples intermediate conformations relevant for peptide exchange. More specifically, we observe two major peptide exchange pathways: the kinetic stability of a pMHCII's ground state defines its propensity for intrinsic peptide exchange, while the population of a rare, intermediate conformation correlates with the propensity of the HLA-DM-catalysed pathway. Helix-destabilizing mutants designed based on our model shift the exchange behaviour towards the HLA-DM-catalysed pathway and further allow us to conceptualize how allelic variation can shape an individual's MHC restricted immune response. MHCII proteins bind and present both foreign and self-antigens to potentially activate CD4+ T cells via cognate T cell receptors (TCRs) during the adaptive immune response. Here, the authors combine NMR-detected H/D exchange with Markov modelling analysis to shed light on the dynamics of MHCII peptide exchange.
Collapse
Affiliation(s)
- Marek Wieczorek
- Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
| | - Jana Sticht
- Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
| | - Sebastian Stolzenberg
- Computational Molecular Biology group, Institute for Mathematics, Arnimallee 6, 14195 Berlin, Germany
| | - Sebastian Günther
- Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany.,Institute of Human Virology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, Maryland 21201, USA
| | - Christoph Wehmeyer
- Computational Molecular Biology group, Institute for Mathematics, Arnimallee 6, 14195 Berlin, Germany
| | - Zeina El Habre
- Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
| | - Miguel Álvaro-Benito
- Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
| | - Frank Noé
- Computational Molecular Biology group, Institute for Mathematics, Arnimallee 6, 14195 Berlin, Germany
| | - Christian Freund
- Protein Biochemistry, Institute for Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
| |
Collapse
|
35
|
Sadegh-Nasseri S. A step-by-step overview of the dynamic process of epitope selection by major histocompatibility complex class II for presentation to helper T cells. F1000Res 2016; 5. [PMID: 27347387 PMCID: PMC4902097 DOI: 10.12688/f1000research.7664.1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/27/2016] [Indexed: 11/25/2022] Open
Abstract
T cell antigen receptors (TCRs) expressed on cytotoxic or helper T cells can only see their specific target antigen as short sequences of peptides bound to the groove of proteins of major histocompatibility complex (MHC) class I, and class II respectively. In addition to the many steps, several participating proteins, and multiple cellular compartments involved in the processing of antigens, the MHC structure, with its dynamic and flexible groove, has perfectly evolved as the underlying instrument for epitope selection. In this review, I have taken a step-by-step, and rather historical, view to describe antigen processing and determinant selection, as we understand it today, all based on decades of intense research by hundreds of laboratories.
Collapse
|
36
|
Stern LJ, Santambrogio L. The melting pot of the MHC II peptidome. Curr Opin Immunol 2016; 40:70-7. [PMID: 27018930 DOI: 10.1016/j.coi.2016.03.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 03/14/2016] [Accepted: 03/15/2016] [Indexed: 02/07/2023]
Abstract
Recent advances in mass spectrometry technology have facilitated detailed examination of MHC-II immunopeptidomes, for example the repertoires of peptides bound to MHC-II molecules expressed in antigen presenting cells. These studies have deepened our view of MHC-II presentation. Other studies have broadened our view of pathways leading up to peptide loading. Here we review these recent studies in the context of earlier work on conventional and non-conventional MHC-II processing. The message that emerges is that sources of antigen beyond conventional endosomal processing of endocytosed proteins are important for generation of cellular immune responses to pathogens and maintenance of central and peripheral tolerance. The multiplicity of pathways results in a broad MHC II immunopeptidome that conveys the sampled environment to patrolling T cells.
Collapse
Affiliation(s)
- Lawrence J Stern
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA 01655, United States; Department of Biochemistry & Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01655, United States; Graduate Program in Immunology and Microbiology, University of Massachusetts Medical School, Worcester, MA 01655, United States.
| | - Laura Santambrogio
- Department of Pathology, Albert Einstein College of Medicine, NY 10461, United States; Department of Microbiology & Immunology, Albert Einstein College of Medicine, NY 10461, United States
| |
Collapse
|
37
|
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: 49] [Impact Index Per Article: 6.1] [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.
Collapse
|
38
|
Monzón-Casanova E, Rudolf R, Starick L, Müller I, Söllner C, Müller N, Westphal N, Miyoshi-Akiyama T, Uchiyama T, Berberich I, Walter L, Herrmann T. The Forgotten: Identification and Functional Characterization of MHC Class II Molecules H2-Eb2 and RT1-Db2. THE JOURNAL OF IMMUNOLOGY 2016; 196:988-99. [DOI: 10.4049/jimmunol.1403070] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 12/01/2015] [Indexed: 11/19/2022]
|
39
|
The Role of Aggregates of Therapeutic Protein Products in Immunogenicity: An Evaluation by Mathematical Modeling. J Immunol Res 2015; 2015:401956. [PMID: 26682236 PMCID: PMC4670651 DOI: 10.1155/2015/401956] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 10/07/2015] [Indexed: 01/12/2023] Open
Abstract
Therapeutic protein products (TPP) have been widely used to treat a variety of human diseases, including cancer, hemophilia, and autoimmune diseases. However, TPP can induce unwanted immune responses that can impact both drug efficacy and patient safety. The presence of aggregates is of particular concern as they have been implicated in inducing both T cell-independent and T cell-dependent immune responses. We used mathematical modeling to evaluate several mechanisms through which aggregates of TPP could contribute to the development of immunogenicity. Modeling interactions between aggregates and B cell receptors demonstrated that aggregates are unlikely to induce T cell-independent immune responses by cross-linking B cell receptors because the amount of signal transducing complex that can form under physiologically relevant conditions is limited. We systematically evaluate the role of aggregates in inducing T cell-dependent immune responses using a recently developed multiscale mechanistic mathematical model. Our analysis indicates that aggregates could contribute to T cell-dependent immune response by inducing high affinity epitopes which may not be present in the nonaggregated TPP and/or by enhancing danger signals to break tolerance. In summary, our computational analysis is suggestive of novel insights into the mechanisms underlying aggregate-induced immunogenicity, which could be used to develop mitigation strategies.
Collapse
|
40
|
Bailey A, Dalchau N, Carter R, Emmott S, Phillips A, Werner JM, Elliott T. Selector function of MHC I molecules is determined by protein plasticity. Sci Rep 2015; 5:14928. [PMID: 26482009 PMCID: PMC5224517 DOI: 10.1038/srep14928] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 09/09/2015] [Indexed: 12/27/2022] Open
Abstract
The selection of peptides for presentation at the surface of most nucleated cells by major histocompatibility complex class I molecules (MHC I) is crucial to the immune response in vertebrates. However, the mechanisms of the rapid selection of high affinity peptides by MHC I from amongst thousands of mostly low affinity peptides are not well understood. We developed computational systems models encoding distinct mechanistic hypotheses for two molecules, HLA-B*44:02 (B*4402) and HLA-B*44:05 (B*4405), which differ by a single residue yet lie at opposite ends of the spectrum in their intrinsic ability to select high affinity peptides. We used in vivo biochemical data to infer that a conformational intermediate of MHC I is significant for peptide selection. We used molecular dynamics simulations to show that peptide selector function correlates with protein plasticity, and confirmed this experimentally by altering the plasticity of MHC I with a single point mutation, which altered in vivo selector function in a predictable way. Finally, we investigated the mechanisms by which the co-factor tapasin influences MHC I plasticity. We propose that tapasin modulates MHC I plasticity by dynamically coupling the peptide binding region and α3 domain of MHC I allosterically, resulting in enhanced peptide selector function.
Collapse
Affiliation(s)
- Alistair Bailey
- Institute for Life Sciences, Building 85, University of Southampton, SO17 1BJ, UK
- Cancer Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, SO16 6YD, UK
- Centre for Biological Sciences, Faculty of Natural & Environmental Sciences, Building 85, University of Southampton, SO17 1BJ, UK
| | - Neil Dalchau
- Computational Science Laboratory, Microsoft Research, 21 Station Road, Cambridge, CB1 2FB, UK
| | - Rachel Carter
- Institute for Life Sciences, Building 85, University of Southampton, SO17 1BJ, UK
- Cancer Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, SO16 6YD, UK
| | - Stephen Emmott
- Computational Science Laboratory, Microsoft Research, 21 Station Road, Cambridge, CB1 2FB, UK
| | - Andrew Phillips
- Computational Science Laboratory, Microsoft Research, 21 Station Road, Cambridge, CB1 2FB, UK
| | - Jörn M. Werner
- Institute for Life Sciences, Building 85, University of Southampton, SO17 1BJ, UK
- Centre for Biological Sciences, Faculty of Natural & Environmental Sciences, Building 85, University of Southampton, SO17 1BJ, UK
| | - Tim Elliott
- Institute for Life Sciences, Building 85, University of Southampton, SO17 1BJ, UK
- Cancer Sciences Unit, Faculty of Medicine, University of Southampton, Southampton, SO16 6YD, UK
| |
Collapse
|
41
|
Yin L, Maben ZJ, Becerra A, Stern LJ. Evaluating the Role of HLA-DM in MHC Class II-Peptide Association Reactions. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2015; 195:706-16. [PMID: 26062997 PMCID: PMC4490944 DOI: 10.4049/jimmunol.1403190] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 05/15/2015] [Indexed: 01/07/2023]
Abstract
Ag presentation by MHC class II (MHC II) molecules to CD4(+) T cells plays a key role in the regulation of the adaptive immune response. Loading of antigenic peptides onto MHC II is catalyzed by HLA-DM (DM), a nonclassical MHC II molecule. The mechanism of DM-facilitated peptide loading is an outstanding problem in the field of Ag presentation. In this study, we systemically explored possible kinetic mechanisms for DM-catalyzed peptide association by measuring real-time peptide association kinetics using fluorescence polarization assays and comparing the experimental data with numerically modeled peptide association reactions. We found that DM does not facilitate peptide association by stabilizing peptide-free MHC II against aggregation. Moreover, DM does not promote transition of an inactive peptide-averse conformation of MHC II to an active peptide-receptive conformation. Instead, DM forms an intermediate with MHC II that binds peptide with faster kinetics than MHC II in the absence of DM. In the absence of peptides, interaction of MHC II with DM leads to inactivation and formation of a peptide-averse form. This study provides novel insights into how DM efficiently catalyzes peptide loading during Ag presentation.
Collapse
Affiliation(s)
- Liusong Yin
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA 01605; and
| | - Zachary J Maben
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA 01605; and
| | - Aniuska Becerra
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA 01605; and
| | - Lawrence J Stern
- Department of Pathology, University of Massachusetts Medical School, Worcester, MA 01605; and Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605
| |
Collapse
|
42
|
Ferrante A, Templeton M, Hoffman M, Castellini MJ. The Thermodynamic Mechanism of Peptide-MHC Class II Complex Formation Is a Determinant of Susceptibility to HLA-DM. THE JOURNAL OF IMMUNOLOGY 2015; 195:1251-61. [PMID: 26116504 DOI: 10.4049/jimmunol.1402367] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 05/28/2015] [Indexed: 11/19/2022]
Abstract
Peptides bind MHC class II molecules through a thermodynamically nonadditive process consequent to the flexibility of the reactants. Currently, how the specific outcome of this binding process affects the ensuing epitope selection needs resolution. Calorimetric assessment of binding thermodynamics for hemagglutinin 306-319 peptide variants to the human MHC class II HLA-DR1 (DR1) and a mutant DR1 reveals that peptide/DR1 complexes can be formed with different enthalpic and entropic contributions. Complexes formed with a smaller entropic penalty feature circular dichroism spectra consistent with a non-compact form, and molecular dynamics simulation shows a more flexible structure. The opposite binding mode, compact and less flexible, is associated with greater entropic penalty. These structural variations are associated with rearrangements of residues known to be involved in HLA-DR (DM) binding, affinity of DM for the complex, and complex susceptibility to DM-mediated peptide exchange. Thus, the thermodynamic mechanism of peptide binding to DR1 correlates with the structural rigidity of the complex, and DM mediates peptide exchange by "sensing" flexible complexes in which the aforementioned residues are rearranged at a higher frequency than in more rigid ones.
Collapse
Affiliation(s)
- Andrea Ferrante
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775;
| | - Megan Templeton
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775; Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK 99775; and
| | - Megan Hoffman
- Department of Veterinary Medicine, University of Alaska Fairbanks, Fairbanks, AK 99775
| | - Margaret J Castellini
- Department of Veterinary Medicine, University of Alaska Fairbanks, Fairbanks, AK 99775
| |
Collapse
|
43
|
God JM, Cameron C, Figueroa J, Amria S, Hossain A, Kempkes B, Bornkamm GW, Stuart RK, Blum JS, Haque A. Elevation of c-MYC disrupts HLA class II-mediated immune recognition of human B cell tumors. THE JOURNAL OF IMMUNOLOGY 2015; 194:1434-45. [PMID: 25595783 DOI: 10.4049/jimmunol.1402382] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Elevated levels of the transcription factor c-myc are strongly associated with various cancers, and in particular B cell lymphomas. Although many of c-MYC's functions have been elucidated, its effect on the presentation of Ag through the HLA class II pathway has not been reported previously. This is an issue of considerable importance, given the low immunogenicity of many c-MYC-positive tumors. We report in this paper that increased c-MYC expression has a negative effect on the ability of B cell lymphomas to functionally present Ags/peptides to CD4(+) T cells. This defect was associated with alterations in the expression of distinct cofactors as well as interactions of antigenic peptides with class II molecules required for the presentation of class II-peptide complexes and T cell engagement. Using early passage Burkitt's lymphoma (BL) tumors and transformed cells, we show that compared with B lymphoblasts, BL cells express decreased levels of the class II editor HLA-DM, lysosomal thiol-reductase GILT, and a 47-kDa enolase-like protein. Functional Ag presentation was partially restored in BL cells treated with a c-MYC inhibitor, demonstrating the impact of this oncogene on Ag recognition. This restoration of HLA class II-mediated Ag presentation in early passage BL tumors/cells was linked to enhanced HLA-DM expression and a concurrent decrease in HLA-DO in BL cells. Taken together, these results reveal c-MYC exerts suppressive effects at several critical checkpoints in Ag presentation, which contribute to the immunoevasive properties of BL tumors.
Collapse
Affiliation(s)
- Jason M God
- Department of Microbiology and Immunology, Hollings Cancer Center and Children's Research Institute, Medical University of South Carolina, Charleston, SC 29425
| | - Christine Cameron
- Department of Microbiology and Immunology, Hollings Cancer Center and Children's Research Institute, Medical University of South Carolina, Charleston, SC 29425
| | - Janette Figueroa
- Department of Microbiology and Immunology, Hollings Cancer Center and Children's Research Institute, Medical University of South Carolina, Charleston, SC 29425
| | - Shereen Amria
- Department of Microbiology and Immunology, Hollings Cancer Center and Children's Research Institute, Medical University of South Carolina, Charleston, SC 29425
| | - Azim Hossain
- Department of Microbiology and Immunology, Hollings Cancer Center and Children's Research Institute, Medical University of South Carolina, Charleston, SC 29425
| | - Bettina Kempkes
- Department of Gene Vectors, German Research Center for Environmental Health, 81377 Munich, Germany
| | - Georg W Bornkamm
- Institute of Clinical Molecular Biology and Tumor Genetics, German Research Center for Environmental Health, 81377 Munich, Germany
| | - Robert K Stuart
- Department of Hematology and Oncology, Medical University of South Carolina, Charleston, SC 29425; and
| | - Janice S Blum
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202
| | - Azizul Haque
- Department of Microbiology and Immunology, Hollings Cancer Center and Children's Research Institute, Medical University of South Carolina, Charleston, SC 29425;
| |
Collapse
|
44
|
Kim A, Sadegh-Nasseri S. Determinants of immunodominance for CD4 T cells. Curr Opin Immunol 2015; 34:9-15. [PMID: 25576665 DOI: 10.1016/j.coi.2014.12.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 12/17/2014] [Indexed: 10/24/2022]
Abstract
The term immunodominance was originally defined as a restricted T cell response to a short peptide sequence derived from a given protein. The question of what determines immunodominance has been a longstanding battle for the past two decades. Hundreds of papers have been written on different aspects of epitope selection during antigen processing documenting the complexity of the process. Antigen processing machinery involves several accessory molecules and chaperons coevolved with proteins of Major Histocompatibility Complex (MHC) molecules that each plays its part in epitope selection. These molecules are targeted to specialized vesicular compartments that also accommodate antigen processing enzymes called cathepsins. Within the antigen processing compartments, highly regulated pH gradient and reducing conditions and enzymes necessary for denaturation of the antigens are available and function to optimize processing of antigen and selection of the fittest for transport to the cell membrane and presentation to T cells. Despite the complexity, a cell free reductionist antigen processing system was recently reported that included only few purified proteins, but was shown to process and select physiologically relevant epitopes from full length protein antigens. Due to its minimalist nature the system has been quite helpful in dissecting the factors that contribute to epitope selection during antigen processing. In this review, we would summarize and highlight models that may explain how the dominant epitope may be selected for presentation to CD4(+) helper T cells.
Collapse
Affiliation(s)
- AeRyon Kim
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | | |
Collapse
|