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Sharma R, Amdare NP, Ghosh A, Schloss J, Sidney J, Garforth SJ, Lopez Y, Celikgil A, Sette A, Almo SC, DiLorenzo TP. Structural and biochemical analysis of highly similar HLA-B allotypes differentially associated with type 1 diabetes. J Biol Chem 2024; 300:107702. [PMID: 39173948 DOI: 10.1016/j.jbc.2024.107702] [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: 07/10/2024] [Revised: 08/09/2024] [Accepted: 08/15/2024] [Indexed: 08/24/2024] Open
Abstract
Type 1 diabetes (T1D) is an autoimmune disease involving T cell-mediated destruction of the insulin-producing beta cells in the pancreatic islets of Langerhans. CD8+ T cells, responding to beta cell peptides presented by class I major histocompatibility complex (MHC) molecules, are important effectors leading to beta cell elimination. Human leukocyte antigen (HLA) B∗39:06, B∗39:01, and B∗38:01 are closely related class I MHC allotypes that nonetheless show differential association with T1D. HLA-B∗39:06 is the most predisposing of all HLA class I molecules and is associated with early age at disease onset. B∗39:01 is also associated with susceptibility to T1D, but to a lesser extent, though differing from B∗39:06 by only two amino acids. HLA-B∗38:01, in contrast, is associated with protection from the disease. Upon identifying a peptide that binds to both HLA-B∗39:06 and B∗39:01, we determined the respective X-ray structures of the two allotypes presenting this peptide to 1.7 Å resolution. The peptide residues available for T cell receptor contact and those serving as anchors were identified. Analysis of the F pocket of HLA-B∗39:06 and B∗39:01 provided an explanation for the distinct peptide C terminus preferences of the two allotypes. Structure-based modeling of the protective HLA-B∗38:01 suggested a potential reason for its peptide preferences and its reduced propensity to present 8-mer peptides compared to B∗39:06. Notably, the three allotypes showed differential binding to peptides derived from beta cell autoantigens. Taken together, our findings should facilitate identification of disease-relevant candidate T cell epitopes and structure-guided therapeutics to interfere with peptide binding.
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Affiliation(s)
- Ruby Sharma
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Nitin P Amdare
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Agnidipta Ghosh
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Jennifer Schloss
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - John Sidney
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, California, USA
| | - Scott J Garforth
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Yessenia Lopez
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Alev Celikgil
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Alessandro Sette
- Center for Infectious Disease and Vaccine Research, La Jolla Institute for Immunology, La Jolla, California, USA; Division of Infectious Diseases and Global Public Health, Department of Medicine, University of California, La Jolla, California, USA
| | - Steven C Almo
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, USA.
| | - Teresa P DiLorenzo
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA; Division of Endocrinology and Diabetes, Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, USA; Einstein-Mount Sinai Diabetes Research Center, Albert Einstein College of Medicine, Bronx, New York, USA; Fleischer Institute for Diabetes and Metabolism, Albert Einstein College of Medicine, Bronx, New York, USA.
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Ahn YM, Maddumage JC, Grant EJ, Chatzileontiadou DS, Perera WG, Baker BM, Szeto C, Gras S. The impact of SARS-CoV-2 spike mutation on peptide presentation is HLA allomorph-specific. Curr Res Struct Biol 2024; 7:100148. [PMID: 38742159 PMCID: PMC11089313 DOI: 10.1016/j.crstbi.2024.100148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 04/11/2024] [Accepted: 04/28/2024] [Indexed: 05/16/2024] Open
Abstract
CD8+ T cells are crucial for viral elimination and recovery from viral infection. Nonetheless, the current understanding of the T cell response to SARS-CoV-2 at the antigen level remains limited. The Spike protein is an external structural protein that is prone to mutations, threatening the efficacy of current vaccines. Therefore, we have characterised the immune response towards the immunogenic Spike-derived peptide (S976-984, VLNDILSRL), restricted to the HLA-A*02:01 molecule, which is mutated in both Alpha (S982A) and Omicron BA.1 (L981F) variants of concern. We determined that the mutation in the Alpha variant (S982A) impacted both the stability and conformation of the peptide, bound to HLA-A*02:01, in comparison to the original S976-984. We identified a longer and overlapping immunogenic peptide (S975-984, SVLNDILSRL) that could be presented by HLA-A*02:01, HLA-A*11:01 and HLA-B*13:01 allomorphs. We showed that S975-specific CD8+ T cells were weakly cross-reactive to the mutant peptides despite their similar conformations when presented by HLA-A*11:01. Altogether, our results show that the impact of SARS-CoV-2 mutations on peptide presentation is HLA allomorph-specific, and that post vaccination there are T cells able to react and cross-react towards the variant of concern peptides.
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Affiliation(s)
- You Min Ahn
- Infection & Immunity Program, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Bundoora, Victoria, Australia
- Department of Biochemistry and Chemistry, School of Agriculture, Biomedicine and Agriculture (SABE), La Trobe University, Bundoora, Victoria, Australia
| | - Janesha C. Maddumage
- Infection & Immunity Program, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Bundoora, Victoria, Australia
- Department of Biochemistry and Chemistry, School of Agriculture, Biomedicine and Agriculture (SABE), La Trobe University, Bundoora, Victoria, Australia
| | - Emma J. Grant
- Infection & Immunity Program, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Bundoora, Victoria, Australia
- Department of Biochemistry and Chemistry, School of Agriculture, Biomedicine and Agriculture (SABE), La Trobe University, Bundoora, Victoria, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Demetra S.M. Chatzileontiadou
- Infection & Immunity Program, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Bundoora, Victoria, Australia
- Department of Biochemistry and Chemistry, School of Agriculture, Biomedicine and Agriculture (SABE), La Trobe University, Bundoora, Victoria, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - W.W.J. Gihan Perera
- Department of Chemistry and Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN, USA
| | - Brian M. Baker
- Department of Chemistry and Biochemistry and the Harper Cancer Research Institute, University of Notre Dame, Notre Dame, IN, USA
| | - Christopher Szeto
- Infection & Immunity Program, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Bundoora, Victoria, Australia
- Department of Biochemistry and Chemistry, School of Agriculture, Biomedicine and Agriculture (SABE), La Trobe University, Bundoora, Victoria, Australia
- Australian Synchrotron, ANSTO, Clayton, Victoria, Australia
| | - Stephanie Gras
- Infection & Immunity Program, La Trobe Institute for Molecular Science (LIMS), La Trobe University, Bundoora, Victoria, Australia
- Department of Biochemistry and Chemistry, School of Agriculture, Biomedicine and Agriculture (SABE), La Trobe University, Bundoora, Victoria, Australia
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
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Contemplating immunopeptidomes to better predict them. Semin Immunol 2023; 66:101708. [PMID: 36621290 DOI: 10.1016/j.smim.2022.101708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 12/16/2022] [Accepted: 12/20/2022] [Indexed: 01/09/2023]
Abstract
The identification of T-cell epitopes is key for a complete molecular understanding of immune recognition mechanisms in infectious diseases, autoimmunity and cancer. T-cell epitopes further provide targets for personalized vaccines and T-cell therapy, with several therapeutic applications in cancer immunotherapy and elsewhere. T-cell epitopes consist of short peptides displayed on Major Histocompatibility Complex (MHC) molecules. The recent advances in mass spectrometry (MS) based technologies to profile the ensemble of peptides displayed on MHC molecules - the so-called immunopeptidome - had a major impact on our understanding of antigen presentation and MHC ligands. On the one hand, these techniques enabled researchers to directly identify hundreds of thousands of peptides presented on MHC molecules, including some that elicited T-cell recognition. On the other hand, the data collected in these experiments revealed fundamental properties of antigen presentation pathways and significantly improved our ability to predict naturally presented MHC ligands and T-cell epitopes across the wide spectrum of MHC alleles found in human and other organisms. Here we review recent computational developments to analyze experimentally determined immunopeptidomes and harness these data to improve our understanding of antigen presentation and MHC binding specificities, as well as our ability to predict MHC ligands. We further discuss the strengths and limitations of the latest approaches to move beyond predictions of antigen presentation and tackle the challenges of predicting TCR recognition and immunogenicity.
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