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Choi S, Paek E. pXg: Comprehensive Identification of Noncanonical MHC-I-Associated Peptides From De Novo Peptide Sequencing Using RNA-Seq Reads. Mol Cell Proteomics 2024; 23:100743. [PMID: 38403075 PMCID: PMC10979277 DOI: 10.1016/j.mcpro.2024.100743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 02/19/2024] [Accepted: 02/21/2024] [Indexed: 02/27/2024] Open
Abstract
Discovering noncanonical peptides has been a common application of proteogenomics. Recent studies suggest that certain noncanonical peptides, known as noncanonical major histocompatibility complex-I (MHC-I)-associated peptides (ncMAPs), that bind to MHC-I may make good immunotherapeutic targets. De novo peptide sequencing is a great way to find ncMAPs since it can detect peptide sequences from their tandem mass spectra without using any sequence databases. However, this strategy has not been widely applied for ncMAP identification because there is not a good way to estimate its false-positive rates. In order to completely and accurately identify immunopeptides using de novo peptide sequencing, we describe a unique pipeline called proteomics X genomics. In contrast to current pipelines, it makes use of genomic data, RNA-Seq abundance and sequencing quality, in addition to proteomic features to increase the sensitivity and specificity of peptide identification. We show that the peptide-spectrum match quality and genetic traits have a clear relationship, showing that they can be utilized to evaluate peptide-spectrum matches. From 10 samples, we found 24,449 canonical MHC-I-associated peptides and 956 ncMAPs by using a target-decoy competition. Three hundred eighty-seven ncMAPs and 1611 canonical MHC-I-associated peptides were new identifications that had not yet been published. We discovered 11 ncMAPs produced from a squirrel monkey retrovirus in human cell lines in addition to the two ncMAPs originating from a complementarity determining region 3 in an antibody thanks to the unrestricted search space assumed by de novo sequencing. These entirely new identifications show that proteomics X genomics can make the most of de novo peptide sequencing's advantages and its potential use in the search for new immunotherapeutic targets.
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Affiliation(s)
- Seunghyuk Choi
- Department of Computer Science, Hanyang University, Seoul, Republic of Korea
| | - Eunok Paek
- Department of Computer Science, Hanyang University, Seoul, Republic of Korea; Institute for Artificial Intelligence Research, Hanyang University, Seoul, Republic of Korea.
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2
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Nicholas B, Skipp P. What do cancer-specific CD8+ T cells see? The contribution of immunopeptidomics. Essays Biochem 2023; 67:957-965. [PMID: 37503576 DOI: 10.1042/ebc20220246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 07/03/2023] [Accepted: 07/13/2023] [Indexed: 07/29/2023]
Abstract
Immunopeptidomics is the survey of all peptides displayed on a cell or tissue when bound to human leukocyte antigen (HLA) molecules using tandem mass spectrometry. When attempting to determine the targets of tumour-specific CD8+ T cells, a survey of the potential ligands in tumour tissues is invaluable, and, in comparison with in-silico predictions, provides greater certainty of the existence of individual epitopes, as immunopeptidomics-confirmed CD8+ T-cell epitopes are known to be immunogenic, and direct observation should avoid the risk of autoreactivity which could arise following immunisation with structural homologues. The canonical sources of CD8+ T-cell tumour specific epitopes, such as tumour associated antigens, may be well conserved between patients and tumour types, but are often only weakly immunogenic. Direct observation of tumour-specific neoantigens by immunopeptidomics is rare, although valuable. Thus, there has been increasing interest in the non-canonical origins of tumour-reactive CD8+ T-cell epitopes, such as those arising from proteasomal splicing events, translational/turnover defects and alternative open reading frame reads. Such epitopes can be identified in silico, although validation is more challenging. Non-self CD8+ T-cell epitopes such as viral epitopes may be useful in certain cancer types with known viral origins, however these have been relatively unexplored with immunopeptidomics to date, possibly due to the paucity of source viral proteins in tumour tissues. This review examines the latest evidence for canonical, non-canonical and non-human CD8+ T-cell epitopes identified by immunopeptidomics, and concludes that the relative contribution for each of these sources to anti-tumour CD8+ T-cell reactivity is currently uncertain.
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Affiliation(s)
- Ben Nicholas
- Centre for Proteomic Research, Biological Sciences and Institute for Life Sciences, Building 85, University of Southampton, SO17 1BJ, U.K
| | - Paul Skipp
- Centre for Proteomic Research, Biological Sciences and Institute for Life Sciences, Building 85, University of Southampton, SO17 1BJ, U.K
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3
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Li X, Pak HS, Huber F, Michaux J, Taillandier-Coindard M, Altimiras ER, Bassani-Sternberg M. A microfluidics-enabled automated workflow of sample preparation for MS-based immunopeptidomics. CELL REPORTS METHODS 2023; 3:100479. [PMID: 37426762 PMCID: PMC10326370 DOI: 10.1016/j.crmeth.2023.100479] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 03/22/2023] [Accepted: 04/19/2023] [Indexed: 07/11/2023]
Abstract
Mass spectrometry (MS)-based immunopeptidomics is an attractive antigen discovery method with growing clinical implications. However, the current experimental approach to extract HLA-restricted peptides requires a bulky sample source, which remains a challenge for obtaining clinical specimens. We present an innovative workflow that requires a low sample volume, which streamlines the immunoaffinity purification (IP) and C18 peptide cleanup on a single microfluidics platform with automated liquid handling and minimal sample transfers, resulting in higher assay sensitivity. We also demonstrate how the state-of-the-art data-independent acquisition (DIA) method further enhances the depth of tandem MS spectra-based peptide sequencing. Consequently, over 4,000 and 5,000 HLA-I-restricted peptides were identified from as few as 0.2 million RA957 cells and a melanoma tissue of merely 5 mg, respectively. We also identified multiple immunogenic tumor-associated antigens and hundreds of peptides derived from non-canonical protein sources. This workflow represents a powerful tool for identifying the immunopeptidome of sparse samples.
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Affiliation(s)
- Xiaokang Li
- Ludwig Institute for Cancer Research, University of Lausanne, Rue du Bugnon 25A, 1005 Lausanne, Switzerland
- Department of Oncology, Centre Hospitalier Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1005 Lausanne, Switzerland
- Agora Cancer Research Centre, Rue du Bugnon 25A, 1005 Lausanne, Switzerland
| | - Hui Song Pak
- Ludwig Institute for Cancer Research, University of Lausanne, Rue du Bugnon 25A, 1005 Lausanne, Switzerland
- Department of Oncology, Centre Hospitalier Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1005 Lausanne, Switzerland
- Agora Cancer Research Centre, Rue du Bugnon 25A, 1005 Lausanne, Switzerland
| | - Florian Huber
- Ludwig Institute for Cancer Research, University of Lausanne, Rue du Bugnon 25A, 1005 Lausanne, Switzerland
- Department of Oncology, Centre Hospitalier Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1005 Lausanne, Switzerland
- Agora Cancer Research Centre, Rue du Bugnon 25A, 1005 Lausanne, Switzerland
| | - Justine Michaux
- Ludwig Institute for Cancer Research, University of Lausanne, Rue du Bugnon 25A, 1005 Lausanne, Switzerland
- Department of Oncology, Centre Hospitalier Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1005 Lausanne, Switzerland
- Agora Cancer Research Centre, Rue du Bugnon 25A, 1005 Lausanne, Switzerland
| | - Marie Taillandier-Coindard
- Ludwig Institute for Cancer Research, University of Lausanne, Rue du Bugnon 25A, 1005 Lausanne, Switzerland
- Department of Oncology, Centre Hospitalier Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1005 Lausanne, Switzerland
- Agora Cancer Research Centre, Rue du Bugnon 25A, 1005 Lausanne, Switzerland
| | - Emma Ricart Altimiras
- Ludwig Institute for Cancer Research, University of Lausanne, Rue du Bugnon 25A, 1005 Lausanne, Switzerland
- Department of Oncology, Centre Hospitalier Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1005 Lausanne, Switzerland
- Agora Cancer Research Centre, Rue du Bugnon 25A, 1005 Lausanne, Switzerland
| | - Michal Bassani-Sternberg
- Ludwig Institute for Cancer Research, University of Lausanne, Rue du Bugnon 25A, 1005 Lausanne, Switzerland
- Department of Oncology, Centre Hospitalier Universitaire Vaudois (CHUV), Rue du Bugnon 46, 1005 Lausanne, Switzerland
- Agora Cancer Research Centre, Rue du Bugnon 25A, 1005 Lausanne, Switzerland
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Lozano-Rabella M, Garcia-Garijo A, Palomero J, Yuste-Estevanez A, Erhard F, Farriol-Duran R, Martín-Liberal J, Ochoa-de-Olza M, Matos I, Gartner JJ, Ghosh M, Canals F, Vidal A, Piulats JM, Matías-Guiu X, Brana I, Muñoz-Couselo E, Garralda E, Schlosser A, Gros A. Exploring the Immunogenicity of Noncanonical HLA-I Tumor Ligands Identified through Proteogenomics. Clin Cancer Res 2023; 29:2250-2265. [PMID: 36749875 PMCID: PMC10261919 DOI: 10.1158/1078-0432.ccr-22-3298] [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: 10/24/2022] [Revised: 12/20/2022] [Accepted: 02/03/2023] [Indexed: 02/09/2023]
Abstract
PURPOSE Tumor antigens are central to antitumor immunity. Recent evidence suggests that peptides from noncanonical (nonC) aberrantly translated proteins can be presented on HLA-I by tumor cells. Here, we investigated the immunogenicity of nonC tumor HLA-I ligands (nonC-TL) to better understand their contribution to cancer immunosurveillance and their therapeutic applicability. EXPERIMENTAL DESIGN Peptides presented on HLA-I were identified in 9 patient-derived tumor cell lines from melanoma, gynecologic, and head and neck cancer through proteogenomics. A total of 507 candidate tumor antigens, including nonC-TL, neoantigens, cancer-germline, or melanocyte differentiation antigens, were tested for T-cell recognition of preexisting responses in patients with cancer. Donor peripheral blood lymphocytes (PBL) were in vitro sensitized against 170 selected nonC-TL to isolate antigen-specific T-cell receptors (TCR) and evaluate their therapeutic potential. RESULTS We found no recognition of the 507 nonC-TL tested by autologous ex vivo expanded tumor-reactive T-cell cultures while the same cultures demonstrated reactivity to mutated, cancer-germline, or melanocyte differentiation antigens. However, in vitro sensitization of donor PBL against 170 selected nonC-TL, led to the identification of TCRs specific to three nonC-TL, two of which mapped to the 5' UTR regions of HOXC13 and ZKSCAN1, and one mapping to a noncoding spliced variant of C5orf22C. T cells targeting these nonC-TL recognized cancer cell lines naturally presenting their corresponding antigens. Expression of the three immunogenic nonC-TL was shared across tumor types and barely or not detected in normal cells. CONCLUSIONS Our findings predict a limited contribution of nonC-TL to cancer immunosurveillance but demonstrate they may be attractive novel targets for widely applicable immunotherapies. See related commentary by Fox et al., p. 2173.
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Affiliation(s)
- Maria Lozano-Rabella
- Tumor Immunology and Immunotherapy, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
| | - Andrea Garcia-Garijo
- Tumor Immunology and Immunotherapy, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
| | - Jara Palomero
- Tumor Immunology and Immunotherapy, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
| | - Anna Yuste-Estevanez
- Tumor Immunology and Immunotherapy, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
| | - Florian Erhard
- Institute for Virology and Immunobiology, University of Würzburg, Würzburg, Germany
| | - Roc Farriol-Duran
- Tumor Immunology and Immunotherapy, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
| | - Juan Martín-Liberal
- Early Drug Development Unit (UITM) Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital, Barcelona, Spain
| | - Maria Ochoa-de-Olza
- Early Drug Development Unit (UITM) Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital, Barcelona, Spain
| | - Ignacio Matos
- Early Drug Development Unit (UITM) Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital, Barcelona, Spain
| | - Jared J. Gartner
- Surgery Branch, National Cancer Institute (NCI), National Institutes of Health, Bethesda, Maryland
| | - Michael Ghosh
- Institute for Cell Biology Department of Immunology, University of Tübingen, Tübingen, Germany
| | - Francesc Canals
- Proteomics, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital, Barcelona, Spain
| | - August Vidal
- Department of Pathology. Hospital Universitari de Bellvitge-IDIBELL, CIBERONC, Barcelona, Spain
| | - Josep Maria Piulats
- Medical Oncology, Catalan Institute of Cancer (ICO), IDIBELL-Oncobell, Hospitalet de Llobregat, Spain
| | - Xavier Matías-Guiu
- Department of Pathology. Hospital Universitari de Bellvitge-IDIBELL, CIBERONC, Barcelona, Spain
| | - Irene Brana
- Early Drug Development Unit (UITM) Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital, Barcelona, Spain
| | - Eva Muñoz-Couselo
- Melanoma and other skin tumors unit, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital, Barcelona, Spain
| | - Elena Garralda
- Early Drug Development Unit (UITM) Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital, Barcelona, Spain
| | - Andreas Schlosser
- Rudolf Virchow Center, Center for Integrative and Translational Bioimaging, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Alena Gros
- Tumor Immunology and Immunotherapy, Vall d'Hebron Institute of Oncology (VHIO), Vall d'Hebron Barcelona Hospital Campus, Barcelona, Spain
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Sharland AF, Hill AE, Son ET, Scull KE, Mifsud NA, Purcell AW. Are Induced/altered Self-peptide Antigens Responsible for De Novo Autoreactivity in Transplantation? Transplantation 2023; 107:1232-1236. [PMID: 36706066 PMCID: PMC10205114 DOI: 10.1097/tp.0000000000004499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 10/10/2022] [Accepted: 11/02/2022] [Indexed: 01/28/2023]
Affiliation(s)
- Alexandra F. Sharland
- Central Clinical School, Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Alexandra E. Hill
- Central Clinical School, Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Eric T. Son
- Central Clinical School, Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, Australia
| | - Katherine E. Scull
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | - Nicole A. Mifsud
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
| | - Anthony W. Purcell
- Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia
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6
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Ahn R, Cui Y, White FM. Antigen discovery for the development of cancer immunotherapy. Semin Immunol 2023; 66:101733. [PMID: 36841147 DOI: 10.1016/j.smim.2023.101733] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 02/15/2023] [Accepted: 02/16/2023] [Indexed: 02/25/2023]
Abstract
Central to successful cancer immunotherapy is effective T cell antitumor immunity. Multiple targeted immunotherapies engineered to invigorate T cell-driven antitumor immunity rely on identifying the repertoire of T cell antigens expressed on the tumor cell surface. Mass spectrometry-based survey of such antigens ("immunopeptidomics") combined with other omics platforms and computational algorithms has been instrumental in identifying and quantifying tumor-derived T cell antigens. In this review, we discuss the types of tumor antigens that have emerged for targeted cancer immunotherapy and the immunopeptidomics methods that are central in MHC peptide identification and quantification. We provide an overview of the strength and limitations of mass spectrometry-driven approaches and how they have been integrated with other technologies to discover targetable T cell antigens for cancer immunotherapy. We highlight some of the emerging cancer immunotherapies that successfully capitalized on immunopeptidomics, their challenges, and mass spectrometry-based strategies that can support their development.
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Affiliation(s)
- Ryuhjin Ahn
- David H. Koch Institute for Integrative Cancer Research, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Yufei Cui
- David H. Koch Institute for Integrative Cancer Research, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Forest M White
- David H. Koch Institute for Integrative Cancer Research, Cambridge, MA 02139, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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Cormican JA, Soh WT, Mishto M, Liepe J. iBench: A ground truth approach for advanced validation of mass spectrometry identification method. Proteomics 2023; 23:e2200271. [PMID: 36189881 PMCID: PMC10078205 DOI: 10.1002/pmic.202200271] [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: 06/30/2022] [Revised: 09/23/2022] [Accepted: 09/28/2022] [Indexed: 01/19/2023]
Abstract
The discovery of many noncanonical peptides detectable with sensitive mass spectrometry inside, outside, and on cells shepherded the development of novel methods for their identification, often not supported by a systematic benchmarking with other methods. We here propose iBench, a bioinformatic tool that can construct ground truth proteomics datasets and cognate databases, thereby generating a training court wherein methods, search engines, and proteomics strategies can be tested, and their performances estimated by the same tool. iBench can be coupled to the main database search engines, allows the selection of customized features of mass spectrometry spectra and peptides, provides standard benchmarking outputs, and is open source. The proof-of-concept application to tryptic proteome digestions, immunopeptidomes, and synthetic peptide libraries dissected the impact that noncanonical peptides could have on the identification of canonical peptides by Mascot search with rescoring via Percolator (Mascot+Percolator).
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Affiliation(s)
- John A. Cormican
- Max‐Planck‐Institute for Multidisciplinary Sciences (MPI‐NAT)GöttingenGermany
| | - Wai Tuck Soh
- Max‐Planck‐Institute for Multidisciplinary Sciences (MPI‐NAT)GöttingenGermany
| | - Michele Mishto
- Centre for Inflammation Biology and Cancer Immunology (CIBCI) & Peter Gorer Department of ImmunobiologyKing's College LondonLondonUK
- The Francis Crick InstituteLondonUK
| | - Juliane Liepe
- Max‐Planck‐Institute for Multidisciplinary Sciences (MPI‐NAT)GöttingenGermany
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Illing PT, Ramarathinam SH, Purcell AW. New insights and approaches for analyses of immunopeptidomes. Curr Opin Immunol 2022; 77:102216. [PMID: 35716458 DOI: 10.1016/j.coi.2022.102216] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 05/10/2022] [Indexed: 11/03/2022]
Abstract
Human leucocyte antigen (HLA) molecules play a key role in health and disease by presenting antigen to T-lymphocytes for immunosurveillance. Immunopeptidomics involves the study of the collection of peptides presented within the antigen-binding groove of HLA molecules. Identifying their nature and diversity is crucial to understanding immunosurveillance especially during infection or for the recognition and potential eradication of tumours. This review discusses recent advances in the isolation, identification, and quantitation of these peptide antigens. New informatics approaches and databases have shed light on the extent of peptide antigens derived from unconventional sources including peptides derived from transcripts associated with frame shifts, long noncoding RNA, incorrectly annotated untranslated regions, post-translational modifications, and proteasomal splicing. Several challenges remain in successful analysis of immunopeptides, yet recent developments point to unexplored biology waiting to be unravelled.
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Affiliation(s)
- Patricia T Illing
- Department of Biochemistry and Molecular Biology and Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Sri H Ramarathinam
- Department of Biochemistry and Molecular Biology and Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Anthony W Purcell
- Department of Biochemistry and Molecular Biology and Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia.
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Thibault P, Perreault C. Immunopeptidomics: Reading the Immune Signal That Defines Self From Nonself. Mol Cell Proteomics 2022; 21:100234. [PMID: 35567924 PMCID: PMC9252926 DOI: 10.1016/j.mcpro.2022.100234] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Pierre Thibault
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Quebec, Canada; Department of Chemistry, Université de Montréal, Montreal, Quebec, Canada
| | - Claude Perreault
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Quebec, Canada; Department of Medicine, Université de Montréal, Montreal, Quebec, Canada
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