title: Identification and Phylogeny of the First T Cell Epitope Identified from a Human Gut Bacteroides Species.
abstract: Host T cell reactivity toward gut bacterial epitopes has been recognized as part of disease pathogenesis. However, the specificity of T cells that recognize this vast number of epitopes has not yet been well described. After colonizing a C57BL/6J germ-free mouse with the human gut symbiotic bacteria Bacteroides thetaiotaomicron, we isolated a T cell that recognized these bacteria in vitro. Using this T cell, we mapped the first known non-carbohydrate T cell epitope within the phylum Bacteroidetes. The T cell also reacted to two other additional Bacteroides species. We identified the peptide that stimulated the T cell by using a genetic approach. Genomic data from the epitope-positive and epitope-negative bacteria explain the cross-reactivity of the T cell to multiple species. This epitope degeneracy should shape our understanding of the T cell repertoire stimulated by the complex microbiome residing in the gastrointestinal tract in both healthy and disease states.
authors.affiliation: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.|Department of Food Science and Technology, University of Nebraska, Lincoln, Nebraska, United States of America.
authors.forename: Maria Elisa
authors.initials: ME
authors.lastname: Perez-Muñoz
authors.affiliation: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.|Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, United States of America.
authors.forename: Payal
authors.initials: P
authors.lastname: Joglekar
authors.forename: Yi-Ju
authors.initials: YJ
authors.lastname: Shen
authors.affiliation: Department of Computer Science and Engineering, National Taiwan Ocean University, Keelung, Taiwan.
authors.forename: Yi-Ji
authors.initials: YJ
authors.lastname: Shen
authors.affiliation: Department of Computer Science and Engineering, National Taiwan Ocean University, Keelung, Taiwan.
authors.forename: Kuan Y
authors.initials: KY
authors.lastname: Chang
authors.affiliation: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Peterson
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000235:genetics / Q000276:immunology*; D001439:Bacteroides / Q000235:genetics / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte / Q000235:genetics / Q000276:immunology*; D000069196:Gastrointestinal Microbiome / Q000235:genetics / Q000276:immunology*; D006801:Humans; D051379:Mice; D010802:Phylogeny; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D018984:Epitopes, T-Lymphocyte