title: Identification of a previously unknown antigen-specific regulatory T cell and its mechanism of suppression.
abstract: Despite increasing evidence for the existence of antigen-specific regulatory T cells, the mechanisms underlying suppression remain unclear. In this study we have identified and cloned a novel subset of antigen-specific regulatory T cells and demonstrated that these T cells possess a unique combination of cell surface markers and array of cytokines. The regulatory T cells are able to inhibit the function of T cells carrying the same T-cell receptor specificity and prevent skin allograft rejection in an antigen-specific, dose-dependent manner. The regulatory T cells are able to acquire alloantigen from antigen-presenting cells, present the alloantigen to activated syngeneic CD8+ T cells and then send death signals to CD8+ T cells. These findings provide a novel mechanism of regulatory T-cell-mediated, antigen-specific suppression.
authors.affiliation: Department of Laboratory of Medicine and Pathobiology, Multi Organ Transplantation Program, Toronto General Hospital Research Institute, UHN, University of Toronto, Toronto, M5G, 2C4, Canada. lzhang@transplantunit.org
authors.forename: Z X
authors.initials: ZX
authors.lastname: Zhang
authors.forename: L
authors.initials: L
authors.lastname: Yang
authors.forename: K J
authors.initials: KJ
authors.lastname: Young
authors.forename: B
authors.initials: B
authors.lastname: DuTemple
authors.forename: L
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000818:Animals; D017951:Antigen Presentation; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D016923:Cell Death; D006085:Graft Survival / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D007108:Immune Tolerance / Q000276:immunology*; D051379:Mice; D008817:Mice, Mutant Strains; D008822:Mice, Transgenic; D018448:Models, Immunological; D015398:Signal Transduction; D016038:Skin Transplantation / Q000276:immunology*; D013154:Spleen / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D019014:fas Receptor
chemical_list: D015395:Histocompatibility Antigens Class I; D019014:fas Receptor