title: Induction of antigen-specific immunologic tolerance by in vivo and in vitro antigen-specific expansion of naturally arising Foxp3+CD25+CD4+ regulatory T cells.
abstract: Naturally arising CD25(+)CD4(+) regulatory T (T(R)) cells can be exploited to establish immunologic tolerance to non-self antigens. In vivo exposure of CD25(+)CD4(+) T cells from normal naive mice to alloantigen in a T cell-deficient environment elicited spontaneous expansion of alloantigen-specific CD25(+)CD4(+) T(R) cells, which suppressed allograft rejection mediated by subsequently transferred naive T cells, leading to long-term graft tolerance. The expanded T(R) cells, which became CD25(low) in the absence of other T cells, stably sustained suppressive activity, maintained expression levels of other T(R) cell-associated molecules, including Foxp3, CTLA-4 and GITR, and could adoptively transfer tolerance to normal mice. Furthermore, specific removal of the T(R) cells derived from originally transferred CD25(+)CD4(+) T(R) cells evoked graft rejection in the long-term tolerant mice, indicating that any T(R) cells deriving from CD25(-)CD4(+) naive T cells minimally contribute to graft tolerance and that natural T(R) cells are unable to infectiously confer significant suppressive activity to other T cells. Similar antigen-specific expansion of T(R) cells can also be achieved in vitro by stimulating naturally present CD25(+)CD4(+) T cells with alloantigen in the presence of IL-2. The expanded CD25(+)CD4(+) T cells potently suppressed even secondary MLR in vitro and, by in vivo transfer, established antigen-specific long-term graft tolerance. Thus, in vivo or in vitro, direct or indirect ways of antigen-specific expansion of naturally arising Foxp3(+)CD25(+)CD4(+) T(R) cells can establish antigen-specific dominant tolerance to non-self antigens, and would also be instrumental in re-establishing self-tolerance in autoimmune disease and antigen-specific negative control of pathological immune responses.
authors.affiliation: Department of Experimental Pathology, Institute for Frontier Medical Sciences, Faculty of Medicine, Kyoto University, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Nishimura
authors.forename: Toshiko
authors.initials: T
authors.lastname: Sakihama
authors.forename: Ruka
authors.initials: R
authors.lastname: Setoguchi
authors.forename: Koichi
authors.initials: K
authors.lastname: Tanaka
authors.forename: Shimon
authors.initials: S
authors.lastname: Sakaguchi
mesh_terms: D019264:Adoptive Transfer; D000818:Animals; D000941:Antigens / Q000276:immunology; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000637:transplantation; D060908:CTLA-4 Antigen; D002452:Cell Count; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000276:immunology*; D051858:Forkhead Transcription Factors; D053450:Glucocorticoid-Induced TNFR-Related Protein; D051379:Mice; D008807:Mice, Inbred BALB C; D015375:Receptors, Interleukin-2 / Q000276:immunology*; D017475:Receptors, Nerve Growth Factor / Q000276:immunology; D018124:Receptors, Tumor Necrosis Factor / Q000276:immunology; D016038:Skin Transplantation / Q000276:immunology*; D023001:Transplantation Tolerance / Q000276:immunology*; D014184:Transplantation, Homologous / Q000276:immunology*
chemical_list: D000941:Antigens; D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556707:Ctla4 protein, mouse; D004268:DNA-Binding Proteins; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D053450:Glucocorticoid-Induced TNFR-Related Protein; D015375:Receptors, Interleukin-2; D017475:Receptors, Nerve Growth Factor; D018124:Receptors, Tumor Necrosis Factor; C106544:Tnfrsf18 protein, mouse