title: A model of suppression of the antigen-specific CD4 T cell response by regulatory CD25+CD4 T cells in vivo.
abstract: Despite intense recent interest, the suppressive mechanisms of regulatory CD25+CD4 T cells remain poorly understood. One deficiency in the field is the lack of in vivo models where the effects of regulatory CD25+CD4 T cells on antigen-specific responder T cells can be measured quantitatively. We describe one such model here. We compared responses of adoptively transferred naive wild-type antigen-specific CD4 T cells in syngeneic CD28-/- and wild-type recipient mice toward a nominal antigen. The cells exhibited a greater degree of proliferation and differentiation in CD28-/- mice and could not be rendered functionally hyporesponsive by systemic exposure to adjuvant-free antigen. The only reason we were able to find to explain this difference was the deficiency of regulatory CD25+CD4 T cells in the CD28-/- mice. Use of CD28-/- mice as adoptive transfer recipients provides a simple model that reveals the contribution of regulatory CD25+CD4 T cells in controlling antigen-driven responses in vivo.
authors.affiliation: Center for Immunology and the Department of Medicine, University of Minnesota, 6-134 BSBE Building, 312 Church Street, SE Minneapolis, MN 55455, USA.
authors.forename: Kristen M
authors.initials: KM
authors.lastname: Thorstenson
authors.forename: Laura
authors.initials: L
authors.lastname: Herzovi
authors.forename: Alexander
authors.initials: A
authors.lastname: Khoruts
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000276:immunology; D000941:Antigens / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D049109:Cell Proliferation; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008954:Models, Biological; D015375:Receptors, Interleukin-2 / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology
chemical_list: D000941:Antigens; D015375:Receptors, Interleukin-2