Antigen-specific CD8+ T cells switch the immune response induced by antigen from an IgG to a cell-mediated mode.
We have developed an in vivo/in vitro immunization procedure with xenogeneic RBC as Ag that results in the generation of a lymphoid population that expresses potent delayed-type hypersensitivity (DTH) and produces little, if any, antibody. This lymphoid population contains Ag-specific CD8+ T cells that can inhibit the induction of a strong IgG response. These CD8+ T cells are shown to not only inhibit the antibody response in an Ag-specific manner but allow the Ag to induce cells of the target population to express DTH. Furthermore, the Ag-specific inhibition of the antibody response and the Ag-specific enhancement of the induction of DTH appear to be coordinately regulated, as the same number of CD8+ T cells cells is required to achieve both effects. Thus these CD8+ T cells are shown to switch the response induced by Ag from a humoral to a cell-mediated mode. These regulatory characteristics are consistent with a physiologic role for these cells of ensuring the absence of antibody production during a strong, cell-mediated response.
Tuttosi
S
S
Department of Microbiology, University of Saskatchewan, Saskatoon, Canada.
Bretscher
P A
PA
D000818:Animals; D000941:Antigens / Q000276:immunology*; D016827:CD8 Antigens / Q000032:analysis*; D006968:Hypersensitivity, Delayed; D007111:Immunity, Cellular; D007074:Immunoglobulin G / Q000096:biosynthesis*; D007167:Immunotherapy; D051379:Mice; D008806:Mice, Inbred AKR; D008808:Mice, Inbred CBA; D013601:T-Lymphocytes / Q000276:immunology*
D000941:Antigens; D016827:CD8 Antigens; D007074:Immunoglobulin G