title: Recognition of MHC class I allodeterminants regulates the generation of MHC class II-specific CTL.
abstract: We have analyzed the signals influencing the generation of major histocompatibility complex (MHC) class II allospecific cytolytic T lymphocytes (CTL) and have found that the development of these CTL is actively regulated in primary in vitro cultures by Lyt-2+ T cells triggered in response to MHC class I alloantigens. Class II allospecific CTL can be readily stimulated in primary cultures, but the presence of a simultaneous class I MHC stimulus in these cultures causes a marked reduction of class II-specific CTL activation. This reduction can be prevented by adding to culture a dose of monoclonal anti-Lyt-2 antibody (in the absence of complement) that does not block the generation of class I-specific CTL. The role of MHC class I alloantigens in the regulation of class II allospecific responses illustrates that T cells recognizing class I and class II MHC antigens in mixed leukocyte cultures interact in a complex and nonreciprocal manner to influence the final effector T cell repertoire elicited by this complex immunogenic challenge.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D006183:H-2 Antigens / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D007111:Immunity, Cellular; D051379:Mice; D008815:Mice, Inbred Strains; D013602:T-Lymphocytes, Cytotoxic / Q000145:classification / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D006183:H-2 Antigens; D000949:Histocompatibility Antigens Class II