title: Antigen-presenting T cells. II. Clonal responses of alloreactive and virus-specific self-restricted human cytotoxic T cell responses stimulated by T lymphoblasts.
abstract: The capacity of various stimulator cell types to present alloantigens or viral antigens to resting human CD8+ cytotoxic lymphocyte precursors (CLP) was analyzed in a limiting dilution culture system. Cell sorter-separated T lymphoblasts of both CD4+ and CD8+ phenotypes but not resting T cells were found to efficiently stimulate the clonal development of allogeneic CD8+ CLP. Thus, 5000 CD4+ T lymphoblasts activated as many (one out of 200 to one out of 300) allogeneic CLP as 50,000 peripheral blood mononuclear stimulator cells. This potent stimulator activity was found in CD4+ and CD8+ T lymphoblasts activated by mitogen, anti-T3 monoclonal antibody, or mixed leukocyte reactions. Cytotoxic T cells generated in this system were highly specific for HLA class I antigens. Furthermore, T lymphoblasts infected with mumps virus efficiently induced development of autologous CLP into CTL clones that were virus specific and self-HLA restricted, as shown by split-well analysis. The possible in vivo significance of antigen-presenting T lymphoblasts is discussed.
mesh_terms: D000938:Antigen-Presenting Cells / Q000276:immunology*; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis; D002469:Cell Separation; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D006801:Humans; D007111:Immunity, Cellular; D008211:Lymphocyte Cooperation; D009109:Mumps virus / Q000276:immunology; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface