title: Capacity of purified Lyt-2+ T cells to mount primary proliferative and cytotoxic responses to Ia- tumour cells.
abstract: Allogeneic gene products of the major histocompatibility complex, the HLA complex in man and the H-2 complex in mice, induce T lymphocytes to exert powerful mixed lymphocyte reactions (MLR) and cell-mediated lympholysis (CML). In mice, the subset of T cells carrying the L3T4 surface antigen but lacking the Lyt-2 antigen responds predominantly to H-2 class II (Ia) differences whereas the L3T4- Lyt-2+ subset reacts to class I (K/D) differences. For primary responses the stimulus for MLR and CML appears to be controlled by Ia+ cells of the macrophage/dendritic cell lineages, for both L3T4+ and Lyt-2+ cells. The finding that Ia+ cells are required for responses involving Lyt-2+ cells has been taken to imply that triggering of these cells is controlled by Ia-restricted L3T4+ cells. Lyt-2+ cells have thus come to be regarded as crippled cells which are heavily dependent on 'help' from other T cells. This well-entrenched view is challenged by evidence presented here that purified Lyt-2+ cells can give high primary responses to certain Ia- tumour cells in vitro.
mesh_terms: D000818:Animals; D000950:Antigens, Ly / Q000276:immunology*; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D008213:Lymphocyte Activation; D012515:Mast-Cell Sarcoma / Q000276:immunology*; D051379:Mice; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000950:Antigens, Ly; D000949:Histocompatibility Antigens Class II