title: Existence of T cells manifesting self-reactivity indistinguishable from alloreactivity.
abstract: The studies reported here were designed to analyze the phenotypic characteristics of self-reactive T lymphocytes induced in culture by allogeneic effect factor (AEF), as well as the control of their functional activities by the major histocompatibility complex (MHC). Unprimed T cells cultured with AEF in the absence of exogenous stimulating target cells become activated against self-antigens, as evidenced by their ability to manifest two distinct activities. First, such cells could lyse syngeneic target cells. This cytolytic activity was directed against H-2K antigens and was mediated by Lyt-2+ T cells. Second, the AEF-activated T cells could be stimulated in a secondary culture to high levels of proliferative activity by irradiated syngeneic spleen cells. The stimulator cells in this syngeneic mixed lymphocyte reaction (MLR) were found to be Thy-1-negative, Ia-positive splenic adherent cells. Stimulation in the secondary syngeneic MLR was provided by I-region specificities, and the majority of the proliferating cells were Lyt-1+ cells. Finally, AEF-induced T cells were effective in serving as effectors of graft-vs-host reactions in vivo in syngeneic recipients. These results prove that, under appropriate conditions, murine T lymphocytes can display aggressive patterns of self-reactivity that are similar in both quantity and quality to the classical patterns of alloreactivity and may have great significance for our understanding of MHC recognition processes.
mesh_terms: D000818:Animals; D003429:Cross Reactions; D003602:Cytotoxicity, Immunologic; D000939:Epitopes / Q000235:genetics; D006087:Graft vs Host Reaction; D006183:H-2 Antigens; D007519:Isoantigens; D007959:Lymphocyte Culture Test, Mixed; D051379:Mice; D008809:Mice, Inbred C3H; D008811:Mice, Inbred DBA; D010641:Phenotype; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000939:Epitopes; D006183:H-2 Antigens; D007519:Isoantigens