Astrocytes as antigen-presenting cells. Part II: Unlike H-2K-dependent cytotoxic T cells, H-2Ia-restricted T cells are only stimulated in the presence of interferon-gamma.
Various studies strongly suggest that astrocytes are potent immune-regulating cells. They can be activated to release prostaglandin E, interleukin-1- and interleukin-3-like factors. Cocultivation of antigen-specific T cell lines and astrocytes results in induction of Ia on astrocytes and antigen-specific proliferation of T cells. In the current study, astrocytes were found to be incapable of serving as stimulator cells when unprimed T lymphocytes were used as responders in syngeneic or allogeneic lymphocyte reactions. However, when interferon-gamma (IFN-gamma) was added, astrocytes became Ia positive and potent stimulators in both syngeneic or allogeneic lymphocyte responses. In the presence of IFN-gamma, astrocytes presented antigens to Ia-restricted T hybridoma cells; in contrast hapten was presented to Kb-restricted cytotoxic cloned T cells by astrocytes in the absence of IFN-gamma. Thus, cultured astrocytes do function directly as accessory cells in class I antigen-dependent T cell activation, whereas Ia induction by IFN-gamma is necessary to enable them to present antigen to class II antigen-restricted T cells.
D000818:Animals; D000938:Antigen-Presenting Cells / Q000187:drug effects / Q000276:immunology*; D001253:Astrocytes / Q000187:drug effects / Q000276:immunology*; D003208:Concanavalin A / Q000494:pharmacology; D006183:H-2 Antigens / Q000276:immunology*; D006825:Hybridomas / Q000276:immunology; D007371:Interferon-gamma / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects / Q000276:immunology*
D006183:H-2 Antigens; D003208:Concanavalin A; D007371:Interferon-gamma