| Abstract: | In vitro culture of murine spleen cells in FCS without prior immunization or allogeneic stimulation leads to the development of spontaneous cytotoxicity. This cytotoxicity is not H-2 restricted and can affect any subsequent in vitro assays using syngeneic cells, especially if those assays include prolonged culture in FCS. Studies on murine spleen cells cultured in NMS, however, led to the detection of a suppressor system that did not display cytotoxic effects. Furthermore, it was found that this suppression, in contrast to the cytotoxicity and suppression generated during culture in FCS, was not sensitive to CYA. The suppressor cell may be an effector or an inducer of suppression and is sensitive to treatment with anti-Thy-1.2 and complement. It is suggested that some in vitro suppression is really due to cytotoxicity that may be directed toward FCS determinants adsorbed onto syngeneic targets. |
