Mixtures of lymph node and spleen cells from normal (untreated) BALB/c mice and from BALB/c mice whose syngeneic tumors had been excised 7-28 days previously ("tumor-excised mice"), were sensitized in vitro by cultivation for 9 days with cells from syngeneic, methylcholanthrene-induced sarcomas. The in vitro-sensitized lymphoid cells were tested in a 36-h microcytotoxicity assay for reactivity against target cells carrying the sensitizing tumor antigens, as well as against control target cells lacking these antigens. After co-cultivation with tumor cells, lymphoid cells from both normal and tumor-excised mice were cytotoxic to tumor cells carrying the sensitizing antigens. The cytotoxicity was generally specific, and occurred at low effector: target cell ratios (in some experiments down to 1:1). When lymphoid cells from tumor-excised mice were exposed in vitro for 9 days to cells carrying the same antigens as those which were originally present on the surgical excised tumors, the effector cells obtained gave a dose-dependent cytotoxic response suggestive of a linear relationship. When lymphoid cells from normal mice were similarly sensitized for 9 days, specifically cytotoxic lymphoid cells were generated but no linear dose-dependent response was detected.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.