In vitro immunization against tumour-associated antigen of methylcholanthrene-induced sarcoma.

Lymph node cells obtained from B10 mice were sensitized in vitro on monolayers of syngeneic methylcholanthrene-induced sarcoma cells. The in vitro sensitized LNC displayed specific cytotoxic and inhibitory effects on sarcoma cells used for sensitization. The effects were detectable by visual counting and inhibition of 3H-thymidine incorporation. The inhibition observed after admixture of in vitro sensitized LNC was more effective than inhibition produced by LNC from mice immunized with the same syngeneic sarcoma in vivo. Solubilization of sarcoma cells with 3M KCl gave rise to antigenic preparation which was unable to sensitize syngeneic LNC under experimental conditions used.