[Induction of immunogenic variant of a murine fibrosarcoma]

Immunogenic variant was induced from the methylcholanthrene induced fibrosarcoma (MCA-F) by in vitro treatment with the mutagen 1-methyl-3-nitro-1-nitrosoguanidine (MNNG). D-10 tumor cell which was cloned from MNNG treated MCA-F tumor cell was rejected by normal syngeneic C3H-HeJ mice but not by 650 rad irradiated immunosuppressed mice. Host which had rejected D-10 tumor growth, rejected parental MCA-F tumor cells. But active immunotherapy using D-10 tumor cell against MCA-F tumor cells. But active immunotherapy using D-10 tumor cell against MCA-F tumor bearing mice was not successful. Cytotoxic T cell (CTL) established from D-10 immunized spleen cells showed D-10 specific cytotoxic activity and not lysed parent MCA-F cells. CTL clone C-E-6 showed specific cytotoxic and proliferative activity against D-10 cell. In vivo tumor neutralizing assay also showed its specificity against D-10 tumor cell. Active immunotherapy and adoptive immunotherapy using immunogenic variant, D-10 was not successful. D-10 tumor cell possesses very strong neoantigen induced by MNNG treatment and parental MCA-F antigen.