Immunologic alteration of the L5178Y
lymphoma was obtained in vivo
after treatment with
5-(3,3-dimethyl-1-triazeno)imidazole-4-carboxamide (
DIC). A single dose of 1,3-bis(2-chlorethyl)-1-nitrosourea (
BCNU) "CURED" MICE CHALLENGED WITH L5178Y cells that had been treated with
DIC (L5178Y/
DIC) for four transplant generations;
BCNU did not cure mice bearing the parent
tumor. The L5178Y/
DIC, treated in vivo for five transplant generations, id not grow in syngeneic mice. L5178Y/OIC cell growth and incidences of death were similar to those of parent cells when inoculated into heavily immunosuppressed mice. Adoptive transfer of lymphocytes from spleens of mice sensitized to the drug-altered
tumor specifically protected immunosuppressed mice bearing the L5178Y/
DIC tumor. Little protection was afforded by lymphocytes immune to the parent L5178Y
tumor, whereas nonimmune lymphocytes or lymphocytes immune against unrelated
tumors were completely ineffective. Anti-L5178Y/
DIC lymphocytes did not cure mice challenged with the parent L5178Y
tumor. Irradiated (400 R) mice previously sensitized to L5178Y/
DIC cells rejected 10(2)-10(7) inocula of L5178Y/
DIC cells and died when the parent L5178Y was used for challenge. It was concluded that antigeni( alterations of L5178Y cells occurred in (BALB/ctcr X DBA/2Cr)F1 mice
after treatment with
DIC in vivo.