Brief Communication: Increased Immunogenicity of Two Lymphoma Lines After Drug Treatment of Athymic (Nude) Mice

Abstract

Highly immunogenic subllnes of L1210 and LSTRA lymphomas were obtained from athymlc (nude) mice treated with 4(5)-(3,3-dlmethyl-1-triazeno)imidazole-5(4)carboxamide (DIC) in vivo. Conventional mice, compatible with the parent tumor, rejected the DIC-treated subllnes and were relatively resistant to a subsequent challenge with the parent lines. The DIC-treated sublines were not rejected by athymic mice, which indicated that the transplantation resistance to these tumors in conventional mice was thymus-eell dependent. In addition, there was marginal or no increase of tumor-cell immunogeniclty when the parent lines were passaged in nude mice without DIC treatment. This indicated that the DIC-dependent immunogenic changes in DIC-treated leukemic conventional mice could not be ascribed merely to protection by naturally occurring antigenic clones that resulted from DIC-induced immunodepression.