Immunologic cross-reactivity of antigen(s) induced by drug treatment in two leukemic sublines.

Previous studies have demonstrated that new antigenic specificities, not detectable on parental cells, can be induced by in vivo treatment of murine leukemic cells with anti-neoplastic agents. The immunologic properties of leukemic cells altered by treatment with 5-(3,3-dimethyl-1-triazeno) imidazole-4-carboxamide (DIC) were investigated further. Immunologic cross-reactivity between two DIC-treated leukemic sublines has been demonstrated by cell-mediated immunity in vitro and by active or adoptive immunity in vivo. Rabbit antiserum to DIC-treated sublines absorbed with the parental cells showed residual activity against the DIC-sublines that was specifically inhibited by further absorption with DIC-cells.