Appearance of strong transplantation antigens in non-immunogenic lymphoma following drug-treatment in vivo.

A chemically induced lymphosarcoma line (LSBM-1) of C57BL/10 (H-2b) origin lacks detectable TATA and is scarcely immunogenic for H-2-incompatible congenic recipients. New antigenic specificities, defined as drug-mediated tumor antigen(s) (DMTA) were found in a subline (LBD-1) obtained by in vivo treatment of LSBM-1 with the anti-neoplastic agent dimethyl-1-triazeno-imidazole-carboxamide (DTIC) over several transplant generations. It was concluded that the presence of detectable TATA is not a prerequisite for the induction of new antigenic specificities (DMTA).