Busulfan and chloramphenicol induced T cell lymphoma: cell surface characteristics and functional properties

We report the immunological studies on three transplantable lymphoma lines that developed when CAF1 mice were injected with busulfan and chloramphenicol. The lymphoma cells displayed Thy-1.2, brain associated antigen, and H-2d alloantigen. They were negative for surface IgM and Ia antigens. Expression of T cell differentiation antigens differed among the three lines. The 508 tumour line displayed only Thy-1.2: 408 tumour line displayed Thy-1.2, Lyt-2.2 and TL; and 808 tumour line was positive for Thy-1.2, Lyt-1.2, Lyt-2.2 and TL antigens. We established in vitro culture lines from 508 and 808 lymphoma cells. The lymphoma cells did not respond to mitogens and antigens. The splenic cells from mice bearing 508 or 808 had decreased phytohaemagglutinin (PHA), concanavalin A (Con A) and mixed leucocyte responses (MLR). When mitomycin-C treated lymphoma cells from the tumour bearing mice were cocultured with normal splenic mononuclear cells, the 808 lymphoma cells suppressed the mitogenic responses of the normal cells more profoundly than 508 lymphoma cells. Adherent cells from both tumours suppressed the Con A responses of normal spleen cells. Cells from in vitro 508 or 808 cell lines had no effect on mitogenic responses of normal cells. Plasma from tumour bearing mice, but not the supernatants taken from cultures of these lymphoma cells, suppressed the mitogenic responses of normal lymphocytes. Spleen cells from normal CAF1 mice responded in mixed leucocyte tumour reactions (MLTR) when cocultured with lymphoma cells. Mice immunized with mitomycin-C treated tumour cells had greater response. Responder cells taken from mice with established 508 or 808 tumors had suppressed MLTR responses. Although prior immunization with tumor antigen increased the MLTR response, injection of live tumour cells into immunized mice resulted in a more rapid tumour growth and suppression of MLTR response.