Augmentation of the cell-mediated cytotoxic response induced in mixed cell culture by adriamycin

The effects of adriamycin (AM) on the generation of cell-mediated cytotoxicity in primary stimulation cultures of human peripheral blood mononuclear cells (PBM) with B-lymphoblastoid cell line Raji were assessed. When AM was added to the culture on day 1 for 24 hr at a concentration of 10(-8)M, the cell-mediated cytotoxic response was significantly augmented as compared to that in untreated culture. The augmented cytotoxic response was significantly depressed when unfractionated cells harvested from untreated culture were added to the effector cells from AM-treated culture. The response was slightly more reduced by addition of cells from untreated culture after treatment with OKT3. However, the addition of cells from untreated culture after removal of adherent cells resulted rather in an increase of the cytotoxic response. When adherent cell fraction was removed from the effector cells, the cytotoxic response in nonadherent fraction from AM-treated culture was similar to that observed in unfractionated cells from the same culture. On the other hand, nonadherent fraction from untreated culture gave an increased cytotoxic response, which was of almost the same magnitude as that of cells from the augmented, AM-treated culture. These results suggested that the augmentation of cytotoxic response observed in AM-treated culture might be due to inhibition by AM of the generation of suppressive activity in the adherent cell population during PBM-Raji cell culture.