1983 Volume 45 Issue 4 Pages 477-485
The enhancement of tumor growth in athymic nude mice transplanted with bovine leukemia cell line (FLK) was observed by inoculation of anti-asialo GM1 (gangliotetra-glycosylceramide) serum which has been shown to eliminate natural killer (NK) activity in vitro and in vivo. The biological mechanisms for the enhancement were investigated by examining NK activity and antibody-dependent cellular cytotoxicity (ADCC) of the spleen cells of the nude mice. FLK cells, that are weakly sensitive to NK cell-mediated immunolysis. were also killed by normal spleen cells of nude mice in the presence of specific antibodies to FLK cells. The ADCC was suppressed by inoculation of anti-asialo GM1 serum, which indicates that ADCC-functioning killer (K) cells too have asialo GM1 as NK cells. These results suggest that normal nude mice reject transplanted FLK cells by K cells as well as NK cells and inoculation of anti-asialo GM1 serum allows the tumor growth through elimination of both the NK and K cell activities.
