Lysis of Cultured Human Melanoma M10 Cells by Polyclonal Xenoantibodies to Melanoma-associated Antigens¹

Cultured human melanoma cells M10 harvested from cultures in different phases of their growth show significant changes in the expression of melanoma-associated antigens (MAA), but they do not vary in susceptibility to lysis mediated by anti-MAA xenoantisera and effected by complement or lymphoid cells. Furthermore, melanoma cells M10 showed a significant increase in susceptibility to immune lysis following treatment with puromycin at doses that do not effect the expression of MAA. The lack of correlation between MAA density and susceptibility to immune lysis supports the contention that, under the experimental conditions used, cellular properties play a major role in the outcome of immune attack.