Production of antisera with specificity for malignant melanoma and human fetal skin.

Complement-dependent cytotoxic antibodies to common cell surface antigens of cultured melanoma cells were produced in guinea pigs. At appropriate dilution, melanoma antisera were cytotoxic only to melanoma target cells. Following absorption with pooled lymphoid cells, additional absorption with melanoma cells but not absorption with fibroblasts or carcinoma cells was found to remove all cytotoxic activity from melanoma antisera. Absorption with human fetal skin cells but not with autologous fetal visceral cells was found to remove cytotoxicity from melanoma antisera. Tissue type-specific antigens may be shared by human malignant melanomas and fetal skin of black racial origin (at 16 to 18 weeks of gestation). The methods may be useful in the production of xenogeneic antisera with "operational monospecificity" for common melanoma-specific antigens. Sera from 47 patients with malignant melanoma failed to evidence specific cytotoxicity for melanoma target cells.