Characterization of melanoma cell membrane tumor-associated antigens using xenoserum, alloserum, and autoserum: I. immunofluorescence.

Xenoantiserum, alloantiserum, and autoantiserum prepared against human melanoma cells from cell lines maintained in tissue culture were evaluated by indirect immunofluorescence (ind IF) for their content of antibodies reactive with melanoma cell membrane tumor-associated antigens (TAA). Following absorptions which removed all detectable anti-human species, anti-RBC, and anti-HLA antigen activity, the antisera were tested against a panel of human cell lines. Three apparently distinct melanoma-associated cell membrane antigens were detected. The first of these was present on all human cells maintained in tissue culture including cells of both malignant and nonmalignant origin. The second antigen was expressed on all cells of malignant origin and also by fetal fibroblasts. The third antigen was detectable only on melanoma cells and was expressed by a majority of the melanomas tested. No evidence was obtained to suggest the presence of melanoma TAA unique to a single melanoma cell line. Marked differences were observed in the antigenic profile detected by the three antisera.