Cell surface antigens of human malignant melanoma: definition of six antigenic systems with mouse monoclonal antibodies.

Publisher Website
Google Scholar
Abstract
Eighteen mouse monoclonal antibodies were selected for reactivity with cell surface antigens of the immunizing human melanoma cell line SK-MEL-28. Six distinct antigenic systems were defined by direct serological assays and absorption tests with a panel of 41 cell lines derived from normal and malignant human tissues. Biochemical analysis indicated that 2 of the antigens are glycoproteins with molecular sizes of 95,000 and 150,000 daltons (gp95 and gp150). Two other antigenic systems (O5 and the R24 group) are associated with heat-stable molecules having the characteristics of glycolipids. The remaining 2 antigens (M19 and R8) are heat labile, but molecular characterization was not possible. Each of the antigenic systems has a distinctive pattern of distribution various cell types, varying from a broad representation to a more restricted occurrence. O5 aapears to be a species antigen, being present on virtually every human cell type tested. gp95, gp150, M19 and R8 are found on a characteristic proportion of melanomas, astrocytomas and epithelial cancers and on normal kidney cells. The antigen defined by the R24 antibody has the most restricted distribution of all. Reactivity is found with melanomas and astrocytomsas, whereas epithelial cell types, fibroblasts and cells of hematopoietic origin lack R24. Although occurrence of gp95, gp150, M19 and R8 distinguishes a small subset of melanomas not expressing these antigens, R24 is found on all melanoma cells.