Characterization of Monoclonal Antibodies to Human Melanoma-Associated Antigens 1,2,3,4

#653.25N derived from the fusion of myeloma cells with spleno-cytes from mice immunized with cultured human melanoma cells secreted monoclonal antibodies recognizing antigenic determi-nants maximally expressed on cultured human melanoma cells and freshly explanted melanoma cells. Monoclonal antibody #376.74T reacted also with carcinoma cell lines but with a significantly lower titer. Rosette inhibition assay showed that these antigenic determinants were expressed on antigenic struc-tures, which are not associated with fl. microglobulin and histocompatibility antigens. Two monoclonal antibodies recog-nized the same or closely associated antigenic determinants, and the remaining two monoclonal antibodies reacted with distinct antigenic determinants. All four monoclonal antibodies could mediate antibody-dependent cellular cytotoxicity of cultured melanoma cells, but none could mediate complement-dependen