Serological characterization of a shared melanoma-associated antigen of mouse melanomas: relationship to the B700 glycoprotein.

A group of murine melanomas, consisting of the C57BL/6 melanomas JB/RH and B16 F10, and the C3H/He melanoma K1735, have been shown to be cross-immunogenic in tumour rejection assays, and to be antigenically distinct from the DBA/2 melanoma S91. In addition, the M(r) 65,000 melanoma-associated glycoprotein, B700, isolated from the B16F10 melanoma, was shown to induce a pattern of cross-immunity in semi-syngeneic mice, which was identical to that obtained with the melanomas. An antigen expressed by the JB/RH melanoma has been serologically defined by complement-dependent cytotoxic antibodies present in the sera of semi-syngeneic mice hyperimmunized against this melanoma. This antigen, designate JB/RH antigen, also was detected on JB/MS, B16 F10 and K1735 melanomas, but not on S91 melanoma. The cytotoxic antibodies defining the JB/RH antigen could be absorbed by the B700 glycoprotein isolated from B16 F10 melanoma, but not from S91 melanoma. Monoclonal antibodies were generated and shown to recognize a M(r) 65,000 antigen expressed by B16 F10 melanoma, but not S91 melanoma, suggesting that they have a specificity similar to that of the anti-JB/RH serum.