Syngeneic monoclonal anti-melanoma antibody that inhibits experimental lung metastasis of B16 melanoma.

An objective method to evaluate experimental lung metastasis of murine melanoma has been established by sandwich radioimmunoassay using monoclonal anti-melanoma antibody (M2590). The assay system quantitatively detected melanoma antigens metastasized in the lung. The data obtained by radioimmunoassay were consistent with those obtained by the usual colony-counting method. By the use of these detection systems for lung metastasis, we found that only one particular syngeneic monoclonal antibody (M562) recognizing a proteinaceous determinant on melanoma antigen significantly inhibited experimental lung metastasis of melanoma cells (1/7-1/10 of controls), whereas other syngeneic monoclonal antibodies with the same specificity and the same immunoglobulin class or control antibody did not. It is therefore strongly suggested that the molecule recognized by M562 antibody plays an important role in lung metastasis of melanoma cells.