Production of murine monoclonal antibodies against cell‐surface antigens of human ovarian carcinoma

Abstract

Splenic lymphocytes of BALB/c mice immunized with human ovarian carcinoma cells were fused with the mouse myeloma cell line, NS-1 in the presence of polyethylene glycol, MW 1500. The hybrid cultures were screened by a viable cell-binding radioimmunoassay (RIA) for the production of relevant antibodies. Hybrids that produced antibodies that bound to the surface of the immunizing cell line and other ovarian carcinoma cell lines, but not to human fibroblast cell lines or erythrocytes and leucocytes isolated from peripheral blood, were cloned twice by the limiting dilution method. Two such clones designated 8C3, of the IgG2a isotype, and 10D6, of the IgG1 isotype, were checked for specificity by a solid-phase membrane RIA. The monoclonal antibodies (MoAbs) recognized an antigenic determinant present on different human adenocarcinomas such as ovary, breast, endometrium, colon, and stomach. The normal counterpart tissues of these histiotypes showed negligible binding to the MoAbs. The relative specificity of these MoAbs encourage further studies towards their characterization and evaluation as possible diagnostic and therapeutic agents in human cancer.