Characterization and cross-reactivity of human and mouse oncofetal antigens. Use of a new solid phase assay for detection of cell surface antigens.

Oncofetal (OF) antigens have been isolated from mouse F9 teratocarcinoma cells, mouse testicular cells, and human molar tissue by detergent extraction followed by dialysis. The soluble antigens have been used in solid phase radioimmunoassay (SPRIA) and enzyme-linked immunosorbent (ELISA) assay. Specific antibodies have been raised to these antigens in mice. By using these antisera, extensive cross-reactivity was found between mouse and human OF antigens. A human trophoblastic tumor cell line BEWO absorbed out mouse anti-F9 reactivity. Patients with tumors of germinal origin were found to have antibodies which cross-react with mouse and human OF antigens. This new assay is a rapid and sensitive method for the screening of monoclonal antibodies against these antigens as well as for detecting antibodies to tumors bearing these antigens in patients.