Identification of a tumor-associated antigen of the guinea pig L2C leukemia by using syngeneic antisera.

Inbred strain 2 guinea pigs immunized with L2C leukemia cells produced antibodies to L2C cells detected by 125I-protein A assay. L2C-associated tumor antigens were reacted with syngeneic antisera and analyzed by immunoprecipitation and SDS-polyacrylamide gel electrophoresis. These sera recognized idiotypic determinants on surface IgM molecules of L2C cells but did not recognize any determinants on normal strain 2 spleen cells. Thus, determinants on IgM molecular act as tumor-associated antigens in the L2C system and can be detected by syngeneic sera.