Serologically defined, unique surface antigen on a mouse mammary adenocarcinoma

Syngeneic A.SW mice were immunized with sublethal viable cells of a spontaneous mammary adenocarcinoma S3W. The serum was tested by complement-dependent cytotoxicity against in vitro-cultured S3W cells and a spectrum of controls. S3W cells were found to react with at least four different kinds of antibodies in the serum. One antigen was present on several leukemia cell lines. A second cross-reactive antigen was detected on polyoma virus-induced tumors. A third was demonstrated on other mammary carcinoma lines and in a sarcoma of C3H origin. Following the removal of all three antibodies by absorption with the appropriate cross-reactive target cells, a fourth antibody remained that gave a strong cytotoxic reaction with S3W but with no other target line tested.