Tumor-bound immunoglobulins. Hemagglutinins on ascites tumor cells grown in mice immunized with xenologous erythrocytes.

In this study we demonstrated that gamma G2A myeloma cells in syngeneic BALB/c mice and Ehrlich adenocarcinoma cells in outbred Swiss mice, when grown in animals previously immunized against RRBC, have RRBC antibodies bound on their surface. Ascites tumor cells obtained from animals not immunized against RRBC can bind RRBC antibodies from the medium. Tumor cells from RRBC-immunized mice and tumor cells with RRBC antibodies bound in vitro were both able to form 'rosettes' when tested with RRBC, thus demonstrating that the combining site of the antibody molecule was not involved in the binding. Some theoretical implications of the presence of nonspecific antitumor immunoglobulins on cancer cell membrane are discussed.