Generation of cytotoxic antibodies to the B16 murine melanoma using a formalinized vaccine.

The goal of our experiments was to determine the extent to which the humoral response to a melanoma vaccine elicits the production of cytotoxic antibodies in tumor-challenged mice. Mice were immunized with a vaccine produced from formalinized extracellular antigens (FECA) derived from B16 F10 melanomas. The production of antibodies that recognized the vaccine preparation was determined by ELISA, as was their cross-reactivity with the B700 melanoma antigen. The antibodies were shown to be anti-proliferative by inhibition of tritiated thymidine incorporation into the DNA of cultured target cells and cytotoxic by assays for complement-mediated and antibody-dependent cellular cytotoxicity. Flow cytometric analyses indicated that approximately 60% of the target cells specifically bound antibody from the immune sera. These results confirm that B700 is a significant antigenic component of the FECA vaccine, and provide encouragement for this approach to developing useful melanoma vaccines.