EFFECT OF ALLOGENEIC-TUMOR CELLS, INTERLEUKIN-2 AND INTERLEUKIN-6, ONTHE GROWTH OF SUBCUTANEOUS SYNGENEIC TUMORS

In the present study we demonstrate the ability of allogeneic M3 tumor cells to induce an antitumor response against the syngeneic tumor, wh en injected locally together with syngeneic B16 melanoma cells. The re placement of the allogeneic tumor cells with either syngeneic or allog eneic splenocytes had no effect on the growth of the syngeneic tumor. Systemic administration of both interleukin-2 (IL-2) and IL-6 did not affect the antitumor response induced by allogeneic tumor cells. When mice, previously injected with B 16 and M3 cells, were rechallenged su bcutaneously with B 16 tumor cells at a different anatomical site, an inhibitory effect in some, but not all, experiments was observed. Syst emic injections of either IL-2 or IL-6 did not alter the antitumor eff ects of the allogeneic and syngeneic tumor-cell mixtures. The signific ance of our results in developing immunotherapy modalities based on ac tive immunization with allogeneic tumor cells and selected cytokines i s discussed.