Influence of tumor cells on NK cell system

IL-2 activation of mouse NK cells was compared when paraformaldehyde fixed tumor cells were present during the IL-2 activation phase. Addition of YAC or EL4 tumor cells significantly boosted the levels of cytotoxic activity generated. Significantly higher anti-YAC cytotoxic activity was however generated when fixed YAC cells instead of EL4 cells were present during the activation phase When fixed EL4 cells were present during the activation phase, relatively greater anti EL4 cytotoxic activity was generated. Addition of fixed syngeneic or allogeneic spleen cells instead of tumor cells, did not boost NK activation in response to IL-2. These results indicate that an exposure to tumor cells during IL-2 activation phase, may boost the activation of NK cells in a tumor specific manner.