Interferon production in the murine mixed lymphocyte culture. I. Interferon production caused by differences in the H‐2 K and H‐2 D region but not by differences in the I region or the M locus

Little has been made previously of the observation that interferon is generated in the murine mixed lymphocyte reaction (MLR). We have found high levels of interferon in the supernatants of MLR between spleen cells of mice of different H-2 type after one to two days of culture. Interferon production was also seen in strain combinations that differed only in the K or D region of the H-2 complex. There was no production of interferon in strain combinations differing in the M locus or in the I region of the H-2 complex. The latter combinations are known not to induce cytotoxic effector cells. Thus, there seems to be a dichotomy in allogeneic determinants between those of the I region and of the M locus inducing primarily lymphoproliferation, and those of H-2K and H-2D inducing cytotoxic activity and interferon production.