Characteristics of alloantigens and cellular mechanisms responsible for gamma-interferon production in primary murine MLC.

We have investigated in primary murine MLC alloantigen differences and characteristics of responding cells responsible for gamma-IFN production. Differences at K, D, or I-S-G regions stimulate gamma-IFN release, though higher levels of production have been observed with differences at I-S-G regions. On the other hand, when mice differing in their minor histocompatibility antigens, notably at the MIs locus, were tested, gamma-IFN production took place even between strain combinations not displaying lymphocyte proliferation. Lastly, using different cell depletion techniques, we demonstrate that T-lymphocytes are the cells producing gamma-IFN upon stimulation with alloantigens. These findings show that T lymphocytes can recognize alloantigens by releasing gamma-IFN even without displaying proliferation.