Murine autogeneic mixed lymphocyte culture. Role of culture conditions.

In an attempt to determine whether culture conditions significantly influence autoreactivity, we tested the effects of fetal calf, syngeneic, and autogeneic serum with and without 2-mercaptoethanol on the murine self-reactive mixed lymphocyte culture. We used both unfractionated and T-enriched lymph node cells as responders and unfractionated and B-enriched irradiated spleen cells as stimulators in a primary mixed lymphocyte culture (MLC). Using unfractionated cells as responders to various stimulator cell populations, we found excellent allogeneic reactions in all media tested but minimal or no self-reactivity in syngeneic of autogeneic serum. When using T-enriched lymph node cells as responders, allogeneic reactivity was excellent but self-reactivity was present only in the cultures supplemented with fetal calf serum and 2-mercaptoethanol. The possibility that the substances in fetal calf serum and/or 2-mercaptoethanol may be needed to enhance minimal, but biologically relevant, self-reactivity is discussed, as well as the possibility that the culture supplements may be inducing "nonspecific" self-reactivity.