Primary in vitro cytotoxic T cell response to non-major histocompatibility complex alloantigens in normal mice.

We have shown for the first time that it is possible to consistently generate a primary in vitro cytotoxic T cell (Tc) response to non-major histocompatibility complex alloantigens using responder cells from a normal mouse strain. This was achieved by carrying out, in the generating phase, a limiting dilution procedure in which it appears that suppressor cells that inhibit Tc activation or expansion are too dilute to manifest their effect. Moreover, the response was observed in mouse serum-(MS) as well as fetal calf serum- (FCS) supplemented media, an important finding in the light of the anomalous nonspecific effects induced by FCS. The cytotoxic response produced in MS-supplemented media was shown to be highly specific in both the generating and effector phases, whereas the responses in FCS had a strong nonspecific component.