Figure 4.

c-rel ^−/− B cells display greater sensitivity to the antiproliferative activity of type I and type II IFNs. Resting splenic lymphocytes from normal (filled circles) and c-rel ^−/− (open circles) mice were stimulated for 72 h with optimal concentrations of anti-RP antibodies plus LPS in the absence or presence of 1, 10, 100, or 1,000 U/ml of IFN-α or IFN-γ. Cellular proliferation was measured at 24-h intervals over 72 h by [³H]thymidine incorporation. Proliferation of normal and c-rel^−/− B cells in the presence of a particular concentration of IFN at the 72-h time point is represented in this figure as a percentage of [³H]thymidine incorporated by normal or c-rel ^−/− cells, respectively, in the absence of IFN. All results represent the mean ± SD from five experiments.