Fig. 6.

PRDI-BF1β represses the CIITA type IV promoter. Transient co-transfections of Raji B cells were performed by electroporation using 10 μg of the wild-type CIITA pIV luciferase reporter plasmid and 10 μg of the full-length PRDI-BF1expression plasmid, the PRDI-BF1β expression plasmid, or the empty vector control. After a 6 h recovery period, half of the cultures were treated with 500 U/ml of recombinant human IFN-γ for 24 h before cultures were harvested. Ectopic expression of either PRDI-BF1 or PRFI-BF1β resulted in a 3-fold reduction of activity in both the treated and untreated samples. Luciferase activity was measured and normalized to Renilla luciferase activity. Bars show the S.E.M., n = 3. At least three independent experiments have been performed with similar results.