FIG. 5.

IFN-γ induces interactions between CTCF sites and MHC-II gene promoters. A-431 epithelial (MHC-II-negative) cells were treated with IFN-γ (500 U/ml) for 72 h to induce CIITA and MHC-II expression. 3C assays were carried out as described in the legend to Fig. 4 and represent the average of three independent experiments with standard errors. The asterisks indicate significant differences (P < 0.05) between control and IFN-γ-treated samples as determined by Student t tests. The anchor CTCF site is indicated at the top of each graph.