Figure 3.

BFRF1 restrains the activation of IRF3 promoter, but not IRF7 or NF-κB promoter. Vector, BFRF1-Flag (100 or 500 ng) or BGLF4-HA (500 ng) expression plasmid was co-transfected with pRL-TK control plasmid and IRF3-Luc (A), IRF7-Luc (B), or NF-κB-Luc (C, D) reporter plasmid into HEK293T cells. At 24 h post-transfection, cells were infected with 100 HAU/ml SeV for 16 h. Cell lysates were then collected, and luciferase activity was measured by DLR. The expression of BFRF1 or BGLF4 protein was also detected by WB using anti-Flag or anti-HA mAb, and β-actin was used to verify equal loading of protein in each lane. Statistical analysis was performed using student’s t test. ns, not significant; **P < 0.01; ***P < 0.001; ****P < 0.0001.