PPRV N and P proteins inhibited STAT1 nuclear translocation. (A and B) HeLa cells (5 × 104) were grown in the glass bottom dish. When the cells reached about 30% confluency, the cells were transfected with N protein expressing plasmids (2 μg), P protein expressing plasmids (2 μg) or vector plasmids (2 μg), followed by IFN-β (2000 U/mL) or IFN-γ (200 ng/mL) treatment for 30 min. The cells were fixed, permeabilized, and incubated with mouse anti-STAT1 antibody and rabbit anti-Flag antibody and appropriate secondary antibodies. The subcellular localization of STAT1 in N protein overexpressing cells (A) or P protein overexpressing cells (B) was observed (Red). Confocal images were obtained using laser confocal microscopy under a 60× objective. (C) Statistical analysis of STAT1 nuclear translocation in the N and P protein expressing cells. One hundred cells were counted in the randomly selected visual fields three times, and the STAT1 nuclear localization ratio was determined. The expression of N and P was further detected by Western blotting.