Fig. 4.
Type I IFN signaling is inhibited in cells infected with RRVPERS. (A) These studies were performed with Vero cells, which do not produce IFN but are able to respond to IFN. Vero cells were transfected with the pISRE (9-27) Lucter plasmid and then infected with RRV-T48 or RRVPERS (5 MOI). IFN-β (100 IU/ml) was added 12 h later, and luciferase expression was measured following incubation for 6 h. Luciferase activity was normalized to β-galactosidase reporter expression. Significant differences in expression (P < 0.05) are marked with an asterisk. (B and C) Western blot analysis of STAT-1 and STAT-2 expression and phosphorylation in HEp2 cells infected with RRV-T48 or RRVPERS (5 MOI) for 12 h, followed by IFN-β (100 IU/ml) treatment for 30 min or no treatment. The cell lysates were examined by Western blotting with antibodies to STAT-1, pY-STAT-1, STAT-2, or pY-STAT-2. The control included the detection of host cell protein expression by anti-α-actin antibody.