Figure 6. Critical role of PKR in formation of avSG and IFN-â gene activation.

(A–C) MEFs derived from WT and PKR KO mice were mock-treated or infected with IAVÄNS1 for 12 h. The cells were stained with anti-RIG-I, anti-IAV NP and anti-TIAR antibodies and DAPI (A). The percentage of cells containing foci of RIG-I (B) or TIAR (C) was determined. (D–F) PKR WT and PKR KO MEFs were mock-treated or infected with IAVÄNS1. The IFN-â mRNA level at 9 h post-infection was determined by qPCR (D). The IFN-â protein levels in culture medium at 15 h post-infection were quantified by ELISA (E). Cell extracts were subjected to Native-PAGE and IRF-3 dimer was detected by immunoblotting using anti-IRF-3 antibody. IAV NP and actin were detected by SDS-PAGE followed by blotting using anti-NP and anti-actin antibodies (F). Data shown in B-E are represented as the mean standard ± error of the mean (SEM).