Figure 11

IRF1 enhances the innate immune response and inhibits PPRV replication. EECs were transfected with increasing amounts of si-IRF1-AS-1 (0, 25, 50 nmol) (A, B) or pCDNA3.1-IRF1-AS plasmids (C, D) for 24 h, and then the cells were infected by PPRV. The mRNA expression levels (A, C) and the protein level (B, D) of IRF1 were measured by qRT-PCR and Western blot assay, respectively. EECs were transfected with si-NC or si-IRF1-1 and si-IRF1-2 for 24 h and then infected with PPRV (E–H). The RNA expression levels of IRF1 (E), IFN-β, ISG15 as well as Mix1 (H) were measured by qRT-PCR, the protein level of IRF1, IRF3 and phosphorylation of IRF3 were measured by Western blot assay and the virus titres were measured by TCID₅₀ assay (F). I–K EECs were co-transfected with siRNA NC or si-IRF1 and pcDNA3.1 empty vector as control group and 3.1-IRF1-AS and si-IRF1 as the rescue group for 24 h, and then infected with PPRV. I The protein level of IRF1, IRF3 and phosphorylation of IRF3 were measured by Western blot assay. J The RNA expression levels of IRF1, IFN-β, ISG15 as well as Mix1 were measured by qRT-PCR. K The virus titres in the supernatants were measured by TCID₅₀ assay. L EECs were transfected with pcDNA3.1 empty vector or pcDNA3.1-flag-IRF1. After 24 h, transfected cells were infected by PPRV and then sample were prepared for co-IP experiment. M The subcellular localization of endogenous IRF1 and IRF3 was analysed by fluorescence microscopy in EECs infected with PPRV or not. The arrows highlight the nuclear colocalization of IRF3 and IRF1 by immunofluorescence staining. P values were calculated using Student’s t test. An asterisk indicates a comparison with the indicated control. *P < 0.01; **P < 0.001.