IRF1 suppresses the replication of HSV-1.

<p>(A) HeLa cells were transfected with IRF1, sh-IRF1 and control vectors, respectively. Total RNA was extracted and analyzed for IRF1 mRNA by quantitative real-time PCR. The cell lysate was extracted and analyzed for IRF1 expression by Western blot. (B) HeLa cells were transfected as indicated in (A), MTT assay of cell viability was conducted at 24 h, 48 h and 72 h post-transfection. To up-regulate IRF1, two doses of vectors were used for transfection, 0.5 µg/well and 0.3 µg/well. Another group was transfected with sh-IRF1 and its control vector in the same way. (C–F) HeLa cells were transfected as indicated in (A), 24 h post-transfection, cells were infected with HSV-1 at 0.01 PFU/cell. At 48 h post-infection, cells were stained with neutral red. The mean radius of the cytopathic area was measured. The scale bar represents 100 µm (C). Total viral yields (D) and Yield of progeny virions from the culture supernatant (E) were determined by standard plaque assays. Level of glycoprotein expression was determined by immunofluorescence assay (F). All data represent the mean value ± SD of at least three independent experiments. *: p<0.05; **: p<0.01; ***: p<0.001; <i>ns</i>: No significant differences by Student's t test.