Reversible Silencing of Cytomegalovirus Genomes by Type I Interferon Governs Virus Latency
Figure 5
IFNβ suppresses MCMV IE gene expression at the transcriptional level by inducing ND10 genes.
LSECs were treated with medium ± IFNβ (500 U/mL) and 24 h later infected with MCMV WT. Virus absorption was restricted to 5 minutes to improve time resolution. Nascent RNA samples were collected at 1 hpi and used for deep-sequencing. (A) Histograms show normalized reads of viral transcripts in IFNβ-treated and untreated LSECs from two replicates. The fraction of the viral transcriptome corresponding to ie1, ie2 or ie3 transcripts is indicated (B) Counts of normalized Daxx, Sp100 and PML transcripts in IFNβ-treated and non-treated LSECs. Histograms show normalized reads from two replicates (C) LSECs were treated with 10, 100 or 500 U/mL IFNβ or left untreated for 24 h and then stained for Daxx. Representative fluorescent pictures are shown. (D) LSECs were transfected with plasmids expressing shRNA against Daxx, Sp100 or PML, treated with IFNβ or left untreated and infected 24 h later with 0.01 MOI of MCMVr. Control cells were transfected with scrambled shRNA in the presence or absence of IFNβ and infected as above. Viral plaques were counted 4 dpi, normalized to represent IFNβ-untreated samples as 100 and average normalized PFU from three independent experiments ± SD are shown. See also Figure S3 and Table S1, S2 and S3.