Figure 7

UL13 deficiency enhances the IRF3-responsive activity of the IFN-β promoter. A A549 cells were infected with 0.1 MOI JSY13 or its ΔUL13 mutants for 12 h. The cells were fixed and stained with UL42 and IRF3 antibodies. The nuclei were then stained with DAPI. B PK15 cells were transfected with IFN-β-Luc (200 ng) and pCMV-RL (2 ng), with or without pcDNA3-Flag-UL13 (100 ng) for 24 h; they were subsequently infected with JSY13 or PRVΔUL13 mutants (0.1 MOI). The cell lysates were collected 6 or 12 h post-infection and then analysed for luciferase activity. The fold activation of luciferase activity is calculated as the luciferase activity induced by the JSY13 and PRVΔUL13 mutants divided by that induced by the empty vector. C The dual-luciferase activity assay was performed as in (B) except that the PK15 cells were transfected with IFN-β-Luc (200 ng), pCMV-RL (2 ng), pcDNA4-HA-cGAS (50 ng), or pcDNA3-Flag-STING (20 ng), with or without pcDNA3-Flag-UL13 (100 ng).