FIG. 5.

HSV-1 down-modulates proinflammatory gene expression at the level of mRNA stability. (A) RAW264.7 cells were infected with HSV-1 or in1814, and RNA was harvested at the indicated time point p.i. IL-6 and β-actin mRNAs were amplified by RT-PCR and visualized by ethidium bromide staining of the agarose gel. Essentially similar results were seen in two independent experiments. (B) NIH 3T3 cells were transiently transfected with a RANTES promoter gene construct and treated as indicated. After 8 and 24 h, cells were lysed and luciferase activity was measured. The results are shown as means ± SEM. RLU, relative luciferase units. Essentially similar results were seen in two independent experiments. (C) J774A.1 cells were treated for 2 h with a mock virus preparation or infected with wt or mutant HSV-1 (MOI of 1) as indicated. Nuclear proteins were harvested, and NF-κB DNA-binding activity was measured by electrophoretic mobility shift assay. Essentially similar results were seen in two independent experiments. (D) RAW264.7 cells were infected with HSV-1 or in1814 for 5 h, at which point ActD was added. RNA was extracted from cells at various intervals after the addition of ActD, and IL-6 and β-actin mRNAs were amplified by RT-PCR and visualized by ethidium bromide staining of the agarose gel. Essentially similar results were seen in two independent experiments.