FIG. 4.

IFN-β regulates Sp100 and PML expression and the ICP0 promoter. (A) Western blot of endogenous Sp100A expression in BL41-LP and Daudi cells treated (+) or untreated (−) with 100 U/mL IFN-β for 24 h. Molecular weight markers are shown to the left side of the blot and Sp100 isoforms are indicated on the right side. α-Tubulin controls are shown in the panel below. (B) Western blot of endogenous PML expression in Daudi cells treated (+) or untreated (−) with 100 U/mL IFN-β for 24 h. Molecular weight markers are shown to the left side of the blot and PML isoforms indicated on the right side. α-Tubulin controls are shown in the panel below. (C) ICP0 promoter activity is inhibited by IFN-β. ICP0 promoter-driven luciferase plasmids were transfected into Daudi cells treated (+) and untreated (−) with IFN-β. A control sample was transfected with empty vector (pGL3). Relative luciferase activity for each of the transfections is indicated on the y-axis. Standard errors are indicated.