Fig. 5

IFN-α increases nuclear CDK8 expression and its association with IE62-expressing replication compartments. Untreated or IFN-α treated HELF monolayers were fixed in 4 % PFA at 12 or 24 h post VZV inoculation. The cell monolayers were double stained with anti-CDK8 (green) and anti-IE62 (red) antibodies for confocal microscopy analysis. Representative double immunofluorescence stained single cells from untreated (a) or IFN-α treated (b) illustrated CDK8 expression in IE62-expressing replication compartments in small, large or large globular pattern. Arrows shown in merged photographs indicate colocalization of IE62 and CDK8. c Expression of Cdk8 mRNA in untreated or IFN-α treated HELFs at 12 and 24 h after incubation with VZV-infected or mock-infected cells was measured by qRT-PCR. The level of expression was normalized to the expression of human β-actin and expressed as relative expression to human β-actin. Each bar represents the mean ± SEM of triplicate measurements from one experiment (unpaired Student’s t test). d CDK8 integrated intensity from each cell was measured by MetaMorph software. The averages of CDK8 integrated intensity in untreated (white bars) or IFN-α treated cells (black bars) without VZV inoculation or with VZV infection are shown in (d). CDK8 integrated intensity expressed in the nucleus of uninfected HELF cells was measured based on DAPI stain. The averages of CDK8 integrated intensity for IE62⁺ cells in various morphological forms in untreated or IFN-α treated cells are shown. Each bar represents the mean ± SEM of CDK8 integrated intensity from 20–40 cells (untreated group) or 20–55 cells (IFN-α treated group) analyzed. Differences between each group were tested by unpaired Student’s t test (**p < 0.01; ***p < 0.001; not significant (n.s.), p > 0.05). Scale bar 5 μm