Level of HSV-1 immediate early, early, and late viral transcripts in DCs isolated from STAT1-/- mice. Subconfluent monolayers of DC cells from STAT1-/- and parental Wt STAT1+/+ 129SVE mice were infected with 10 PFU/cell as in Fig. 1. Total RNA was isolated and TaqMan RT-PCR was performed using ICP0-, ICP4-, TK-, and gB-specific primers as described in Materials and Methods. ICP0, ICP4, TK, and gB mRNA levels were normalized in comparison to each transcript at 0 hr post infection. GAPDH was used as internal control. Each point represents the mean ± SEM (n = 16) from three separate experiments for gB and two experiments for ICP0, ICP4, and TK. Note that the mRNA levels are normalized to the levels present one hour after virus is first added to the cell monolayer (the adsorption period), a time is routinely taken as t = 0. However, significant levels of ICP0 and ICP4 mRNA are already present at this time (Ct of 20–21) which masks these mRNA levels at early times.