A Stat1-dependent host response restricts the spread of HSV-1 strain KOS-GFP into the central nervous system. Strain 129 mice, rag2-/- mice, stat1-/- mice, or rag2-/- stat1-/- mice were inoculated with 2 × 105 pfu per eye of HSV-1 strain KOS-GFP. A. The mean ± sem of the logarithm of viral titers recovered from homogenates of mouse eyes, TG, and hindbrain is plotted as a function of the time p.i. at which tissues were harvested (n = 5 per time point). Asterisks denote significant differences between stat1+/+ versus stat1-/- tissues (p < 0.001, as determined by two-way ANOVA). Dashed lines indicate the lower limit of detection of each plaque assay. B. GFP expression in tissues of KOS-GFP-infected mice. Representative photographs are shown of eyes harvested on day 3 p.i. (4× magnification, 250 ms exposure), TG harvested on day 5 p.i. (2× magnification, 500 ms exposure), and the ventral side of brains harvested on day 7 p.i. (2× magnification, 1000 ms exposure).