ABSTRACT: The overall goal of the study was to use in vivo data combined with functional genomics to define gene expression signatures representative of a spectrum of HSV CNS infections. Innate immune deficiencies result in a spectrum of severe clinical outcomes following infection. In particular, there is a strong association between loss of the signal transducer and activator of transcription (Stat) pathway, breach of the blood-brain barrier (BBB), and virus-induced neuropathology. The gene signatures that characterize resistance, disease, and mortality in the virus-infected nervous system have not been defined. Herpes simplex virus type 1 (HSV-1) is commonly associated with encephalitis in humans, and humans and mice lacking Stat1 display increased susceptibility to HSV central nervous system (CNS) infections. In this study, two HSV-1 strains were used, KOS (wild type [WT]), and Δvhs, an avirulent recombinant lacking the virion host shutoff (vhs) function. In addition, two mouse strains were used: strain 129 (control) and a Stat1-deficient (Stat1(-/-)) strain. Using combinations of these virus and mouse strains, we established a model of infection resulting in three different outcomes: viral clearance without neurological disease (Δvhs infection of control mice), neurological disease followed by viral clearance (Δvhs infection of Stat1(-/-) mice and WT infection of control mice), or neurological disease followed by death (WT infection of Stat1(-/-) mice). Through the use of functional genomics on the infected brain stem and liver, we determined gene signatures that were representative of the three infection outcomes. Gender matched, 6- to 8- week old immunocompetent, control 129S6 and 129S6 Stat1 knockout mice were infected corneally with 2x10^6 PFU of either wild type HSV-1, a vhs-null HSV virus, or mock-infected. Brain stems and liver of individual mice were isolated at days 1, 3, 5 and 7 post-inoculation for microarray analysis. For microarray analysis, samples were collected from n=2 animals (1 male, 1 female) per mouse strain and virus strain for each time point. Equal masses of tissue were pooled from two mock-infected mice per time point and run on microarray.
