Microarray Analysis of Intraocular Response to Herpes Simplex Type 1

Abstract

Abstract: : Purpose We sought to identify mediators of intraocular immune response and immune privilege by comparing genes induced by anterior chamber herpes simplex (HSV-1) injection to those induced by a saline (PBS) control injection. Methods 2.5 x 10⁴ pfu of KOS strain HSV-1 or PBS were injected in the anterior chamber of one eye of C57Bl/6 mice. Mice were sacrificed and eyes taken at 2 hours and 30 hours post injection. Total eye RNA was converted to biotinylated cRNA which was hybridized to an Affymetrix Mu74Av2 oligonucleotide microarray. All experiments were performed at least twice. Hybridization signals were analyzed by dChip. Results Compared with uninjected control mice, 22 genes were induced by five-fold or greater 2 hours after PBS injection. MCP-1 and IL-6 were the most highly induced genes. 11 of these genes were also induced 5-fold or more 2 hours after HSV-1 injection. No HSV-1-specific early genes were induced. 30 hours after PBS injection, 10 genes showed 5-fold or greater elevation; of these only MCP-1 remained elevated from the early set. In contrast to the early response to HSV-1, many late genes (total 47) are 5-fold or greater elevated 30 hours following HSV-1 injection, including several known interferon-regulated genes. Comparison of genes induced in conditions allowing or eliminating anterior chamber associated immune deviation (i.e. light and dark-reared mice) showed no significant differences in gene induction profiles. Conclusions The early inflammatory response to intraocular injection is pathogen-independent. Intraocular injection results in long-lasting gene expression changes, some of which are pathogen-dependent. There do not appear to be genes whose induction is specific to immune deviation.

Keywords: gene microarray • immune tolerance/privilege • herpes simplex virus