Abstract
Abstract: :
Purpose: Adenovirus infection of the cornea manifests as punctate epithelial keratitis, geographic epithelial erosions, and delayed-onset subepithelial corneal infiltrates. We have previously shown that (1)adenovirus type 19 (Ad19) infection of human corneal fibroblasts (HCF) induces expression of the neutrophil chemokine interleukin-8 (IL-8); (2) Ad19 infection of HCF induces tyrosine phosphorylation of the intracellular signaling protein c-src; and (3) phosphorylation of c-src is necessary for the expression of IL-8 by Ad19-infected HCF. These data suggest that Ad19 induces IL-8 expression in HCF by a signaling cascade involving c-src. In the experiments described herein, we sought to determine whether adenovirus infection of HCF might induce other host responses dependent on c-src associated signaling pathways. Methods: HCF were derived from donor corneas and infected for one hour with Ad19, or mock-infected with virus-free media. Parallel experiments were performed with the c-src-specific signaling inhibitor, PP2, at a concentration confirmed by src kinase assay sufficient to inhibit c-src activity. RNA isolated from mock- and Ad19-infected HCF was analyzed by a microarray-based gene profile (Clontech human 1.2K glass array with 1186 genes). Proinflamatory gene transcription was confirmed by RT-PCR. Results: Infection of HCF with Ad19 induced expression of several genes associated with inflammation, including IL-8, MCP-1, and ICAM-1, although induction of the latter 2 genes was less prominent than that seen for IL-8. Interestingly, all the genes found to be up-regulated by Ad19-infection were down-regulated in the presence of PP2. Independent analysis by duplex RT-PCR confirmed the suppressive effect of PP2 on the induction of both MCP-1 and ICAM-1. Conclusion: Inhibition of proinflammatory gene expression in Ad19-infected HCF by PP2 suggests a central role for c-src in the earliest corneal stromal responses to infection. Elucidation of the role of signaling proteins in gene expression in Ad19-infected corneal cells may allow the development of novel therapeutic agents for the corneal inflammation associated with infection.
Keywords: 374 cornea: stroma and keratocytes • 417 gene/expression • 437 inflammation