Role of Interferon Regulatory Factor 7 in Corneal Endothelial Cells After HSV-1 Infection

Abstract

Viral infections of the cornea including herpes simplex virus 1 (HSV-1) cause visual morbidity, and the corneal endothelial cell damage leads to significant visual impairment. Interferon regulatory factor 7 (IRF7) has been identified as a significant regulator in corneal endothelial cells after an HSV-1 infection. To examine the role played by IRF7, the DNA binding domain (DBD) of IRF7 of human corneal endothelial cells (HCEn) was disrupted. An RNAi inhibition of IRF7 and IRF7 DBD disruption (IRF7 ∆DBD) led to impairment of IFN-β production. Impaired IFN-β production by IRF7 ∆DBD was regained by IRF7 DNA transfection. Transcriptional network analysis indicated that IRF7 played a role in antigen presentation function of corneal endothelial cells. When the antigen presentation activity of HCEn cells were examined for priming of memory CD8 T cells, IRF7 disruption abolished the anti-viral CTL response, which was dependent on major histocompatibility complex (MHC) class I.To further examine roles of IRF7 in CTL induction as acquired immunity, contribution of IRF7 to MHC class I-mediated antigen presentation was assessed. Analysis of IRF7 ∆DBD cells indicated that IRF7 has previously unrecognized role in MHC class I induction, and viral infection induced-MHC class I induction was abolished by IRF7 disruption.Collectively, the IRF7 in corneal endothelial cells not only contributes to type I IFN response, but also mediates viral infection-induced MHC class I upregulation and priming of CD8 arm of acquired immunity.