Viral microRNA inhibition enhances antiviral immunity by modulating corneal inflammatory and resolution pathways in HSV-1 induced keratitis.

Abstract

Herpes simplex virus type 1 (HSV-1) is a leading cause of infectious corneal blindness worldwide. Viral persistence and disease severity are strongly influenced by the virus's ability to modulate host immune responses; however, the mechanisms by which HSV-1 alters corneal immunity are incompletely understood. In particular, the role of virus-encoded microRNAs (v-miRs) in shaping corneal immune responses during herpes simplex infection remains unclear. We previosuly showed that inhibition of selected HSV-1 v-miRs reduced viral replication and disease severity in a mouse model of ocular infection. Building on these findings, the present study investigated how v-miR inhibition affects corneal immune responses. Using corneal tissue RNA from HSV-1-infected mice, we performed an immune profiling PCR array by analyzing the expression of 88 genes associated with immune cell markers and polarization states. Topical inhibition of miR-H1-5p, miR-H3-3p, and miR-H6-3p resulted in distinct patterns of immune gene expression compared with the control treatment. Inhibition of these v-miRs altered 16, 31, and 57 immune-related genes, respectively, spanning both myeloid- and lymphoid-associated pathways. Notably, the anti-inflammatory genes Arg1 and Il10 were consistently upregulated across all v-miR inhibitor-treated groups. In parallel, increased expression of the pro-resolution enzymes 15-lox and Alox5 suggested enhanced engagement of resolution pathways. Mechanistic studies demonstrated that v-miRs directly target immune regulatory genes through binding sites within their untranslated regions. Together, these findings suggest that HSV-1 v-miRs contribute to corneal immunopathology by suppressing anti-inflammatory and pro-resolving immune pathways, and that targeted inhibition of v-miRs may promote immune resolution during HSV-1-induced keratitis.