Defining Ocular Monkey Pox Pathogenic Mechanisms

PROJECT SUMMARY: Mpox virus (MPXV), formerly Monkeypox virus is a zoonotic pathogen that spreads rapidly through human- human transmission via respiratory droplets and direct contact, causing painful rashes and systemic issues. It also causes moderate to severe ophthalmic manifestations, most commonly ocular surface complications such as keratitis, conjunctivitis, and blepharitis, with poorly understood pathogenic processes. The 2022 MPXV strain (Clade IIb) has caused approximately 100,000 infections and 207 deaths to date, indicating its evolution towards more rapid human-to-human transmission compared to previous strains (Clade I and Clade IIa). Our preliminary data show that the 2022 MPXV strain induces an inflammatory response and increases cell death in human corneal epithelial cells. Similarly, MPXV infection in mouse eyes causes periocular pock lesions, ptosis, and corneal opacity, indicating keratitis. Infected mouse corneas exhibit increased infiltration of CD45+ immune cells. Moreover, MPXV infection decreases levels of the antiviral STING protein that senses cytoplasmic DNA through cGAS and triggers type I interferon responses to restrict virus replication. Genomic analysis of the 2022 MPXV strain indicates the acquisition of new mutations across the viral genome. Two genes have been identified among the 21 Clade IIb viral gene variants that degrade antiviral STING proteins. Based on these data, we hypothesize that MPXV continuously evolves to better circumvent the host innate immune system and cause ocular Mpox. The overall goal of this study is to define both viral and host determinants of MPXV in causing ocular pathology and to identify potential therapeutic targets for antiviral therapy. This will be accomplished through three specific aims. Aim 1 is designed to determine the in vitro susceptibility of ocular cell types and host inflammatory responses to MPXV. In addition, using a library of kinase inhibitors and innate immune agonists, we will dissect cellular signaling and innate immune pathways during MPXV infection of ocular cells. In Aim 2, we will characterize the MPXV viral genes antagonizing antiviral STING pathway activation. Recombinant MPXV mutant viruses lacking the ability to evade cGAS-STING detection will be evaluated for their ability to replicate and modulate innate responses in ocular cells. In Aim 3, we will study the pathogenesis of ocular Mpox caused by MPXV clades in mouse models and test the efficacy of two novel antiviral compounds (kinase inhibitors). Collectively, this proposed study would yield novel insights into the pathogenesis of ocular Mpox and potentially lead to the identification of newer therapeutic targets.