The role of ZBP1 in controlling HSV-1 pathogenesis

Herpes simplex virus type 1 (HSV-1) is a highly prevalent human pathogen with worldwide prevalence levels of about 67%. The outcome of infection with HSV-1 can be asymptomatic, mild, or life-threatening. Our previous work has shown that HSV-1 activates Z-form nucleic acid Binding Protein 1 (ZBP1)-driven cell death, mediated by the receptor-interacting protein kinase (RIPK) 3. The mechanisms underlying the generation of ZBP1 ligands and the regulation of the ZBP1-signaling pathway during HSV-1 infections are unknown. Our preliminary studies have now demonstrated that HSV-1 generates both Z-DNA and Z-RNA (the left-handed dsDNA and dsRNA duplexes, respectively), of which Z-RNAs likely serve as essential ZBP1-activating ligands. We have also made the unanticipated discovery that ZBP1 requires the kinase RIPK1 to recruit and activate RIPK3 for the execution of downstream necroptosis in HSV-1-infected human cells. Importantly, we find that ZBP1-driven necroptosis is essential for limiting HSV-1 spread in a mouse model of transdermal infection. These findings allow us to put forward the hypothesis that ZBP1 senses Z-RNA species generated in HSV-1-infected cells, following which it triggers RIPK1/3-dependent cell death to restrict viral spread. This proposal will test these hypotheses by (1) identifying the Z-RNA ligands for ZBP1 are, and determining how these are formed during HSV-1 infections; (2) understanding how RIPK1 regulates ZBP1-driven RIPK3 activation; and (3) determining the role of ZBP1- activated cell death signaling (primarily necroptosis, but also apoptosis) in anti-HSV-1 host defense and pathogenesis in vivo. Together, these studies will provide pioneering insight into the mechanism, role, and function of ZBP1-initiated programmed cell death during HSV-1 infections. Project Number: 1R01AI189875-01A1 | Fiscal Year: 2026 | NIH Institute/Center: National Institute of Allergy and Infectious Diseases (NIAID) | Principal Investigator: Hongyan Guo | Institution: LOUISIANA STATE UNIV HSC SHREVEPORT, SHREVEPORT, LA | Award Amount: $660,723 | Activity Code: R01 | Study Section: Molecular and Cellular Biology of Virus Infection Study Section[MCV] View on NIH RePORTER: https://reporter.nih.gov/project-details/1R01AI18987501A1