Neu1 inhibition restrains BCoV replication and modulates ZBP1-dependent PANoptosis.

Abstract

As a member of the Betacoronavirus genus, bovine coronavirus (BCoV) is a major etiological agent in cattle, causing diarrhea, fever, and reduced milk production, thereby imposing a substantial economic burden on the livestock industry. However, the molecular mechanisms underlying BCoV pathogenesis remain incompletely defined. In this study, we report that BCoV infection of Madin-Darby bovine kidney (MDBK) cells activates ZBP1-PANoptosome-associated signaling and induces the host sialidase neuraminidase 1 (Neu1). Functional studies using CRISPR-Cas9-mediated knockdown revealed that Neu1 depletion attenuated ZBP1-PANoptosome activation and reduced viral replication in vitro. Co-immunoprecipitation and GST pull-down assays, together with molecular docking and molecular dynamics analyses, supported a physical association between Neu1 and ZBP1, suggesting a potentially stable interaction interface. In vivo, oral inoculation of BALB/c mice with BCoV resulted in increased Neu1 and ZBP1 signals with partial colocalization in brain and colonic tissues, accompanied by decreased serum sialic acid levels and elevated interleukin-1 beta (IL-1β), which was consistent with Neu1 activation and enhanced inflammatory responses. Histopathological examination further revealed progressive vascular congestion and epithelial injury, suggesting an association between Neu1-ZBP1 signaling and virus-induced tissue damage. Collectively, our findings suggest that Neu1 may contribute to ZBP1-associated PANoptosis during BCoV infection and link sialic acid metabolism to nucleic acid-sensing and inflammatory cell death responses. These results provide mechanistic insight into BCoV pathogenesis and suggest Neu1 as a potential target for future studies aimed at controlling coronavirus infections in cattle and possibly other species.