翌圣生物 Yeasen｜生命科学试剂与诊断原料一站式平台

Abstract

The persistent threat of porcine epidemic diarrhea virus (PEDV) to the global swine industry is compounded by high neonatal piglet mortality and the absence of effective antiviral therapies. Host-directed strategies that reinforce immunity offer a promising avenue to counter viral immune evasion. Through screening of an FDA-approved compound library, we identify the small-molecule cyclocytidine hydrochloride (Cyclo-C) as a potent inhibitor of PEDV replication that acts by stabilizing the peroxisomal biogenesis factor PEX13, a previously unrecognized host restriction factor. The antiviral activity of Cyclo-C is strictly PEX13-dependent, as it is completely abrogated in PEX13 knockout cells. Mechanistically, Cyclo-C disrupts the interaction between PEX13 and the viral nonstructural protein 8 (NSP8), thereby preventing NSP8-mediated PEX13 degradation and the subsequent induction of PI3K/AKT/mTOR-driven pexophagy. Preservation of peroxisomal integrity stabilizes the peroxisome-localized pool of MAVS, leading to a robust enhancement of type III interferon (IFN-III) responses that suppress viral replication. Critically, this mechanism translates in vivo, where Cyclo-C treatment of PEDV-challenged piglets significantly reduces mortality, lowers viral loads, and protects intestinal villus architecture. Our findings establish Cyclo-C as a first-in-class host-directed therapeutic candidate and validate the concept that pharmacological preservation of peroxisome-mediated innate immunity represents an effective antiviral strategy against enteric coronaviruses.