Development of a Cellular Membrane Nanovesicle-Based Vaccine Against Porcine Epidemic Diarrhea Virus.

Abstract

() has emerged as a major pathogen responsible for porcine diarrheal diseases, causing outbreaks of severe diarrhea and high mortality in neonatal piglets, thereby inflicting severe economic losses on the global swine industry. Current commercialvaccines, comprising conventional inactivated and live attenuated formulations, have exhibited progressively diminished efficacy in the face of emergingvariants. The development of high-efficiency vaccine platforms is therefore critical forcontrol. This study engineered a cellular membrane nanovesicle (CMN)-based vaccine, which differs from existing inactivated or subunit vaccines by presenting the PEDV spike (S) protein on the cell membranes to mimic the bilayer phospholipid structure of the viral envelope. The full-length S protein (FS, aa 19-1309) or a truncated S protein fragment (TS, aa 19-726) was expressed in Expi293F cells, followed by extraction of cell membranes to assemble antigen-displaying CMN vaccines. Compared with commercial live attenuated vaccine, administration of the CMN vaccine elicited high-titer neutralizing antibodies and elevated IFN-γ-producing CD8T cells in murine studies. Safety assessments revealed no adverse effects on body weight, hepatic/renal function indices, or histopathological parameters in vaccinated mice. Furthermore, immunization of piglets elicited notable humoral and CD8T cell immune responses. Collectively, the strategy of CMN-based vaccine described herein delivers a potentialvaccine platform, thereby offering a novel avenue for next-generation veterinary vaccine development.