猪流行性腹泻病毒截短S蛋白纳米颗粒的制备及其对小鼠免疫效果评价OA

Emergence of variant strains of Porcine Epidemic Diarrhea Virus(PEDV)compromises the protective efficacy of conventional vaccines,which urgently requires novel rapid and efficient vaccine development strategies.In this study,a ferritin nanoparticle-based antigen display platform was constructed to present S10,a key epitope derived from the S1 protein of variant PEDV.After codon optimization,the S10 gene fused with a C-terminal VL12.3 tag was cloned into the pET-32a vector,followed by prokaryotic expression in Escherichia coli and purification to obtain recombinant S10-VL12.3 protein.Meanwhile,Helicobacter pylori-derived ferritin(Fer)with an N-terminal HTT tag was expressed and purified.Relying on specific covalent interaction between HTT and VL12.3,the two purified proteins were assembled in vitro into PEDV S10-Fer conjugates.Transmission electron microscopy revealed that the assembled S10-Fer existed as uniform spherical nanoparticles with characteristic surface protrusions and an average diameter of 32.7 nm.Female BALB/c mice were immunized with prepared formulations,and serum samples were collected two weeks after the third immunization.Virus neutralization assay demonstrated that S10-Fer nanoparticles elicited markedly superior immune responses compared with soluble S10 protein;the neutralizing antibody titer in the S10-Fer group was extremely significantly higher than that of the S10 group(P＜0.01).In conclusion,the ferritin nanoparticle scaffold effectively improves antigen immunogenicity and triggers robust immune responses in mice,providing a promising strategy for rapid development of nanoparticle vaccines against variant PEDV and other pathogenic viruses.