Highlights • The immunodominant region of the porcine deltacoronavirus S protein, is the C-terminal domain of its S1 subunit. • Three truncations of the PDCoV S protein were generated, the C and N-terminal domains of the S1 subunit, and S2 subunit. • Three S protein truncations are capable of inducing PDCoV-neutralizing antibody responses in vivo . • The C-terminal domains of the S1 subunit-specific antisera showed the most potent PDCoV-neutralizing effect. Porcine deltacoronavirus (PDCoV), is an emerging enteropathogenic coronavirus in pigs, that poses a novel threat to swine husbandry worldwide. Crucial to halting PDCoV transmission and infection is the development of effective therapies and vaccines. The spike (S) protein of coronavirus is the major target of host neutralizing antibodies, however the immunodominant neutralizing region in the S protein of PDCoV has not been defined. Here, three truncations of the PDCoV S protein were generated, the N-terminal domain of the S1 subunit (NTD, amino acids (aa) 50–286), the C-terminal domain of the S1 subunit (CTD, aa 278–616), and S2 subunit (aa 601–1087). The proteins were expressed using an E. coli expression system. Polyclonal antisera against the three recombinant proteins were produced in rabbits and mice. All three antisera were able to inhibit PDCoV infection in vitro , as determined by virus neutralization assay, fluorescent focus neutralization assay, and plaque-reduction neutralization. The CTD-specific antisera had the most potent PDCoV-neutralizing effect, indicating that the CTD region may contain the major neutralizing epitope(s) in the PDCoV S protein. Based on these findings, CTD may be a promising target for development of an effective vaccine against PDCoV infection in pigs.
【저자키워드】 neutralizing antibody, spike glycoprotein, porcine deltacoronavirus (PDCoV), Epitope region, 【초록키워드】 Vaccine, coronavirus, Vaccines, S protein, Neutralizing antibodies, neutralization, Antibody Response, Infection, Transmission, in vitro, Protein, Neutralization assay, mice, Virus neutralization, Neutralizing, NTD, in vivo, expression, S2 subunit, Antisera, N-terminal domain, Amino acid, C-terminal domain, S1 subunit, Recombinant protein, E. coli, effective therapy, fluorescent, immunodominant, Host, Porcine deltacoronavirus, effective, defined, produced, the S1 subunit, inhibit, the S protein, were expressed, CTD, 【제목키워드】 Region, Neutralizing, identification, immunodominant, Porcine deltacoronavirus,