Nanoparticle vaccines based on the receptor binding domain of porcine deltacoronavirus elicit robust protective immune responses in mice

Front Immunol. 2024 Mar 14:15:1328266. doi: 10.3389/fimmu.2024.1328266. eCollection 2024.

Abstract

Background: Porcine deltacoronavirus (PDCoV), a novel swine enteropathogenic coronavirus, challenges the global swine industry. Currently, there are no approaches preventing swine from PDCoV infection.

Methods: A new PDCoV strain named JS2211 was isolated. Next, the dimer receptor binding domain of PDCoV spike protein (RBD-dimer) was expressed using the prokaryotic expression system, and a novel nanoparticle containing RBD-dimer and ferritin (SC-Fe) was constructed using the SpyTag/SpyCatcher system. Finally, the immunoprotection of RBD-Fe nanoparticles was evaluated in mice.

Results: The novel PDCoV strain was located in the clade of the late Chinese isolate strains and close to the United States strains. The RBD-Fe nanoparticles were successfully established. Immune responses of the homologous prime-boost regime showed that RBD-Fe nanoparticles efficiently elicited specific humoral and cellular immune responses in mice. Notably, high level PDCoV RBD-specific IgG and neutralizing antibody (NA) could be detected, and the histopathological results showed that PDCoV infection was dramatically reduced in mice immunized with RBD-Fe nanoparticles.

Conclusion: This study effectively developed a candidate nanoparticle with receptor binding domain of PDCoV spike protein that offers protection against PDCoV infection in mice.

Keywords: RBD; SpyTag/SpyCatcher; ferritin; nanoparticle vaccine; porcine deltacoronavirus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Deltacoronavirus
  • Immunity
  • Mice
  • Nanovaccines*
  • SARS-CoV-2
  • Spike Glycoprotein, Coronavirus*
  • Swine

Substances

  • Nanovaccines
  • Spike Glycoprotein, Coronavirus

Supplementary concepts

  • Porcine coronavirus HKU15

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This study was supported by the foundation from Shanghai Agriculture Applied Technology Development Program, China (NO.X2023-02-08-00-12-F04612), the Key Laboratory of Veterinary Biotechnology (No. BB1500010), Shanghai, P.R. China, and the Agricultural-Science and Technology InnovationProgram (CAAS-ASTIP-2021-SHVRI).