Recombinant adenovirus carrying a core neutralizing epitope of porcine epidemic diarrhea virus and heat-labile enterotoxin B of Escherichia coli as a mucosal vaccine

Arch Virol. 2020 Mar;165(3):609-618. doi: 10.1007/s00705-019-04492-7. Epub 2020 Jan 16.

Abstract

Porcine epidemic diarrhea virus (PEDV) targets the intestinal mucosa in pigs. To protect against PEDV invasion, a mucosal vaccine is utilized effectively. In this study, we generated a recombinant adenovirus vaccine encoding the heat-labile enterotoxin B (LTB) and the core neutralizing epitope (COE) of PEDV (rAd-LTB-COE). The fusion protein LTB-COE was successfully expressed by the recombinant adenovirus in HEK293 cells, and the immunogenicity of the vaccine candidate was assessed in BALB/c mice and piglets. Three intramuscular or oral vaccinations with rAd-LTB-COE at two-week intervals induced robust humoral and mucosal immune responses. Moreover, a cell-mediated immune response was promoted in immunized mice, and the neutralizing antibody inhibited both the vaccine strain and the emerging PEDV isolate. Immunization experiments in piglets revealed that rAd-LTB-COE was immunogenic and induced good immune responses in piglets. Further studies are required to evaluate the efficacy of rAd-LTB-COE against a highly virulent PEDV challenge.

MeSH terms

  • Adenoviridae / genetics
  • Adenoviridae / immunology
  • Animals
  • Cell Line
  • Coronavirus Infections / immunology
  • Coronavirus Infections / prevention & control*
  • Coronavirus Infections / veterinary*
  • Enterotoxins / genetics
  • Enterotoxins / immunology
  • Epitopes / genetics
  • Epitopes / immunology
  • Escherichia coli / immunology
  • Escherichia coli / pathogenicity
  • Female
  • HEK293 Cells
  • Humans
  • Mice
  • Mice, Inbred BALB C
  • Porcine epidemic diarrhea virus / genetics
  • Porcine epidemic diarrhea virus / immunology*
  • Recombinant Fusion Proteins / immunology
  • Swine
  • Swine Diseases / immunology
  • Swine Diseases / prevention & control*
  • Swine Diseases / virology
  • Viral Vaccines / administration & dosage
  • Viral Vaccines / immunology*
  • Viral Vaccines / therapeutic use

Substances

  • Enterotoxins
  • Epitopes
  • Recombinant Fusion Proteins
  • Viral Vaccines