Expression and immunogenicity of non-structural protein 8 of porcine epidemic diarrhea virus

Hong Chen; Jiawu Wan; Meihua Wei; Ping Liu; Lingbao Kong; Xiu Xin

doi:10.30466/vrf.2023.2009322.3977

Expression and immunogenicity of non-structural protein 8 of porcine epidemic diarrhea virus

Vet Res Forum. 2024;15(2):65-73. doi: 10.30466/vrf.2023.2009322.3977. Epub 2024 Feb 15.

Authors

Hong Chen^{1

2}, Jiawu Wan^{1

2}, Meihua Wei^{1

2}, Ping Liu^{1

2}, Lingbao Kong^{1

2}, Xiu Xin^{1

2}

Affiliations

¹ Institute of Pathogenic Microbiology, College of Biological Science and Engineering, Jiangxi Agricultural University, Nanchang, China.
² Nanchang Key Laboratory of Animal Virus and Genetic Engineering, College of Biological Science and Engineering, Jiangxi Agricultural University, Nanchang, China.

Abstract

The non-structural protein (nsp) 8 of the porcine epidemic diarrhea virus (PEDV) is highly stable across different PEDV strains and plays an important role in PEDV virulence. In current study, nsp8 prokaryotic expression vectors were constructed based on parental vectors pMAL-c2x-maltose binding protein (MBP) and pET-28a (+). Subsequently, the optimization of expression conditions in Escherichia coli, including induced temperature, time and isopropyl β-D-thiogalactopyranoside concentration were performed to obtain a stable expression of MBP-nsp8 and nsp8. The nsp8 fused with MBP increased the water solubility of the expressed products. Target proteins were further purified from E. coli culture and their immunogenicities were evaluated in vivo by mice. The antibody titers of serum from nsp8 immunized mice were up to 1:7,750,000 when measured by indirect enzyme-linked immunosorbent assay; meanwhile, the mice immunized with MBP-nsp8 gave an antibody titer reaching 1:1,000,000. In all, the expression and purification system of PEDV nsp8 and MBP-nsp8 were successfully established in this work and a strong immune response was elicited in mice by both purified nsp8 and MBP-nsp8, providing a basis for the study of the structure and function of PEDV nsp8.

Keywords: Escherichia coli; Immunogenicity; Non-structural protein 8; Porcine epidemic diarrhea virus.