Expression and immunogenicity of non-structural protein ۸ of porcine epidemic diarrhea virus

The non-structural protein (nsp) ۸ 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, nsp۸ prokaryotic expression vectors were constructed based on parental vectors pMAL-c۲x-maltose binding protein (MBP) and pET-۲۸a (+). 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-nsp۸ and nsp۸. The nsp۸ 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 nsp۸ immunized mice were up to ۱:۷,۷۵۰,۰۰۰ when measured by indirect enzyme-linked immunosorbent assay; meanwhile, the mice immunized with MBP-nsp۸ gave an antibody titer reaching ۱:۱,۰۰۰,۰۰۰. In all, the expression and purification system of PEDV nsp۸ and MBP-nsp۸ were successfully established in this work and a strong immune response was elicited in mice by both purified nsp۸ and MBP-nsp۸, providing a basis for the study of the structure and function of PEDV nsp۸.

کلیدواژه ها:

Escherichia coli ، Immunogenicity ، Non-structural protein ۸ ، Porcine epidemic diarrhea virus