Expression and immunogenicity of nsp10 protein of porcine epidemic diarrhea virus

Porcine epidemic diarrhea virus (PEDV), a swine enteropathogenic coronavirus, causes lethal watery diarrhea to the piglets, which poses significant economic losses and public health concerns. The nsp10 protein of PEDV is essential regulatory subunits that are critical for virus replication. Since PEDV nsp10 is a crucial regulator of viral RNA synthesis, it is promising that nsp10 might become anti-virus drugs target or candidate for rapid diagnosis of PEDV infection. In this study, the PEDV nsp10 was inserted into pMAL-c2x-MBP / pET-28a vector, efficiently and stably expressed in E.coli system. Then the purified nsp10 protein was found to mediate potent antibody responses in immunized mice. The antibodies of immunized mice and PEDV infection swine strongly recognized purified nsp10 protein from cell lysates. Furthermore, cytokines test revealed that the expression of IL-2, IL-4, IL-10, TNF-α, IFN-γ were significantly higher than those in control group, indicated that purified nsp10 protein induce the cellular immune response mechanism in mice. Using modified seroneutralization test, we also demonstrated that sera from nsp10-immunized mice inhibited PEDV replication to some extent. These findings suggest that nsp10 has a high immunogenicity. This study may have implications for future development of PEDV detection or anti-virus drugs for swine.