›› 2020, Vol. 32 ›› Issue (5): 779-788.DOI: 10.3969/j.issn.1004-1524.2020.05.04

• Animal Science • Previous Articles     Next Articles

Prokaryotic expression of porcine type Ⅲ interferon and studying on its antiviral activity

CHEN Yunlu1, SHAN Ying1, LUO Hao1, XU Jidong1, ZHAO Lingyan2, FANG Weihuan1, LI Xiaoliang1,*   

  1. 1. Zhejiang Provincial Key Lab of Preventive Veterinary Medicine, Institute of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China;
    2. Zhejiang Provincial Center for Animal Disease control and Prevention, Hangzhou 310020, China
  • Received:2019-11-02 Online:2020-05-25 Published:2020-05-29

Abstract: Normally, type III interferon (IFN-λ) was highly expressed in intestinal mucosa and other mucosal systems, with relatively stronger broad-spectrum antiviral ability and immune regulating ability. Porcine epidemic diarrhea virus (PEDV) and porcine deltacorona virus (PDCoV) were two major intestinal pathogens causing diarrhea in piglets, which hindered the swine industry severely. In this study, the recombinant plasmid containing PoIFN-λ3 fragment was constructed. The recombinant plasmid was then transformed into E.coli Rosaetta cells for recombinant expression. Analyzed by SDS-PAGE and western blotting, the results showed that the recombinant PoIFN-λ3 (27 ku) was successfully expressed in the inclusion bodies of E. coli cells. After denaturation, purification and renaturation, the active PoIFN-λ3 recombinant protein was obtained and was used to treat IPEC-J2 cells. Challenged by recombinant PoIFN-λ3, the immune-stimulating genes (ISGs), such as ISG-15, OAS1, Mx-1, IFIT1, IFITM1 and IFITM3 were all up-regulated significantly and reached to the peak (P<0.001) at 12 h post challenge. For PEDV and PDCoV infection in IPEC-J2, the virus replication was detected after pretreatment, simultaneous treatment and post-infection treatment of recombinant PoIFN-λ3. Compared with the control, the viral copy numbers of both PEDV and PDCoV were decreased significantly (P<0.05) after treatment of recombinant PoIFN-λ3. The above results indicated that the purified and renatured PoIFN-λ3 recombinant protein could have good biological activity. The recombinant PoIFN-λ3 can induce high expression of different ISGs in IPEC-J2, and can also inhibit PEDV and PDCoV replication in the host cells. In summary, our study provided a basis for preventing and treating viral diarrhea in piglets.

Key words: type Ⅲ, interferon, prokaryotic expression, inclusion bodies, PEDV, PDCoV

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