Production of African Swine Fever Virus p54 ectodomain and p30 in an E. coli system and their potential application in immunodetection

Abstract

African swine fever (ASF) is a lethally infectious viral disease caused by the African swine fever virus (ASFV), leading to a high mortality of almost 100% in domestic pigs worldwide. ASFV has significantly impacted the global swine industry and food security. Highly effective vaccines are in high demand; however, no current vaccines provide effective immunity against ASFV. Therefore, there is an urgent need to develop reliable immunodetection assays to prevent the spread of ASFV. Traditionally, ASFV antigens are produced using mammalian expression systems, which are labor-intensive, costly, time-consuming, and challenging to scale up. In this study, two ASFV structural proteins associated with viral infection, p30 and the p54 ectodomain from genotype II ASFV, were recombinantly expressed in E. coli BL21(DE3). The results demonstrated that recombinant p54 ectodomain and p30 were highly expressed in E. coli BL21(DE3) using the pET28a system. Both recombinant p54 ectodomain and p30 were then validated for their ability to serve as antigens to detect anti-ASFV antibodies in an indirect ELISA platform. The p54 ectodomain/p30-based indirect ELISA was validated using serum from ASFV-infected pigs and serum from ASFV-uninfected pigs. Both p54 ectodomain and p30 demonstrated binding ability in the serum from ASFV-infected pigs, while no binding was observed in the serum from ASFV-uninfected pigs. Collectively, our recombinant p30 and p54 ectodomain were successfully expressed in E. coli and can be used as antigens to develop an indirect ELISA-based detection assay for anti-ASFV antibodies.