Expression Of The Gene Encoding The A/D Antigenic Domains Of The E2 Glycoprotein Of HCLV In Escherichia Coli And Preliminary Use Of The Recombinant Protein

Two recombinant prokaryotic vectors, pTH-E2 and pET-E2 were constructed containing classical swine fever virus C strain E2 gene ( A and D antigenic domain) using pThioHisB and pET-32a(+) expressing vectors. Their expressing characteristics were compared and it was found that pET-E2 in BL21(DE3) (BL21E2) can present more production of recombinant protein. So pET-E2 was chosen to continue later work and the conditions for expressing recombinant protein were optimized. After that, a gene encoding three consecutive HA epitope was inserted into it to get pET-E2HA. The BL21(DE3) containing pET-E2HA (BL21E2HA) was cultured in a larger scale and the recombinant protein was purified by Ni+ affinity chromatography. Purified protein was quantified and an indirect ELISA method was established. Using this method about 150 serum samples from pigs vaccinated with CSFV vaccine (most with bursin versus a few without bursin) were detected for their liters. And this method was compared for its sensitivity with the existing indirect-HA method(IHA) to detect the liters of antibodies against classical swine fever virus. In the last part of this paper, we describe a recombinant plasmid constructed to detect classical swine fever virus in cell culture.