Cloning and High Level Expression of Gene Encoding ES Antigen from Trichinella spiralis Muscle Larvae
旋毛虫肌幼虫ES抗原的基因克隆及高效表达

The partial structure gene encoding ES antigen derived from T. spiralis (TSP) muscle larvae was cloned,characterized,and expressed in E. colt. The target DNA (0. 7kb) was directly obtained by using RNA PCR technique from the TSP total RNA. Analysed it with the RE digestion, the fragment was cloned into the fusion expression vector pEX31C. It was shown that a kind of 37 kDa fusion proteins was expressed in E. colt containing the recombinant plasmid by SDS-PAGE electrophoresis. The expressed . proteins was over 22% of the total cell protein and it was aggregated in the form of inclusion bodies in E. coll. The purified protein could be recognized in ELISA both by sera from swine-infected with TSP and by the monoclonal antibody against TSP. These findings suggest that the recombinant protein is a potentially valuable antigen both for im-munodiagnosis and vaccine development of trichinellosis. This is the first demonstration of cloning and high level expression for structure gene encoding ES antigen in our country.