[Study on the subcloning, expression and immunoprotection with Schistosoma japonicum CAI gene].

Objective: To subclone and express the new gene of Schistosoma japonicum (Sj) CAI and evaluate the immunoprotective effect of the recombinant molecule.

Methods: The cDNA of SjCAI gene was subcloned into expression vector pGEX-5X-3 to form recombinants which were then used to transform to E. coli strain ER 2566. Expression was induced by IPTG. The mice were vaccinated with the expressed protein and the immunoprotective effect was tested.

Results: Fusion protein of SjGST-CAI was highly expressed in E. coli as inclusion bodies. The worm reduction rate and the liver egg reduction rate in vaccination group of SjGST-CAI were 29.87% and 63.71%, respectively.

Conclusion: SjCAI gene can be highly expressed in E. coli after subcloning into pGEX-5X-3 vector and the expressed fusion protein can induce immunoprotective effect against Sj in mice.