Cloning, expression, and primary identification of a new candidate antigen for diagnosis of Angiostrongylus cantonensis.

Objective A specific candidate antigen of stage V larvae of Angiostrongylus cantonensis was cloned,expressed,and identified.Methods Based on the results of screening the stage V larvae of A.cantonensis cDNA library using immuno-probes,the Ac11 gene was immunoreactive.The Ac11 gene was amplified and submitted for BLAST analysis online.Then,it was subcloned into the expression vector pET28a(+) and expressed in E.coli.The recombinant protein Ac11 was purified and identified immunologically.Results The Ac11 gene was predicted to encode sulfite oxidase.The recombinant plasmid pET28a(+)-Ac11 was successfully constructed.The recombinant protein Ac11 with a molecular weight of about 30 kd was highly expressed in the form of inclusion bodies according to SDS-PAGE analysis.It was also highly immunoreactive in Western blot.Conclusion The recombinant protein Ac11,which is highly immunoreactive,was obtained in vitro and may provide a basis for further immunodiagnostic study of angiostrongyliasis.