[Cloning, expression and immunologic identification of Eg10 gene of Echinococcus granulosus].

Objective: To clone and express Eg10 gene of Echinococcus granulosus, and investigate the immunological characteristic of the recombinant.

Methods: Eg10 gene was subcloned into pET28a vector. The recombinant plasmid was transformed into E. coli BL21 and induced with IPTG. The recombinant protein was purified with His-bind purification kit. Forty-eight mice were randomly divided into 4 groups. Mice in groups A and B were injected with PBS and PBS+Freund's adjuvant (100 microl) as control. Mice in groups C and D were immunized with 10 mg and 50 microg purified Eg10 antigen formulated in Freund's adjuvant, respectively. All the mice received three immunizations at 2-week intervals with the same dose of antigen. Serum samples were collected at pre-immunization and certain time after immunization. The immunological characteristics of recombinant Eg10 was analyzed by Western blotting and ELISA.

Results: The recombinant Eg10 protein (Mr 31 000) was expressed in E. coli BL21. The recombinant Eg10 and expression product of PET28a/Eg10 were recognized by sera from mice immunized with recombinant Eg10. ELISA showed that the titer of IgG reached a peak at the 8th week in groups C and D, the level of IgG in sera of groups C or D was higher than that of groups A or B (P < 0.05) at the 2nd, 4th, 6th, 8th, and 10th week. There was no significant difference in the level of IgG between group C and group D (P > 0.05).

Conclusion: The Eg10 gene has been expressed with immunogenicity.