Echinococcus granulosus 14-3-3 protein: a potential vaccine candidate against challenge with Echinococcus granulosus in mice.

OBJECTIVE: To investigate the protective immunity against Echinococcus granulosus in mice immunized with rEg14-3-3. METHODS: ICR mice were subcutaneously immunized three times with rEg14-3-3, followed by the challenge with Echinococcus granulosus protoscoleces intraperitoneally and then sacrificed after six months of post-challenge to detect the proliferation of splenocytes by MTT assay, and to measure the secretion of IL-2, IL-4, IL-10, and IFN-γ by ELISA. The rate of reduced hydatid cyst and the levels of IgE, IgG and IgG subclasses in sera were examined. RESULTS: Mice vaccinated with rEg14-3-3 and challenged with protoscoleces revealed significant protective immunity of 84.47%. ELISA analysis indicated that the immunized mice generated specific high levels of IgG and the prevailing isotypes of IgG were IgG1 and IgG2a. Splenocytes from mice immunized with rEg14-3-3 showed a significant proliferation response. The secretion of IFN-γ and IL-2 increased significantly in the vaccinated mice whereas there was no significant difference in IL-4 and IL-10 levels between vaccinated and control mice. CONCLUSION: The results indicate that the rEg14-3-3 vaccine could induce a high level of protective immunity as a promising vaccine candidate to prevent cystic echinococcosis.