Study on the immunity protection of 14-3-3–MPLA–liposome vaccine against cystic echinococcosis in mice

The study aims to investigate the protective immunity against Echinococcus granulosus in mice immunized with14-3-3–MPLA–liposome vaccine. ICR (Institute of Cancer Research) mice were subcutaneously immunized three times with 14-3-3–MPLA–liposome vaccine, followed by the challenge with Echinococcus granulosus protoscoleces intraperitoneally and then sacrificed after six months of post-challenge. The levels of IL-4, and IFN-γ were measured by ELISA. The rate of reduced hydatid cyst and the levels of IgE, IgG and IgG subclasses in sera were examined. The result showed that mice vaccinated with14-3-3–MPLA–liposome vaccine and challenged with protoscoleces revealed significant protective immunity of 95.07%. ELISA analysis indicated that the immunized mice generated specific high levels of IgG and the prevailing isotypes of IgG were IgG1 and IgG2a. The level of IFN-γ increased significantly in the vaccinated mice whereas there was no significant difference in IL-4 levels between vaccinated and control mice. It is concluded that the14-3-3–MPLA–liposome vaccine could induce a high level of protective immunity to prevent cystic echinococcosis. The MPLA and liposome are promising vaccine adjuvant and delivery system.