This study is to predict and purify the T-B combined epitopes of egG1Y162 antigen in Echinococcus granulosus, and to evaluate their immunogenicity in mice.Methods:
The bioinformatics software was used to predict the T-B combined epitopes of egG1Y162 antigen. Recombinant egG1Y161/2 peptides were constructed, expressed and purified. Mice were immunized with egG1Y161/2 peptides. The serum and spleen cells were isolated. The isolated spleen cells were stimulated with egG1Y161/2 peptides in vitro and the culture supernatant was collected. The levels of IgG in serum and levels of IL-4 and IFN-γ in the culture supernatant were measured by ELISA. The weight and number of the fresh hydatid cysts were evaluated. The serum ptotoscolicidal activity was measured by the complement dependent cytotoxicity assay.Results:
Peptides of 6–19aa, 64–82aa, 106–119aa were predicted as T-B combined epitopes of egG1Y162 antigen. And, recombinant protein egG1Y162–1 or egG1Y162–2, which contained T-B combined epitope(s) of the 6–19aa, or the 64–82aa and the 106–119aa in egG1Y162 antigen, respectively, was successfully expressed and purified. Serum IgG levels of mice immunized with egG1Y162–1/2 were significantly increased during the immune response to Echinococcus granulosus. The levels of IFN-γ, IL-4 and the ratio of IFN-γ/IL-4 after egG1Y162–1/2 immunization were significantly higher. Weight and number of the fresh hydatid cysts in egG1Y162–1/2 immunized mice was significantly decreased. And, the serum protoscolicidal activity after egG1Y162–1/2 immunization was enhanced.Conclusions:
The egG1Y162–1/2 induces production of serum IgG levels and Th1 cell immune response, which enhances the protective immunity in Echinococcus granulosus challenged mice and thus may be used as a potential vaccine candidate.