[Molecular adjuvant FAI3 enhances the antifertility of Lagurus lagurus zona pellucida 3 DNA vaccine by intranasal route].

OBJECTIVE

To investigated whether fai3 as molecular adjuvant can enhance antifertility effect of contraceptive DNA vaccine pcD-Lzp3 through intranasal route.

METHODS

FAI was a fibrinogen-albumin-IgG receptor of group C streptococci in which exhibits adjuvant properties. The third gene fragment of FAI-fai3 (415~702 bp) has the function of mucosal adjuvant. In this study, Plasmid pcD-Lzp3and pcD-fai3were encapsulated separately or together with chitosan to generate chitosan-DNA complexes, chi-pcD-Lzp3, chi-pcD-fai3, and chi-(pcD-Lzp3+ pcD-fai3), as the DNA vaccines. ICR mice were immunized with these chitosan nanoparticles, respectively, on day 0, 14, 28 and 42. Indirect ELISA was employed to determine the anti-Lzp3 specific IgG, IgG1and IgG2a antibody in sera, and the anti-Lzp3 specific IgA in vaginal secretion and the feces.

RESULTS

The results showed that higher levels of serum IgG and mucosal secreted IgA were induced significantly in the mice of intranasally co-administered with chi-(pcD-Lzp3+pcD-fai3). The antifertility results showed that the mice of co-immunized group had the lowest birth rate and mean litter size.

CONCLUSIONS

The intranasal delivery of the molecular adjuvant fai3 with chi-pcD-Lzp3 could significantly enhance the antifertility of the Lzp3 DNA vaccine for contraception by enhancing both the systemic and mucosal immune responses.