分子佐剂FAI3通过滴鼻途径增强草原兔尾鼠ZP3DNA疫苗抗生育效果

Molecular adjuvant FAI3 enhances the antifertility of Lagurus lagurus Zona Pellucida 3 DNA vaccine by intranasal route

目的：探讨纤维蛋白原/白蛋白/IgG受体3（FAI3）作为分子佐剂,通过滴鼻途径增强免疫反应以提高草原兔尾鼠ZP3 DNA疫苗的抗生育效果。方法：FAI是来自C群链球菌的一种多配基结合蛋白,它能同时结合纤维蛋白原、白蛋白和免疫球蛋白G,FAI的基因片段-fai3（415~702 bp）具有黏膜佐剂的功能。通过构建pcD-fai3重组质粒,用chitosan包裹质粒DNA不育疫苗pcD-Lzp3和质粒pcD-fai3,形成复合物的chi-（pcD-Lzp3＋pcD-fai3）,以及单独的chi-pcD-Lzp3和chi-pcD-fai3,三种chitosan包裹质粒,分别用这些质粒作为DNA疫苗,分别于第0、14、28、42天,通过滴鼻途径免疫小鼠。间接ELISA检测免疫小鼠血清中抗LZP3特异性IgG,IgG1和IgG2a,同时检测阴道洗液和粪便中的特异性IgA。结果：滴鼻共免疫chi-（pcD-Lzp3＋pcD-fai3）诱导产生了高水平的血清IgG和黏膜sIgA,生育率和平均窝仔数显著降低。结论：fai3作为分子佐剂与DNA不育疫苗pcD-Lzp3滴鼻共免疫小鼠,能诱导免疫小鼠产生较强的体液免疫反应和黏膜免疫反应,增强DNA不育疫苗的抗生育效果。

AIM： 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-fai3 were 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-Lzp3specific 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.CONCLUSION： 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.