表达精子抗原受精素β的重组沙门氏菌疫苗株的免疫性避孕效应研究

Immunocontraceptive Effects of the Recombinant Attenuated Salmonella Typhimurium Expressing Mouse Sperm Antigen Fertilin Bata Subunit

目的 :探讨表达精子抗原受精素β胞外区的重组沙门氏菌疫苗株用作避孕疫苗的可行性。方法 :应用表达精子抗原受精素β胞外区的两种重组沙门氏菌疫苗株 X46 3 2 (p FEC)和 X45 5 0(p FEC)口服接种雌鼠 ,通过 ELISA方法检测其激发雌鼠产生抗重组受精素 β蛋白的血清 Ig G抗体和阴道分泌物 Ig A抗体滴度变化 ,并观察其诱导的雌鼠免疫性避孕效应情况。结果 :重组 X46 3 2(p FEC)和 X45 5 0 (p FEC)疫苗株不但可激发雌鼠产生高水平血清抗重组受精素 β蛋白和抗菌体LPS Ig G抗体 ,而且在阴道分泌物中可出现一定程度抗重组受精素 β蛋白和抗菌体 LPS Ig A抗体。同时 ,口服免疫后的雌鼠生育能力明显降低 ,两实验组雌鼠妊娠率降低 3 0～ 3 5 %,一胎产仔数量平均降低 6 4 .76～ 6 5 .6 4 %。结论 :表达精子抗原受精素β的重组沙门氏菌疫苗株可在小鼠中诱导免疫避孕效应。

Objective: To explore the possibility of the recombinant Salmonella Typhimurium expressing mouse sperm fertilin beta subunit used as a vaccine strains. Methods: The female Kunming mice were immunized with X4632(pFEC)and X4550(pFEC)respectively, which are two strains of the recombinant Salmonella Typhimurium expressing the extracellular domain of mouse sperm fertilin beta subunit. Their serum IgG titres and vaginal secretions IgA titres against to fertilin beta protein and Salmonella Typhimurium LPS were detected using ELISA assay. Their immunological contraceptive effects induced by the two recombinant strains were observed at the same period. Results: High level serum IgG titres and mild level vaginal mucosal IgA titres induced by oral immunization in mice were detected. Meanwhile, the fertility of the immunized mice were significantly decreased. The pregnant rates of the mice immunized by either X4632(pFEC) or X4550(pFEC)were decreased by 30~35% (P<0.01). Each litter sizes of the two groups were significantly reduced by 64.76～65.64% (P<0.01). Conclusions: The two recombinant strains expressing the extracellular domain of mouse sperm fertilin beta subunit can effectively induce specific humoral and mucosal antibody response and contraceptive effects in mice.