不同佐剂和免疫途径对柔嫩艾美耳球虫SO7抗原免疫保护效果的影响

利用PGEX-6P-1融合表达系统将SO7基因在大肠杆菌中进行融合表达,对表达产物进行初步纯化和复性,制备免疫原。分别使用不同剂量的人参总皂甙和重组γ-干扰素以及弗氏完全佐剂作为免疫佐剂,于5日龄、12日龄和19日龄对雏鸡进行3次免疫,同时设立蛋白口服免疫组、蛋白皮下注射免疫组、卵囊口服免疫组、未免疫未攻毒组和未免疫攻毒组作对照,于26日龄用105个柔嫩艾美耳球虫卵囊进行攻毒,8d后扑杀,对各组的存活率、相对增重率、病变减少率、相对卵囊产量和抗球虫指数ACI等指标进行统计分析,比较免疫保护效果。与非免疫攻毒组以及不加佐剂的免疫攻毒组相比,佐剂使用后各组的增重、病变记分、相对卵囊产量、ACI等指标均有一定的改善,对柔嫩艾美耳球虫的人工感染可以提供部分保护。3种佐剂中,γ-干扰素和人参总皂甙能增强重组蛋白的免疫保护效果,且佐剂的剂量对免疫保护的效果有一定的影响,以5000Uγ-干扰素效果最佳,效果与E.tenella活卵囊免疫相当,弗氏完全佐剂的免疫增强效果不明显。单独使用重组蛋白皮下注射或口服免疫,虽有一定的保护作用,但不明显。一定剂量的γ-干扰素对SO7抗原的免疫保护效果起明显的增强作用,是一个具有很好临床应用前景的新型佐剂。

Protective effects of recombinant SO7 antigen against Eimeria tenella infections using various adjuvant and immune routes

The effects of adjuvant on SO7 immunoefficacy by different routes were investigated.Five-day old chickens were subcutaneously immunized with 100 mg recombinant SO7 antigen with adjuvant or without adjuvant,and boosted with the same dosage at 12,19 days of age.The SO7 antigen was administered with various amount of adjuvant,including ginsenosides,chicken recombinant interferon-gamma(chIFN-gamma),and FCA adjuvant via different routs,Chickens were orally challenged with homologous sporulated oocysts at 26 days of age,and killed at eight days postchallenge.Mortality,weight gains,lesion scores,Oocyst output,and ACI were determined and compared with those of the controls.All groups administered with adjuvant showed higher protective immunity compared to those administered antigen alone and the unimmunized negative control.The protective immunity was affected by chIFN-gamma and ginsenosides in a dose dependent manner,in which the group receiving antigen with 5000 units chIFN-gamma showed strongest adjuvant effects.In group administered antigen alone,no significant protective immunity was observed.