柔嫩艾美耳球虫(Eimeria tenella)BJ株SO7重组抗原的免疫试验

Vaccination against Coccidiosis with SO7 Recombinant Antigen of Eimeria tenella BJ Strain

将柔嫩艾美耳球虫 ( Eimeria tenella) BJ株 SO7基因插入 p Thio His B载体中 ,构建了 1个表达载体 ,命名为 p Thio His SO7。将此表达载体转入大肠杆菌 DH5α,经 IPTG诱导表达后 ,用 SDS-PAGE检测表达产物。结果表明 ,含 p Thio His SO7质粒的工程菌具有明显的表达产物 ,表达效率为 1 7.1 %。用超声波粉碎仪裂解含重组抗原的工程菌 ,加入钾明矾作佐剂 ,用 2个剂量 ( 1 0、1 0 0μg)分别于 4日龄、1 1日龄、1 8日龄 3次免疫雏鸡 ,同时设置 SO7+弱毒株组、SO7+强毒株组、弱毒株组、强毒株组、未免疫未攻毒组和未免疫攻毒组作对照 ,于 2 5日龄用 3× 1 0 4个 E.tenella强毒卵囊进行攻毒。结果表明 ,用大剂量 SO7重组抗原免疫 ( 3次 ) ,鸡可获得部分保护力 ,其病变计分比未免疫攻毒组下降 3 1 %。

A expression vector, designated pTHioHisSO7, was constructed with inserting SO7 gene into pTHioHisB vector and expressed in E. coli DH5α with inducting of IPTG. pTHioHisSO7 protein of approximately 40 000 in size was synthesized in E. coli at high level(17 1% of protein visible on coomassie blue stained gels) E.coli transformants containing pTHioHisSO7 was sonicated and added alum as a adjuvant at final concentration of 1%. Young chickens were vaccinated at 4, 11, 17 days of age respectively weth SO7 recombinant antigen at 100 μg of large dose or 10 μg of low dose. The groups of unvaccinated/unchallenged(uvuc), unvaccinated/challenged(uvc), SO7+live vaccine(virulent or attenuated) and live vaccine were set up as controls. Experimental birds were challenged with 3×10 4 sporulated oocysts of E. tenella at 25 days of age. The results showed that SO7 recombinant antigen with adjuvant at 100 μg of larg dose could induce a partial protection for chickens against coccidiosis by decreasing of 30% in cecal lesion score, but no protection was observed at 10 μg of low dose.