为评价Serpin基因重组表达产物对预防鸡柔嫩艾美耳球虫(Eimeria tenella,E.tenella)感染的效果,克隆和表达E.tenella Serpin基因,对表达产物进行初步纯化和复性,制备免疫原.设计了重组蛋白肌肉注射组、重组蛋白口服组、重组蛋白滴鼻组3个试验组以及红、白对照组.分别于7、14和28日龄对雏鸡进行3次免疫,35日龄时用3×104个E.tenella孢子化卵囊攻虫,第7天末宰杀,对各组的存活率、相对增重率、卵囊减少率、ACI等指标进行统计分析.结果表明,各免疫组的平均增重与红对照组相比均有显著增加(P＜0.05),其中以重组蛋白肌肉注射组增重最多,相对增重率为66.73％,优于其他免疫组；各免疫组卵囊产量较红对照组均有显著的下降,其中重组蛋白肌肉注射组卵囊减少率最高,为30.01％;各免疫组ACI均明显高于红对照组,其中以重组蛋白口服组最高,但仍低于160,暗示Serpin蛋白并不是一个理想的球虫疫苗保护性抗原.%To assess the immunoefficacy of recombinant Serpin against E. tenella infection in chickens, Serpin gene of E. tenella was cloned and expressed, subsequently, the recombinant Serpin was purified and refolded. Three experimental groups i. e. intramuscular injection, oral administration and intranasal administration groups were designed. At the same time, the challenged and unchallenged groups were also designed as positive and negative control, respectively. Seven-day old chickens were immunized with the recombinant Serpin protein, and boosted with the same method at 14 and 28 days of age. All chickens were orally challenged with sporulated oocysts at 35 days of age and killed at day 7 post challenge. Survival rate ,relative weight gain, oocyst decrease ratio and anticoccidial index were used as the main criteria for the assessment of the protective effect. The results showed the weight gains of the immunized chickens were significantly higher than that of the positive control group (P<0. 05). The oocyst outputs in immunized chickens dropped significantly when compared with the positive control. In comparison with the positive control, the ACI in immunized groups were significantly higher,and the ACI of group immunized orally with recombinant antigen was the highest, the results that the ACI of all immunized group were below 160 implied that the Serpin protein is not an ideal coccidiosis vaccines candidate antigen.
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