巨型艾美球虫gam56基因的截短原核表达及其产物的免疫保护效果  

Protective efficacy of recombinant gam56 gene expressed in E.coli

作　　者：许金俊[1] 姜慧婕[1] 陶建平[1] 彭昊[1] 张艳[1] 孙文瑶[1] 

机构地区：[1]扬州大学兽医学院,江苏扬州225009

出　　处：《中国预防兽医学报》2009年第11期892-897,共6页Chinese Journal of Preventive Veterinary Medicine

基　　金：江苏省自然科学研究基金(BK2007079);扬州大学科技创新培育基金(2006CXJ013)

摘　　要：为评价gam56基因重组表达产物作为亚单位疫苗预防鸡巨型艾美球虫(E.maxima)感染的效果,以E.maximaNT株配子体总RNA为模板,RT-PCR扩增和克隆gam56基因,选择该基因两段含丰富抗原表位的编码区片段,利用原核表达载体pGEX-6P-1在大肠杆菌中进行截短表达。以可溶性的GST-gam56-2融合蛋白为免疫原,设立高、中、低(1.0mg、0.5mg、0.25mg)3个剂量,单独或使用弗氏完全佐剂,于5d、12d和19d对雏鸡进行3次免疫,26d用5×104个E.maxima孢子化卵囊进行攻虫,8d后迫杀,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。结果显示:就相对增重率而言各免疫组比未免疫攻毒组的高27.6%以上,而各免疫组之间差异不显著(p>0.05);就卵囊减少率指标而言,各免疫组较未免疫攻毒组均有不同程度减少,但是均小于75%;就ACI指标而言,各免疫组较未免疫攻毒组均有不同程度增加,以中剂量蛋白佐剂组为最高。GST-gam56-2融合蛋白对于E.maxima感染具有一定的免疫保护效力。To assess the protective effect of recombinant gam56 against E.maxima infection in chickens, gam56 gene of E, maxima was amplified by RT-PCR from total RNA of purified gametocytes. Two fragments with rich antigenic epitopes were subcloned into pGEX-6P-1 and expressed. Five-day old chickens were subcutaneously immunized with soluble GST-gam56-2 antigen with or without adjuvant, and boosted with the same dosage at 12, 19 days of age. All chickens were orally challenged with homologous sporulated oocysts at 26 days of age and killed at eight days post challenge. Weight gains, anticoccidial index and oocyst output were determined and compared with those of the control animals. The results showed the weight gains of the immunized chickens were significantly higher than that of the control group （p〈0.05）. The oocyst outputs in immunized chickens dropped by 35.92 to 57.75 percent compared with the controls. It was concluded that recombinant protein GST-gam56-2 could induce partial protection against E.maxima infection.

关 键 词：巨型艾美球虫 gam56基因 重组蛋白 保护效果 

分 类 号：S852.723[农业科学—基础兽医学]