鸡IFN-γ与鸡柔嫩艾美耳球虫3-1E抗原共表达DNA疫苗的免疫保护性研究

Protective effect of a DNA vaccine co-expressing both chicken IFN-γ and E.tenella 3-1E

采用SOE-PCR将鸡柔嫩艾美耳球虫3-1E抗原基因与鸡IFN-γ基因用(GGGGS)3接头融合,扩增出IFN-γ/3-1E融合基因,将其克隆到真核表达载体proVAX中构建双价融合表达质粒proIE。通过IFA检测proI、proE、proIE重组质粒在转染细胞PK-15后的蛋白表达情况。将重组质粒于14、21日龄免疫AA肉鸡,28日龄感染5×104个柔嫩艾美耳球虫孢子化卵囊,观察免疫保护效果。结果显示,与proE和proI相比,proIE双价融合DNA疫苗具有增强免疫保护作用,可显著降低粪便中的卵囊排出量(P<0.05),但体重增加并不显著(P>0.05)。

The IFN-γ/3-1E fusion gene encoding E.tenella 3-1E antigen and chicken IFN-γ linked with Gly4Ser 3 was amplified by SOE-PCR,and the fusion gene was subcloned into the mammalian expression vector proVAX forming the chimeric plasmid proIE.The expressed proteins of purified plasmids transfected PK-15 cells were detected by IFA.Broilers were vaccinated with the DNA vaccines respectively at the age of 14 and 21 days.Chickens were challenged with 5×104 E.tenella sporulated oocysts at 28 days and the immune protective efficacy was observed.The results indicated that the proIE showed the enchanced protective immunity as demonstrated by significantly reduced oocyst shedding compared with proE and proI（P0.05）,but the proIE did not have an effect of body weight gain（P0.05）.