College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
Res Vet Sci. 2013 Jun;94(3):562-7. doi: 10.1016/j.rvsc.2012.11.006. Epub 2012 Dec 21.
The protective efficacy of recombinant vaccines encoding an Eimeria refractile body antigen SO7 was assessed in broiler chickens following oral infection with Eimeria tenella. The SO7 and chicken IL-2 genes were cloned into the expression vector pVAX1 consecutively to construct DNA vaccines pVAX-SO7 and pVAX-SO7-IL-2. Expression of SO7 and IL-2 gene transcripts and proteins encoded by the plasmid DNAs in vivo was detected by reverse transcription-polymerase chain reaction and Western blot. Chickens were inoculated with 100 μg of plasmids pVAX-SO7 or pVAX-SO7-IL-2, or 200 μg of recombinant SO7 protein or chicken IL-2 protein by leg intramuscular injection. At 28days of age, all chickens except the unchallenged control group were challenged orally with 5×10(4) sporulated oocysts of E. tenella. All chickens were euthanized to determine the effects of immunization on the 7th day post-challenge. The results showed that both DNA vaccines containing the SO7 gene and the recombinant SO7 protein could obviously alleviate body weight loss and cecal lesions compared with unvaccinated and challenged control. These findings also suggested that chicken IL-2 could effectively enhance the immunity of SO7 against E. tenella challenge compared with vaccination using pVAX-SO7 alone.
口服感染柔嫩艾美耳球虫后，评估编码艾美耳属折射体抗原 SO7 的重组疫苗对肉鸡的保护效力。将 SO7 和鸡 IL-2 基因连续克隆到表达载体 pVAX1 中，构建 DNA 疫苗 pVAX-SO7 和 pVAX-SO7-IL-2。通过反转录-聚合酶链反应和 Western blot 检测体内质粒 DNA 编码的 SO7 和 IL-2 基因转录本和蛋白质的表达。通过腿部肌肉内注射 100 μg 的质粒 pVAX-SO7 或 pVAX-SO7-IL-2，或 200 μg 的重组 SO7 蛋白或鸡 IL-2 蛋白，对鸡进行接种。在 28 日龄时，除未攻毒对照组外，所有鸡均经口接受 5×10(4)个孢子化的柔嫩艾美耳球虫卵囊攻毒。所有鸡均安乐死，以确定免疫接种对攻毒后第 7 天的影响。结果表明，与未接种和攻毒对照组相比，含有 SO7 基因的两种 DNA 疫苗和重组 SO7 蛋白均可明显减轻体重减轻和盲肠病变。这些发现还表明，与单独使用 pVAX-SO7 进行疫苗接种相比，鸡 IL-2 可有效增强 SO7 对柔嫩艾美耳球虫攻毒的免疫力。
