Yang Guilian, Wang Chunfeng, Hao Fengqi, Zhao Dan, Zhang Yunlong, Li Yu
College of Animal Science and Technology, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, China.
Parasitol Int. 2010 Dec;59(4):517-23. doi: 10.1016/j.parint.2010.06.010. Epub 2010 Jul 1.
Eimeria spp. are the causative agents of coccidiosis, a major disease affecting the poultry industry. A recombinant non-antibiotic Escherichia coli that expresses the Eimeria tenella SO7 gene was constructed and its protective efficacy against homologous infection in chickens was determined. The three-day-old chickens were orally immunized with the recombinant non-antibiotic SO7 gene expressing E. coli and boosted two weeks later. Four weeks after the second immunization, the chickens were challenged with 5 × 10(4) homologous sporulated oocysts. The protective effects of the recombinant non-antibiotic E. coli were determined by measuring body weight change, mortality, histopathology, lesion scores, oocyst counts, the specific antibody response and the frequency of CD4(+) and CD8(+) lymphocytes in peripheral blood. The results showed that immunization with SO7 expressing E. coli resulted in significantly improved body weight gain, reduced lesion scores and oocyst shedding in immunized chickens compared to controls. Furthermore, administration of recombinant SO7 expressing E. coli leads to a significant increase in serum antibody, CD4(+) and CD8(+) T cells in peripheral blood of chickens. These results, therefore, suggest that the recombinant non-antibiotic E. coli that expresses the SO7 gene is able to effectively stimulate host protective immunity as evidenced by the induction of development of both humoral and cell-mediated immune responses against homologous challenge in chickens.
艾美耳球虫属是球虫病的病原体，球虫病是影响家禽业的一种主要疾病。构建了一种表达柔嫩艾美耳球虫SO7基因的重组非抗生素大肠杆菌，并测定了其对鸡同源感染的保护效果。给3日龄的鸡口服免疫表达该重组非抗生素SO7基因的大肠杆菌，两周后进行加强免疫。第二次免疫后四周，用5×10⁴个同源有孢子卵囊攻击鸡。通过测量体重变化、死亡率、组织病理学、病变评分、卵囊计数、特异性抗体反应以及外周血中CD4⁺和CD8⁺淋巴细胞的频率来确定重组非抗生素大肠杆菌的保护作用。结果表明，与对照组相比，用表达SO7的大肠杆菌免疫可使免疫鸡的体重增加显著改善，病变评分降低，卵囊排出减少。此外，给予表达重组SO7的大肠杆菌可使鸡外周血中的血清抗体、CD4⁺和CD8⁺T细胞显著增加。因此，这些结果表明，表达SO7基因的重组非抗生素大肠杆菌能够有效刺激宿主的保护性免疫，这一点通过在鸡中诱导针对同源攻击的体液免疫和细胞介导免疫反应的发展得到了证明。
