Tian Zhi-Jun, Qiu Hua-Ji, Ni Jian-Qiang, Zhou Yan-Jun, Cai Xue-Hui, Zhou Guo-Hui, Wang Yun-Feng, Tong Guang-Zhi
National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, CAAS, Harbin 150001, China.
Yi Chuan Xue Bao. 2005 Dec;32(12):1248-55.
The GP5 gene of porcine reproductive and respiratory syndrome virus (PRRSV) was integrated into the TK gene locus of pseudorabies virus (PRV) vaccine strain Bartha-K61, resulting in a TK- and gE- negative recombinant PRV harboring GP5 gene, designated as rPRV-GP5. The in vitro expression of the GP5 by rPRV-GP5-infected cells was analyzed by single-step growth analysis,Western blot,and indirect immunofluorescence test. It was shown that GP5 gene can be expressed authentically in the cytoplasm of rPRV-GP5-infected cells. Compared to its parental virus, rPRV-GP5 showed no obvious difference regarding viral replication and cytopathogenic effects in several cell cultures. Four PRV-negative sheep immunized intramuscularly with 10(6.0) PFU of rPRV-GP5 were fully protected from challenge with 10(3) LD50 of highly virulent PRV S strain of porcine origin. Ten PRV- and PRRSV-negative piglets given intranasally with 10(7.0) PFU of rPRV-GP5 and challenged intranasally with 10(5.0) TCID50 of virulent PRRSV CH-1a strain at day 63 post-inoculation developed antibodies against PRRSV 3, 5, 14 days post-challenge, as revealed by indirect immunofluorescence test, enzyme-linked immunosorbent assay and virus neutralization test. The results suggest that rPRV-GP5 is capable of inducing anamnestic immune response to PRRS in inoculated animals.
猪繁殖与呼吸综合征病毒（PRRSV）的GP5基因整合到伪狂犬病病毒（PRV）疫苗株Bartha-K61的TK基因位点，产生了一株携带GP5基因的TK和gE双阴性重组PRV，命名为rPRV-GP5。通过一步生长分析、蛋白质免疫印迹法和间接免疫荧光试验分析了rPRV-GP5感染细胞中GP5的体外表达情况。结果表明，GP5基因能在rPRV-GP5感染细胞的细胞质中真实表达。与亲本病毒相比，rPRV-GP5在几种细胞培养物中的病毒复制和细胞病变效应无明显差异。4只PRV阴性绵羊肌肉注射10(6.0) PFU的rPRV-GP5后，能完全抵抗10(3) LD50猪源强毒PRV S株的攻击。10只PRV和PRRSV双阴性仔猪在接种后63天经鼻接种10(7.0) PFU的rPRV-GP5，并在接种后第63天经鼻用10(5.0) TCID50的强毒PRRSV CH-1a株攻击，间接免疫荧光试验、酶联免疫吸附试验和病毒中和试验结果显示，仔猪在攻击后3、5、14天产生了针对PRRSV的抗体。结果表明，rPRV-GP5能够在接种动物中诱导对PRRS的回忆性免疫反应。
