Du Luping, Li Bin, Pang Fengjiao, Yu Zhengyu, Xu Xiangwei, Fan Baochao, Tan Yeping, He Kongwang, Huang Kehe
College of Veterinary Medicine, Nanjing Agricultural University, No. 1 Wei-gang, Nanjing 210095, China; Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology Ministry of Agriculture, Nanjing, 210014 Jiangsu Province, China; Jiangsu Co-infection Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, 225009 Jiangsu Province, China.
Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Key Laboratory of Veterinary Biological Engineering and Technology Ministry of Agriculture, Nanjing, 210014 Jiangsu Province, China; Jiangsu Co-infection Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, 225009 Jiangsu Province, China.
Vet Immunol Immunopathol. 2017 Jan;183:31-39. doi: 10.1016/j.vetimm.2016.12.001. Epub 2016 Dec 6.
Porcine reproductive and respiratory syndrome virus (PRRSV) has been causing huge economic losses to the swine industry worldwide. Commercial PRRSV vaccines including killed and modified live ones are available. However the protective efficacy of these vaccines is incomplete. Thus, it is in urgent need to develop safer and more effective PRRSV vaccines. In this study, we constructed a recombinant plasmid co-expressing porcine glutathione peroxidase-1 (GPX1) and the envelope glycoprotein (GP5) encoding-gene of PRRSV (pcDNA3.1-GPX1-LSynORF5), and investigated the immune response induced following inoculation of mice and piglets. Significantly enhanced GP5-specific antibody, PRRSV-specific neutralizing antibody, IFN-γ level, as well as lymphocyte proliferation response, were induced in mice and pigs immunized with the DNA construct encoding GPX1 and GP5 compared with those inoculated with a construct encoding PRRSV GP5 only (pcDNA3.1-SynORF5). The enhanced cellular immune response in pigs induced by pcDNA3.1-GPX1-LSynORF5 was comparable to that induced by the attenuated virus vaccine JXA1-R, although the humoral immune response induced by the plasmid was much lower than the response induced by JXA1-R. Following the challenge with highly pathogenic PRRSV, less-severe clinical signs and rectal temperatures were observed in pigs immunized with the GPX1-GP5 construct compared with the control group. However, the viraemia of groups immunized with plasmid was more severe than that inoculated with JXA1-R, and it is likely that this could be attributed to the poor humoral response induced by the GPX1-GP5 construct. These results demonstrated that inclusion of GPX1 in a PRRSV DNA vaccine leads to an adjuvant effect, enhancing the humoral and cellular responses following vaccination.
猪繁殖与呼吸综合征病毒（PRRSV）给全球养猪业造成了巨大经济损失。目前有包括灭活疫苗和改良活疫苗在内的商业化PRRSV疫苗。然而，这些疫苗的保护效果并不完全。因此，迫切需要研发更安全、更有效的PRRSV疫苗。在本研究中，我们构建了一个共表达猪谷胱甘肽过氧化物酶-1（GPX1）和PRRSV包膜糖蛋白（GP5）编码基因的重组质粒（pcDNA3.1-GPX1-LSynORF5），并研究了接种小鼠和仔猪后诱导的免疫反应。与仅接种编码PRRSV GP5的构建体（pcDNA3.1-SynORF5）的小鼠和猪相比，用编码GPX1和GP5的DNA构建体免疫的小鼠和猪中，GP5特异性抗体、PRRSV特异性中和抗体、IFN-γ水平以及淋巴细胞增殖反应均显著增强。尽管该质粒诱导的体液免疫反应远低于JXA1-R诱导的反应，但pcDNA3.1-GPX1-LSynORF5诱导的猪细胞免疫反应增强程度与减毒活疫苗JXA1-R诱导的相当。在用高致病性PRRSV攻毒后，与对照组相比，用GPX1-GP5构建体免疫的猪临床症状较轻，直肠温度较低。然而，用质粒免疫的组的病毒血症比接种JXA1-R的组更严重，这可能归因于GPX1-GP5构建体诱导的体液反应较差。这些结果表明，在PRRSV DNA疫苗中加入GPX1会产生佐剂效应，增强疫苗接种后的体液和细胞反应。
