畜牧兽医学报2018，Vol.49Issue(6)：1222-1230,9.DOI:10.11843/j.issn.0366-6964.2018.06.014
针对不同形式猪繁殖与呼吸综合征病毒GP5重组蛋白的抗体中和活性比较
Comparison of Neutralizing Antibodies Induced by PRRSV GP5 Recombinant Proteins in Different Forms of Truncation
摘要
Abstract
GP5 protein of porcine reproductive and respiratory virus(PRRSV)is considered to be the main protein that inducing production of neutralizing antibodies.In order to investigate the ability of the protective immunity induced by the GP5 protein,the full-length GP5 and the trun-cated GP5 lacking of the signal peptide(aa 1-31)and transmembrane region(aa 66-125)were expressed using baculovirus and prokaryotic expression systems.Additionally,the truncated GP5 lacking of the signal peptide(aa 1-31)and transmembrane region(aa 66-125)were expressed using E.coli expression systems.Three anti-sera(ELISA assay antibody titre :800,1600,and 200 respectively)specific for each recombinant protein were derived from mice immunized with three recombinant proteins with Freund＇s Incomplete Adjuvant.PAM cells used in neutralization assay were obtained from PRRSV-negative healthy pigs by bronchoalveolar lavage after necropsy.PRRSV HeN-3(the heterologous strain)and VR2332(the homologous strain)strains were isola-ted in Marc-145 cells.The real-time quantitative PCR was used to detect PRRSV RNA levels in infected PAM cells.It was considered positive that virus blocking rate was higher than 70％which had been established in our laboratory.Results were as follows :1)The results showed that three anti-sera specific for three recombinant proteins did not have neutralizing activities a-gainst two strains of PRRSV(titers were＜ 1 :2).2)The anti-sera of PRRSV VR2332 had neu-tralizing activity against PRRSV VR2332 strain(titers were 1 :8),and hadn′t neutralizing activity against PRRSV HeN-3 strain but rather enhanced infection.Our current work showed the main neutralizing epitopes of GP5 were probably conformational epitopes and the neutralizing epitopes of PRRSV were not fully presented in the GP5 protein.The positive anti-sera of PRRSV could provide immune protection,but the immune protection occurs only in the same strain.It would mediate the ADE effect on heterologous strains on the contrary.关键词
猪繁殖与呼吸综合征病毒/GP5/杆状病毒表达系统/真核表达/中和试验Key words
PRRSV/GP5/baculovirus expression system/prokaryotic expression/neutralization test分类
农业科技引用本文复制引用
冯延,郭嘉,许瑞勤,马思续,魏凤灵,张留君,杨国宇,夏平安,张改平..针对不同形式猪繁殖与呼吸综合征病毒GP5重组蛋白的抗体中和活性比较[J].畜牧兽医学报,2018,49(6):1222-1230,9.基金项目
国家自然科学基金重大项目(31490600) （31490600）
国家自然科学基金面上项目(31572520) （31572520）
