Porcine reproductive and respiratory syndrome virus(PRRSV)is characterized by its genetic variation and limited cross protection among heterologous strains.Even though several viral structural proteins have been regar...Porcine reproductive and respiratory syndrome virus(PRRSV)is characterized by its genetic variation and limited cross protection among heterologous strains.Even though several viral structural proteins have been regarded as inducers of neutralizing antibodies(NAs)against PRRSV,the mechanism underlying limited cross-neutralization among heterologous strains is still controversial.In the present study,examinations of NA cross reaction between a highly pathogenic PRRSV(HP-PRRSV)strain,JXwn06,and a low pathogenic PRRSV(LP-PRRSV)strain,HB-1/3.9,were conducted with viral neutralization assays in MARC-145 cells.None of the JXwn06-hyperimmuned pigs’sera could neutralize HB-1/3.9 in vitro and vice versa.To address the genetic variation between these two viruses that are associated with limited crossneutralization,chimeric viruses with coding regions swapped between these two strains were constructed.Viral neutralization assays indicated that variations in nonstructural protein 2(nsp2)and structural proteins together contribute to weak cross-neutralization activity between JXwn06 and HB-1/3.9.Furthermore,we substituted the nsp2-,glycoprotein2(GP2)-,GP3-,and GP4-coding regions together,or nsp2-,GP5-,and membrane(M)protein-coding regions simultaneously between these two viruses to construct chimeric viruses to test cross-neutralization reactivity with hyperimmunized sera induced by their parental viruses.The results indicated that the swapped nsp2 and GP5-M viruses increased the neutralization reactivity with the donor strain antisera in MARC-145 cells.Taken together,these results show that variations in nsp2 and GP5-M correlate with the limited neutralization reactivity between the heterologous strains HP-PRRSV JXwn06 and LP-PRRSV HB-1/3.9.展开更多
In the present study, 89 porcine reproductive and respiratory syndrome virus(PRRSV) isolates in China during 2007 to 2012 were randomly selected from the GenBank genetic sequence database. Evolutionary characteristics...In the present study, 89 porcine reproductive and respiratory syndrome virus(PRRSV) isolates in China during 2007 to 2012 were randomly selected from the GenBank genetic sequence database. Evolutionary characteristics of these isolates were analyzed based on the sequences of non-struc-tural protein 2(Nsp2) and glycoprotein 5(GP5). The genetic variations of the isolates were also compared with six representative strains. The results showed that a high degree of genetic diversity exists among the PRRSV population in China. Highly pathogenic PRRSV isolates, with a discon-tinuous deletion of a 30 amino acid residue in the Nsp2 region, remained the most dominant virus throughout 2007–2012 in China. Owing to the extensive use of representative vaccine strains, natu-ral recombination events occurred between strains. Three isolates – HH08, DY, and YN-2011 – were more closely related to vaccine strains than the other isolates. Both YN-2011 and DY were the evolu-tionary products of recombination events between strains SP and CH-1R. The results of the present study provide useful information for the epidemiology of PRRSV as well as for vaccine development.展开更多
目的：表达纯化人星状体病毒（ human astrovirus， HAstV）非结构蛋白nsP1a／1，免疫动物制备多克隆抗体。方法利用PCR技术扩增nsP1a／1基因序列，构建到大肠埃希菌原核表达系统中表达重组nsP1a／1蛋白，使用镍柱亲和层析法对重组蛋白...目的：表达纯化人星状体病毒（ human astrovirus， HAstV）非结构蛋白nsP1a／1，免疫动物制备多克隆抗体。方法利用PCR技术扩增nsP1a／1基因序列，构建到大肠埃希菌原核表达系统中表达重组nsP1a／1蛋白，使用镍柱亲和层析法对重组蛋白进行纯化，十二烷基磺酸钠-聚丙烯酰胺凝胶电泳（ SDS-PAGE）和二噻啉甲酸（BCA）实验对重组蛋白的纯度与浓度进行分析，以重组的nsP1a／1蛋白为抗原，免疫雄性SPF级SD 大鼠获得多抗血清，用 ELISA 测定抗体效价、 Western 印迹检测抗体特异性。结果nsP1a／1-pET28a原核表达载体构建成功，将其转化至大肠埃希菌BL21（DE3）细菌中诱导表达了重组蛋白，免疫大鼠获得的多抗血清几何平均效价达到1∶406374。结论本实验成功地运用原核表达系统表达并鉴定了人星状体病毒非结构蛋白nsP1a／1，为进一步研究人星状病毒的复制及病毒感染的临床诊断奠定基础。展开更多
基金supported by the Major Program of National Natural Science Foundation of China (31490603, 31572549)the National Key Technology R & D Program of China (2015BAD12B01-2)
文摘Porcine reproductive and respiratory syndrome virus(PRRSV)is characterized by its genetic variation and limited cross protection among heterologous strains.Even though several viral structural proteins have been regarded as inducers of neutralizing antibodies(NAs)against PRRSV,the mechanism underlying limited cross-neutralization among heterologous strains is still controversial.In the present study,examinations of NA cross reaction between a highly pathogenic PRRSV(HP-PRRSV)strain,JXwn06,and a low pathogenic PRRSV(LP-PRRSV)strain,HB-1/3.9,were conducted with viral neutralization assays in MARC-145 cells.None of the JXwn06-hyperimmuned pigs’sera could neutralize HB-1/3.9 in vitro and vice versa.To address the genetic variation between these two viruses that are associated with limited crossneutralization,chimeric viruses with coding regions swapped between these two strains were constructed.Viral neutralization assays indicated that variations in nonstructural protein 2(nsp2)and structural proteins together contribute to weak cross-neutralization activity between JXwn06 and HB-1/3.9.Furthermore,we substituted the nsp2-,glycoprotein2(GP2)-,GP3-,and GP4-coding regions together,or nsp2-,GP5-,and membrane(M)protein-coding regions simultaneously between these two viruses to construct chimeric viruses to test cross-neutralization reactivity with hyperimmunized sera induced by their parental viruses.The results indicated that the swapped nsp2 and GP5-M viruses increased the neutralization reactivity with the donor strain antisera in MARC-145 cells.Taken together,these results show that variations in nsp2 and GP5-M correlate with the limited neutralization reactivity between the heterologous strains HP-PRRSV JXwn06 and LP-PRRSV HB-1/3.9.
基金supported by the Jilin Province Science and Technology Development Project(No.20140101123JC)the Fundamental Research Fund of Jilin Universitythe Program for Changjiang Scholars and Innovative Research Team in University(No.IRT1248)
文摘In the present study, 89 porcine reproductive and respiratory syndrome virus(PRRSV) isolates in China during 2007 to 2012 were randomly selected from the GenBank genetic sequence database. Evolutionary characteristics of these isolates were analyzed based on the sequences of non-struc-tural protein 2(Nsp2) and glycoprotein 5(GP5). The genetic variations of the isolates were also compared with six representative strains. The results showed that a high degree of genetic diversity exists among the PRRSV population in China. Highly pathogenic PRRSV isolates, with a discon-tinuous deletion of a 30 amino acid residue in the Nsp2 region, remained the most dominant virus throughout 2007–2012 in China. Owing to the extensive use of representative vaccine strains, natu-ral recombination events occurred between strains. Three isolates – HH08, DY, and YN-2011 – were more closely related to vaccine strains than the other isolates. Both YN-2011 and DY were the evolu-tionary products of recombination events between strains SP and CH-1R. The results of the present study provide useful information for the epidemiology of PRRSV as well as for vaccine development.
文摘目的：表达纯化人星状体病毒（ human astrovirus， HAstV）非结构蛋白nsP1a／1，免疫动物制备多克隆抗体。方法利用PCR技术扩增nsP1a／1基因序列，构建到大肠埃希菌原核表达系统中表达重组nsP1a／1蛋白，使用镍柱亲和层析法对重组蛋白进行纯化，十二烷基磺酸钠-聚丙烯酰胺凝胶电泳（ SDS-PAGE）和二噻啉甲酸（BCA）实验对重组蛋白的纯度与浓度进行分析，以重组的nsP1a／1蛋白为抗原，免疫雄性SPF级SD 大鼠获得多抗血清，用 ELISA 测定抗体效价、 Western 印迹检测抗体特异性。结果nsP1a／1-pET28a原核表达载体构建成功，将其转化至大肠埃希菌BL21（DE3）细菌中诱导表达了重组蛋白，免疫大鼠获得的多抗血清几何平均效价达到1∶406374。结论本实验成功地运用原核表达系统表达并鉴定了人星状体病毒非结构蛋白nsP1a／1，为进一步研究人星状病毒的复制及病毒感染的临床诊断奠定基础。
