猪瘟病毒基因2型流行毒株和疫苗C株抗血清与相应E2蛋白交叉免疫反应性分析  

Analysis of cross-reactivity of different E2 proteins with antisera of subgroup 2 field isolates and vaccine C-strain of classic swine fever virus

作　　者：廖迅[1] 王作欢 曹统[1] 谷元兴[1] 李肖梁[1] 方维焕[1] 

机构地区：[1]浙江大学动物预防医学研究所/浙江省动物预防医学重点实验室,浙江杭州310058

出　　处：《中国预防兽医学报》2017年第3期172-176,共5页Chinese Journal of Preventive Veterinary Medicine

基　　金：高等学校博士学科点专项科研基金(20120101130014)

摘　　要：为研究猪瘟病毒(CSFV)2.1基因亚型病毒株和疫苗C株E2蛋白与相应抗血清的免疫反应性差异,本研究在分析4株CSFV浙江流行株(QZ-14、JH-14、QZ-07和HZ-08)与疫苗C株E2变异程度的基础上,制备了流行病毒株和疫苗C株全病毒猪抗血清以及针对流行株E2的单克隆抗体(MAb)4F4,比较了它们与同源株和异源株重组杆状病毒表达的E2蛋白的亲和性。结果显示,4株浙江分离株中2株(QZ-14和JH-14)属于亚型2.1d,另2株(QZ-07和HZ-08)为亚型2.1b,它们与C株E2的核苷酸同源性在82%~84%;间接免疫荧光鉴定显示MAb 4F4能够识别4株流行株,但不与C株反应;接种流行株的动物均出现不同程度临床症状;ELISA分析显示疫苗C株血清与流行株E2蛋白的反应性约为C株E2蛋白的27%~49%,2株流行株感染血清与C株E2蛋白反应性约为流行株E2蛋白的34%~50%,免疫印迹分析显示类似结果。以上结果表明CSFV基因2型流行株与疫苗C株E2蛋白的差异显著影响其与相应抗血清的交叉免疫反应性,这一现象是否与C株猪瘟疫苗免疫保护效果下降有关还有待于进一步研究。To investigate the difference of cross-reactivity of E2 proteins in classical swine fever virus （CSFV） vaccine C-strain and field isolates with corresponding antisera, the recent and early CSFV Zhejiang isolates of QZ-14, JH-14, QZ-07 and HZ-08 as well as C-strain were compared on the variations of their E2 genes. The antisera to C-strain and field isolates （QZ-14, QZ-07 and HZ-08） were prepared in pigs with recombinant E2 proteins （rE2） of CSFV expressed from baculovirus expression systems and used to examine cross-reactivity with rE2. The monoclonal antibody （MAb） 4F4 prepared against E2 of field isolates was used for detection of CSFVs in cells . The phylogenetic analysis based on E2 gene sequences of CSFV shown that isolate of QZ-14 and JH-14 belonged to subgroup 2.1d, and the isolates of QZ-07 and HZ-08 were subgroup 2.1b, which were 82-84% nucleotide identity to C-strain. Immunofluorescence assay indicated that MAb 4F4 recognized the 4 field isolates, but not the C-strain. All pigs inoculated with field isolates displayed certain degree of clinical symptoms and their antisera had lower level of reactivity with E2 of C-strain. ELISA showed that reactivity of anti-C-strain sera collected at day 28 post inculcation with E2 of subgroup 2 isolates was only 27%-49% of its homologous E2, while that of antisera from field isolates to the C-strain E2 was 34% -50% of the homologous E2 proteins. Western blot detection also had the similar results. These results suggest that the variations of the E2 proteins between the group 2 CSFV isolates and C-strain could affect cross-reactivity with heterolgous antisera. Further research is needed to examine if such decreased immuno-reactivity is related to reduce protection of C-strain-based vaccine.

关 键 词：猪瘟病毒 囊膜糖蛋白E2 抗原性变异 

分 类 号：S852.65[农业科学—基础兽医学]