一组绵羊OLA Ⅰ蛋白与绵羊痘病毒多肽的复性组装  

Expression and refolding of OLA Ⅰ protein with peptides derived from sheeppox virus

作　　者：王战红 赵志荀[1] 吴国华[1] 邓阳[1] 朱国强 赵芳燕 卢曾军[1] 张强[1] WANG Zhanhong;ZHAO Zhixun;WU Guohua;DENG Yang;ZHU Guoqiang;ZHAO Fangyan;LU Zengjun;ZHANG Qiang(State Key Laboratory of Veterinary Etiological Biology,Lanzhou Veterinary Research Institute,Chinese Academy of Agricultural Sciences,Lanzhou 730046,Gansu,China)

机构地区：[1]中国农业科学院兰州兽医研究所家畜疫病病原生物学国家重点实验室,甘肃兰州730046

出　　处：《生物工程学报》2022年第1期139-147,共9页Chinese Journal of Biotechnology

基　　金：国家自然科学基金(31872449,31972687)。

摘　　要：本研究旨在体外组装小尾寒羊OLA Ⅰ蛋白与绵羊痘病毒多肽复合物,筛选绵羊痘病毒CTL表位肽。首先克隆小尾寒羊OLA Ⅰ重链基因胞外区OLA Ⅰα-BSP和轻链基因OLA Ⅰ-β2m,将获得的轻、重链基因分别插入原核表达载体pET-28a(+)并转化至BL21(DE3)细胞进行诱导表达,收集菌体超声破碎,过镍柱纯化获得一定纯度的OLA Ⅰ重链和轻链β2m包涵体蛋白,稀释复性法将获得的轻、重链包涵体蛋白与绵羊痘病毒多肽PV4按摩尔比为1︰1︰1的比例进行共复性,分子筛层析验证复性情况,ELISPOT试验评价OLA Ⅰ分子限制性多肽引起的T细胞免疫应答。结果表明,克隆获得的重、轻链基因正确表达,大小分别为36.3 kDa和16.7 kDa,分子筛和SDS-PAGE结果表明,绵羊痘病毒多肽PV4与OLA Ⅰ分子稳定结合,ELISPOT试验确定该多肽可刺激引起T细胞免疫应答。本研究建立了小尾寒羊OLA Ⅰ分子轻、重链的原核表达体系,实现该轻、重链与绵羊痘病毒多肽PV4的复性,确定了1个绵羊痘病毒CTL表位肽,为下一步解析该复合物的结构及对羊痘CTL表位筛选提供思路。The aim of this study was to refold the OvisAries leukocyte antigen(OLA) class Ⅰ protein with peptides derived from sheeppox virus(SPPV) to identify SPPV T cell epitopes. Two pairs of primers were designed based on the published sequence of a sheep major histocompatibility complex Ⅰ to amplify the heavy chain gene of OLA Ⅰ α-BSP and the light chain gene of OLA Ⅰ-β2 m. Both genes were cloned into a pET-28 a(+) expression vector, respectively, and induced with ITPG for protein expression. After purification, the heavy chain and light chain proteins as well as peptides derived from SPPV were refolded at a ratio of 1:1:1 using a gradual dilution method. Molecular exclusion chromatography was used to test whether these peptides bind to the OLA Ⅰ complex. T-cell responses were assessed using freshly isolated PBMCs from immunized sheep through IFN-γ ELISPOT with peptides derived from SPPV protein. The results showed that the cloned heavy chain and light chain expressed sufficiently, with a molecular weight of 36.3 kDa and 16.7 kDa, respectively. The protein separated via a SuperdexTM 200 increase 10/300 GL column was collected and verified by SDS-PAGE after refolding. One SPPV CTL epitope was identified after combined refolding and functional studies based on T-cell epitopes derived from SPPV. An OLA Ⅰ/peptide complex was refolded correctly, which is necessary for the structural characterization. This study may contribute to the development of sheep vaccine based on peptides.

关 键 词：OLAⅠ 绵羊痘病毒 分子筛 CTL表位 

分 类 号：S858.26[农业科学—临床兽医学]