大肠埃希菌F4菌毛凝集性单抗制备及抗原表位差异

Escherichia coli ETEC F4 pilus agglutinative single preparation and the difference between antigen epitope

采用杂交瘤单克隆抗体制备技术,获得4株能稳定分泌产肠毒素大肠埃希菌(ETEC)F4菌毛特异性抗体的杂交瘤细胞株,分别命名为8EH2、8EH3、9E10、11D4。免疫印迹和凝集反应结果表明:这4株单抗均能与纯化的F4菌毛蛋白发生特异性反应,且与F4大肠埃希菌不同血清型变异株F4ab、F4ac和F4ad发生特异性肉眼可见的凝集反应;而与F18、F6(987P)、F5(K99)产肠毒素大肠埃希菌参考株、分离株以及肠炎沙门氏菌参考株50336、分离株等多种肠杆菌科细菌无任何交叉反应。对单抗亚类的特性检测结果显示,这4株单抗均属于IgG1抗体,且主要识别F4ac的抗原表位,其中,8EH2、8EH3、9E10也能够较好地识别F4ab的抗原表位。结果说明F4菌毛凝集性单克隆抗体为ETEC F4感染的快速特异诊断提供技术基础。

By adopting monoclonal antibody preparation, we obtained four hybridoma cells, named 8EH2, 8EH3, 9E10, 11D4 respectively, which secret specific monoclonal antibody against Enterotoxigenic l）2scherichia coli （ETEC） F4 fimbriae steadily. Both immunoblotting and agglutination assays demonstrated that all four monoclonal antibodies reacted specifically to the purified F4 fimbriae and F4 Escherictzia coli of different serotypes F4ab, F4ac and F4ad with the char- acteristic of agglutinating the bacteria. While no across reaction with F18, FG（987P） and F5（K99） Escherichia coli Sal- monella enteritidis 50 336 strains and their isolates was shown. They all belong to IgG1 antibody and can recognize the epitope of F4ac, among them 8EH2, 8EH3, 9E10 also can better recognize the epitope of F4ab.