CS3菌毛可以作为异源抗原决定簇的嵌合表达载体  

CS3 fimbriae of enterotoxigenic Escherichia coli as chimeric expression carriers of heterologous antigenic determinants

作　　者：董自正[1] 张兆山[1] 李淑琴[1] 张蓓宁 黄翠芬[1] 

机构地区：[1]军事医学科学院生物工程研究所,北京100071

出　　处：《生物技术通讯》1998年第1期20-24,34,共6页Letters in Biotechnology

基　　金：国家科委"863"基金课题

摘　　要：CS3是肠毒素源性大肠杆菌的菌毛蛋白,是一种很强的免疫原。研究了利用CS3菌毛作为异源抗原决定簇载体的可能性。在计算机分析预测CS3亚基的抗原表位区、二级结构的基础上,运用PCR定点突变在CS3亚基结构基因中引入了SacⅡ酶切位点序列,插入编码霍乱毒素B亚基抗原表位CTP3的DNA序列,构建了表达CS3/CTP3的重组菌株。电镜和免疫电镜观察证明,CS3/CTP3以杂合菌毛的形式存在于菌体表面,SDS聚丙烯酰胺凝胶电泳显示了CS3/CTP3杂合蛋白的存在。口服和腹腔注射免疫Bal b/c小鼠,该重组菌株可诱发抗CS3和抗CTP3的双重免疫应答。结果表明CS3可以作为表达异源抗原决定簇的表达载体,可望成为研制口服粘膜免疫多价疫苗的新型系统。CS3 fimbriae as a strong immunogen are produced by human enterotoxigenic Escherichia coli (ETEC). The possibility of using CS3 as a carrier for foreign antigenic determinants was investigated. A Sac Ⅱ site sequence was inserted into the structural gene of CS3 subunit by site specific mutagenesis based on analyzing and predicting the properties of the proteins. A recombinant strain expressing CS3/ CTP3 hybrid fimbriae was constructed by inserting the sequence encoding CTP3 epitopes into the Sac Ⅱ site created by directed mutagenesis in the structural gene of CS3 subunit and transforming the recombinant plasmids into the host Escherichia coli DH5α. The result of SDS-PAGE showed that the hybrid CS3/CTP3 molecules were the fusion proteins with molecular masses more than the CS3 subunit. Inoculating mice orally and intraperitoneally showed that both antibodies against CS3 and CTP3 were elicited. These results indicate that CS3 pill could be an exposure vector for heterologous antigenic detemi-nants and become a powerful tool for the development of oral vaccines directed against mucosal pathogens.

关 键 词：CS3菌毛 基因融合 载体蛋白 重组疫苗 

分 类 号：R392[医药卫生—免疫学]