用人源肠毒素性大肠杆菌CS3菌毛构建新型呈现载体(英文)

Construction of a Novel Display Vector Deriving from CS3 Fimbriae of Human Enterotoxigenic Escherichia coli

根据对人源大肠杆菌菌毛CS3亚单位亲水性、表位、二级结构和柔韧性计算机预测结果 ,以CS3亚单位第 72位氨基酸残基之后作为外源表位的插入位点 ,构建了一种新的表面呈现载体pCSX72。用该载体分别表达口蹄疫病毒 (FMDV)的VP1表位和C -myc的十肽表位 (4 1 0～ 4 1 9aa)。SDS -PAGE结果以及电镜和免疫电镜观察证明 ,插入的外源表位和CS3亚单位以杂合菌毛的形式呈现在菌体表面。ELISA检测结果表明 ,pCSX72表达的杂合蛋白的抗原性较之其他插入位点的载体要高得多。用重组细菌腹腔免疫小鼠 ,能够诱发机体对杂合蛋白的双重免疫应答。

Based on the prediction of the hydrophilicity, epitopes, secondary structure and flexibility of the CS3 subunit, a novel vector pCSX72 which permits the insertion of foreign epitopes into CS3 at the position of 72nd aa was constructed. Two epitopes,the VP1 of FMDV and a ten-peptides epitope of C-myc, were displayed with it respectively. Compared with the two previously-constructed vectors, the vector pCSX72 expressed the hybrid fimbriae in higher level. Mice produced dual immune response against the CS3 and the inserted epitopes when they were immunized by injecting the live recombinant bacteria intraperitoneally.