人产肠毒素大肠杆菌ST、LT-B肠毒素基因融合的研究

Study on the Genetic Fusion of Heat-stable and Heat-labile B Subunit of the Enterotoxin of Enterotoxigenic Escherichia coli

将人产肠毒素大肠杆菌(ETEC),编码耐热肠毒素(ST)的基因片段与编码不耐热肠毒素B亚基(LT-B)的基因进行融合,并在此基础上进行不同数目ST基因的串联,ELISA检测融合基因表达蛋白产物观察到ST与LT-B之间存在着相互影响。ST的检测滴度随基因串联个数增加而逐渐升高,而LT的ELISA滴度则减弱。说明了ST可以通过基因串联提高表达产物抗原活性,这为产肠毒素大肠杆菌多价疫苗的研制提供了重要的研究基础。

The gene encoding pro-ST of heat-stable enterotoxin(ST) of enterotoxigenic Escherichia coli(ETEC)was fused to the gene encoding the B subunit of heat-labile en-terotoxin (LT-B). And based on this clone,a series of plasmids harbouring 2-5 tandem copies of ST gene plus LT-B gene were constructed. The expression of ST and LT-B fusion gene were detected by ELISA technique. The ELISA titers of ST increased but LT-B decreased with the increase of the ST gene copy number. It showed that the ST antigenicity could be improved and provide theoretical basis for developing a divalent vaccine against ETEC.