BACKGROUNDTo construct the Bifidobacterium Infantis/CD tumor targeting gene therapy system.

METHODSPCR expanded CD gene and pGEX-1LambdaT plasmid was transferred into E.Coli. JM109. with TSS solution. Then a dual restriction enzyme (EcoR I and BamH I) digestion was carried out to cut CD gene and pGEX-1LambdaT plasmid. Two segments (4.9 kb and 1.3 kb) were selected and extracted from the gel. T4 DNA Ligase was added to these two segments' mixture. Finally, reconstruction fragment was transferred into Bifidobacterium Infantis by electroporation. The plasmid was extracted from the positive clone selected and testified by an agarose eletrophoresis after enzymed.

RESULTSA positive transferred Bifidobacterium Infantis with 6.2 kb long reconstruction plasmid fragment with CD gene was established which was in accordance with theoretical calculation.

CONCLUSIONSThe Bifidobacterium Infantis/CD tumor targeting gene therapy system could be successfully constructed.