Abstract:

Objective　Human soluble tumor necrosis factor receptor(sTNFR) can interfere with the biological functions of in- terleukin-1, which may be appropriate to the treatment of periodontitis. The eukaryote expression vector of the human sTNFR gene must be constructed prior to conducting transgene therapy of periodontitis.Methods　Both sTNFR gene and plasmid pcDNA 3·1(+) DNAwere digested withKpnⅠandXhoⅠ. After purification, the two fragmentswere ligated byTakaRa DNALigation Kit (Ver 2·0). This recombinant DNAwas then transformed intoE.ColiCompetent Cells JM109 and positive cloneswere select- ed on the LB agarose plate containing ampicillin (80μg/ul).Results　Six single cloneswere indentified by double digestionwith kpnⅠandxhoⅠand two fragments with the size of 5·4 kb and 1·0 kb were produced as expected.Conclusion　The sTNFR gene was successfully inserted into the eukaryote expression vector plasmid pcDNA3·1(+) by recombination technologyin vitro

Key words: human soluble tumor necrosis factor receptor, eukaryote vector, plasmid