微环DNA研究进展

Research Progress of Minicircle DNA

质粒载体在基因治疗中占据重要地位。传统质粒DNA在真核生物中可能会引起严重的炎症反应,未甲基化的CpG序列可能抑制基因的表达,最好的解决办法是在生产质粒载体过程中将细菌调控序列整体消除。微环DNA是一种新颖的小环超螺旋表达框,它是传统质粒在大肠杆菌体内通过位点特异性重组得到的。微环DNA缺乏抗性标记基因、复制原点等细菌序列,增强了在临床上的安全性。体内、外研究表明,微环DNA提高了转基因表达效率。我们就重组酶系统及微环DNA的生产、纯化和转染效率等方面的研究进行了综述。

Plasmid DNA play an important role in gene therapy.Plasmid DNA used for non-viral gene delivery may cause unacceptable inflammatory responses in eukaryotes.Unmethylated CpG is likely to inhibit gene expression.A good solution is to entirely eliminate the bacterial control regions from gene delivery vectors during the process of plasmid production.Minicircle DNA is a novel supercoiled minimal expression cassette containing the eukaryotic gene,derived from conventional plasmid DNA by site-specific recombination in vivo in Escherichia coli.Minicircle DNA lacks the bacterial backbone sequence consisting of an antibiotic resistance gene,an origin of replication to bacterial DNA,so their improved safety in clinic.Minicircles have been shown to greatly improve the efficiency of transgene expression in vitro and in vivo studies.In this paper,we introduced the recombinase system containing phiC31,parA,Cre and the production,purification of minicircle DNA,and discussed the efficiency of gene transfer