Establishment of gene therapy vector by using DNA replication origin and virus vector

构建了由腺病毒、β-半乳糖苷酶和DNA复制起点（ori）组成的表达载体，所用的Oris分别来自c-myc、hsp 70和免疫球蛋白重链基因，并以SV 40为阳性对照。将重组腺病毒插入到含有Cre-lox系统的腺病毒载体中，并从用这些载体转染的人2983细胞中回收重组腺病毒。首先将含有SV 40来源的腺病毒感染猴CosI细胞，回收表达β-半乳糖苷酶的环状腺病毒。然后将含有hsp 70基因来源的腺病毒感染人HeLa细胞，也回收了环状形式的腺病毒DNA。而hsp 70 ori来源的质粒DNA在细胞中的拷贝数比SV 40来源的质粒DNA低10个数量<-3>级。结果表明，该系统应该是有用的表达载体的基因治疗。

Expression vector composed of adenovirus, beta-galactosidase, and DNA replication origin (ori) was constricted.Oris used here were from genes of c-myc, human hsp70 and immunoglobulin heavy chain in addition to SV40 origin as a positive control. These origins were inserted to adenovirus vector containing Cre-lox system, and the recombinant adenovirus were recovered from human 2983 cells transfected with these vectors. Adenovirus containing SV40 origin were first infected to monkey CosI cells, and the circular adenovirus expressing beta-galactosidase was recovered. Adenovirus containing hsp70 gene origin were then infected to human HeLa cells, and the circular form of adenovirus DNA was also recovered. Copy number of hsp70 ori derived plasmid DNA in the cells, however, was lower than that of SV40 origin in 10^<-3> order. Results suggest that this system should be useful for an expression vector for gene therapy.