title: Establishment and applications of epstein-barr virus-based episomal vectors in human embryonic stem cells.
abstract: Human embryonic stem (hES) cells are capable of unlimited cell proliferation yet maintain the potential to differentiate into many cell types. Here we reported an Epstein-Barr virus (EBV)-based vector system used to improve transfection efficiency in hES cells. Plasmids containing oriP, the latent replication origin of EBV, can be propagated stably as episomal DNA in human cells that express the EBV nuclear antigen 1 (EBNA1), which binds to oriP and functions as the trans-acting replication initiator. It was reported that the EBV replicon could harbor a DNA fragment of up to 330 kilobase pairs. Plasmids containing an enhanced green fluorescent protein (EGFP)/puromycin resistance gene cassette along with or without oriP were used to transfect hES cells that stably express EBNA1. The presence of oriP moderately increased the transient transfection efficiency and more importantly it elevated the stable transfection efficiency by approximately 1,000-fold as compared with oriP-minus plasmids. The oriP plasmid as episomal DNA and green fluorescent protein expression in hES cells was maintained for months in the presence of drug selection and gradually lost (2%-4% per cell doubling) in the absence of selection. The presence of EBNA1 did not interfere with the hES cell properties or differentiation we tested and could maintain stable EGFP expression during differentiation. In addition to transgene expression, the EBV vector system could effectively enhance the RNA interference efficiency in hES cells. Thus, the EBV vector system that allows a large DNA insert and sustained expression of transgene or small hairpin RNA will enhance basic and translational research using hES cells.
authors.affiliation: Cancer Research Institute, Xiang-Ya School of Medicine, Central South University, Changsha 410078, Hunan, People's Republic of China. rencaiping@xysm.net
authors.forename: Caiping
authors.initials: C
authors.lastname: Ren
authors.forename: Ming
authors.initials: M
authors.lastname: Zhao
authors.forename: Xuyu
authors.initials: X
authors.lastname: Yang
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Li
authors.forename: Xingjun
authors.initials: X
authors.lastname: Jiang
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Wenjiao
authors.initials: W
authors.lastname: Shan
authors.forename: Hong
authors.initials: H
authors.lastname: Yang
authors.forename: Liang
authors.initials: L
authors.lastname: Zhou
authors.forename: Wen
authors.initials: W
authors.lastname: Zhou
authors.forename: Hongbo
authors.initials: H
authors.lastname: Zhang
mesh_terms: D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology; D002454:Cell Differentiation; D002460:Cell Line; D053595:Embryonic Stem Cells / Q000187:drug effects / Q000378:metabolism* / Q000821:virology; D019309:Epstein-Barr Virus Nuclear Antigens / Q000235:genetics / Q000378:metabolism; D005456:Fluorescent Dyes / Q000378:metabolism; D005822:Genetic Vectors / Q000235:genetics*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D010957:Plasmids / Q000235:genetics*; D014162:Transfection
chemical_list: C525809:BMP4 protein, human; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D019309:Epstein-Barr Virus Nuclear Antigens; D005456:Fluorescent Dyes; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; C417029:EBV-encoded nuclear antigen 1