title: Mechanism of prolonged gene expression by Epstein-Barr virus-based plasmid in porcine cells.
abstract: BACKGROUND
  We previously showed that an Epstein-Barr virus (EBV)-based plasmid, pEBVGFP, exerts prolonged gene expression in porcine neonatal pancreatic cell clusters (NPCCs). In this study, the mechanism underlying this was investigated.
  
  
  METHODS
  GFP expression was analyzed in porcine cells transfected with pEBVGFP by FACS analysis and confocal microscopy. The possible integration of pEBVGFP into the chromosomal DNA was analyzed by Southern blot. Self-replication of the EBV-based plasmid in porcine cells was investigated by PCR. The NPCCs were immunostained to characterize cells transfected with pEBVGFP.
  
  
  RESULTS
  The EBV based plasmid provided prolonged GFP expression in porcine cells and duct cells were the main cells transfected among NPCCs. Southern blot showed that the transfected pEBVGFP stayed for a long time as an episome rather than integrating into the chromosomal DNA. pEBVGFP isolated from the transfected porcine cells had methylated CpG suggesting that they self-replicated in those cells.
  
  
  CONCLUSIONS
  The EBV-based plasmid may be useful for genetically manipulating porcine cells to enhance their value as xenotransplantation sources.
authors.affiliation: Research Institute of Immunobiology, Department of Biomedical Sciences, The Catholic University of Korea, Seoul, Korea.
authors.forename: Jung Kyu
authors.initials: JK
authors.lastname: Son
authors.forename: Sang Taek
authors.initials: ST
authors.lastname: Oh
authors.forename: Sung Kyu
authors.initials: SK
authors.lastname: Cho
authors.forename: Kun Ho
authors.initials: KH
authors.lastname: Yoon
authors.forename: Suk Kyeong
authors.initials: SK
authors.lastname: Lee
mesh_terms: D000818:Animals; D002460:Cell Line; D002875:Chromosomes / Q000235:genetics; D002934:Cinnamates / Q000494:pharmacology; D004247:DNA / Q000235:genetics; D015870:Gene Expression / Q000235:genetics; D017930:Genes, Reporter / Q000235:genetics; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D006921:Hygromycin B / Q000031:analogs & derivatives / Q000494:pharmacology; D008745:Methylation; D010957:Plasmids / Q000235:genetics*; D013552:Swine; D013997:Time Factors; D014162:Transfection
chemical_list: D002934:Cinnamates; D006921:Hygromycin B; C026273:hygromycin A; D004247:DNA