title: An OriP/EBNA-1-based baculovirus vector with prolonged and enhanced transgene expression.
abstract: BACKGROUND
  The baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) has been explored as a gene delivery vehicle for a variety of mammalian cell lines. However, the transient expression nature due to its incapability to replicate in mammalian cells and insufficient transduction efficiency limit its application.
  
  
  METHODS
  Recombinant baculovirus vectors containing genetic elements from Epstein-Barr virus (EBV), OriP and EBNA-1, which are essential for the episomal maintenance of the EBV genome in latently infected cells, were constructed and tested for their ability to sustain and express transgene (enhanced green fluorescence protein (egfp)) in mammalian cells.
  
  
  RESULTS
  The recombinant baculovirus containing OriP and EBNA-1 genes driven by the cytomegalovirus (CMV) promoter was capable of persisting in a significant proportion of infected mammalian cells, HEK293, Vero, Cos-7, and Hone-1, without any selective pressure. In HEK293, the expression of EGFP lasted for 60 days with markedly enhanced expression level. The persistence of baculovirus genome correlated with the expression of EBNA-1.
  
  
  CONCLUSIONS
  The improved baculovirus vector could mediate prolonged and enhanced foreign gene expression in some mammalian cells. Furthermore, an adequate level of the EBNA-1 protein was essential for the maintenance of the OriP-containing baculovirus genome. The new vector has potential for use in gene therapy.
authors.affiliation: Department of Microbiology and Microbial Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Shan
authors.forename: Leyao
authors.initials: L
authors.lastname: Wang
authors.forename: Juan
authors.initials: J
authors.lastname: Yin
authors.forename: Peng
authors.initials: P
authors.lastname: Zhong
authors.forename: Jiang
authors.initials: J
authors.lastname: Zhong
mesh_terms: D000818:Animals; D016367:Baculoviridae / Q000235:genetics*; D002460:Cell Line; D002478:Cells, Cultured; D019309:Epstein-Barr Virus Nuclear Antigens / Q000235:genetics*; D005456:Fluorescent Dyes; D015870:Gene Expression / Q000235:genetics*; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D018741:Replication Origin / Q000235:genetics*; D019076:Transgenes; D015854:Up-Regulation
chemical_list: D019309:Epstein-Barr Virus Nuclear Antigens; D005456:Fluorescent Dyes; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins