title: An oriP expression vector containing the HIV-1 Tat/TAR transactivation axis produces high levels of protein expression in mammalian cells.
abstract: A mammalian gene expression vector based on cytomegalovirus (CMV)enhancer/promoter (CMVe/p) for the regulation of gene expression was further optimized by adding oriP elements derived from Epstein-Barr virus (EBV) and the Tat/TAR transactivation axisfrom human immunodeficiency virus type 1 (HIV-1). Using the Tat/TAR-oriP expression vector, a transient transfection system was optimized for an extended culture period to produce large amounts of secreted IL-2SA (an IL-2 mutein) in HKB11 cells. We observed a 4-fold increase in IL-2SA expression in cells transfected with vectors containing the HIV-1 transactivation axis (Tat/TAR) or oriP elements alone when compared to cells transfected with the control vector having a CMVe/p. Cells transfected with expression vectors equipped with both oriP and Tat/TAR showed an 18-fold increase in IL-2SA expression. This transient transfection system maintained high secretion of IL-2SA for a period of 10-day with no appreciable loss in expression. We demonstrate that during this 10-day culture period, it was possible to produce 1-100 mg of proteins using 500 mug of plasmid DNA.
authors.affiliation: Molecular and Cell Biology, Process Sciences, Biotechnology, Bayer Corporation, Berkeley, CA, U.S.A., myung-sam.cho.b@bayer.com.
authors.forename: M S
authors.initials: MS
authors.lastname: Cho
authors.forename: H
authors.initials: H
authors.lastname: Yee
authors.forename: C
authors.initials: C
authors.lastname: Brown
authors.forename: K T
authors.initials: KT
authors.lastname: Jeang
authors.forename: S
authors.initials: S
authors.lastname: Chan