title: Construction of retroviral vectors with enhanced efficiency of transgene expression.
abstract: Retroviral vectors have been widely used in gene therapy due to their simple genomic structure and high transduction efficiency. We report a construction of Moloney murine sarcoma virus (MoMSV) and Moloney murine leukemia virus (MoMLV) hybrid-based retroviral vectors with significantly improved efficiency of transgene expression after stable incorporation into the host genome. In these vectors, the residual gag gene coding sequence located in the extended region of packaging signal was removed. These vectors, therefore, contain no coding sequence for the gag, pol, or env gene that can be used for homologous recombination with sequences introduced in the packaging system for a recombinant competent retrovirus (RCR) generation. A strong splice acceptor site obtained from the exon/intron junction of either the chimpanzee EF1-alpha gene or the human CMV major immediate early gene was placed downstream of the MoMSV packaging signal (Psi), significantly improving the efficiency of transgene expression. The 5' LTR U3 sequence was replaced with an extended human CMV major immediate early gene enhancer/promoter for a strong expression of full-length messages from the viral backbone, helping to maintain high levels of viral titer. These newly developed retroviral vectors should facilitate RCR-free gene transfer with significantly improved efficacy in clinical gene therapy trials.
authors.affiliation: Omegagen, Inc., Baltimore, MD 21227, USA.
authors.forename: Sung Ho
authors.initials: SH
authors.lastname: Hahm
authors.forename: Youngsuk
authors.initials: Y
authors.lastname: Yi
authors.forename: Dug Keun
authors.initials: DK
authors.lastname: Lee
authors.forename: Moon Jong
authors.initials: MJ
authors.lastname: Noh
authors.forename: Lillian
authors.initials: L
authors.lastname: Yun
authors.forename: Sally
authors.initials: S
authors.lastname: Hwang
authors.forename: Kwan Hee
authors.initials: KH
authors.lastname: Lee
mesh_terms: D000818:Animals; D003587:Cytomegalovirus / Q000235:genetics; D004742:Enhancer Elements, Genetic; D015870:Gene Expression; D005818:Genetic Engineering; D015316:Genetic Therapy; D005822:Genetic Vectors; D017874:Immediate-Early Proteins / Q000235:genetics; D051379:Mice; D008979:Moloney murine leukemia virus / Q000235:genetics*; D008980:Moloney murine sarcoma virus / Q000235:genetics*; D041681:NIH 3T3 Cells; D020648:Peptide Elongation Factor 1 / Q000235:genetics; D011401:Promoter Regions, Genetic; D019076:Transgenes; D014779:Virus Replication
chemical_list: D017874:Immediate-Early Proteins; D020648:Peptide Elongation Factor 1