title: Multiply attenuated, self-inactivating lentiviral vectors efficiently deliver and express genes for extended periods of time in adult rat cardiomyocytes in vivo.
abstract: BACKGROUND
  Among retroviral vectors, lentiviral vectors are unique in that they transduce genes into both dividing and nondividing cells. However, their ability to provide sustained myocardial transgene expression has not been evaluated.
  
  
  RESULTS
  Multiply attenuated, self-inactivating lentivectors based on human immunodeficiency virus-1 contained the enhanced green fluorescent protein (EGFP) gene under the transcriptional control of either the cytomegalovirus (CMV) immediate-early enhancer/promoter, the elongation factor-1alpha (EF-1alpha) promoter, or the phosphoglycerate-kinase (PGK) promoter. Lentivectors transduced adult rat cardiomyocytes in a dose-dependent manner (transduction rates, >90%; multiplicity of infection, approximately 5). The CMV promoter achieved higher EGFP expression levels than the EF-1alpha and PGK promoters. Insertion of the central polypurine tract pol sequence improved gene transfer efficiency by approximately 2-fold. In vivo gene transfer kinetics was studied by measuring the copy number of integrated lentivirus DNA and EGFP concentrations in cardiac extracts by real-time polymerase chain reaction and ELISA, respectively. With CMV promoter-containing lentivectors, vector DNA peaked at day 3, declined by approximately 4-fold at day 14, but then remained stable up to week 10. Similarly, EGFP expression peaked at day 7, decreased by approximately 7-fold at day 14, but was essentially stable thereafter. In contrast, vector DNA and EGFP expression declined rapidly with EF-1alpha promoter-containing lentivectors. Peak EGFP expression with titer-matched adenovectors was approximately 35% higher than with CMV lentivectors but was lost rapidly over time.
  
  
  CONCLUSIONS
  Lentivectors efficiently transduce and express genes for extended periods of time in cardiomyocytes in vivo. Lentivectors provide a useful tool for studying myocardial biology and a potential system for gene heart therapy.
authors.affiliation: Division of Cardiology, University of Lausanne, Lausanne, Switzerland.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Fleury
authors.forename: Eleonora
authors.initials: E
authors.lastname: Simeoni
authors.forename: Christian
authors.initials: C
authors.lastname: Zuppinger
authors.forename: Nicole
authors.initials: N
authors.lastname: Déglon
authors.forename: Ludwig K
authors.initials: LK
authors.lastname: von Segesser
authors.forename: Lukas
authors.initials: L
authors.lastname: Kappenberger
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Vassalli
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D004279:DNA, Viral / Q000032:analysis; D015870:Gene Expression; D005822:Genetic Vectors; D007700:Kinetics; D016086:Lentivirus / Q000235:genetics*; D008297:Male; D009205:Myocarditis / Q000473:pathology / Q000821:virology; D032383:Myocytes, Cardiac / Q000378:metabolism*; D011687:Purines / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D014161:Transduction, Genetic; D019076:Transgenes; D038301:Virus Inactivation
chemical_list: D004279:DNA, Viral; D011687:Purines