title: Analysis of cell-specific promoters for viral gene therapy targeted at the vascular endothelium.
abstract: The use of viral vectors for vascular gene therapy targeted at the endothelium is limited by the promiscuous tropism of vectors and nonspecificity of viral promoters, resulting in high-level transgene expression in multiple tissues. To evaluate suitable endothelial cell (EC)-specific promoters for vascular gene therapy, we directly compared the ability of the fms-like tyrosine kinase-1 (FLT-1), intercellular adhesion molecule-2 (ICAM-2), and von Willebrand factor (vWF) promoters to drive EC-restricted transcription after cloning into adenoviral vectors upstream of lacZ. Vastly different expression profiles were observed. Whereas both FLT-1 and ICAM-2 promoters generated transgene expression levels similar to cytomegalovirus in ECs in vitro, vWF expression levels were extremely low. Analysis of non-EC types revealed that ICAM-2 but not FLT-1 evoked leaky transgene expression, thus identifying FLT-1 as the most selective promoter. With an ex vivo human gene therapy model, the FLT-1 promoter demonstrated EC-specific transgene expression in intact human vein but no detectable expression from infected exposed smooth muscle cells in EC-denuded vein. Furthermore, when adenoviruses were systemically administered to mice, the FLT-1 promoter demonstrated extremely low-level gene expression in the liver, the major target organ for adenoviral transduction in vivo. This study highlights the potential of using the FLT-1 promoter for local and systemic human gene therapy in hypertension and its complications.
authors.affiliation: Department of Medicine and Therapeutics, University of Glasgow, Western Infirmary, Glasgow, United Kingdom.
authors.forename: S A
authors.initials: SA
authors.lastname: Nicklin
authors.forename: P N
authors.initials: PN
authors.lastname: Reynolds
authors.forename: M J
authors.initials: MJ
authors.lastname: Brosnan
authors.forename: S J
authors.initials: SJ
authors.lastname: White
authors.forename: D T
authors.initials: DT
authors.lastname: Curiel
authors.forename: A F
authors.initials: AF
authors.lastname: Dominiczak
authors.forename: A H
authors.initials: AH
authors.lastname: Baker
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000502:physiology*; D016326:Extracellular Matrix Proteins / Q000235:genetics; D020869:Gene Expression Profiling; D018390:Gene Targeting; D015316:Genetic Therapy; D005822:Genetic Vectors; D006801:Humans; D006973:Hypertension / Q000473:pathology / Q000628:therapy*; D011401:Promoter Regions, Genetic / Q000502:physiology*; D012501:Saphenous Vein / Q000502:physiology; D040281:Vascular Endothelial Growth Factor Receptor-1; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D016326:Extracellular Matrix Proteins; C501162:FLT1 protein, human; D040281:Vascular Endothelial Growth Factor Receptor-1; D001616:beta-Galactosidase