Analysis of cell-specific promoters for viral gene therapy targeted at the vascular endothelium.
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.
Nicklin
S A
SA
Department of Medicine and Therapeutics, University of Glasgow, Western Infirmary, Glasgow, United Kingdom.
Reynolds
P N
PN
Brosnan
M J
MJ
White
S J
SJ
Curiel
D T
DT
Dominiczak
A F
AF
Baker
A H
AH
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
D016326:Extracellular Matrix Proteins; C501162:FLT1 protein, human; D040281:Vascular Endothelial Growth Factor Receptor-1; D001616:beta-Galactosidase