title: Targeting transgene expression for cystic fibrosis gene therapy.
abstract: We have developed an expression cassette for cystic fibrosis (CF) gene therapy using control elements from the human cytokeratin 18 gene (KRT18, also known as K18). KRT18 is naturally expressed in a spatial pattern similar to that of CFTR, the gene mutated in CF. We delivered a KRT18-driven lacZ plasmid complexed with cationic liposomes intravenously to mice and examined expression in various tissues. We found expression in nasal and bronchial epithelium, airway submucosal glands, gall bladder, and kidneys. Expression was low in pancreas and gut, and absent from liver and alveolar lung. This is consistent with the expression pattern reported for a K18lacZ transgenic mouse. Following delivery of a cytomegalovirus (CMV) major immediate-early promoter/enhancer-driven lacZ plasmid, we found expression in bronchi, submucosal glands, alveolar cells, liver, and kidney. We did not detect expression in nose, pancreas, gall bladder, or gut. Using fluorescently labeled plasmid delivered by means of liposomes, we identified the liver, alveolar lung, and kidneys as the major plasmid deposition sites. Our data demonstrate that a KRT18-driven expression vector delivered systemically can target gene expression to CF-affected tissues, despite an uneven distribution of plasmid DNA. A KRT18-based vector may be a useful alternative to viral promoter-based vectors in clinical gene therapy trials to treat CF.
authors.affiliation: Programme in Lung Biology Research, Canadian Institutes of Health Research Group in Lung Development, The Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: D R
authors.initials: DR
authors.lastname: Koehler
authors.forename: V
authors.initials: V
authors.lastname: Hannam
authors.forename: R
authors.initials: R
authors.lastname: Belcastro
authors.forename: B
authors.initials: B
authors.lastname: Steer
authors.forename: Y
authors.initials: Y
authors.lastname: Wen
authors.forename: M
authors.initials: M
authors.lastname: Post
authors.forename: G
authors.initials: G
authors.lastname: Downey
authors.forename: A K
authors.initials: AK
authors.lastname: Tanswell
authors.forename: J
authors.initials: J
authors.lastname: Hu
mesh_terms: D000818:Animals; D003550:Cystic Fibrosis / Q000628:therapy*; D015870:Gene Expression; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D005822:Genetic Vectors; D020404:Glycerophospholipids / Q000008:administration & dosage; D006801:Humans; D007275:Injections, Intravenous; D007633:Keratins / Q000235:genetics*; D007763:Lac Operon / Q000502:physiology*; D008081:Liposomes; D051379:Mice; D008815:Mice, Inbred Strains; D009928:Organ Specificity; D010714:Phosphatidylethanolamines; D000644:Quaternary Ammonium Compounds / Q000008:administration & dosage; D013501:Surface-Active Agents; D014018:Tissue Distribution; D019076:Transgenes
chemical_list: C410262:1,2-dioleoyl-glycero-3-phosphatidyl ethanolamine; D020404:Glycerophospholipids; D008081:Liposomes; D010714:Phosphatidylethanolamines; D000644:Quaternary Ammonium Compounds; D013501:Surface-Active Agents; C015831:dimethyldioctadecylammonium; D007633:Keratins