title: Pancreatic transduction by helper-dependent adenoviral vectors via intraductal delivery.
abstract: Pancreatic gene transfer could be useful to treat several diseases, such as diabetes mellitus, cystic fibrosis, chronic pancreatitis, or pancreatic cancer. Helper-dependent adenoviral vectors (HDAds) are promising tools for gene therapy because of their large cloning capacity, high levels of transgene expression, and long-term persistence in immunocompetent animals. Nevertheless, the ability of HDAds to transduce the pancreas in vivo has not been investigated yet. Here, we have generated HDAds carrying pancreas-specific expression cassettes, that is, driven either by the elastase or insulin promoter, using a novel and convenient plasmid family and homologous recombination in bacteria. These HDAds were delivered to the pancreas of immunocompetent mice via intrapancreatic duct injection. HDAds, encoding a CMV-GFP reporter cassette, were able to transduce acinar and islet cells, but transgene expression was lost 15 days postinjection in correlation with severe lymphocytic infiltration. When HDAds encoding GFP under the control of the specific elastase promoter were used, expression was detected in acinar cells, but similarly, the expression almost disappeared 30 days postinjection and lymphocytic infiltration was also observed. In contrast, long-term transgene expression (>8 months) was achieved with HDAds carrying the insulin promoter and the secretable alkaline phosphatase as the reporter gene. Notably, transduction of the liver, the preferred target for adenovirus, was minimal by this route of delivery. These data indicate that HDAds could be used for pancreatic gene therapy but that selection of the expression cassette is of critical importance to achieve long-term expression of the transgene in this tissue.
authors.affiliation: 1 Center of Animal Biotechnology and Gene Therapy, Universitat Autònoma de Barcelona , Bellaterra 08193, Spain .
authors.forename: Meritxell
authors.initials: M
authors.lastname: Morró
authors.forename: Joan
authors.initials: J
authors.lastname: Teichenne
authors.forename: Veronica
authors.initials: V
authors.lastname: Jimenez
authors.forename: Ramona
authors.initials: R
authors.lastname: Kratzer
authors.forename: Serena
authors.initials: S
authors.lastname: Marletta
authors.forename: Luca
authors.initials: L
authors.lastname: Maggioni
authors.forename: Cristina
authors.initials: C
authors.lastname: Mallol
authors.forename: Jesus
authors.initials: J
authors.lastname: Ruberte
authors.forename: Stefan
authors.initials: S
authors.lastname: Kochanek
authors.forename: Fatima
authors.initials: F
authors.lastname: Bosch
authors.forename: Eduard
authors.initials: E
authors.lastname: Ayuso
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000469:Alkaline Phosphatase / Q000097:blood; D000818:Animals; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000235:genetics*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D007150:Immunohistochemistry; D007328:Insulin / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D010179:Pancreas / Q000378:metabolism*; D010196:Pancreatic Elastase / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D014161:Transduction, Genetic / Q000379:methods*
chemical_list: D007328:Insulin; D049452:Green Fluorescent Proteins; D000469:Alkaline Phosphatase; D010196:Pancreatic Elastase