title: Transduction of rat pancreatic islets with pseudotyped adeno-associated virus vectors.
abstract: BACKGROUND
  Pancreatic islet transplantation is a promising treatment for type I diabetes mellitus, but current immunosuppressive strategies do not consistently provide long-term survival of transplanted islets. We are therefore investigating the use of adeno-associated viruses (AAVs) as gene therapy vectors to transduce rat islets with immunosuppressive genes prior to transplantation into diabetic mice.
  
  
  RESULTS
  We compared the transduction efficiency of AAV2 vectors with an AAV2 capsid (AAV2/2) to AAV2 vectors pseudotyped with AAV5 (AAV2/5), AAV8 (AAV2/8) or bovine adeno-associated virus (BAAV) capsids, or an AAV2 capsid with an insertion of the low density lipoprotein receptor ligand from apolipoprotein E (AAV2apoE), on cultured islets, in the presence of helper adenovirus infection to speed expression of a GFP transgene. Confocal microscopy and flow cytometry were used. The AAV2/5 vector was superior to AAV2/2 and AAV2/8 in rat islets. Flow cytometry indicated AAV2/5-mediated gene expression in approximately 9% of rat islet cells and almost 12% of insulin-positive cells. The AAV2/8 vector had a higher dependence on the helper virus multiplicity of infection than the AAV 2/5 vector. In addition, the BAAV and AAV2apoE vectors were superior to AAV2/2 for transducing rat islets. Rat islets (300 per mouse) transduced with an AAV2/5 vector harboring the immunosuppressive transgene, tgf beta 1, retain the ability to correct hyperglycemia when transplanted into immune-deficient diabetic mice.
  
  
  CONCLUSIONS
  AAV2/5 vectors may therefore be useful for pre-treating donor islets prior to transplantation.
authors.affiliation: Laboratory of Molecular and Cellular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892, USA. anthonycraig3@gmail.com
authors.forename: Anthony T
authors.initials: AT
authors.lastname: Craig
authors.forename: Oksana
authors.initials: O
authors.lastname: Gavrilova
authors.forename: Nancy K
authors.initials: NK
authors.lastname: Dwyer
authors.forename: William
authors.initials: W
authors.lastname: Jou
authors.forename: Stephanie
authors.initials: S
authors.lastname: Pack
authors.forename: Eric
authors.initials: E
authors.lastname: Liu
authors.forename: Klaus
authors.initials: K
authors.lastname: Pechhold
authors.forename: Michael
authors.initials: M
authors.lastname: Schmidt
authors.forename: Victor J
authors.initials: VJ
authors.lastname: McAlister
authors.forename: John A
authors.initials: JA
authors.lastname: Chiorini
authors.forename: E Joan
authors.initials: EJ
authors.lastname: Blanchette-Mackie
authors.forename: David M
authors.initials: DM
authors.lastname: Harlan
authors.forename: Roland A
authors.initials: RA
authors.lastname: Owens
mesh_terms: D000818:Animals; D002460:Cell Line; D000229:Dependovirus / Q000235:genetics* / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics / Q000601:surgery / Q000628:therapy*; D005260:Female; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D007515:Islets of Langerhans / Q000378:metabolism / Q000821:virology*; D016381:Islets of Langerhans Transplantation; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D051381:Rats; D017208:Rats, Wistar; D014161:Transduction, Genetic / Q000379:methods*