title: Adeno-associated virus-mediated rhodopsin replacement provides therapeutic benefit in mice with a targeted disruption of the rhodopsin gene.
abstract: The rhodopsin gene (RHO) encodes a highly expressed G protein-coupled receptor that is central to visual transduction in rod photoreceptors. A suite of recombinant 2/5 adeno-associated viral (AAV) RHO replacement vectors has been generated in an attempt to recapitulate endogenous rhodopsin levels from exogenously delivered AAV vectors in the retina of mice with a targeted disruption in the rhodopsin gene (Rho(-/-) mice). Approximately 40% of wild-type mouse rhodopsin mRNA levels (RNA taken from whole retinas) was achieved in vivo in AAV-RHO-injected eyes, representing approximately 50-fold increases in expression compared with the initial vector. The main focus of this study was to test whether expression of AAV-RHO replacement in Rho(-/-) mice provided therapeutic benefit, which to date had not been achieved. Rho(-/-) mice neither elaborate rod outer segments nor have rod-derived electroretinograms (ERGs). Our results indicate for the first time in this model that subretinal AAV-RHO delivery leads not only to RHO immunolabeling but the generation of rod outer segments as evaluated by light and transmission electron microscopy. Improved histology was accompanied by rod photoreceptor activity as assessed by ERG for at least 12 weeks postinjection. The most efficient AAV-RHO constructs presented in this study provide sufficient levels of RHO to be of therapeutic benefit in Rho(-/-) mice and therefore represent important steps toward generating potent AAV-RHO replacement genes for gene therapy in RHO-linked human retinopathies.
authors.affiliation: Department of Genetics, Trinity College Dublin, Dublin 2, Ireland. palfia@tcd.ie
authors.forename: Arpad
authors.initials: A
authors.lastname: Palfi
authors.forename: Sophia
authors.initials: S
authors.lastname: Millington-Ward
authors.forename: Naomi
authors.initials: N
authors.lastname: Chadderton
authors.forename: Mary
authors.initials: M
authors.lastname: O'Reilly
authors.forename: Tobias
authors.initials: T
authors.lastname: Goldmann
authors.forename: Marian M
authors.initials: MM
authors.lastname: Humphries
authors.forename: Tiansen
authors.initials: T
authors.lastname: Li
authors.forename: Uwe
authors.initials: U
authors.lastname: Wolfrum
authors.forename: Peter
authors.initials: P
authors.lastname: Humphries
authors.forename: Paul F
authors.initials: PF
authors.lastname: Kenna
authors.forename: G Jane
authors.initials: GJ
authors.lastname: Farrar
mesh_terms: D000818:Animals; D015153:Blotting, Western; D000229:Dependovirus / Q000235:genetics*; D004596:Electroretinography; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D005822:Genetic Vectors; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012160:Retina / Q000378:metabolism* / Q000473:pathology; D017948:Retinal Rod Photoreceptor Cells / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012243:Rhodopsin / Q000502:physiology*
chemical_list: D012333:RNA, Messenger; D012243:Rhodopsin