Reversal of blindness in animal models of leber congenital amaurosis using optimized AAV2-mediated gene transfer.
We evaluated the safety and efficacy of an optimized adeno-associated virus (AAV; AAV2.RPE65) in animal models of the RPE65 form of Leber congenital amaurosis (LCA). Protein expression was optimized by addition of a modified Kozak sequence at the translational start site of hRPE65. Modifications in AAV production and delivery included use of a long stuffer sequence to prevent reverse packaging from the AAV inverted-terminal repeats, and co-injection with a surfactant. The latter allows consistent and predictable delivery of a given dose of vector. We observed improved electroretinograms (ERGs) and visual acuity in Rpe65 mutant mice. This has not been reported previously using AAV2 vectors. Subretinal delivery of 8.25 x 10(10) vector genomes in affected dogs was well tolerated both locally and systemically, and treated animals showed improved visual behavior and pupillary responses, and reduced nystagmus within 2 weeks of injection. ERG responses confirmed the reversal of visual deficit. Immunohistochemistry confirmed transduction of retinal pigment epithelium cells and there was minimal toxicity to the retina as judged by histopathologic analysis. The data demonstrate that AAV2.RPE65 delivers the RPE65 transgene efficiently and quickly to the appropriate target cells in vivo in animal models. This vector holds great promise for treatment of LCA due to RPE65 mutations.
Bennicelli
Jeannette
J
Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6069, USA. jebennet@mail.med.upenn.edu
Wright
John Fraser
JF
Komaromy
Andras
A
Jacobs
Jonathan B
JB
Hauck
Bernd
B
Zelenaia
Olga
O
Mingozzi
Federico
F
Hui
Daniel
D
Chung
Daniel
D
Rex
Tonia S
TS
Wei
Zhangyong
Z
Qu
Guang
G
Zhou
Shangzhen
S
Zeiss
Caroline
C
Arruda
Valder R
VR
Acland
Gregory M
GM
Dell'Osso
Lou F
LF
High
Katherine A
KA
Maguire
Albert M
AM
Bennett
Jean
J
D000818:Animals; D001766:Blindness / Q000235:genetics / Q000628:therapy*; D002352:Carrier Proteins / Q000235:genetics / Q000502:physiology; D000229:Dependovirus / Q000235:genetics*; D004285:Dogs; D004596:Electroretinography; D005136:Eye Proteins / Q000235:genetics / Q000502:physiology; D005822:Genetic Vectors / Q000235:genetics; D007150:Immunohistochemistry; D051379:Mice; D018345:Mice, Knockout; D029242:Optic Atrophy, Hereditary, Leber / Q000235:genetics / Q000628:therapy; D019745:cis-trans-Isomerases; D000099178:Retinoid Isomerohydrolase
D002352:Carrier Proteins; D005136:Eye Proteins; D019745:cis-trans-Isomerases; D000099178:Retinoid Isomerohydrolase