Tyrosine capsid-mutant AAV vectors for gene delivery to the canine retina from a subretinal or intravitreal approach.
Recombinant adeno-associated viruses are important vectors for retinal gene delivery. Currently utilized vectors have relatively slow onset, and for efficient transduction it is necessary to deliver treatment subretinally, with the potential for damage to the retina. Amino-acid substitutions in the viral capsid improve efficiency in rodent eyes by evading host responses. As dogs are important large animal models for human retinitis pigmentosa, we evaluated the speed and efficiency of retinal transduction using capsid-mutant vectors injected both subretinally and intravitreally. We evaluated AAV serotypes 2 and 8 with amino-acid substitutions of surface-exposed capsid tyrosine residues. The chicken beta-actin promoter was used to drive green fluorescent protein expression. Twelve normal adult beagles were injected; four dogs received intravitreal injections and eight dogs received subretinal injections. Capsid-mutant viruses tested included AAV2(quad Y-F) (intravitreal and subretinal) and self-complementary scAAV8(Y733F) (subretinal only). Contralateral control eyes received injections of scAAV5 (subretinal) or scAAV2 (intravitreal). Subretinally delivered vectors had a faster expression onset than intravitreally delivered vectors. Subretinally delivered scAAV8(Y733F) had a faster onset of expression than scAAV5. All subretinally injected vector types transduced the outer retina with high efficiency and the inner retina with moderate efficiency. Intravitreally delivered AAV2(quad Y-F) had a marginally higher efficiency of transduction of both outer retinal and inner retinal cells than scAAV2. Because of their rapid expression onset and efficient transduction, subretinally delivered capsid-mutant AAV8 vectors may increase the efficacy of gene therapy treatment for rapid photoreceptor degenerative diseases. With further refinement, capsid-mutant AAV2 vectors show promise for retinal gene delivery from an intravitreal approach.
Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, MI, USA.
F M
FM
Mowat
Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, MI, USA.
K R
KR
Gornik
Department of Ophthalmology, University of Florida College of Medicine, Gainesville, FL, USA.
A
A
Dinculescu
Department of Ophthalmology, University of Florida College of Medicine, Gainesville, FL, USA.
S L
SL
Boye
Department of Ophthalmology, University of Florida College of Medicine, Gainesville, FL, USA.
W W
WW
Hauswirth
Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, MI, USA.
S M
SM
Petersen-Jones
Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, MI, USA.
J T
JT
Bartoe
D019943:Amino Acid Substitution; D000818:Animals; D002213:Capsid; D000229:Dependovirus / Q000235:genetics* / Q000502:physiology; D004285:Dogs; D005260:Female; D005822:Genetic Vectors; D006801:Humans; D056965:Injections, Intraocular; D008297:Male; D009154:Mutation; D011994:Recombinant Proteins / Q000378:metabolism; D012160:Retina / Q000378:metabolism* / Q000821:virology; D014161:Transduction, Genetic; D014443:Tyrosine; D056189:Viral Tropism
D011994:Recombinant Proteins; D014443:Tyrosine