Alternate serotype adenovector provides long-term therapeutic gene expression in the eye.
OBJECTIVE
To determine whether the duration of transgene expression from an alternate adenovector serotype, Ad35, can provide advantages over an Ad5 serotype vector following a single intravitreal (IVT) administration.


METHODS
To assess the transgene expression profile, mice received one IVT injection of Ad5- or Ad35-based vectors expressing green fluorescent protein (GFP), luciferase or pigment epithelium-derived factor (PEDF). At specified time points following vector administration, eyes were monitored for GFP expression, or eyes were harvested and assayed for adenovector genomes, luciferase activity or PEDF levels. Ad35-based vector in vivo biologic activity was investigated using a mouse model of laser-induced choroidal neovascularization (CNV). On Day 0, mice received one IVT injection of Ad5.PEDF or Ad35.PEDF (HI-RGD) followed by laser-induced CNV on Day 28. Fourteen days later, animals were perfused with fluorescein-labeled dextran and CNV lesion size quantitated in choroidal flat mounts.


RESULTS
These studies demonstrate that following a single IVT adenovector administration: 1) gene expression is prolonged following administration of an Ad35 compared to an Ad5-based vector; 2) the amount of vector genomes in the eye remain constant out to 60 days post injection of both Ad5 and Ad35-based vectors; and 3) an Ad35.PEDF (HI-RGD) vector inhibits CNV in a mouse model at 42 days post injection.


CONCLUSIONS
These studies show that transgene and genome levels are prolonged in the eye following 1 IVT injection of an Ad35-based vector. Moreover, therapeutic gene levels from 1 IVT administration of Ad35.PEDF (HI-RGD) vector block abnormal blood vessel growth in a laser-induced CNV mouse model.
Hamilton
Melissa M
MM
Pre-Clinical Sciences, GenVec Inc, Gaithersburg, MD 20878, USA.
Byrnes
Gordon A
GA
Gall
Jason G
JG
Brough
Douglas E
DE
King
C Richter
CR
Wei
Lisa L
LL
D000256:Adenoviridae / Q000145:classification* / Q000235:genetics*; D000818:Animals; D020256:Choroidal Neovascularization / Q000235:genetics / Q000473:pathology / Q000628:therapy; D005123:Eye / Q000378:metabolism* / Q000473:pathology; D005136:Eye Proteins / Q000235:genetics / Q000627:therapeutic use; D005260:Female; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000235:genetics*; D016678:Genome; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D007267:Injections; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009414:Nerve Growth Factors / Q000235:genetics / Q000627:therapeutic use; D016133:Polymerase Chain Reaction; D012703:Serotyping; D015843:Serpins / Q000235:genetics / Q000627:therapeutic use; D013997:Time Factors; D019076:Transgenes; D000099174:Pigment Epithelium-Derived Factor
D005136:Eye Proteins; D049452:Green Fluorescent Proteins; D008156:Luciferases; D009414:Nerve Growth Factors; D015843:Serpins; D000099174:Pigment Epithelium-Derived Factor