Abstract
Purpose :
The majority of retinal disorders involve the Photoreceptors (PR). AAV-mediated gene delivery to these cells requires a subretinal injection- a surgical approach. In contrast, intravitreal injections are a routine office procedure. Recombinant AAV vectors do not penetrate the retina when injected into the vitreous. One purpose of our study was to develop an AAV vector that can infect cells in the outer retina following intravitreal injection. Another purpose of our study was to develop an AAV vector that can infect the Ciliary Body (CB) and Trabecular Meshwork (TM) to deliver genes relevant for the treatment of glaucoma.
Methods :
We developed a cell penetrating peptide (Nuc1) that could deliver proteins into cells of the outer retina following intravitreal injection. Nuc1 did not need to be chemically linked to its cargo. We discovered that Nuc1 could facilitate the penetration of large molecules including AAV vectors into the outer retina. We genetically incorporated the Nuc1 sequence directly into the AAV capsid. Using this platform, we generated GFP-expressing AAV vectors and injected them intravitreally or intracamerally in mice. In addition, we generated AAV vectors expressing NRF2, R-Ras, Aflibercept and Decorin. Each of these vectors were injected into the vitreous of an appropriate murine model of retinal degeneration or intracamerally in a model of glaucoma.
Results :
Mice injected intravitreally with AAV expressing GFP exhibited pan retinal expression of GFP in the photoreceptors, RPE, bipolar cells and retinal ganglion cells. Mice injected intracamerally exhibited expression of GFP in the CB, TM and cornea. NRF2 expressing virus injected into the vitreous significantly reduced oxidative stress in wild type and NRF2 -/- mice following injection with MNU. R-Ras and Aflibercept -expressing AAV significantly reduced laser induced choroidal neovascularization (CNV). Decorin-expressing AAV significantly reduced CNV and fibrosis in the retina. Furthermore, decorin-expressing AAV injected intracamerally significantly reduced intraocular pressure (IOP) and ganglion cell (GC) death in a model of glaucoma.
Conclusions :
We have generated an AAV vector that can deliver transgenes to the outer retina including PR and RPE following intravitreal injection or CB, TM and cornea following intracameral injection.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.