AAV8-vectored suprachoroidal gene transfer produces widespread ocular transgene expression
Kun Ding, Jikui Shen, Zibran Hafiz, Sean F. Hackett, Raquel Lima e Silva, Mahmood Khan, Valeria E. Lorenc, Daiqin Chen, Rishi Chadha, Minie Zhang, Sherri Van Everen, Nicholas Buss, Michele Fiscella, Olivier Danos, Peter A. Campochiaro
Kun Ding, Jikui Shen, Zibran Hafiz, Sean F. Hackett, Raquel Lima e Silva, Mahmood Khan, Valeria E. Lorenc, Daiqin Chen, Rishi Chadha, Minie Zhang, Sherri Van Everen, Nicholas Buss, Michele Fiscella, Olivier Danos, Peter A. Campochiaro
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Research Article Ophthalmology

AAV8-vectored suprachoroidal gene transfer produces widespread ocular transgene expression

Abstract

There has been great progress in ocular gene therapy, but delivery of viral vectors to the retinal pigmented epithelium (RPE) and retina can be challenging. Subretinal injection, the preferred route of delivery for most applications, requires a surgical procedure that has risks. Herein we report a novel gene therapy delivery approach, suprachoroidal injection of AAV8 vectors, which is less invasive and could be done in an outpatient setting. Two weeks after suprachoroidal injection of AAV8.GFP in rats, GFP fluorescence covered 18.9% of RPE flat mounts and extended entirely around sagittal and transverse sections in RPE and photoreceptors. After 2 suprachoroidal injections of AAV8.GFP, GFP fluorescence covered 30.5% of RPE flat mounts. Similarly, widespread expression of GFP occurred in nonhuman primate and pig eyes after suprachoroidal injection of AAV8.GFP. Compared with subretinal injection in rats of RGX-314, an AAV8 vector expressing an anti-VEGF Fab, suprachoroidal injection of the same dose of RGX-314 resulted in similar expression of anti-VEGF Fab and similar suppression of VEGF-induced vascular leakage. Suprachoroidal AAV8 vector injection provides a noninvasive outpatient procedure to obtain widespread transgene expression in retina and RPE.

Authors

Kun Ding, Jikui Shen, Zibran Hafiz, Sean F. Hackett, Raquel Lima e Silva, Mahmood Khan, Valeria E. Lorenc, Daiqin Chen, Rishi Chadha, Minie Zhang, Sherri Van Everen, Nicholas Buss, Michele Fiscella, Olivier Danos, Peter A. Campochiaro

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Figure 3

Increase in area and level of GFP expression after a second suprachoroidal injection of AAV8.GFP in rats.

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Increase in area and level of GFP expression after a second suprachoroid...
Brown Norway rats (n = 21) were given a 3 μL suprachoroidal injection containing 2.85 × 1010 GCs of AAV8.GFP vector superiorly in both eyes. Three days later, one eye was given an inferior 3 μL suprachoroidal injection containing 2.85 × 1010 GCs of AAV8.GFP and the other eye received no injection. After 11 days, RPE flat mounts showed high GFP fluorescence in 1 localized region of eyes that had received 1 injection (A) and in 2 regions of eyes that received 2 injections (B); scale bars: 1000 μm. The mean percentage of total RPE area that was fluorescent was significantly greater in eyes that received 2 injections (30.52%) compared with those that received 1 injection (18.85 %, n = 6, P = 0.026 by Mann-Whitney U test). (C) For the remaining 15 rats, 2 eyes in the single injection group had been traumatized and could not be used, but for the remainder, homogenates of RPE/choroid and retinas were used to measure total protein and then GFP protein was measured by ELISA. The mean (± SEM) level of GFP per mg protein was significantly higher in retinas and RPE/choroid from eyes that received 2 injections compared with those that received 1 injection. *P = 0.0008; **P = 0.005 by Mann-Whitney U test and unpaired t test.