Intracameral Delivery of AAV to Corneal Endothelium for Expression of Secretory Proteins

Matrix metalloproteinase-3 (MMP-3)-mediated gene therapy for glaucoma

Approximately 80 million people globally are affected by glaucoma, with a projected increase to over 110 million by 2040. Substantial issues surrounding patient compliance remain with topical eye drops, and up to 10% of patients become treatment resistant, putting them at risk of permanent vision loss. The major risk factor for glaucoma is elevated intraocular pressure, which is regulated by the balance between the secretion of aqueous humor and the resistance to its flow across the conventional outflow pathway. Here, we show that adeno-associated virus 9 (AAV9)-mediated expression of matrix metalloproteinase-3 (MMP-3) can increase outflow in two murine models of glaucoma and in nonhuman primates. We show that long-term AAV9 transduction of the corneal endothelium in the nonhuman primate is safe and well tolerated. Last, MMP-3 increases outflow in donor human eyes. Collectively, our data suggest that glaucoma can be readily treated with gene therapy-based methods, paving the way for deployment in clinical trials.

Controlled Release of rAAV Vectors from APMA-Functionalized Contact Lenses for Corneal Gene Therapy

As an alternative to eye drops and ocular injections for gene therapy, the aim of this work was to design for the first time hydrogel contact lenses that can act as platforms for the controlled delivery of viral vectors (recombinant adeno-associated virus, rAAV) to the eye in an effective way with improved patient compliance. Hydrogels of hydroxyethyl methacrylate (HEMA) with aminopropyl methacrylamide (APMA) (H₁: 40, and H₂: 80 mM) or without (H_c: 0 mM) were synthesized, sterilized by steam heat (121 °C, 20 min), and then tested for gene therapy using rAAV vectors to deliver the genes to the cornea. The hydrogels showed adequate light transparency, oxygen permeability, and swelling for use as contact lenses. Loading of viral vectors (rAAV-lacZ, rAAV-RFP, or rAAV-hIGF-I) was carried out at 4 °C to maintain viral vector titer. Release in culture medium was monitored by fluorescence with Cy3-rAAV-lacZ and AAV Titration ELISA. Transduction efficacy was tested through reporter genes lacZ and RFP in human bone marrow derived mesenchymal stem cells (hMSCs). lacZ was detected with X-Gal staining and quantified with Beta-Glo^®, and RFP was monitored by fluorescence. The ability of rAAV-hIGF-I-loaded hydrogels to trigger cell proliferation in hMSCs was evaluated by immunohistochemistry. Finally, the ability of rAAV-lacZ-loaded hydrogels to transduce bovine cornea was confirmed through detection with X-Gal staining of β-galactosidase expressed within the tissue.