AAV2-antiVEGFscFv gene therapy for retinal neovascularization

Retinal neovascularization (NV) may lead to irreversible vision impairment, the main treatment for which is the inhibition of vascular endothelial growth factor (VEGF). Existing drugs show limited clinical benefits because of their high prices and short half-lives, which increase the financial burden and medical risks to patients. Gene therapy on the basis of adeno-associated viruses is a promising approach to overcome these limitations because of the nonintegrative nature, low immunogenicity, and potential long-term gene expression of adeno-associated viruses. In this study, we constructed a novel recombinant adeno-associated virus with the single-chain fragment variable (scFv) fragment of the anti-VEGF antibody, AAV2-antiVEGFscFv, consisting of the VH and VL structural domains of IgG. AAV2-antiVEGFscFv effectively inhibited NV, retinal leakage, and retinal detachment in oxygen-induced retinopathy (OIR) mice, Tet/opsin/VEGF double-transgenic mice, and VEGF-induced rabbit NV models. AAV2-antiVEGFscFv also significantly suppressed VEGF-induced inflammation. Furthermore, we showed that AAV2-antiVEGFscFv could be sustainably expressed for a prolonged period and exhibited low immunotoxicity in vivo. This study indicates that AAV2-antiVEGFscFv could be a potential approach for NV treatment and provides strong support for preclinical research.