Retinal photoreceptor cells (via AAV5 capsid and GRK1 promoter) (AAV5-GRK1)

Retinal photoreceptor cells via AAV5 capsid and GRK1 promoter-mediated transduction describes a specialized gene therapy delivery platform designed for high-precision targeting of rods and cones within the neurosensory retina. The Adeno-associated virus serotype 5 (AAV5) is selected for its superior ability to penetrate the deep layers of the retina and transduce photoreceptors compared to other serotypes like AAV2 (Auricchio et al., 2001, Molecular Therapy). To ensure cell-type specificity, the G protein-coupled receptor kinase 1 (GRK1) promoter—also known as the rhodopsin kinase promoter—is utilized to drive transgene expression exclusively in photoreceptor cells, avoiding off-target expression in the retinal pigment epithelium or inner retinal layers (Khani et al., 2007, IOVS). The mechanism involves the binding of AAV5 to cell surface receptors, followed by endocytosis and nuclear entry, where the GRK1 promoter initiates the transcription of the therapeutic gene only in the presence of photoreceptor-specific transcription factors (Auricchio et al., 2001). This strategy is a cornerstone for treating inherited retinal diseases (IRDs) such as X-linked retinitis pigmentosa (XLRP) and achromatopsia, where the primary pathology is located in the photoreceptors (Beltran et al., 2017, PNAS). Clinical candidates like botaretigene kuprevigene (AAV5-hGRK1-hRPGR) leverage this system to restore functional protein levels in patients with RPGR mutations (MeiraGTx, 2023). Safety considerations for this approach include potential immune responses to the viral capsid and risks associated with the subretinal surgical delivery procedure (Bucher et al., 2021, Frontiers in Immunology).

Other names

Photoreceptor-specific AAV5 deliveryAAV5-GRK1 expression systemRod and cone transduction system

Viral-mediated delivery of therapeutic genetic material specifically to rod and cone photoreceptors using a cell-specific promoter.