Abstract
Purpose: :
The newly developed viral vector adeno-associated virus serotype-9 (AAV-9) has shown high transduction efficiency in a variety of tissues, including the heart, liver, lung, kidney, and skeletal muscle. We studied AAV-9-mediated gene transfer in the mouse retina.
Methods: :
1×109 viral genome particles of AAV-9 AV.RSV.AP (single injection in 1 µl) were administered either subretinally or intravitreally to young (17-day-old) and adult (2 to 3-month-old) mice. Transgene expression was examined by histochemical staining at 20 and 50 days after injection.
Results: :
Subretinal injection yielded widespread transduction throughout the retina. High expression was observed in the middle retina outer plexiform layer (OPL) and Müller cells in both young and adult mice. Expressions were also observed in the retinal pigment epithelium (RPE) layer, inner plexiform layer (IPL), and retinal ganglion cell (RGC) layer. Transduction was not as efficient with the intravitreal approach. No expression was observed in young mice. In adult mice, expression was localized at the injection site.
Conclusions: :
Our data suggest that AAV-9 is a potent vector to deliver the therapeutic gene(s) to the whole retina. The middle retina has been a challenging structure to target by the available gene therapy vectors. Efficient AAV-9 transduction of the mid-retina OPL is particularly encouraging for developing treatments for diseases that primarily affect this layer.
Keywords: gene transfer/gene therapy • adenovirus • retina: distal (photoreceptors, horizontal cells, bipolar cells)