AAV DJ-GFP

Adeno-associated virus (AAV) vectors are widely used to treat inherited retinal diseases, but their transduction efficiency by intravitreal injection still needs to be improved. Here, the researchers explored the transduction efficiency of AAV-DJ(K137R)-GFP in different retinal cells of normal mice and the therapeutic effect of AAV-DJ(K137R)-Rs1 on the retinal function and structure of Rs1-KO mice. Intravitreal injection of AAV-DJ(K137R)-GFP showed that the vector transduced cells in various layers of the retina, including the inner nuclear layer and the photoreceptor layer. Intravitreal injection of AAV-DJ(K137R)-Rs1 found that retinal function and structure of Rs1-KO mice were improved 3 months after injection of the vector. These findings show that the AAV-DJ (K137R) vector can efficiently and safely penetrate the inner limiting membrane and transduce different layers of retinal cells for a long time, while being able to continuously and efficiently express the target therapeutic protein, making it a candidate therapeutic vector for X-linked retinoschisis (XLRS).

The researchers first observed the time course of enhanced retinal green fluorescent protein (GFP) expression after intravitreal injection of AAV in mice. Images taken 14d\21d\28d\35d\3M\6M\12M after intravitreal injection clearly showed fluorescent expression in the retina, with the optic disc as the focal point. Among them, AAV-DJ-GFP and AAV-DJ (K137R)-GFP vectors showed GFP fluorescence expression on the 14th day after injection, and the fluorescence intensity reached a peak 35 days after injection. GFP fluorescence could still be detected 12 months after fluorescence. GFP expression in the retina injected with AAV8 was limited to the optic disc (Figure 1A). In contrast, after injection of AAV-DJ-GFP and AAV-DJ (K137R)-GFP, GFP signals accumulated in specific areas, such as around blood vessels covering Müller glial processes and around the optic disc (Figure 1B, C and D). Immunohistochemical analyses revealed GFP fluorescence expression in nerve fiber cells, horizontal cells, and Müller cells for AAV-DJ-GFP and AAV-DJ(K137R)-GFP (Figure 1F and G).

Figure 1. GFP expression in the murine retina following intravitreal injection of three AAV vectors. (Sun Y, et al., 2024)