Intravitreal Injection of an Exosome-Associated Adeno-Associated Viral Vector Enhances Retinoschisin 1 Gene Transduction in the Mouse Retina
Weiping Wang, Jingyang Liu, Mingzhu Yang, Ruiqi Qiu, Ya Li, Shasha Bian, Bingtao Hao, Bo Lei
Abstract
To investigate whether exosome-associated adeno-associated virus (AAV) retinoschisin 1 ( RS 1) vector improved the transduction efficiency of RS 1 in the mouse retina. pAAV2-RS1-ZsGreen plasmid was constructed by homologous recombination. Exosome-associated AAV vectors containing human RS 1 gene (exosome-associated AAV [exo-AAV]2-RS1-ZsGreen) were isolated from producer cells' supernatant, and confirmed by transmission electron microscopy, nanoparticle tracking analysis, and western blotting. In vitro , HEK-293T cells were transduced with AAV2-RS1-ZsGreen and exo-AAV2-RS1-ZsGreen. In vivo , 1 μL of AAV2-RS1-ZsGreen or 1 μL exo-AAV2-RS1-ZsGreen (2 × 10 8 genome copies/μL) was injected intravitreally into the C57BL/6J mouse eyes. Phosphate buffer saline was injected as controls. The mRNA and the protein expression in the retina were detected. Exo-AAV2-RS1-ZsGreen possessed lipid bilayers, a saucer-like structures and an average of 120 nm particle size. The expression of RS 1 and ZsGreen in exo-AAV2-RS1-ZsGreen group were 7.6 times and 5.7 times that of AAV2-RS1-ZsGreen group in HEK-293T cells, respectively. Furthermore, RS1 protein expression increased by 11.8 times in HEK-293T cells. Intravitreal injection of exo-AAV significantly increased the transduction efficiency of RS1 than AAV. Exo-AAV may be a powerful gene delivery system for gene therapy of X-link retinoschisis as well as other inherited retina degenerations.