Intravitreal injection of an exosome-associated adeno-associated viral vector enhances retinoschisin 1 gene transduction in the mouse retina.

Abstract

To investigate whether exosome-associated adeno-associated virus Retinoschisin 1 vector improved the transduction efficiency of RS1 in the mouse retina. pAAV2-RS1-ZsGreen plasmid was constructed by homologous recombination. Exosome-associated adeno-associated virus vectors containing human Retinoschisin 1 (RS1) gene (exo-AAV2-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 (2×108 genome copies/μl) was injected intravitreally into the C57BL/6J mouse eyes. PBS was injected as controls. The mRNA and the protein expression in the retina were detected. The results demonstrated exo-AAV2-RS1-ZsGreen possessed lipid bilayers, a saucer-like structures and an average of 120 nm particle size. The expression of RS1 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. RS1 protein expression increased by 11.8 times in HEK-293T. Furthermore, 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.