AAV9-CAG-shRNA

Adeno-associated viruses (AAVs) are non-pathogenic, single-stranded DNA (ssDNA) viruses of the Parvoviridae family that are used as vectors for gene delivery applications. To date, three AAV vector-mediated gene therapies have received commercial approval: Glybera, an AAV1 vector for the treatment of lipoprotein lipase deficiency, approved by the European Medicines Agency (EMA); Luxturna, an AAV2 vector for the treatment of Leber congenital amaurosis; and Zolgensma, an AAV9 vector for the treatment of spinal muscular atrophy type 1, both approved by the U.S. Food and Drug Administration (FDA). These approvals ushered in a new era of using this vector system to treat monogenic diseases. The virions of these viruses consist of a non-enveloped capsid with T=1 icosahedral symmetry and a diameter of ∼260 Å, encapsulating a ssDNA genome. Currently, 13 human and primate AAV serotypes have been described, as well as a large number of additional genomic isolates from different primate and non-primate species. The capsids of these different AAVs can differ by approximately 50% in amino acid sequence identity. The capsid is assembled from 60 subunits of three overlapping capsid viral proteins (VPs)—VP1 (∼82 kDa), VP2 (∼73 kDa), and VP3 (∼61 kDa)—in a 1:1:10 ratio. The individual VPs are expressed in the same open reading frame and share a C-terminus that contains the entire VP3. VP1 and VP2 represent N-terminal extended forms of VP3. In addition, VP1 shares the approximately 137 amino acids (aa) N-terminal to VP2. This unique region of VP1 (VP1u) contains the phospholipase A2 (PLA2) domain, the calcium-binding domain, and the nuclear localization signal, all of which are required for AAV infection.