CAG-ChIEF-tdTOMATO AAV (Serotype 2)

Adeno-associated viruses (AAVs) are small, non-enveloped ssDNA viruses that are not associated with any known disease. They package a linear 4.7 kb ssDNA genome into a T = 1 icosahedral capsid. The genome contains 2 open reading frames (ORFs), rep and cap, encoding replication (Rep) and capsid viral proteins (VP), respectively. In addition, frameshift reading in the cap ORF leads to the expression of assembly activation protein (AAP) and membrane-associated accessory protein (MAAP). The capsid is randomly assembled from 60 copies of VP (VP1, VP2, and VP3) in a ratio of 1:1:10, respectively. The sequence of VP3 is contained in VP2, and the sequence of VP2 is contained in VP1, so the N-terminus of VP1 is called the VP1 unique region (VP1u). The overlapping region between VP1 and VP2 is called the VP1/2 common region. AAP is important for the translocation of translated VP from the cytoplasm to the nucleus and aids in the assembly of the viral capsid.

Currently, 13 AAV serotypes (AAV1-AAV13) have been identified and more than 150 genotypes have been isolated from humans and non-human primates. Specifically, AAV1, AAV2, AAV3, AAV5, AAV6, and AAV9 have been isolated from human hosts. AAV4, AAV7, AAV8, AAV10, and AAV11 have been found in non-human primates, and two serotypes, AAV12 and AAV13, have been found as contaminants in adenovirus stocks. AAV-based viral vectors show good promise in therapeutic gene transfer and are the most commonly used viral gene delivery method. AAV2 is the most widely used AAV serotype in clinical gene therapy trials.