AAV PHP.S-CAG-GFP

AAV was originally discovered in the 1960s as a contaminant of adenovirus stocks. Today, AAV is one of the most commonly used viral vectors currently used to deliver genes to the brain due to its lack of cytotoxicity and long-term expression in neurons. In addition, they are attractive candidates for creating viral vectors for gene therapy due to their ability to infect humans. Notably, the immune response induced by AAV is very mild, making it an excellent candidate for gene therapy with minimal risk of side effects.

AAV has a linear, single-stranded DNA genome of approximately 4.7 kb in length. Lacking its own polymerase, the AAV genome relies on cellular polymerases for replication. Despite the widespread distribution of AAV, its almost non-existent pathogenicity can be attributed to its inability to replicate on its own. Instead, they require a replicating co-infecting virus to initiate an effective infection. Only replication and capsid genes are present in their genome for viral replication regulation and capsid structure. During the infection cycle, AAV enters cells via receptor-mediated endocytosis and is transported to the nucleus via clathrin-coated vesicles. Once inside the nucleus, the viral capsid is lost and the viral genome is released, which can either integrate into the host cell genome (in the absence of co-infecting viruses) or enter the lytic cycle (in the presence of co-infecting viruses).