What are adeno-associated viruses (AAVs) and why are they used as vectors?

Adeno-associated viruses (AAVs) are single-stranded non-enveloped DNA viruses which reproduce only in the presence of a helper virus (either an adenovirus or a herpesvirus). AAVs have two stages in their life cycle post-infection. If a helper virus is present, AAVs enter the lytic stage, resulting in gene expression, genome replication, and virus production. If not, AAVs repress gene expression and replication while establishing latency by integrating into chromosome 19 of the human genome.1

AAVs can stably infect both dividing and non-dividing cells, and this, combined with the wild-type virus’s lack of pathogenicity makes AAVs an attractive choice for research and therapeutic gene transfer approaches. However, AAVs are highly immunogenic, and many individuals possess pre-existing antibodies against AAVs from prior infection.1 For further expansion on related areas and topics please visit viral vectors in our resource center here.

Reference:
1. S. Daya and K.I. Berns, “Gene Therapy Using Adeno-Associated Virus Vectors,” Clin Microbiol Rev 21(4): 583-593, 2008.