What is Adeno-associated virus (AAV) vector?

Adeno Associated Virus (AAV) Adeno-associated virus (AAV) is a small-single strand DNA virus, member of human parvovirus, originally described in the 1960s by Bob Atchison at Pittsburgh and Wallace Rowe at NIH as a contaminant in preparation of adenovirus [1,2]. Shortly after its discovery, AAV was then isolated from humans, but serological studies suggested that AAV itself did not cause any disease despite being present in people infected with helper viruses such as adenovirus or herpes virus [3].

With the development of recombinant AAV vectors (rAAV), the adenovirus helper genes required for AAV replication have been identified, which can be cloned into plasmids for AAV production to liberate the need of helper virus. Currently, AAV production adopts the 3-plasmid co-transfection system (AAV plasmid with gene of interest, AAV packaging plasmid AAV-RC (AAV replication and AAV capsid) and pHelper (AAV helper plasmid)) in AAV-293 cells, which significantly simplifies the AAV purification process.