ABSTRACT
The adeno-associated virus (AAV) has been the subject of intense study recently by investigators working with viral-based gene delivery systems. AAV is a member of the Dependovirus genus in the Parvoviridae family. The features that make AAV an attractive potential gene therapy vector include nonpathogenicity, site-specific integration in the absence of a helper virus infection, and the ability to remove all of the viral genes without loss of infectivity. AAV will undergo a productive infection in the presence of a helper virus, either adenovirus or herpes simplex virus. The preintegration site has been cloned and inserted into an Epstein-Barr virus-based shuttle vector for delivery to the cell. No pathogenic consequences have been implicated for latent AAV infection. A key issue for gene therapists has been whether subsequent infection in vivo with adenovirus and AAV would lead to rescue, replication, and loss of transgene. AAV vectors have been reported to have high transduction frequencies in cells of diverse lineages.
