Adeno-Associated Viruses

Abstract

Publisher Summary The adeno-associated viruses (AAV) are defective parvoviruses that require coinfection with an adenovirus for a productive infection. In many ways AAV is a unique virus because of its special properties of dependence on adenovirus for replication and the fact that both plus and minus strands are encapsidated. It is a parvovirus but differs from the autonomous parvoviruses in its defectiveness, the encapsidation of both DNA strands, and the existence of an inverted terminal nucleotide sequence repetition in its genome. The ability of AAV to inhibit adenovirus DNA replication may indicate a common feature in an early step of DNA replication in spite of the apparent overall differences in the mechanism of initiation. The ability of various adenovirus variants to help AAV DNA replication may be used to screen for new genes involved in adenovirus DNA replication. AAV may inhibit SV40 DNA replication but is not helped by SV40 coinfection at the level of DNA. AAV inhibition of adenovirus and herpes simplex virus oncogenicity is another interesting phenomenon. There are no data concerning the level at which the interference takes place. The only suggestive data in this regard come from the observation that AAV does not have an effect on adenovirus oncogenicity in newborn Syrian hamsters. AAV can establish a latent infection in the normal host in the absence of concomitant adenovirus infection.