Intrinsic phospholipase A2 activity of adeno-associated virus is involved in endosomal escape of incoming particles.

The unique region of the VP1 capsid protein of adeno-associated viruses (AAV) in common with autonomously replicating parvoviruses comprises a secreted phospholipase A2 (sPLA2) homology domain. While the sPLA2 domain of Minute Virus of Mice has recently been shown to mediate endosomal escape by lipolytic pore formation, experimental evidence for a similar function in AAV infection is still lacking. Here, we explored the function of the sPLA2 domain of AAV by making use of the serotype 2 mutant (76)HD/AN.

Engineering adeno-associated virus serotype 2-based targeting vectors using a new insertion site-position 453-and single point mutations.

Background: Genetic modification of capsid proteins by peptide insertion has created the possibility of using adeno-associated viral (AAV) vectors for receptor specific gene transfer (AAV targeting). The most common site used for insertion in AAV serotype 2 capsids are amino acid positions 587 and 588 located at the second highest capsid protrusion. Reasoning that peptide insertions at the most exposed position augments target receptor interaction, we explored position 453 as a new insertion site.

Combinatorial engineering of a gene therapy vector: directed evolution of adeno-associated virus.

Background: Viruses are being exploited as vectors to deliver therapeutic genetic information into target cells. The success of this approach will depend on the ability to overcome current limitations, especially in terms of safety and efficiency, through molecular engineering of the viral particles.

Methods: Here we show that in vitro directed evolution can be successfully performed to randomize the viral capsid by error prone PCR and to obtain mutants with improved phenotype.