Previous Article | Next Article ![]()
Journal of Virology, November 2007, p. 12260-12271, Vol. 81, No. 22
0022-538X/07/$08.00+0 doi:10.1128/JVI.01304-07
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Department of Biochemistry and Molecular Biology, Center for Structural Biology, McKnight Brain Institute,1 Division of Cellular and Molecular Therapy, Department of Pediatrics,2 Department of Molecular Genetics and Microbiology and Powell Gene Therapy Center, College of Medicine, University of Florida, Gainesville, Florida 326103
Received 14 June 2007/ Accepted 30 July 2007
Adeno-associated viruses (AAVs) are being developed as gene therapy vectors, and their efficacy could be improved by a detailed understanding of their viral capsid structures. AAV serotype 8 (AAV8) shows a significantly greater liver transduction efficiency than those of other serotypes, which has resulted in efforts to develop this virus as a gene therapy vector for hemophilia A and familial hypercholesterolemia. Pseudotyping studies show that the differential tissue tropism and transduction efficiencies exhibited by the AAVs result from differences in their capsid viral protein (VP) amino acids. Towards identifying the structural features underpinning these disparities, we report the crystal structure of the AAV8 viral capsid determined to 2.6-Å resolution. The overall topology of its common overlapping VP is similar to that previously reported for the crystal structures of AAV2 and AAV4, with an eight-stranded ß-barrel and long loops between the ß-strands. The most significant structural differences between AAV8 and AAV2 (the best-characterized serotype) are located on the capsid surface at protrusions surrounding the two-, three-, and fivefold axes at residues reported to control transduction efficiency and antibody recognition for AAV2. In addition, a comparison of the AAV8 and AAV2 capsid surface amino acids showed a reduced distribution of basic charge for AAV8 at the mapped AAV2 heparin sulfate receptor binding region, consistent with an observed non-heparin-binding phenotype for AAV8. Thus, this AAV8 structure provides an additional platform for mutagenesis efforts to characterize AAV capsid regions responsible for differential cellular tropism, transduction, and antigenicity for these promising gene therapy vectors.
Published ahead of print on 29 August 2007.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»