Recombinant AAV vectors are promising candidates for gene therapy of several human genetic disorders. Despite early successes in clinical trials, our understanding of the mechanisms underlying AAV host and tissue tropism is incomplete. During the previous funding period, we made significant progress in mapping novel AAV-glycan receptor interactions and engineering a new class of liver-detargeted AAV vectors. In addition, we optimized structural tools, in vitro cellular assays and in vivo animal studies pertinent to the characterization of AAV vectors. Although this information provided further insight into the biology of certain AAV serotypes, significant gaps exist in our understanding of numerous other AAV strains currently being tested in clinical studies. In the current proposal, we have assembled a team of experienced investigators in the fields of structural virology, glycobiology, vascular biology and AAV vectors to dissect the biology of several naturally occurring as well as new, lab-derived AAV mutants. Specifically, we will map the structural determinants of AAV-glycan interactions using a battery of molecular modeling, computational ligand docking, glycan array and molecular cloning tools. We then propose to reengineer glycan binding footprints on different AAV serotypes to generate novel mutants with altered tissue tropism. Comprehensive studies investigating the role of different tissue glycans as well as integrin co-receptors on the tropism, biodistribution, pharmacokinetics, and transvascular transport of AAV vectors using mouse models will also be undertaken. The long term goal of the proposed studies is to obtain a thorough understanding of AAV biology in different hosts. If successful, the current proposal could provide significant new insight into the influence of glycans and integrins on AAV tissue tropism. In addition to providing a roadmap for structure-driven design of improved AAV vectors, the proposed studies could guide the selection of appropriate AAV strains for further clinical development.

Public Health Relevance

Despite early successes in gene therapy clinical trials, our understanding of viral vectors remains incomplete. Studying the biology of viral vectors using different cross-disciplinary tools is likely to provide new insight into the factors that determine viral tissue tropism in different hosts. If successful, the current proposal could provide a roadmap for designing safer and improved viral vectors for further clinical development.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
2R01HL089221-06
Application #
8577188
Study Section
Gene and Drug Delivery Systems Study Section (GDD)
Program Officer
Banks-Schlegel, Susan P
Project Start
2007-07-01
Project End
2017-12-31
Budget Start
2014-01-01
Budget End
2014-12-31
Support Year
6
Fiscal Year
2014
Total Cost
$347,447
Indirect Cost
$106,881
Name
University of North Carolina Chapel Hill
Department
Genetics
Type
Schools of Medicine
DUNS #
608195277
City
Chapel Hill
State
NC
Country
United States
Zip Code
27599
Murlidharan, Giridhar; Samulski, Richard J; Asokan, Aravind (2014) Biology of adeno-associated viral vectors in the central nervous system. Front Mol Neurosci 7:76
Ishikawa, Kiyotake; Fish, Kenneth M; Tilemann, Lisa et al. (2014) Cardiac I-1c overexpression with reengineered AAV improves cardiac function in swine ischemic heart failure. Mol Ther 22:2038-45
Horowitz, Eric D; Rahman, K Shefaet; Bower, Brian D et al. (2013) Biophysical and ultrastructural characterization of adeno-associated virus capsid uncoating and genome release. J Virol 87:2994-3002
Shen, Shen; Horowitz, Eric D; Troupes, Andrew N et al. (2013) Engraftment of a galactose receptor footprint onto adeno-associated viral capsids improves transduction efficiency. J Biol Chem 288:28814-23
Pulicherla, Nagesh; Kota, Pradeep; Dokholyan, Nikolay V et al. (2012) Intra- and inter-subunit disulfide bond formation is nonessential in adeno-associated viral capsids. PLoS One 7:e32163
Horowitz, Eric D; Finn, M G; Asokan, Aravind (2012) Tyrosine cross-linking reveals interfacial dynamics in adeno-associated viral capsids during infection. ACS Chem Biol 7:1059-66
Asokan, Aravind; Schaffer, David V; Samulski, R Jude (2012) The AAV vector toolkit: poised at the clinical crossroads. Mol Ther 20:699-708
Pulicherla, N; Asokan, A (2011) Peptide affinity reagents for AAV capsid recognition and purification. Gene Ther 18:1020-4
Horowitz, Eric D; Weinberg, Marc S; Asokan, Aravind (2011) Glycated AAV vectors: chemical redirection of viral tissue tropism. Bioconjug Chem 22:529-32
Phillips, Jana L; Hegge, Julia; Wolff, Jon A et al. (2011) Systemic gene transfer to skeletal muscle using reengineered AAV vectors. Methods Mol Biol 709:141-51

Showing the most recent 10 out of 14 publications