Engineering and Selection of Shuffled AAV Genomes: A New Strategy for Producing Targeted Biological Nanoparticles.
We report a DNA shuffling-based approach for developing cell type-specific vectors through directed evolution. Capsid genomes of adeno-associated virus (AAV) serotypes 1-9 were randomly fragmented and reassembled using PCR to generate a chimeric capsid library. A single infectious clone (chimeric-1829) containing genome fragments from AAV1, 2, 8, and 9 was isolated from an integrin minus hamster melanoma cell line previously shown to have low permissiveness to AAV. Molecular modeling studies suggest that AAV2 contributes to surface loops at the icosahedral threefold axis of symmetry, while AAV1 and 9 contribute to two- and fivefold symmetry interactions, respectively. The C-terminal domain (AAV9) was identified as a critical structural determinant of melanoma tropism through rational mutagenesis. Chimeric-1829 utilizes heparan sulfate as a primary receptor and transduces melanoma cells more efficiently than all serotypes. Further, chimeric-1829 demonstrates altered tropism in rodent skeletal muscle, liver, and brain including nonhuman primates. We determined a unique immunological profile based on neutralizing antibody (NAb) titer and crossreactivity studies strongly supporting isolation of a synthetic laboratory-derived capsid variant. Application of this technology to alternative cell/tissue types using AAV or other viral capsid sequences is likely to yield a new class of biological nanoparticles as vectors for human gene transfer.
Gene Therapy Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Wuping
W
Li
Gene Therapy Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Aravind
A
Asokan
Gene Therapy Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Zhijian
Z
Wu
Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Terry
T
Van Dyke
Gene Therapy Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Nina
N
DiPrimio
Gene Therapy Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Jarrod S
JS
Johnson
Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, Florida, USA.
Lakshmanan
L
Govindaswamy
Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, Florida, USA.
Mavis
M
Agbandje-McKenna
Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut, USA.
Stefan
S
Leichtle
Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut, USA.
D
D
Eugene Redmond
Gene Therapy Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Thomas J
TJ
McCown
Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Kimberly B
KB
Petermann
Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
Norman E
NE
Sharpless
Gene Therapy Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA. Electronic address: rjs@med.unc.edu.
Richard J
RJ
Samulski