Targeting of adenovirus via genetic modification of the viral capsid combined with a protein bridge.
A potential barrier to the development of genetically targeted adenovirus (Ad) vectors for cell-specific delivery of gene therapeutics lies in the fact that several types of targeting protein ligands require posttranslational modifications, such as the formation of disulfide bonds, which are not available to Ad capsid proteins due to their nuclear localization during assembly of the virion. To overcome this problem, we developed a new targeting strategy, which combines genetic modifications of the Ad capsid with a protein bridge approach, resulting in a vector-ligand targeting complex. The components of the complex associate by virtue of genetic modifications to both the Ad capsid and the targeting ligand. One component of this mechanism of association, the Fc-binding domain of Staphylococcus aureus protein A, is genetically incorporated into the Ad fiber protein. The ligand is comprised of a targeting component fused with the Fc domain of immunoglobulin, which serves as a docking moiety to bind to these genetically modified fibers during the formation of the Ad-ligand complex. The modular design of the ligand solves the problem of structural and biosynthetic compatibility with the Ad and thus facilitates targeting of the vector to a variety of cellular receptors. Our study shows that targeting ligands incorporating the Fc domain and either an anti-CD40 single-chain antibody or CD40L form stable complexes with protein A-modified Ad vectors, resulting in significant augmentation of gene delivery to CD40-positive target cells. Since this gene transfer is independent of the expression of the native Ad5 receptor by the target cells, this strategy results in the derivation of truly targeted Ad vectors suitable for tissue-specific gene therapy.
Korokhov
Nikolay
N
VectorLogics, Inc., Alabama 35294, USA.
Mikheeva
Galina
G
Krendelshchikov
Alexander
A
Belousova
Natalya
N
Simonenko
Vera
V
Krendelshchikova
Valentina
V
Pereboev
Alexander
A
Kotov
Alexander
A
Kotova
Olga
O
Triozzi
Pierre L
PL
Aldrich
Wayne A
WA
Douglas
Joanne T
JT
Lo
Kin-Ming
KM
Banerjee
Papia T
PT
Gillies
Stephen D
SD
Curiel
David T
DT
Krasnykh
Victor
V
D000260:Adenoviruses, Human / Q000235:genetics* / Q000378:metabolism; D019013:CD40 Antigens / Q000378:metabolism; D036022:Capsid Proteins / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D004220:Disulfides / Q000378:metabolism*; D018390:Gene Targeting; D018014:Gene Transfer Techniques; D005818:Genetic Engineering / Q000379:methods*; D005822:Genetic Vectors; D006801:Humans; D007128:Immunoglobulin Fragments / Q000235:genetics / Q000378:metabolism; D008024:Ligands; D011994:Recombinant Proteins; D013205:Staphylococcal Protein A / Q000235:genetics / Q000378:metabolism; D014161:Transduction, Genetic
D019013:CD40 Antigens; D036022:Capsid Proteins; D004220:Disulfides; D007128:Immunoglobulin Fragments; D008024:Ligands; D011994:Recombinant Proteins; D013205:Staphylococcal Protein A; C018315:hexon capsid protein, Adenovirus