Functional and selective targeting of adenovirus to high-affinity Fcgamma receptor I-positive cells by using a bispecific hybrid adapter.
Adenovirus (Ad) efficiently delivers its DNA genome into a variety of cells and tissues, provided that these cells express appropriate receptors, including the coxsackie-adenovirus receptor (CAR), which binds to the terminal knob domain of the viral capsid protein fiber. To render CAR-negative cells susceptible to Ad infection, we have produced a bispecific hybrid adapter protein consisting of the amino-terminal extracellular domain of the human CAR protein (CARex) and the Fc region of the human immunoglobulin G1 protein, comprising the hinge and the CH2 and CH3 regions. CARex-Fc was purified from COS7 cell supernatants and mixed with Ad particles, thus blocking Ad infection of CAR-positive but Fc receptor-negative cells. The functionality of the CARex domain was further confirmed by successful immunization of mice with CARex-Fc followed by selection of a monoclonal anti-human CAR antibody (E1-1), which blocked Ad infection of CAR-positive cells. When mixed with Ad expressing eGFP, CARex-Fc mediated an up to 250-fold increase of transgene expression in CAR-negative human monocytic cell lines expressing the high-affinity Fcgamma receptor I (CD64) but not in cells expressing the low-affinity Fcgamma receptor II (CD32) or III (CD16). These results open new perspectives for Ad-mediated cancer cell vaccination, including the treatment of acute myeloid leukemia.
Ebbinghaus
C
C
Institute of Molecular Biology, University of Zürich, CH-8057 Zürich, Switzerland.
Al-Jaibaji
A
A
Operschall
E
E
Schöffel
A
A
Peter
I
I
Greber
U F
UF
Hemmi
S
S
D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D002213:Capsid / Q000502:physiology*; D002478:Cells, Cultured; D015316:Genetic Therapy; D006801:Humans; D007114:Immunization; D015470:Leukemia, Myeloid, Acute / Q000628:therapy; D051379:Mice; D008807:Mice, Inbred BALB C; D017452:Receptors, IgG / Q000032:analysis / Q000502:physiology*; D011991:Receptors, Virus / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000502:physiology*; D019076:Transgenes
D000911:Antibodies, Monoclonal; D017452:Receptors, IgG; D011991:Receptors, Virus; D011993:Recombinant Fusion Proteins