scholarly journals Functional and Selective Targeting of Adenovirus to High-Affinity Fcγ Receptor I-Positive Cells by Using a Bispecific Hybrid Adapter

2001 ◽  
Vol 75 (1) ◽  
pp. 480-489 ◽  
Author(s):  
Christina Ebbinghaus ◽  
Ahmed Al-Jaibaji ◽  
Elisabeth Operschall ◽  
Angelika Schöffel ◽  
Isabelle Peter ◽  
...  
Keyword(s):  
Fold Increase ◽  
Adapter Protein ◽  
Fcγ Receptor ◽  
Monocytic Cell ◽  
Coxsackie Adenovirus Receptor ◽  
Amino Terminal ◽  
High Affinity ◽  
Selective Targeting ◽  
Human Monocytic Cell ◽  
Adenovirus Receptor

ABSTRACT 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 Fcγ receptor I (CD64) but not in cells expressing the low-affinity Fcγ receptor II (CD32) or III (CD16). These results open new perspectives for Ad-mediated cancer cell vaccination, including the treatment of acute myeloid leukemia.

Characterization of a Mode of Specific Binding of Fibrin Monomer through its Amino-Terminal Domain by Macrophages and Macrophage Cell-Lines

1990 ◽  
Vol 63 (02) ◽  
pp. 193-203 ◽  
Author(s):  
John R Shainoff ◽  
Deborah J Stearns ◽  
Patricia M DiBello ◽  
Youko Hishikawa-Itoh
Keyword(s):  
Peritoneal Macrophages ◽  
Affinity Binding ◽  
Macrophage Cell ◽  
High Affinity Binding ◽  
Amino Terminal ◽  
High Affinity ◽  
Terminal Domain ◽  
Weak Binding ◽  
Amino Terminal Domain

SummaryThe studies reported here probe the existence of a receptor-mediated mode of fibrin-binding by macrophages that is associated with the chemical change underlying the fibrinogen-fibrin conversion (the release of fibrinopeptides from the amino-terminal domain) without depending on fibrin-aggregation. The question is pursued by 1) characterization of binding in relation to fibrinopeptide content of both the intact protein and the CNBr-fragment comprising the amino-terminal domain known as the NDSK of the protein, 2) tests of competition for binding sites, and 3) photo-affinity labeling of macrophage surface proteins. The binding of intact monomers of types lacking either fibrinopeptide A alone (α-fibrin) or both fibrinopeptides A and B (αβ-fibrin) by peritoneal macrophages is characterized as proceeding through both a fibrin-specific low density/high affinity (BMAX ≃ 200–800 molecules/cell, KD ≃ 10−12 M) interaction that is not duplicated with fibrinogen, and a non-specific high density/low affinity (BMAX ≥ 105 molecules/cell, KD ≥ 10−6 M) interaction equivalent to the weak binding of fibrinogen. Similar binding characteristics are displayed by monocyte/macrophage cell lines (J774A.1 and U937) as well as peritoneal macrophages towards the NDSK preparations of these proteins, except for a slightly weaker (KD ≃ 10−10 M) high-affinity binding. The high affinity binding of intact monomer is inhibitable by fibrin-NDSK, but not fibrinogen-NDSK. This binding appears principally dependent on release of fibrinopeptide-A, because a species of fibrin (β-fibrin) lacking fibrinopeptide-B alone undergoes only weak binding similar to that of fibrinogen. Synthetic Gly-Pro-Arg and Gly-His-Arg-Pro corresponding to the N-termini of to the α- and the β-chains of fibrin both inhibit the high affinity binding of the fibrin-NDSKs, and the cell-adhesion peptide Arg-Gly-Asp does not. Photoaffinity-labeling experiments indicate that polypeptides with elec-trophoretically estimated masses of 124 and 187 kDa are the principal membrane components associated with specifically bound fibrin-NDSK. The binding could not be up-regulated with either phorbol myristyl acetate, interferon gamma or ADP, but was abolished by EDTA and by lipopolysaccharide. Because of the low BMAX, it is suggested that the high-affinity mode of binding characterized here would be too limited to function by itself in scavenging much fibrin, but may act cooperatively with other, less limited modes of fibrin binding.

scholarly journals Crystal Structure of Fcγ Receptor I and Its Implication in High Affinity γ-Immunoglobulin Binding

2011 ◽  
Vol 286 (47) ◽  
pp. 40608-40613 ◽  
Author(s):  
Jinghua Lu ◽  
Jeff L. Ellsworth ◽  
Nels Hamacher ◽  
Si Won Oak ◽  
Peter D. Sun
Keyword(s):  
Crystal Structure ◽  
Fcγ Receptor ◽  
High Affinity ◽  
Immunoglobulin Binding

Adenovirus-induced thrombocytopenia: the role of von Willebrand factor and P-selectin in mediating accelerated platelet clearance

Blood ◽  
2006 ◽  
Vol 109 (7) ◽  
pp. 2832-2839 ◽  
Author(s):  
Maha Othman ◽  
Andrea Labelle ◽  
Ian Mazzetti ◽  
Hisham S. Elbatarny ◽  
David Lillicrap
Keyword(s):  
Von Willebrand Factor ◽  
Cell Activation ◽  
Endothelial Cell Activation ◽  
Platelet Surface ◽  
Adenoviral Gene Transfer ◽  
Coxsackie Adenovirus Receptor ◽  
Transfer Vectors ◽  
Adenovirus Receptor ◽  
Von Willebrand ◽  
Willebrand Factor

AbstractThrombocytopenia has been consistently reported following the administration of adenoviral gene transfer vectors. The mechanism underlying this phenomenon is currently unknown. In this study, we have assessed the influence of von Willebrand Factor (VWF) and P-selectin on the clearance of platelets following adenovirus administration. In mice, thrombocytopenia occurs between 5 and 24 hours after adenovirus delivery. The virus activates platelets and induces platelet-leukocyte aggregate formation. There is an associated increase in platelet and leukocyte-derived microparticles. Adenovirus-induced endothelial cell activation was shown by VCAM-1 expression on virus-treated, cultured endothelial cells and by the release of ultra-large molecular weight multimers of VWF within 1 to 2 hours of virus administration with an accompanying elevation of endothelial microparticles. In contrast, VWF knockout (KO) mice did not show significant thrombocytopenia after adenovirus administration. We have also shown that adenovirus interferes with adhesion of platelets to a fibronectin-coated surface and flow cytometry revealed the presence of the Coxsackie adenovirus receptor on the platelet surface. We conclude that VWF and P-selectin are critically involved in a complex platelet-leukocyte-endothelial interplay, resulting in platelet activation and accelerated platelet clearance following adenovirus administration.

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