Effect of anticoagulants on binding and neutralization of lipopolysaccharide by the peptide immunoglobulin conjugate CAP18(106-138)-immunoglobulin G in whole blood
| Autor: | M F Fletcher, M W Vermeulen, Paul M. Loiselle, E M Zanzot, Kloczewiak M, H S Warren, M Ogata |
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| Rok vydání: | 1997 |
| Předmět: |
Lipopolysaccharides
medicine.drug_class Immunology Peptide Microbiology Immunoglobulin G Cathelicidins medicine Animals Humans Whole blood chemistry.chemical_classification biology Tumor Necrosis Factor-alpha Ligand binding assay Anticoagulant Anticoagulants Biological activity Heparin Molecular biology Infectious Diseases Biochemistry chemistry biology.protein Parasitology Rabbits Antibody Carrier Proteins Antimicrobial Cationic Peptides Research Article medicine.drug |
| Zdroj: | Infection and Immunity. 65:2160-2167 |
| ISSN: | 1098-5522 0019-9567 |
| Popis: | The 18-kDa cationic protein CAP18 is an antimicrobial protein isolated from rabbit granulocytes that binds lipopolysaccharide (LPS) and inhibits many of its biological activities. We covalently coupled a synthetic peptide representing amino acids 106 to 138 of CAP18 to human immunoglobulin G (IgG) by using the heterobifunctional linker N-succinimidyl-3-(2-pyridyidithio)propionate. The ability of CAP18(106-138)-IgG to bind and neutralize LPS in whole blood in the presence and absence of anticoagulants was studied. Both CAP18(106-138) and CAP18(106-138)-IgG significantly suppressed LPS-induced tumor necrosis factor (TNF) production in whole blood in the absence of anticoagulants. EDTA potentiated the ability of CAP18(106-138) and CAP18(106-138)-IgG to decrease LPS-induced TNF production in a dose-dependent manner. In contrast, heparin inhibited the ability of CAP18(106-138) and CAP18(106-138)-IgG to suppress LPS-induced TNF production. EDTA also enhanced LPS capture in a fluid-phase binding assay that utilizes magnetic anti-IgG beads to capture CAP18(106-138)-IgG (and bound [3H]LPS) in whole blood. In contrast, heparin inhibited the binding dose dependently. We conclude that CAP18(106-138)-IgG binds to and neutralizes LPS in whole blood in the absence of anticoagulants. Further studies of its protective efficacy in animal models are warranted. Caution should be used in interpreting assays that measure the binding and neutralization of LPS in whole blood in the presence of calcium-binding anticoagulants or heparin. |
| Databáze: | OpenAIRE |
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