Characterisation of a monoclonal antibody to von Willebrand factor as a potent inhibitor of ristocetin-mediated platelet interaction and platelet adhesion.
We studied a murine monoclonal antibody (211 A6) to von Willebrand factor (vWF) with a view to investigating structure-relationship of plasma vWF. The specificity of this antibody has been substantiated by ELISA tests and indirect immunofluorescence. It reacts with purified vWF, normal plasma but not with plasma or platelets from a severe von Willebrand's disease patient. Monoclonal antibody 211 A6 is a potent inhibitor of ristocetin-induced platelet aggregation. The 125I-FVIII/vWF binding to platelets in presence of ristocetin is totally inhibited by low 211 A6 concentrations. Thrombin-induced binding of vWF to platelets is not affected by 211 A6. The ability of this antibody to inhibit platelet adhesion to subendothelium and to collagen was investigated with a perfusion model. The complete inhibition of platelet adhesion by 211 A6 questions the similarity or the interrelationship in vWF domains involved in ristocetin-induced platelet functions and platelet adhesion.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000302:isolation & purification* / Q000502:physiology; D000918:Antibody Specificity; D002850:Chromatography, Gel; D003094:Collagen / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004727:Endothelium / Q000378:metabolism; D005169:Factor VIII / Q000037:antagonists & inhibitors / Q000378:metabolism; D006801:Humans; D051379:Mice; D010973:Platelet Adhesiveness / Q000187:drug effects*; D010974:Platelet Aggregation / Q000187:drug effects*; D011485:Protein Binding; D014841:von Willebrand Factor / Q000037:antagonists & inhibitors* / Q000276:immunology* / Q000502:physiology
D000911:Antibodies, Monoclonal; D014841:von Willebrand Factor; D005169:Factor VIII; D003094:Collagen