Characterization of murine anti-glycoprotein Ib monoclonal antibodies that differentiate between shear-induced and ristocetin/botrocetin-induced glycoprotein Ib-von Willebrand factor interaction.
Platelet adhesion to vascular subendothelium under conditions of high shear stress is mediated by the platelet glycoprotein (GP) Ib-von Willebrand Factor (vWF) interaction. The aim of this study was to characterize the murine monoclonal antibodies (MoAbs) 27A10 and 28E6, both raised against purified GPIb. The MoAb 27A10 is a potent inhibitor of shear-induced platelet adhesion to collagen type I in a flow chamber at shear rates of 1,300 and 2,700 s(-1). 20 microg/ml of MoAb 27A10, furthermore, could completely block shear-induced aggregation in a modified Couette viscometer at shear rates of 1,000 and 4,000 s(-1). On the other hand, MoAb 27A10 had a negligible effect on botrocetin-induced GPIb-vWF binding and is only a poor inhibitor of the ristocetin-dependent interaction. In contrast, MoAb 28E6 did abolish both the ristocetin- and botrocetin-induced GPIb-vWF binding, whereas it did not block the shear-induced interaction. Thus, we identify here two anti-GPIb MoAbs 27A10 and 28E6 that either preferentially inhibit the shear-induced or the ristocetin/botrocetin-induced platelet-vWF interaction. With these tools it should be possible to more clearly define the mechanisms by which platelets bind to vWF in vivo.
Cauwenberghs
N
N
Laboratory for Thrombosis Research, Interdisciplinary Research Center, KU Leuven Campus Kortrijk, Belgium. Nancy.Cauwenberghs@kulak.ac.be
Ajzenberg
N
N
Vauterin
S
S
Hoylaerts
M F
MF
Declerck
P J
PJ
Baruch
D
D
Deckmyn
H
H
D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000494:pharmacology*; D000918:Antibody Specificity; D001667:Binding, Competitive; D003435:Crotalid Venoms / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C / Q000276:immunology; D010973:Platelet Adhesiveness / Q000187:drug effects / Q000276:immunology; D010974:Platelet Aggregation / Q000187:drug effects / Q000276:immunology; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D012310:Ristocetin / Q000494:pharmacology; D013314:Stress, Mechanical; D014841:von Willebrand Factor / Q000187:drug effects / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D003435:Crotalid Venoms; D019038:Platelet Glycoprotein GPIb-IX Complex; D014841:von Willebrand Factor; D012310:Ristocetin; C030961:botrocetin