- 作者: Shyh-Chyi Lo; Ching-Yu Hung; Dong-Tsamn Lin; Hui-Chin Peng; Tur-Fu Huang
- 作者服務機構: 1 Department of Pharmacology, College of Medicine, National Taiwan University, No. 1, Jen-Ai Rd., Sec. 1, Taipei, Taiwan; ; 2 Department of Laboratory Medicine, National Taiwan University Hospital, No. 7 Chung-Shan S Rd., 100, Taipei, Taiwan, ROC
- 中文摘要: --
- 英文摘要: Platelet microparticles (MPs) are membrane vesicles shed by platelets after activation, and carry antigens characteristic of intact platelets, such as glycoprotein (GP) IIb/IIIa, GPIb and P-selectin. Elevated platelet MPs have been observed in many disorders in which platelet activation is documented. Recently, platelet GPIb has been implicated in the mediation of platelet-leukocyte interaction via binding to its ligand Mac-1 on leukocyte. The role of GPIb for mediating adhesion-activation interactions between platelet MPs and leukocytes has not been clarified. In this study we investigate the role of GPIb in the interplay between platelet MPs and neutrophils. Platelet MPs were obtained from collagen-stimulated platelet-rich plasma (PRP). In a study model of neutrophil aggregation, platelet MPs can serve a bridge to support neutrophil aggregation under venous level shear stress, suggesting that platelet MPs may enhance leukocyte aggregation, which would bear clinical relevance in diseases where the platelet MPs are elevated. The level of aggregation can be reduced by GPIb blocking antibodies, AP1 and SZ2, but not by anti-CD 18 mAb. The GPIb blocking antibodies also decreased platelet MP-mediated neutrophil activation, including β2 integrin expression, adherence-dependent superoxide release and platelet MP-mediated neutrophil adherence to immobilized fibrinogen. Our data provide the evidence for the involvement of GPIb-Mac-1 interaction in the cross-talk between platelet MPs and neutrophils.
- 中文關鍵字: --
- 英文關鍵字: glycoprotein Ib antagonist, leukocyte, microparticle, platelet