Specific Accumulation of Circulating Monocytes and Polymorphonuclear Leukocytes on Platelet Thrombi in a Vascular Injury Model

作者：Daniel Kirchhofer, Markus A. Riederer, Hans Rudolf Baumgartner · 发表于：Blood · 年份：1997 · DOI：10.1182/blood.v89.4.1270 · 被引用次数：120 · 研究领域：Platelet Disorders and Treatments、Cell Adhesion Molecules Research、Blood properties and coagulation

The adhesion of leukocytes to platelets deposited at the site of vascular injury may represent an important mechanism by which leukocytes contribute to hemostasis and thrombosis. In this study, we examined whether, in comparison with their distribution in circulating blood, certain leukocyte types are enriched at sites of platelet deposition. We used an experimental vascular injury model, in which human fibrillar collagen was exposed to anticoagulated human whole blood flowing through parallel-plate chambers (venous shear rate, 65/s). The platelet-adherent leukocytes were detached by EDTA treatment and analyzed by flow cytometry using cell-type-specific antibodies. The predominant leukocytes found in platelet thrombi were polymorphonuclear leukocytes, accounting for 76% of bound leukocytes (62% in circulating blood), whereas T and B lymphocytes did not significantly accumulate on thrombi, comprising a fraction of less than 5% (32% in circulating blood). Monocytes constituted 16% of platelet thrombus-bound leukocytes, which represents an almost fourfold enrichment as compared with their proportion in circulating blood. Almost identical results were obtained when we analyzed leukocytes adhering to platelet monolayers, which were formed by blocking glycoprotein IIb-IIIa, thus preventing platelet aggregation on top of the collagen-adherent platelets. Furthermore, leukocyte adhesion to platelet monolayers was completely inhibited by an anti-P-selectin antibody (50% inhibitory conc...