title: Interaction of leukocytes with platelet microparticles derived from outdated platelet concentrates.
abstract: Platelet microparticles (PMP) were isolated from outdated platelets by a combination of differential centrifugation and gel filtration, and the concentration of PMP was expressed in the equivalent of GPIIb/IIIa complex measured by captured ELISA. PMP bound to isolated neutrophils and macrophages in a dose-dependent manner, but they did not bind to lymphocytes. Incubation of PMP with neutrophils did not activate these cells as measured by up-regulation of Mac-1, release of human granulocyte elastase, and calcium mobilization. Incubation of PMP with macrophages did not enhance IL-8 production and the oxygen burst but slightly and significantly increased production of MCP-1. After 10 min incubation of PMP with macrophages, an increase of GPIIb/IIIa antigen was observed suggesting that PMP may be endocytosed by macrophages. In conclusion, PMP bind to leukocytes, but, in contrast to activated platelets, do not play a significant role in leukocyte activation.
authors.affiliation: Department of Surgery, University of Pennsylvania School of Medicine, Philadelphia, USA.
authors.forename: S
authors.initials: S
authors.lastname: Miyamoto
authors.forename: M A
authors.initials: MA
authors.lastname: Kowalska
authors.forename: C
authors.initials: C
authors.lastname: Marcinkiewicz
authors.forename: M M
authors.initials: MM
authors.lastname: Marcinkiewicz
authors.forename: D
authors.initials: D
authors.lastname: Mosser
authors.forename: L H
authors.initials: LH
authors.lastname: Edmunds
authors.forename: S
authors.initials: S
authors.lastname: Niewiarowski
mesh_terms: D015415:Biomarkers; D001792:Blood Platelets / Q000166:cytology* / Q000378:metabolism; D001793:Blood Preservation; D002469:Cell Separation; D002498:Centrifugation; D018932:Chemokine CCL2 / Q000032:analysis; D002850:Chromatography, Gel; D004705:Endocytosis; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D016209:Interleukin-8 / Q000032:analysis; D007962:Leukocytes / Q000166:cytology* / Q000378:metabolism; D008262:Macrophage Activation; D008264:Macrophages / Q000166:cytology / Q000502:physiology; D009504:Neutrophils / Q000166:cytology / Q000378:metabolism; D019007:P-Selectin / Q000032:analysis; D013997:Time Factors
chemical_list: D015415:Biomarkers; D018932:Chemokine CCL2; D016209:Interleukin-8; D019007:P-Selectin