P-selectin mediates Ca(2+)-dependent adhesion of activated platelets to many different types of leukocytes: detection by flow cytometry.

摘要: Previous studies have shown that thrombin-activated platelets interact through the P-selectin with neutrophils and monocytes. To identify other types of leukocytes capable such an interaction, eosinophils, basophils, lymphocytes were isolated from whole blood. Binding these cells to activated was examined in a double immunofluorescence assay results show not only bind monocytes, but also subpopulations T lymphocytes. Using monoclonal antibodies (MoAbs) specific for subsets cells, we could further demonstrate which are natural killer (NK) undefined subpopulation CD4+ CD8+ cells. All interactions dependent on divalent cations completely inhibited by MoAb against P-selectin. Thus, mediates binding many different leukocytes. Studies treated proteases or neuraminidase structures recognized glycoproteins carrying sialic acid residues. Because loss neuraminidase-treated almost complete, partial latter cell may ligands addition those present neutrophils. We found two previously identified P-selectin, oligosaccharides Le(x) sialyl-Le(x), had little no inhibitory effect adhesion MoAbs oligosaccharides. In addition, there correlation between expression several their capacity platelets. contrast, sialyl-Le(x) perfectly correlated ability while cannot be major ligand possible role P-selectin-mediated processes dismissed. Finally, normally monocytes patients paroxysmal nocturnal hemoglobulinuria (PNH) phosphatidyl inositol (PI)-linked proteins been removed glycosylphosphatidyl inositol-specific phospholipase C (GPI-PLC) digestion. This suggests at least part GPI-anchored.