Table 1. P-selectin and PSGL1 Antibodies Inhibit Platelet–Leukocyte Conjugate Formation in TRAP-activated Whole Blood
Whole blood samples were incubated in the presence and absence of P-selectin, P-selectin glycoprotein ligand 1 (PSGL1), and immunoglobin G (IgG) isotype control antibodies for 20 min before placement in an aggregometer and thrombin receptor–activating peptide (TRAP) activation (unstimulated control samples did not receive TRAP). Five minutes after activation, an aliquot of blood was removed from the aggregometer and incubated with PE-CD15 and perCP-CD61 antibodies. After 20 min, samples were fixed, and red cells were lysed with fluorescent-activated cell sorter lysing solution. Platelet–leukocyte conjugate formation was determined by two-color flow cytometry. PerCP-fluorescence histograms generated from the gated granulocyte population were used to determine the percent of platelet positive granulocytes, as described in the Methods. In each set of experiments (n = 5), data were significantly different by repeated measures analysis of variance (P < 0.0001).
*P < 0.001 versus unstimulated control by Bonferroni post hoc test.
†P < 0.001 versus no antibody and IgG control antibody by Bonferroni post hoc test.
PMN = polymorphonuclear leukocytes.