Siglec-E does not regulate “inside-out” signaling of CD11b in neutrophils. (A) Whole blood or bone marrow cells from WT and siglec-E^−/− mice, were incubated for 30 minutes at 37°C with the indicated stimuli. Surface expression of CD11b and CD62L on mature neutrophils (SSC^intGr-1^hiCD11b⁺) was assessed by flow cytometry. Data are expressed as mean ± standard deviation; n = 3 for blood and for bone marrow as the mean, representative of 2 independent experiments. (B) Adhesion of WT and siglec-E^−/− bone marrow cells to fibrinogen (Fb) in the presence and absence of PDBu. To investigate integrin-dependent adhesion, cells were pretreated with 20 μg/mL anti-CD11b antibody (5C6 clone 1) or 10 mM EDTA 20 minutes before plating. Data are expressed as mean ± SEM with 5 replicates for each data point and are representative of 2 independent experiments.