SSL5 inhibition of chemokine- and anaphylatoxin-induced cell activation depends on sLex at the cell surface. (A) Binding of 10 μg/mL SSL5-FITC, preincubated with different concentrations of sLex, to neutrophils. Results are expressed relative to buffer-treated SSL5-FITC. (B) Calcium mobilization in neutrophils induced by 0.1 nM CXCL8 after incubation of cells with (+) or without (−) 10 μg/mL SSL5 that was preloaded with different concentrations of sLex for 15 minutes. (C) SSL5-FITC binding to untreated (■) or neuraminidase-treated (□) neutrophils. Results are expressed relative to control-treated cells. (D-G) Untreated or neuraminidase-treated neutrophils were incubated with (▴) or without (■) 10 μg/mL SSL5 and stimulated with CXCL8 (D,E) or C5a (F,G). Cell activation was measured by calcium mobilization. (H) Neutrophils were incubated with (□) or without (■) 10 μg/mL SSL11 for 30 seconds. Calcium mobilization was measured on stimulation with 1 nM fMLP, 0.5 nM CXCL8, or 0.1 nM C5a. Results represent mean plus or minus SEM of 3 independent experiments.