SSL5 induces chemokine binding to glycoproteins independent of chemokine receptors. (A) Binding of CXCL8-biotin was measured to neutrophils (■), U937 (▴), and U937-CXCR2 (▾) cells after treatment with SSL5 for 15 minutes. (B) U937 cells were incubated for 15 minutes with SSL5. Binding of biotin-labeled control protein (●), CXCL8 (■), CXCL12 (▾), or CCL2 (▴) untreated or preincubated with blocking α-CXCL8 (□), α-CXCL12 (▿), or α-CCL2 (▵), respectively, was measured. (C) C5a-FITC binding to U937 (▴) or U937-C5aR (■) cells was measured after incubation with SSL5. (D) Binding of CXCL8-biotin was measured to untreated (■) or neuraminidase-treated (▴) U937 cells after incubation with SSL5 that was preloaded without or with sLex (▾) for 15 minutes. (E) Binding of CXCL8-biotin was measured to U937 cells after treatment with SSL5 (■) or SSL11 (▴) for 15 minutes. (F) Cells were treated with SSL5 for 15 minutes and binding of CXCL8-biotin preincubated with (▴) or without (■) heparan sulfate for 30 minutes was measured. Results are representative of 3 independent experiments.