Figure 1.

Effects of NH₂-terminal processing on CXCL8-induced receptor internalization. Flow cytometry was used to determine CXCR1 (A) and CXCR2 (B) expression levels on freshly purified neutrophils that were stimulated with the indicated concentrations of CXCL8(1-77) (black bars), [Cit5]CXCL8(1-77) (blue bars) or CXCL8(6-77) (red bars) during 1 h. Results are represented as relative receptor expression levels (compared to buffer treated control cells) ± SEM (n = 6) after stimulation with the indicated concentrations of CXCL8 forms. Wilcoxon matched pairs test were performed to calculate whether stimulation with [Cit5]CXCL8(1-77) or CXCL8(6-77) induced a significantly different response compared to stimulation with native CXCL8(1-77). * p < 0.05 compared to CXCL8(1-77).