FIG 1.
F2Pal12 induces CR3 upregulation and superoxide production in neutrophils through interaction with FPR2. (A) Neutrophils were treated with FPR2-specific agonist WKYMVM (0.1 μM final concentration) or F2Pal12 (1 μM final concentration) in the presence or absence of FPR2 inhibitor PBP10 (1 μM final concentration) and subjected to flow cytometry analysis of surface-exposed CR3. The histograms show CR3 staining in control (nontreated, gray line), WKYMVM-stimulated (dotted), and F2Pal12-treated neutrophils without (solid) or with (dashed) PBP10 from one representative experiment out of three. The results are summarized in the inset as the percentage of fluorescence increase from control (mean ± standard deviation [SD], n = 3 experiments). (B) The effects of FPR2 inhibitor PBP10 (1 μM final concentration, dotted line) and FPR1 antagonist cyclosporin H (1 μM final concentration, dashed line) on the release of superoxide anions from human neutrophils activated with F2Pal12 were determined. The control F2Pal12 response is also shown (solid line). The time for addition of the pepducin is indicated by the arrow, and the release of superoxide was followed continuously. Abscissa, time in minutes; ordinate, superoxide release (Mcpm, 106 counts per minute).