ADAM17 sheds L-selectin during integrin outside-in signaling in an IRhom2-dependent manner. ADAM17 activity (A) and levels of shed L-selectin (B) in unstimulated WT neutrophils or pRGD-stimulated (10 minutes) WT neutrophils that were left untreated or were pretreated with R18 inhibitor. (C) Immunoprecipitation of IRhom2 and Western blots of phosphorylated (p)-Ser 14-3-3 binding motif and total IRhom2 (tlRhom2) in lysates of HL-60 cells that were left unstimulated or were stimulated with pRGD (10 minutes). (D) Adhesion-dependent oxidative burst of WT and Sell^−/− neutrophils, which were left untreated or were pretreated with R18 inhibitor, following plating on fibrinogen in the presence of TNF-α. (E-H) Chemotaxis of WT and Sell^−/− neutrophils, which were left untreated or were pretreated with R18 inhibitor, on fibronectin in response to a soluble CXCL1 gradient in vitro. Forward migration index (E), velocity (F), and accumulated (G) and Euclidian (H) distance for chemotaxing neutrophils. A total of 40 cells was analyzed per experiment. n = 4. Mac-1 clustering on WT and Sell^−/− neutrophils. Representative microscopy images (scale bar, 4 µm) (I) and percentage of cells (J) showing Mac-1 clusters on neutrophils that were left unstimulated or were stimulated with pRGD. A total of 30 cells was analyzed per experiment. n = 3. Data are mean ± standard error of the mean. *P = .05, **P = .01, ***P = .001, 1-way ANOVA.