PSGL-1 and integrin signaling pathways in neutrophils require distinct tyrosine residues on SLP-76. (A-D) Bone marrow leukocytes (A-B) of the indicated genotype were incubated on immobilized control CD45-IgM or P-selectin–IgM. Isolated bone marrow neutrophils (C-D) of the indicated genotype were incubated on control F(ab′)2 or anti-β2 integrin F(ab′)2. Lysates were analyzed by immunoblotting with the indicated antibodies. (E-F) Rolling velocities of neutrophils of the indicated genotype on P-selectin with or without coimmobilized ICAM-1 in the presence or absence of anti–ICAM-1 mAb. (G,I) Rolling velocities of neutrophils of the indicated genotype on P-selectin coimmobilized with ICAM-1 and low-dose CXCL1 (0.1 μg/mL) in the presence or absence of anti–ICAM-1 mAb. (H,J) Percentages of neutrophils of the indicated genotype rolling, arrested and round, or arrested and spread on coimmobilized P-selectin, ICAM-1, and low-dose CXCL1. The data in panels A through D are representative of 3 experiments. The data in panels E through J represent the mean ± SEM from 5 experiments, with 5 mice in each experimental group. *P < .05 for rolling velocity; #P < .05 for number of rolling cells.