Integrin α₃β₁ blockade or targeted genetic depletion impedes neutrophil extravasation at the basement membrane. (A) The effect of α₃β₁ blockade on neutrophil migration in vivo was assessed by intravital multiphoton microscopy in the 1 μM fMLP-superfused cremaster vessels of LysM-GFP mice after IV injections of either control (Ctrl) peptide or LXY2 (88 μg or 100 nmole). (B) Transmission electron microscopy imaging of fMLP-superfused cremaster microvasculature of mice administered LXY2. Endo, endothelium; L, lumen; peri, pericyte; P, polymorphonuclear leukocytes. (C) The effect of α₃β₁ conditional deletion in α₃ cKO (Itga3^flox/flox; Ela-Cre) mice compared with control Ela-Cre (Itga3^wt/wt; Ela-Cre) mice on neutrophil transmigration in response to fMLP (1 μM), assessed by intravital multiphoton microscopy. (A-C) Results are representative of 3 independent experiments. (A,C) Results were quantified and expressed as mean ± SEM. *P < .05 (Mann-Whitney test).