5 integrin, compared with β2, is enhanced toward the front of polarized PMNs.

PMNs were plated on fibronectin, stimulated with 10 nmol/L fMLP, and then simultaneously fixed and permeabilized with 6.6% paraformaldehyde/0.05% gluteraldehyde in PBS containing 0.25 mg/mL saponin. Samples were incubated with 5 μg/mL of either a monoclonal antibody to the extracellular domain of α5 integrin (VC5, panel C), or a monoclonal antibody to the extracellular domain of β2 integrin (MAB1962, panel D). The samples were rinsed with PBS and then incubated with a TRITC-conjugated secondary antibody. The leading edge of the cells can be determined morphologically from differential interference contrast (DIC) images (A, B). Bar = 10 μm.