Figure 2. Chemokine signalling through CXCR2 is essential for neutrophil activation on TNF-stimulated endothelial cells.

Using a flow-based adhesion assay, neutrophils isolated from whole blood were perfused across endothelial cells. Neutrophils were recruited to endothelial cells treated with TNF, but did not adhere to unstimulated endothelium. Detailed analysis of neutrophil behaviour showed that on TNF-stimulated endothelial cells, the majority of recruited cells transmigrated across the monolayer. When neutrophils were treated with anti-CXCR2, but not anti-CXCR1, neutrophil activation was inhibited so that nearly all of the recruited neutrophils rolled indefinitely on the monolayer and could not migrate; data are mean±SEM of four experiments **p<0.01 for comparison by paired t-test of neutrophil behaviour on TNF stimulated endothelial cells in the presence or absence of anti-CXCR2.