The circulating neutrophil (a) and the initiation of rolling (b) as molecular tethers are formed between selectin and CHO ligands on neutrophils and endothelial cells. If an adequate number of tethers are formed, the neutrophil completely decelerates and with chemotactic stimulation of the neutrophil, L-selectin is rapidly shed while other receptors like E-selectin, CD11b and ICAM-1 are up-regulated by cytokines and other inflammatory mediators (c). Firm neutrophil/endothelial cell adhesion is mediated by CD11b and ICAM-1 and is followed by emigration of the neutrophil through the endothelium (d).
