Figure 1.

Biology of PMNs in response to injury and inflammation. Localized overexpression of E‐selectin and P‐selectin on activated endothelial cells slow the PMN roll upon the endothelium via leukocyte‐derived L‐selectin. Responding PMNs transmigrate through the endothelial cells after LFA‐1 hooks intercellular adhesion molecule 1 (ICAM‐1) and arrive at the site of damage just before diapedesis caused by the increased vascular permeability from histamine released from the mast cells. PMNs undergo phagocytosis of the invasive microbes once they arrive at the infection site. In addition, MPO is secreted from the patrolled PMNs to produce the potent antimicrobial reagent HOCl in response to infection.