ABSTRACT
Neutrophil infi ltration of mucosal surfaces is a common event in many disease states and is a critical component of the host defense response. Activation and migration of neutrophils into tissues also contribute to infl ammatory tissue injury and remodeling of tissue architecture. For example, in the kidney and bladder, the migration of neutrophils across tubular or transitional epithelia accompanies pyelonephritis and cystitis, respectively. In infl ammatory pulmonary disorders, acute infl ammation of the airway is characterized by the transmigration of neutrophils across the bronchial epithelium. In the alimentary tract, active infl ammatory disease is characterized by the migration of neutrophils across the epithelial lining. While these disorders are diverse with distinct causes and pathologies, the underlying immune response to infection is very similar. In most instances, there is a large and oft en excessive infl ux of neutrophils. Th is infl ammatory process consists of several steps: initial emigration of neutrophils from the microcirculation, subsequent migration of neutrophils across the subepithelial matrix, and fi nally transepithelial migration. Th us, neutrophils must undergo specifi c and highly coordinated interactions with the endothelium, as well as epithelium. Knowledge of the mechanisms of neutrophil migration has
greatly expanded in recent years and has signifi cant clinical implications. Th is work highlights general mechanisms of the adhesive interactions involved in the migration of neutrophils to sites of injury.
