Migration of neutrophils through epithelial monolayers.

Acute bacterial infections are a major challenge to epithelial linings that interface indirectly with the external world. Such infections are in part fought by neutrophils, which phagocytose and destroy pathogens. Neutrophils arrive at the infection sites by emigrating from small blood vessels and subsequently interacting with and transmigrating across columnar epithelia. There is substantial interest in defining the mechanisms and functional consequences of neutrophil-epithelial interactions. Model systems reveal that specific molecular events are required for appropriate neutrophil-epithelial interactions and, as a result of these interactions, neutrophils may reversibly modulate diverse epithelial functions.