Model Systems to Investigate Neutrophil Adhesion and Chemotaxis

Polymorphonuclear neutrophil (PMN) recruitment from the blood stream into surrounding tissues, followed by migration through the tissue with triggered release of oxidative enzymes or eventual clearance from the epithelial surface, involves a regulated series of events central to acute responses in host defense (1 ). Accumulations of large numbers of neutrophils within mucosal tissues are pathognomonic features of both acute and chronic inflammatory conditions including sepsis (2 ,3 ) and inflammatory bowel disease (4 ), but the precise signals governing neutrophil adhesion and transmigration remain to be fully characterized. Previous chapters examine methods employed for both neutrophil isolation and study of the mechanisms underlying regulation of PMN rolling behavior. Here, we describe in vitro experimental models for the examination of PMN adhesion to endothelial and epithelial monolayers as well as the characterization of signals influencing neutrophil migration, both along acellular matrices and across endothelial and epithelial monolayers, in the physiologically relevant directions. Studies employing these model systems allow further elucidation of the mechanisms governing PMN adhesion and transmigration.