The function and fate of neutrophils at the inflamed site: prospects for therapeutic intervention.

Neutrophils play a key role in the immediate non-specific immune response, and defects in their function increase host susceptibility to a range of infective agents. However, excess activation and/or delayed clearance of these cells from an inflamed site can lead to significant tissue damage. Neutrophil priming by agents such as endotoxin, granulocyte macrophage colony stimulating factor (GM-CSF), platelet activating factor (PAF) and tumour necrosis factor-alpha (TNF alpha) may play a pivotal role in modulating the adhesive and secretory properties of these cells. Priming also appears to affect the survival of neutrophils by delaying constitutive apoptosis. The unique signal transduction events that control neutrophil priming and apoptosis, and particularly the importance of the phospholipase C and phosphoinositide 3-kinase pathways, suggest opportunities for selective pharmacological intervention.