Granulocyte apoptosis and the control of inflammation.

Abstract

We have described a novel pathway available for the clearance of extravasated granulocytes from inflamed tissues whereby aging granulocytes undergo apoptosis, a process which leads to their phagocytosis by inflammatory macrophages. By contrast with necrosis, which may also be seen at inflamed sites, apoptosis represents a granulocyte fate which by a number of mechanisms would tend to limit inflammatory tissue injury and promote resolution rather than progression of inflammation: (i) apoptosis is responsible for macrophage recognition of senescent neutrophils with intact cell membranes which exclude vital dyes and retain their potentially histotoxic granule contents; (ii) the apoptotic neutro..