Assays of eosinophil apoptosis and phagocytic uptake

Eosinophilic inflammation plays an important role in driving a variety of inflammatory and allergic conditions. Delineating the mechanisms by which these terminally differentiated granulocytes undergo programmed cell death (apoptosis) and their subsequent clearance by surrounding phagocytes are central to understanding disease pathogenesis and development of novel pharmacological agents. Dysregulation of the processes of either apoptosis or phagocytosis can result in chronic inflammation and disease progression due to either increased eosinophil life-span or cell necrosis with loss of cell membrane integrity and release of toxic intracellular mediators. A variety of in vitro methods have therefore been developed to understand these mechanisms in isolated primary human eosinophils. Here we describe the key assays used to study eosinophil apoptosis and the intracellular signalling pathways involved as well as phagocytic clearance of these cells.