Apoptosis in human eosinophils: Programmed cell death in the eosinophil leads to phagocytosis by macrophages and is modulated by IL-5

Abstract

Eosinophils are believed to injure tissues in a variety of allergic diseases by virtue of their highly histotoxic contents and metabolites. They are readily observed in tissues during the allergic response yet the mechanisms governing the duration of tissue residence and route of removal remain obscure. We have previously reported in vitro and in vivo evidence that neutrophils undergo apoptosis (programmed cell death) and are recognized and ingested as intact cells by macrophages. We report that eosinophils, purified from the peripheral blood of asymptomatic healthy atopics, undergo apoptosis in vitro. After 72 to 96 h in culture, 57.0 ± 6.2% (mean ± SE) of the eosinophil population showed c..