Abstract
Eosinophils play an important role in certain aspects of asthma pathogenesis. This review focuses on the mechanism of activation of eosinophils by the growth factor interleukin-5 and the CC chemokine receptor-3. Interleukin-5 activates members of the Janus and Src family of kinases. The latter kinases are largely responsible for the generation of initial signaling events. CC chemokine receptor-3, in contrast, signals through heterotrimeric G-proteins. Subsequently, various signaling pathways are activated, which converge on four major pathways – the mitogen-activated protein kinase pathway, the phosphoinositide-3 kinase pathway, the calcium signaling pathway and the Janus–signal transducer and activator of transcription signaling pathway. The biologic consequences of many of these signaling pathways are also discussed.