Figure 1.

Signal transduction pathways underlying the biological actions exerted by IL-5 on eosinophils.

Notes: The interaction of IL-5 with the α subunit of the IL-5 receptor (IL-5Rα) aggregates and stimulates the receptor complex consisting of both IL-5Rα and βc subunits. This event is responsible for the following involvement of multiple signaling pathways mediated by JAK/STAT interactions, as well as by activation of MAPK, PI3K, and NF-κB. The biologic actions of these kinases and transcription factors converge to induce the expression of key genes implicated in maturation, survival, degranulation, adhesion, and chemotaxis of eosinophils. See “IL-5 and eosinophilic asthma” section for additional information.

Abbreviations: IL-5, interleukin-5; JAK, Janus kinase; MAPK, mitogen-activated protein kinases; NF-κB, nuclear factor-κB; PI3K, phosphoinositide 3-kinase; STAT, signal transducers and activators of transcription.