The emerging role of interleukin-21 in allergic diseases (Review)

Abstract

Interleukin (IL)-21 is a newly discovered member of the type I cytokine family. Since its discovery in 2000, IL-21 has been the focus of extensive investigation, due to its homology to IL-2, IL-4 and IL-15 and its pleiotropic effects on innate and adaptive immune responses. An increasing amount of experimental evidence supports a role for IL-21 in the pathogenesis of several allergic diseases, such as allergic rhinitis, atopic dermatitis (AD) and atopic asthma. In this review, we aimed to discuss the biological characteristics of IL-21 and summarize the current progress on the role of IL-21 in the regulation of allergic inflammation.

Keywords: allergic rhinitis; atopic asthma; atopic dermatitis; interleukin-21.

Figures

Figure 1

Schematic representation of the interleukin (IL)-21 receptor signaling pathway. IL-21R/γc-driven signaling may activate three pathways, namely the JAK/STAT, PI3K/Akt and MAPK pathways. JAK, Janus-activated kinase; STAT, signal transducer and activator of transcription; PI3K, phosphatidylinositol 3-kinase; MAPK, mitogen-activated protein kinase.