Interleukin-21 receptor and common gamma chain complex (IL-21R/γc complex)

The interleukin-21 receptor and common gamma chain complex (IL-21R/γc complex) is a heterodimeric type I cytokine receptor that binds interleukin-21 (IL-21), a crucial immune regulatory cytokine. IL-21R provides ligand specificity while the common gamma chain (γc, also known as CD132 or IL2RG) is an essential signaling subunit shared among several cytokine receptors. Upon ligand binding, the complex activates the Janus kinase (JAK1/JAK3) and signal transducer and activator of transcription (STAT1, STAT3, and sometimes STAT5) pathways, modulating critical immune functions, including proliferation, differentiation, and survival of B cells, T cells, and natural killer (NK) cells. The complex plays pivotal roles in host defense, immune homeostasis, inflammation, and is implicated in pathological processes such as cancer, autoimmune disorders, and cardiovascular diseases. Mutations or dysfunction in the γc chain can lead to severe combined immunodeficiency. Therapeutic interventions that block this receptor complex are under investigation for various immune and inflammatory diseases[1][3][4][5][6][7][8][9].

Other names

Interleukin-21 receptor complexIL21R and common gamma chainIL-21 receptor and IL2RG complexIL21R/IL2RGCytokine receptor complex (IL-21R/γc)NILR and γcCD360 and CD132 complex

Inhibition of IL-21/IL-21R/γc signaling blocks Jak-STAT pathway activation, thereby reducing proliferation, differentiation, and survival of immune cells. Targeting γc broadly blocks signaling of several interleukins (IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21), leading to immunosuppression[1][5][8][9].