Type I interleukin-4 receptor complex (Type I IL-4R)

The Type I interleukin-4 receptor complex is a heterodimeric transmembrane signaling unit composed of the interleukin-4 receptor alpha (IL-4Rα) chain and the common gamma chain (γc/IL-2RG) (Source: UniProt P24394, P31785). It is predominantly expressed on the surface of hematopoietic cells, such as T cells, B cells, and monocytes, where it serves as the primary high-affinity receptor for interleukin-4 (IL-4) (Source: PMID: 10485909). Upon binding of IL-4, the complex activates the Janus kinase (JAK) 1 and JAK3 pathways, leading to the phosphorylation and nuclear translocation of the transcription factor STAT6 (Source: StatPearls, Interleukin 4). This signaling cascade is critical for the differentiation of naive T cells into Th2 cells and the induction of immunoglobulin E (IgE) class switching in B cells, making it a central driver of type 2 allergic inflammation (Source: PMID: 22460230). Dysregulation of this receptor complex is implicated in the pathogenesis of several chronic inflammatory diseases, including asthma and atopic dermatitis (Source: PubMed Central PMC4159119). Therapeutic agents like dupilumab target the shared IL-4Rα subunit, effectively blocking the formation of the Type I complex and inhibiting the downstream inflammatory response (Source: FDA Label, Dupixent).

Other names

IL-4Rα/γc complexInterleukin-4 receptor type IIL4R-IL2RG complexIL-4 receptor alpha/common gamma chain complex

The mechanism of action involves the competitive or non-competitive inhibition of the interleukin-4 receptor alpha (IL-4Rα) subunit or the interleukin-4 (IL-4) ligand, which prevents the assembly of the Type I receptor complex. This blockade inhibits the recruitment and activation of Janus kinases JAK1 and JAK3, thereby preventing the phosphorylation of STAT6 and the subsequent transcription of genes responsible for Th2-mediated inflammation and IgE production (Source: PMID: 28435139, PMID: 22460230).