Human IL-13

Interleukin 13 (IL-13), encoded by the IL13 gene, is a cytokine primarily secreted by T helper type 2 (Th2) cells, as well as other immune cells like CD4 cells, mast cells, and eosinophils. It plays a crucial role in allergic inflammation and the immune response to parasitic infections, stimulating B-cell proliferation and activating eosinophils, basophils, and mast cells. IL-13 also downregulates pro-inflammatory cytokines and antagonizes Th1-driven immune responses, partly by suppressing NF-kappa-B activity. It exerts its effects through a receptor complex composed of IL4R and IL13RA1, activating JAK1 and TYK2 to initiate the STAT6 signaling pathway, while the IL13RA2 receptor acts as a high-affinity decoy, internalizing and depleting extracellular IL-13.