Human IL13

Interleukin-13 (IL-13) is a monomeric 17 kDa immunoregulatory cytokine that plays a key role in the pathogenesis of allergy, cancer, and tissue fibrosis. It is secreted by several helper T cell subsets, NK cells, mast cells, eosinophils, basophils, and visceral smooth muscle cells, and it suppresses the production of proinflammatory cytokines and other cytotoxic substances by macrophages, fibroblasts, and endothelial cells. IL-13 binds with low affinity to the transmembrane IL-13 R alpha 1 which then forms a signaling complex with the transmembrane IL-4 R alpha. IL 13 R alpha 2 inhibits responses to both IL-13 and IL-4. In addition, IL-13-bound IL-13 R alpha 2 can directly promote tumor cell invasiveness and the development of tissue fibrosis (1-5).