Description
Human Interleukin 13 (IL-13) is produced by activated Th0, Th1, Th2 and CD8 T cells. IL-13 is a pleiotropic immune regulatory cytokine that promotes growth of human B cells; induces expression of germ line Ce transcripts, directs na?ve B cells to switch to the synthesis of IgE and IgG4, and induces expression of CD23 and ClassII-MHC. In monocytes, IL-13 down-regulates FcgR expression; inhibits synthesis of proinflammatory cytokines, including TNF-a, IL-1b, IL-6 and IL-8; induces monocyte/macrophage fusion and mannose receptor expression. IL-13 inhibits the synthesis of IL-12, nitric oxide synthase and cyclooxigenase-2. The human IL-13 cDNA encodes a 132 amino acid protein containing a 20 amino acid signal peptide. IL-13 binds to a heterodimeric receptor formed by the IL-13Ra and the IL-4Rb. Several high affinity IL-13 binding proteins have been reported