Description
Interleukin 15 (IL-15) is a novel cytokine that uses beta- and gamma-chain of IL-2R for signal transduction and is structurally similarity to IL-2. IL-15 is secreted by activated monocytes/macrophages following infection by virus. This cytokine induces cell proliferation of natural killer cells. This cytokine and interleukin 2 share many biological activities. They are found to bind common hematopoietin receptor subunits, and may compete for the same receptor, and thus negatively regulate each other"s activity. This cytokine induces the activation of JAK kinases, as well as the phosphorylation and activation of transcription activators STAT3, STAT5, and STAT6. IL-15 can recruit and activate T lymphocytes in the synovial membrane, thereby contributing to Rheumatoid arthritis pathogenesis