Interleukin-15 (IL-15) stimulates the proliferation of T lymphocytes and shares many biological properties with IL-2. It exerts its biological activities primarily on T cells. It is also essential in the development, survival and activation of NK cells. On binding to its receptor, IL-15 is indirectly involved in activating proto-oncogenes. Increased expression of IL-15 has been implicated with rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis and diseases affiliated with retroviruses like human immunodeficiency virus (HIV) and human T-lymphotropic virus-1 (HTLV-I).
