IL-2 (Interleukin 2)

Interleukin-2 (IL-2) is a naturally produced cytokine whose key function is to activate the immune system during an infectious attack. Foreign antigens trigger IL-2 secretion. When IL-2 binds to its receptor IL-2R, the complex stimulates immune cell proliferation and differentiation, including cytotoxic T-cells, natural killer cells, lymphocytes, monocytes and macrophages. Interestingly, research suggests that impaired IL-2 activity has been linked to the development of autoimmunity rather than immunodeficiency. Autoimmune system hyperactivity may cause chronic inflammatory

disorders, lymphadenopathy, hepatomegaly, and splenomegaly. Recent studies also suggest an important role for IL-2 in the regulation of innate immunity.