Interleukin-6 (IL-6) is a pleiotropic cytokine that plays an important role in host defense by regulating immune and inflammatory responses. It is produced mainly by T cells, macrophages, monocytes, endothelial cells and muscle cells.
The biological functions of IL-6 are diverse. It stimulates B cell differentiation and antibody production, synergizes with IL-3 in megakaryocyte development and platelet production, induces expression of hepatic acute-phase proteins, and regulates bone metabolism. It also acts as a myokine, produced by muscle cells in response to muscle contraction and released into the blood stream to help break down fats and improve insulin resistance.
