Description
Interleukin-6 (IL-6) is a multi-functional cytokine that regulates immune responses, acute phase reactions and hematopoiesis and may play a central role in host defense mechanisms. IL-6 is usually not produced constitutively by normal cells, but its expression is readily induced by a variety of cytokines, lipopolysaccharide or viral infections. IL-6 is a pleiotropic cytokine produced by a variety of cells. It acts on a wide range of tissues, exerting growth-induction, growth-inhibition, and differentiation respectively, depending on the nature of the target cells. IL-6 is involved in: − the induction of B-cell differentiation, − the induction of acute phase proteins in liver cells, − growth promotion of myeloma/plasmacytoma/hybridoma cells, − induction of IL-2 and IL-2 receptor expression, − proliferation and differentiation of T cells, − inhibition of cell growth of certain myeloid leukemic cell lines and induction of their differentiation to macrophages, − enhancement of IL-3-induced multipotential colony cell formation in hematopoietic stem cells and induction of maturation of megakaryocytes as a thrombopoietic factor, − induction of mesangial cell growth, − induction of neural differentiation of PC 12 cells and − induction of keratinocyte growth