Eotaxin/CCL11

CCL11, also known as eosinophil chemotactic protein, eotaxin-1, is a small cytokine of the CC chemokine family and in humans is a protein encoded by the CCL11 gene on chromosome 17. CCL11 is constitutively expressed in a variety of tissues including the intestine, lymph nodes, thymus, skin, heart, kidney and breast. CCL11 can act by binding to chemokine receptors including CCR2, CCR3 and CCR5. The primary receptor mediating the biological effects of CCL11 is CCR3, a seven-transmembrane receptor coupled to a heterotrimeric G protein. Eotaxin-1/CCL11 is initially associated with selective recruitment of eosinophils to sites of inflammation during allergic reactions. Once bound to CCR3 receptors expressed on the surface of eosinophils, eotaxin-1/CCL11 activates a series of intracellular signaling cascades that lead to eosinophil recruitment to sites of inflammation. Eosinophils are a source of cytotoxic granule proteins and growth factors responsible for tissue damage and remodeling, respectively, associated with the pathophysiology of a variety of diseases such as asthma. Examples include mycobacterial and schistosome-induced granulomas, which are involved in ischemia-induced remodeling of the vascular wall. It has also been shown that CCL11 is associated with aging, neurogenesis and neurodegeneration and is able to affect neural progenitor cells and microglia as a diagnostic marker^[1][2].