Description:This monoclonal antibody 47.7G7.1F2 reacts with human CD126, also known as IL-6 receptor alpha. It associates with the gp130 chain to form the high-affinity receptor for IL-6. Although gp130 is ubiquitously expressed, CD126 is only found on mature T cells, activated B cells, macrophages, hepatocytes, and myeloma cells. Upon binding to IL-6, two heterotrimeric complexes of receptor and ligand associate into a hexamer and are then internalized, initializing Jak/STAT signaling pathways. IL-6 induces the proliferation and survival of T cells, Th2 differentiation, and acute-phase protein production in the liver. A soluble form of CD126 lacking the transmembrane domain is also present and can be generated by cleavage at the cell surface or alternative splicing. Soluble CD126 can bind IL-6 and activate cells expressing only gp130 through trans-presentation.