CD127 (IL-7Rα) Antigen

The CD127 antigen is a 75-80 kDa type I transmembrane glycoprotein also known as IL-7 receptor α chain or IL-7Rα. It forms a heterodimer with the common γ chain CD132 (IL-2Rγ), which is shared with the receptors for IL-2, IL-4, IL-9, IL-13, IL-15, and IL-21, to form the high affinity IL-7 receptor. CD127 is found on normal B cell precursors but not on mature B lymphocytes. It is also expressed by thymocytes, the majority of peripheral T lymphocytes, a subset of monocytes and a subset of CD34+ cells. CD127 is a useful marker for identifying memory and effector T cells. Its expression is down-modulated on Treg cells. The ligation of IL-7 with its receptor is important for stimulation of mature and immature T cells as well as immature B cell proliferation and development.