Invitrogen™ CD127 Monoclonal Antibody (A7R34), eFluor™ 450, eBioscience™, Invitrogen™

CD127, also known as the Interleukin-7 receptor alpha chain (IL-7Ralpha), is a type I glycoprotein with a molecular weight of 75-80 kDa. It forms a multi-functional receptor complex with CD132, the common gamma chain, to create the IL-7 receptor (IL-7R), which is crucial for lymphopoiesis. The active IL-7 receptor is an alpha/gamma chain heterodimer, where the gamma chain also associates with the interleukin-2 receptor and primarily activates signal transduction, while the alpha chain determines specific signaling events through its association with cytoplasmic signaling molecules. CD127 is expressed by immature B cells through the early pre-B stage, thymocytes during various stages of development, and most mature T cells, with transient down-regulation upon activation. It promotes the proliferation of precursor B cells, thymocytes, T cell progenitors, and mature CD4+ and CD8+ T cells. Binding of IL-7 to CD127 results in signal transduction through several tyrosine kinase pathways, including the Jak/STAT pathway, and is indispensable for lymphocyte development and the control of homeostatic proliferation of T cells in the periphery. Additionally, IL-7R signaling is involved in the regulation of T cell receptor (TCR) locus rearrangement in gamma delta T cells. Interestingly, CD127 expression is down-regulated on CD4+CD25+ regulatory T cells (T regs). While CD4 and CD25 co-expression is commonly used to identify T regs, this method may include cells without suppressive activity. CD4+CD25+ cells that have down-regulated CD127 expression are significantly enriched for the regulatory T cell population, as defined by the expression of the T reg-specific transcription factor Foxp3 and their suppressive activity in vitro. Diseases associated with CD127 dysfunction include severe combined immunodeficiency and T cell negative/B cell negative/NK positive severe combined immunodeficiency.