IL-21 Mouse anti-Human, PE, Clone: 3A3-N2.1 (also known as 3A3-N2), BD

Human Interleukin-21 (IL-21) is a member of the type I cytokine family that is encoded by a gene resident on chromosome 4. The mature form of human IL-21 is a 131 amino acid protein. IL-21 is produced by activated NKT and multiple CD4+ T cell subsets including effector memory and central memory CD4+ T cells and differentiated T helper cell subsets polarized towards Th17 cell and T follicular helper (Tfh) phenotypes. IL-21 plays important protective roles in the regulation of hematopoiesis and both innate and adaptive immune responses and adverse roles in promoting autoimmunity. IL-21 costimulates the proliferation and differentiation of CD4+ T cells. It enhances the proliferation of and cytotoxicity mediated by natural killer (NK) cells and CD8+ T cells. IL-21 costimulates B cell proliferation and differentiation into plasma cells producing immunoglobulins with IgG isotypes. IL-21 can also regulate the functions of dendritic cells and other myeloid cells. IL-21 exerts its biological activities by binding to and activating the Janus activating kinases (JAK1 and JAK3) and signal transducers and activators of transcription (STAT1, STAT3, STA5a and STAT5b) signaling pathways through the IL-21 receptor (IL-21R) complex. The IL-21R complex is comprised of the IL-21R alpha subunit and the common cytokine receptor gamma subunit (γ c; CD132).

The monoclonal 3A3-N2 antibody specifically binds to human IL-21.