Recombinant Human IL-21

Interleukin 21 (IL-21) is a T cell-derived pleiotropic cytokine that has potent regulatory effects on cells of the immune system, including natural killer (NK) cells and cytotoxic T cells that can destroy virally infected or cancerous cells.^1,2 This cytokine induces cell division/proliferation in its target cells. IL-21 elicits its effects on immune cells by interacting with a cell surface receptor known as the interleukin 21 receptor, IL-21R, which is expressed in bone marrow cells and various lymphocytes. IL-21 is closely related to IL-2 and IL-15³ and is a key factor in the transition between innate and adaptive immune responses.⁴ The critical role of IL21 in promoting humoral immune responses makes it an important focus of potential therapeutic interventions in conditions characterised by overproduction of pathogenic autoantibodies.⁵