IL-21 Antibody [SB134b]

Interleukin-21 (IL-21) is a four helical bundle type I cytokine. The mature form of human IL-21 is a 131 amino acid protein. IL-21 is expressed primarily by NKT and CD4+ T cells, particularly the inflammatory Th17 subset, and has pleiotropic effects on both innate and adaptive immune responses. The effects of IL-21 include promotion of antibody production, NK cell differentiation, proliferation and differentiation of cells of monocyte and granulocyte lineages, costimulation of T cells, and augmentation of antitumor activity of CD8+ T cells. Studies have shown that IL-21 is also an autocrine cytokine that potently induces Th17 differentiation and suppresses Foxp3 expression, and serves as a target for treating inflammatory diseases.