Human IL-21 Single-Use ELISA RSG Standard

Description: Human Interleukin-21 (IL-21) is a 131-amino acid protein with 57% identity to the mouse gene. It contains a 24-amino acid signal peptide and a 4-helix-bundle cytokine domain homologous to IL-2, IL-4 and IL-15. IL-21 stimulates B cell proliferation in an anti-CD40 dependent manner but inhibits B cell proliferation stimulated by IL-4 plus anti-IgM. IL-21 is induced by IL-6 in activated T cells, a process that is dependent on STAT3 but not on ROR-gamma. IL-21 induces Th17 differentiation and suppresses FOXP3 expression, which requires STAT3 and ROR-gamma.

References: Ettinger, R., et al., J. Immunol., 2005, 175: 7867 - 7879. IL-21 Induces Differentiation of Human Naive and Memory B Cells into Antibody-Secreting Plasma Cells. Ozaki, K., et al., J. Immunol., 2004; 173: 5361 - 5371. Regulation of B Cell Differentiation and Plasma Cell Generation by IL-21, a Novel Inducer of Blimp-1 and Bcl-6. Zeng, R., et al., Blood, 2007; 109: 4135 - 4142. The molecular basis of IL-21–mediated proliferation. Zeng, R., et al., J. Exp. Med., Jan 2005; 201: 139 - 148. Synergy of IL-21 and IL-15 in regulating CD8+ T cell expansion and function.