Recombinant Caprine IL-21 (N-His)

Goat interleukin-21 (Capra hircus Interleukin-21, Goat IL-21) is a secreted cytokine with immunomodulatory activity, belonging to the IL-15/IL-21 family of four-helix bundle cytokines. It is produced mainly by activated CD4+ T cells (especially follicular helper T cells (Tfh), Th17 cells, and NKT cells), is secreted into the extracellular space via an N-terminal 1–17 signal peptide, and acts through the IL-21 receptor complex on target cells (B cells, T cells, NK cells, dendritic cells, etc.). Functionally, goat IL-21 induces IgG1 and IgG3 production by B cells, cooperates with IL-6 to control early Tfh cell generation and germinal center formation, synergizes with IL-15 to promote NK cell proliferation and maturation, synergizes with IL-15/IL-18 to stimulate IFN-γ production by T cells and NK cells, regulates mature B/T cell proliferation, and suppresses dendritic cell activation and maturation in T cell-mediated immune responses.