IL21 Recombinant Proteins and Neutralizing Antibody Tools

IL21 belongs to the common γ-chain cytokine family, which also includes IL-2, IL-4, IL-7, IL-9, and IL-15. These cytokines share use of the common γ-chain receptor subunit and collectively regulate lymphocyte development, survival, and function. IL-21 is produced primarily by activated CD4+ T cells, T follicular helper cells, and selected NKT-cell populations. It binds IL21R, which associates with the common γ chain to activate JAK1/JAK3 and STAT3-centered signaling. The pathway regulates B-cell differentiation, plasma-cell generation, antibody production, T-cell responses, and NK-cell activity. Depending on cellular context, IL-21 can enhance antiviral and antitumor immunity or contribute to pathogenic lymphocyte activation in autoimmune disease. ICOS signaling promotes T follicular helper-cell differentiation and IL-21 production, creating a close biological connection between the ICOS-ICOSL and IL-21 pathways.

DIMA BIOTECH provides human IL-21 recombinant proteins in His-, human Fc-, and mouse Fc-tagged formats for IL-21/IL21R interaction studies, ELISA, SPR/BLI, antibody screening, and assay development. A chimeric monoclonal antibody and reference antibodies, including biotinylated formats, support IL-21 detection and neutralizing-antibody screening.