IL-21 Recombinant Protein

IL-21 is a pleiotropic cytokine produced by CD4+ T cells in response to antigenic stimulation. Its action generally enhances antigen-specific responses of immune cells. The biological effects of IL-21 include: inducing the differentiation of T cell-stimulated B cells into plasma cells and memory B cells; the stimulation of IgG production in conjunction with IL-4; and the induction of apoptotic effects in naïve B cells and stimulated B cells in the absence of T cell signaling. Additionally, IL-21 promotes the anti-tumor activity of CD8+ T cells and NK cells. IL-21 exerts its effect through binding to a specific type I cytokine receptor, IL-21R, which also contains the γ chain (γc) found in other cytokine receptors, including IL-2, IL-4, IL-7, IL-9 and IL-15. The IL-21/IL-21R interaction triggers a cascade of events, which includes activation of the tyrosine kinases JAK1 and JAK3, followed by activation of the transcription factors STAT1 and STAT3. Recombinant Human IL-21 is a 15.4 kDa protein consisting of 132 amino acid residues.

The recombinant protein is stable for at least 2 years from date of receipt at -20˚ C. Reconstituted protein is stable for at least 3 months when stored in working aliquots with a carrier protein at -20˚ C. As with any protein, exposing the recombinant protein to repeated freeze / thaw cycles is not recommended. When working with proteins care should be taken to keep recombinant protein at a cool and stable temperature.