IL-21 (human), animal-free recombinant

Product Description: IL-21, a versatile cytokine, originates from CD4+ T cells upon encountering antigens. Its primary role involves enhancing the immune system's antigen-specific responses. IL-21 influences various immune cell activities: it fosters the transformation of T cell-activated B cells into plasma and memory B cells, boosts IgG production in tandem with IL-4, and prompts apoptosis in naive and stimulated B cells without T cell input. Furthermore, IL-21 bolsters the anti-tumor functions of CD8+ T cells and natural killer (NK) cells. To execute its functions, IL-21 binds to the IL-21R, a type I cytokine receptor that includes the gamma chain (gammac) shared with other cytokine receptors like IL-2, IL-4, IL-7, IL-9, and IL-15. This interaction sets off a chain reaction involving JAK1 and JAK3 tyrosine kinases' activation, ultimately leading to STAT1 and STAT3 transcription factor activation. The recombinant Human IL-21, a 15.4 kDa protein composed of 132 amino acids, mirrors these biological activities. . Amino acid sequence: MQDRHMIRMR QLIDIVDQLK NYVNDLVPEF LPAPEDVETN CEWSAFSCFQ KAQLKSANTG NNERIINVSI KKLKRKPPST NAGRRQKHRL TCPSCDSYEK KPPKEFLERF KSLLQKMIHQ HLSSRTHGSE DS. Endotoxin concentration: <0.1 EU/µg. Activity: Determined by its ability to stimulate the proliferation of human ANBL-6 cells. The expected ED50 is = 0.5 ng/ml, corresponding to a specific activity of > 2 x10^6 units/mg. Contains no preservative. Protein function: Cytokine with immunoregulatory activity. May promote the transition between innate and adaptive immunity. Induces the production of IgG(1) and IgG(3) in B-cells. Implicated in the generation and maintenance of T follicular helper (Tfh) cells and the formation of germinal-centers. Together with IL6, control the early generation of Tfh cells and are critical for an effective antibody response to acute viral infection. May play a role in proliferation and maturation of natural killer (NK) cells in synergy with IL15. May regulate proliferation of mature B- and T-cells in response to activating stimuli. In synergy with IL15 and IL18 stimulates interferon gamma production in T-cells and NK cells (PubMed:11081504, PubMed:15178704). During T-cell mediated immune response may inhibit dendritic cells (DC) activation and maturation. [The UniProt Consortium]