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 γ chain (γc) 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.
Expression System: E. coli
Molecular Weight: 15.4 kDa
Class: Recombinant
Endotoxin Concentration: <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.
Form: Lyophilized
Contains: no preservative
Storage Conditions: -20°C
Purity: ≥ 98% by SDS-PAGE gel and HPLC analyses
Caution: For Research Use Only. Not for use in diagnostic procedures.
Gene Symbol: IL21
Protein ID: Q9HBE4