IL-21 stimulates proliferation of B cell stimulated by crosslinking of the CD40 antigen. It inhibits proliferation stimulated by IL-4 plus anti-IgM. IL-21 augments stimulation of the proliferation of naive CD45RA(+) but not memory CD45R0(+) T cells mediated by engagement of CD3. IL-21 stimulates the proliferation of bone marrow progenitor cells and the expression of the natural killer cell marker CD56 in the presence of IL-15. The Interleukin-21 receptor is closely related to human IL-2 beta receptor. The receptor contains a WSXWS motif in the extracellular region, typical of type 1 cytokine receptors. The receptor is expressed on natural killer cells, T cells, and B cell line. The functional signaling complex activates Janus kinases JAK1, JAK3, and the STAT proteins STAT1, and STAT3.
Aliases- IL-21, Za11
- Recombinant Human Interleukin-21 (IL21)
Formulation- Recombinant Interleukin-21 was lyophilized from a 0.2 µm filtered PBS solution pH 7.5.
Endotoxin Level- <1.0 EU/µg of recombinant protein as determined by the LAL method.
Storage Condition- The lyophilized protein is stable for at least one year from date of receipt at -70°C. Upon reconstitution, this cytokine can be stored in working aliquots at +2° to +8°C for one month, or at -20°C for six months, with a carrier protein without detectable loss of activity. Avoid repeated freeze/thaw cycles.