IL-21

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 induction of differentiation of T-cells-stimulated-B-cells into plasma cells and memory B-cells, stimulation (in conjunction) with IL-4 of IgG production, and 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 murine IL-21 is a 15.0 kDa protein consisting of 130 amino acid residues.

Product Specifications

Synonyms

Il21

NCBI Gene ID

60505

UniProt

Q9ES17

Accession Number

NP_068554.1

Accession Number mRNA

NM_021782

Chromosomal Location

3 B; 3

Reactivity

Mouse

Cross Reactivity

Mouse

Sequence

MHKSSPQGPD RLLIRLRHLI DIVEQLKIYE NDLDPELLSA PQDVKGHCEH AAFACFQKAK LKPSNPGNNK TFIIDLVAQL RRRLPARRGG KKQKHIAKCP SCDSYEKRTP KEFLERLKWL LQKMIHQHLS

Assay Protocol

Centrifuge vial prior to opening. Reconstitute in water to a concentration of 0.1-1.0 mg/ml. Do not vortex. This solution can be stored at 2-8°C for up to 1 week. For extended storage, it is recommended to further dilute in a buffer containing a carrier protein (example 0.1% BSA) and store in working aliquots at ‑20°C to -80°C.

Endotoxin

< 0.1 ng/µg of protein (< 1EU/µg)

Purity

> 98% by SDS-PAGE & HPLC analyses

Bioactivity

Measured by its ability to increase proliferation in mouse splenocytes induced by anti-hCD40 mAb. The expected ED50 is 15-20 ng/ml.

Length

130

Form

Lyophilized

Buffer

10 mM sodium citrate pH 4.0

Reconstitution

Water

Molecular Weight

15 kDa

Storage Conditions

The lyophilized protein is stable at room temperature for 1 month and at 4°C for 6 months. Reconstituted working aliquots are stable for 1 week at 2°C to 8°C and for 3 months at -20°C to -80°C.