Reactivity | HuSpecies Glossary |
Applications | Bioactivity |
Additional Information | Analyzed by SEC-MALS |
Details of Functionality | Measured by its ability to enhance IFN-gamma secretion in NK-92 human natural killer lymphoma cells. The ED50 for this effect is ≤ 8 ng/mL. |
Source | E. coli-derived human IL-21 protein Gln32-Ser162 with a N-terminal Met |
Accession # | |
N-terminal Sequence | Met |
Protein/Peptide Type | Recombinant Proteins |
Gene | IL21 |
Purity | >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining. |
Endotoxin Note | <0.10 EU per 1 μg of the protein by the LAL method. |
Dilutions |
|
|
Theoretical MW | 15 kDa. Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors. |
|
SDS-PAGE | 17 kDa, reducing conditions |
|
Publications |
|
Storage | Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
|
Buffer | Lyophilized from a 0.2 μm filtered solution in PBS with BSA as a carrier protein. |
Purity | >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining. |
Reconstitution Instructions | Reconstitute at 100 μg/mL in PBS containing at least 0.1% human or bovine serum albumin. |
IL-21 (Interleukin-21) is a potent cytokine regulating many cell types of the immune system. IL-21 is produced by activated T follicular helper cells (Tfh), Th17 cells, and NKT cells (2-6). Tfh-derived IL-21 plays an important role in the development of humoral immunity through its autocrine effects on the Tfh cell and paracrine effects on immunoglobulin affinity maturation, plasma cell differentiation, and B cell memory responses (4, 8, 9). IL-21 protein regulates several aspects of T cell function. It co-stimulates the activation, proliferation, and survival of CD8+ T cells and NKT cells and promotes Th17 cell polarization (3, 5, 6, 11, 12). IL-21 blocks the generation of regulatory T cells and their suppressive effects on CD4+ T cells (13, 14). In addition to its role in T cell biology, IL-21 also plays a critical role in B cell activation, proliferation, differentiation, and apoptosis (2). It is also required for the migration of dendritic cells to draining lymph nodes (10). And IL-21 suppresses cutaneous hypersensitivity reactions by limiting allergen-specific IgE production and mast cell degranulation (16). In the autoimmune disease Systemic lupus erythematosus (SLE), a link between IL-21 and SLE disease susceptibility and progression was recently reported (19).
IL-21 protein exerts its biological effects through a heterodimeric receptor complex of gamma c and the IL-21-specific IL-21 R (2, 7). IL-21 is an approximately 14 kDa four-helix-bundle member of the family of cytokines that utilize the common gamma chain (gamma c) as a receptor subunit. gamma c is also a subunit of the receptors for IL-2, IL-4, IL-7, IL-9, and IL-15 (1). IL-21 R engagement enhances the cytolytic activity and IFN-gamma production of activated NK cells but limits the expansion of resting NK cells (15). Dysregulation of the IL-21/IL-21 R system contributes to the development of multiple immunological disorders (1, 17). The 133 amino acid (aa) mature human IL-21 protein shares 63% and 61% aa sequence identity with mouse and rat IL-21 protein, respectively. Alternative splicing generates an additional isoform with a substitution of the C-terminal 16 amino acids (18).
Perforin Antibodies Reveal Links to Apoptosis and Immune Response Perforin, also known as the pore-forming protein, pfp, is a 70 kD cytolytic protein expressed in the cytoplasmic granules of cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. It is one of the major effector molecules used by CTL and NK cel... Read full blog post. |
The concentration calculator allows you to quickly calculate the volume, mass or concentration of your vial. Simply enter your mass, volume, or concentration values for your reagent and the calculator will determine the rest.