Biolegend, 534303, LEAF™ Purified anti-human IL-21 Antibody, 100μg

IL-21 was identified by a functional screening from conditioned medium of activated T cells using Baf3-IL-21R transfectants. In normal B cells, IL-21 can mediate cell proliferation, growth arrest, and terminal differentiation, or apoptosis, depending on their activation status. IL-21 enhances B cell proliferation following incubation with an activating CD40 antibody. This result suggests that IL-21 enhances B cell function following T and B cell interactions. Nevertheless, IL-21 inhibits the proliferation of murine and human B cells stimulated with anti-IgM antibodies. In addition, IL-21 enhances proliferation, cytotoxic activity, and IFN-γ production by CD8-effector T cells, and induces terminal differentiation of activated natural killer (NK) cells. Also, IL-21 can drive Th17 responses in conjunction with TGF-β. Nevertheless, IL-21 is not essential for the differentiation of Th17 cells in vitro or in vivo , as it was showed using IL-21 and IL-21R-deficient mice. IL-6 induces the production of IL-21 from CD4 T cells upon TCR stimulation. In addition, IL-6 and IL-21 are key players in the Tfh differentiation, characterized by increased protein expression of both Bcl-6 and CXCR5. IL-21R complex is formed with the IL-21R-alpha chain and the common subunits (γc) shared with other interleukins, such as IL-2, IL-4, IL-7, IL-9, and IL-15.
100μg
Verified Reactivity: Human
Antibody Type: Polyclonal
Host Species: Goat
Immunogen: Recombinant human IL-21
Formulation: 0.2 µm filtered in phosphate-buffered solution, pH 7.2, containing no preservative.
Endotoxin Level: Less than 0.1 EU/µg of the protein (< 0.01 ng/µg of the protein) as determined by the LAL test.
Preparation: The LEAF™ (Low Endotoxin, Azide-Free) antibody was purified by affinity chromatography.
Concentration: The antibody is bottled at the concentration indicated on the vial. To obtain lot-specific concentration and expiration, please enter the lot number in our Certificate of Analysis online tool.
Storage & Handling: Upon receipt, store frozen at -20°C. Make small volume aliquots if needed and avoid repeated freeze-thaw cycles to prevent denaturing the antibody.
Application: Neut - Quality tested
Recommended Usage: Each lot of this antibody is quality control tested by the neutralization of HT-2 cell proliferation induced by recombinant human IL-21 at 0.6 µg/mL. ND50 range is 3 -15 μg/mL. It is recommended that the reagent be titrated for optimal performance for each application.
RRID: AB_2894672 (BioLegend Cat. No. 534303)
Structure: Interleukin
Distribution: CD4 activated T cells, Th17 cells, NK T cells
Function: IL-21 induces T and B cell proliferation, B cell Ig class switching to IgG production, decreases dendritic cell function, enhances differentiation of effector and central memory T cells, and regulates T cell and hematopoietic progenitor cell homeostasis.
Interaction: T cells, B cells, NK cells, dendritic cells, and some nonimmune cells, such as fibroblasts and epithelial cells
Ligand/Receptor: IL-21R and the common γc subunit (CD132) are components of the IL-21R complex.
Cell Type: B cells, Dendritic cells, Hematopoietic stem and progenitors, NKT cells, T cells, Th17, Tregs
Biology Area: Cell Biology, Immunology, Innate Immunity, Neuroscience, Stem Cells
Molecular Family: Cytokines/Chemokines
Antigen References: Parrish-Novak J, et al. 2000. Nature. 408:57-63. de Totero D, et al. 2006. Blood. 107:3708-15. Korn T, et al. 2007. Nature. 448:484-487. Coquet JM, et al. 2008. J Immunol. 180:7097-101. Dienz O, et al. 2009. J Exp Med. 206:69-78. Kaplan MH, et al. 2011. Blood. 117:6198-201. Eto D, et al. 2011. PLoS One. 6:e17739.
Gene ID: 59067
UniProt: View information about IL-21 on UniProt.org
Clone: Poly5343
Regulatory Status: RUO
Other Names: B cell growth factor 1 (Interleukin 21)
Isotype: Goat Polyclonal IgG
Q: Do you guarantee that your antibodies are totally pathogen free?
A: BioLegend does not test for pathogens in-house aside from the GoInVivo™ product line. However, upon request, this can be tested on a custom basis with an outside, independent laboratory.
Q: Does BioLegend test each Ultra-LEAF™ antibody by functional assay?
A: No, BioLegend does not test Ultra-LEAF™ antibodies by functional assays unless otherwise indicated. Due to the possible complexities and variations of uses of biofunctional antibodies in different assays and because of the large product portfolio, BioLegend does not currently perform functional assays as a routine QC for the antibodies. However, we do provide references in which the antibodies were used for functional assays and we do perform QC to verify the specificity and quality of the antibody based on our strict specification criteria.
Q: Does BioLegend test each Ultra-LEAF™ antibody for potential pathogens?
A: No, BioLegend does not test for pathogens in-house unless otherwise indicated.  However, we can recommend an outside vendor to perform this testing as needed.
Q: Have you tested this Ultra-LEAF™ antibody for in vivo or in vitro applications?
A: We don't test our antibodies for in vivo or in vitro applications unless otherwise indicated. Depending on the product, the TDS may describe literature supporting usage of a particular product for bioassay. It may be best to further consult the literature to find clone specific information.