IL-21 Monoclonal Antibody (eBio3A3-N2 (3A3-N2)), eFluor™ 660, eBioscience™, Invitrogen™

Description

• Description: The monoclonal antibody eBio3A3-N2 reacts with human IL-21, a potent stimulator of NK and cytolytic T cells
• IL-21 is a 131 amino acid protein most closely related to IL-2 and IL-15
• Expression is found in CD4+ cells upon activation
• In addition to its effect on NK cells, IL-21 stimulates proliferation of B-cell stimulated by crosslinking of the CD40 antigen and stimulates the proliferation of bone marrow progenitor cells and the expression of the NK-cell marker CD56 in the presence of IL-15
• Applications Reported: This eBio3A3-N2 (3A3-N2) antibody has been reported for use in intracellular staining followed by flow cytometric analysis
• Applications Tested: This eBio3A3-N2 (3A3-N2) antibody has been pre-titrated and tested by intracellular staining and flow cytometric analysis of restimulated, Th17-polarized normal human peripheral blood cells
• This can be used at 5 μL (0.125 μg) per test
• A test is defined as the amount (μg) of antibody that will stain a cell sample in a final volume of 100 μL
• Cell number should be determined empirically but can range from 10^5 to 10^8 cells/test
• Staining for IL-21 has shown donor variability
• stimulation times may vary depending on the donor and should be optimized
• Increased staining levels have been observed on Th17-polarized normal human peripheral blood cells
• eFluor™ 660 is a replacement for Alexa Fluor™ 647
• IL-21 is a 17 kDa immunomodulatory cytokine produced mainly by Natural Killer Cells (NKT), T helper (Th) 17 and T follicular helper (TFH) cells
• In TFH cells, IL-21 expression leads to autocrine signaling through the IL-21 receptor (IL-21R) and STAT3, which leads to additional transcriptional activation by Bcl6
• As with IFN gamma for Th1 and IL-4 for Th2 cells, IL-21 is critical for TFH cell development and effector function
• IL-21 plays a role in T cell-dependent B cell differentiation into plasma cells and memory cells, stimulation of IgG production and induction of apoptotic signaling in naive B cells
• In Th17 cells, IL-21 expression and autocrine feedback through STAT3, IRF4 and ROR gamma t lead to upregulation of the IL-23R, thereby preparing Th17 cells for maturation and maintenance by the inflammatory cytokine IL-23
• While upregulating IRF4 and ROR gamma t, IL-21 also mediates the downregulation of Foxp3
• IL-21 deficient mice are protected from developing colitis upon chemical treatment by their inability to upregulate Th17-associated molecules
• In comparison, elevated levels of IL-21 are present in chemically-induced colitis mouse models.