Description: This FlowCytomix Simplex Kit is designed for the measurement of Mouse IL-21 in an immunoassay analyzed on a flow cytometer. Together with the FlowCytomix Mouse Basic Kit (cat. BMS8440FF), this kit can be used to detect IL-21 alone or can be multiplexed with other Simplex Kits to measure a variety of analytes.
This kit contains bead population A9.
IL-21 is a 17 kDa immunomodulatory cytokine produced mainly by NKT, Th17 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. This cytokine 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. High levels of IL-21 are present in chemically induced colitis models. IL-21-deficient mice are protected from developing colitis upon chemical treatment by their inability to upregulate Th17-associated molecules.