LEGEND MAX™ Mouse IL-21 ELISA Kit with Pre-coated Plates

Interleukin 21 (IL-21) is a cytokine produced by CD4⁺ T cells, including T helper 17 (Th17) cells, T follicular helper (Tfh) cells, and natural killer T (NKT) cells. Functionally, IL-21 has pleiotropic effects on both innate and adaptive immune responses.  IL-21 enhances IFNγ production and cytotoxicity in CD8⁺ T effector cells, and terminal differentiation in activated natural killer (NK) cells. Though not essential for the differentiation of Th17 cells in vitro or in vivo, IL-21 can drive Th17 responses in conjunction with TGF-β. Production of IL-21 in CD4⁺ T cells is induced by IL-6 upon TCR stimulation; IL-6 and IL-21 are also key players in Tfh differentiation, driving increased expression of both bcl6 and CXCR5. In addition to its effects on T cells, IL-21 can also mediate cell proliferation, growth arrest, terminal differentiation, and apoptosis in normal B cells, depending on the target cell’s activation status. However, IL-21 has been reported to inhibit the proliferation of both human and murine B cells that have been stimulated with anti-IgM antibodies.

The BioLegend LEGEND MAX™ Mouse IL-21 ELISA Kit is a Sandwich Enzyme-Linked Immunosorbent Assay (ELISA) with a 96-well strip plate that is pre-coated with a polyclonal goat anti-mouse IL-21 capture antibody. The detection antibody is a biotinylated polyclonal goat anti-mouse IL-21 antibody. This kit is specifically designed for the accurate quantitation of mouse IL-21 from cell culture supernatant, serum, plasma, and other biological fluids. It is analytically validated with ready-to-use reagents.