Anti-Mouse IL-21R (Clone 4A9) - APC (I-833-50ug)

Interleukin-21 receptor (IL-21R) is a single pass type I membrane protein and a member of the type I cytokine receptor family. It is the receptor for Interleukin-21 (IL-21) and upon binding forms a heterodimer with the common gamma subunit (CD132; IL-2RG). IL-21R and IL-21 are important for the proliferation and differentiation of B cells, T cells, and natural killer cells. They function in survival signalling for antiviral CD8+ T cells during chronic infections and induce growth and differentiation of mature B cells in Ig-secreting plasma cells. Additionally, they prevent T cell exhaustion and viral persistence by limiting virus driven Treg cell proliferation1. IL-21 and IL21-R function as early as the pro-B cell stage, with receptor-mediated signalling increasing as cells mature2. When IL-21R binds IL-21, the JAK/STAT transduction pathway is activated. 4A9 was generated by immunizing Lewis rats with IL-21R-transfected YB2/0 and subsequent fusion of immunized spleen cells to SP2/03. FACS analysis and immunoprecipitation studies show that 4A9 selectively binds to IL-21R. Additionally, 4A9 stains the majority of spleen cells from wild type C57BL/6 mice but not IL-21R deficient mice. IL-21 blocks the binding of 4A9 to IL-21R-transfected YB2/0 cells.