Active Interleukin 21 (IL21)

Figure. The binding activity of IL21 with IL2Rg.
Interleukin-21 (IL21) is a cytokine that has potent regulatory effects on cells of the immune system, including natural killer (NK) cells and cytotoxic T cells that can destroy virally infected or cancerous cells. This cytokine induces cell division/proliferation in its target cells. IL21 may be a critical factor in the control of persistent viral infections. Besides, Interleukin 2 Receptor Gamma (IL2Rg) has been identified as an interactor of IL21, thus a binding ELISA assay was conducted to detect the interaction of recombinant human IL21 and recombinant human IL2Rg. Briefly, IL21 were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100uL were then transferred to IL2Rg-coated microtiter wells and incubated for 2h at 37℃. Wells were washed with PBST and incubated for 1h with anti-IL21 pAb, then aspirated and washed 3 times. After incubation with HRP labelled secondary antibody, wells were aspirated and washed 3 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50µL stop solution to the wells and read at 450nm immediately. The binding activity of IL21 and IL2Rg was shown in Figure 1, and this effect was in a dose dependent manner.