IL-1RA is an agent that binds non-productively to the cell surface?interleukin-1 receptor?(IL-1R), the same receptor that binds?interleukin 1?(IL-1), preventing IL-1 from sending a signal to that cell. Besides, Interleukin 1 Alpha (IL-1a) has been identified as an interactor of IL-1RA, thus a binding ELISA assay was conducted to detect the interaction of recombinant human IL-1RA and recombinant human IL-1a. Briefly, IL1RA were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100μL were then transferred to IL-1a-coated microtiter wells and incubated for 2 h at 37℃. Wells were washed with PBST and incubated for 1 h with anti-IL-1RA 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 IL-1RA and IL-1a was shown in Figure 1, and this effect was in a dose dependent manner.
Figure. The binding activity of IL-1RA with IL-1a.