CD125 (IL-5RA): IL-5 [Biotinylated] Inhibitor Screening Chemiluminescence Assay Kit

The CD125 (IL-5RA): IL-5 [Biotinylated] Inhibitor Screening Chemiluminescence Assay Kit is an ELISA-based assay designed to measure the binding between CD125 (also known as IL-5RA or Interleukin 5 receptor subunit alpha) and IL-5 protein for screening and profiling applications. This kit comes with enough purified CD125 (amino acids 21-342) and biotinylated IL-5 (amino acids 20-134(end)), streptavidin-HRP, assay buffer, and detection reagent for 100 enzyme reactions. Figure 1. CD125 (IL-5RA): IL-5 [Biotinylated] Inhibitor Screening Chemiluminescence Assay Kit schematic. A 96-well plate is coated with CD125 protein. After coating and blocking, biotinylated IL-5 is added in an optimized assay buffer. Next, unbound biotinylated IL-5 is washed away, and the plate is incubated with streptavidin-HRP. After a final wash, ELISA ECL substrate is added to produce chemiluminescence that can be measured using a chemiluminescence reader. The chemiluminescence signal is proportional to the efficacy of IL-5 binding to CD125. Need us to run inhibitor screens or profile your compounds that block the binding of IL-5 to IL-5RA? Check out our Immunotherapy Biochemical Screening Services. IL-5 (interleukin-5) is a pro-inflammatory protein that functions as an intermediary cytokine in the TH2 (T helper 2) cells response in asthma and other eosinophilic allergic diseases. IL-5 functions by promoting eosinophil maturation, activation, and migration into target tissues. It binds to the IL-5 specific cell surface receptor IL-5RA (IL-5 receptor alpha) and further recruits the common beta chain receptor (CSF2RB) to initiate downstream signaling through JAK1/2 (Janus kinase 1/2) and STAT5. Activated eosinophils contribute to airway damage through degranulation, resulting in the release of pro-inflammatory cytokines and enzymatic mediators contributing to local inflammation and tissue damage. IL-5 signaling plays a critical role in allergic and eosinophilic asthma subtypes and has been an active area for drug discovery. Antibodies targeting both IL-5 ligand and CD125 have been FDA (Food and Drug Administration) approved for the treatment of severe eosinophilic asthma and other eosinophilic conditions. These antibodies function by neutralizing IL-5-mediated signaling in eosinophils. Additionally, IL-5Ra targeting antibodies and CAR (chimeric antigen receptor)-T cells can induce immune-mediated cytotoxicity of IL-5RA expressing cells, including eosinophils through ADCC (antibody-dependent cellular cytotoxicity) and CAR-T cell mediated killing respectively.