|Detection of IL‑3 R alpha /CD123 in IL-3 Dependent DA3 Mouse Cell Line by Flow Cytometry. IL-3 dependent myeloid leukemia DA3 mouse myeloma cell line was stained with Rat Anti-Mouse IL‑3 R alpha /CD123 PE‑conjugated Monoclonal Antibody (Catalog # FAB983P, filled histogram) or isotype control antibody (Catalog # IC006P, open histogram). View our protocol for Staining Membrane-associated Proteins.|
Interleukin 3 (IL-3) is a cytokine produced primarily by activated T cells or mast cells. IL-3 stimulates the proliferation and differentiation of hematopoietic cells including pluripotent hematopoietic stem cells as well as various lineage-committed cells. The biological effects of IL-3 on the various cell types are mediated by the binding of IL-3 to a specific cell surface receptor complex. The functional high-affinity IL-3 receptor is a heterodimer consisting of a ligand binding alpha subunit and a beta subunit. The alpha subunit alone binds IL-3 with low affinity. The beta subunit is required for the high-affinity binding of IL-3 to the heterodimeric receptor complex. The beta subunit has also been found to be a component of the high-affinity receptor complex for IL-5 and GM-CSF and is also referred to as the beta common ( beta c) chain. In the mouse, there are two IL-3 R beta proteins. The first identified mouse IL-3 R beta was also called AIC2A and binds IL-3 with low affinity (1). The second mIL-3 R beta was referred to as AIC2B (2). AIC2B doesn’t bind IL-3 and is the homolog of the human IL-3 R beta. AIC2A was found to be the result of a gene duplication event. The mouse IL-3 R alpha, also called SUT-1, will form complexes with either mouse IL-3 R beta protein (3). The alpha subunit is a member of the type I cytokine receptor family, type 5 subfamily (4,5). The mouse IL-3 R alpha extracellular domain (ECD) shares 42% and 29% amino acid sequence identity with rat and human IL-3 R alpha ECD, respectively.