Description
IL-3R alpha/CD123, also known as interleukin 3 receptor subunit alpha, is a member of the type 1 cytokine receptor family and type 5 subfamily. It is expressed on multiple cell types, including endothelial cells, monocytes, eosinophils, basophils plus mast cells, and plasmacytoid CD4+ T cells. It serves as a low affinity binding protein for monomeric IL?3. The IL?3 and IL?3 R alpha complex likely interacts with a preformed signaling homodimer comprised of either beta IL-3 or beta c chains. The extracellular domain of mouse IL?3 R alpha/CD123 shares only 44% and 29% aa sequence identity with rat and human IL?3 R alpha, respectively. Nevertheless, human IL?3 is reported to be active on the mouse receptor complex that is expressed on select cell types. Also, the specific alpha subunit of the interleukin 3 receptor is strongly expressed in various leukemic blasts and leukemic stem cells and seems to be an excellent target for the therapy of leukemias. Recombinant mouse IL-3R alpha/CD123, fused to hIgG-His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques