The U29-93 monoclonal antibody specifically binds to the mouse Interleukin-33 Receptor (IL-33 Receptor, or IL-33R) which is also known as ST2. The IL-33R exists in either a type I transmembrane or soluble glycoprotein form. These IL-33R forms are encoded by the Il1rl1 (Interleukin-1 receptor-like 1) gene which belongs to the IL-1 Receptor family within the Ig superfamily. The IL-33R is expressed by subsets of T cells, including Th2-like cells and some regulatory T cells, as well as some innate lymphocytes, eosinophils, basophils, and mast cells. The IL-33R (also known as the IL-33R alpha subunit, or IL-33Rα) binds IL-33 and complexes with the IL-1R Accessory Protein (IL1RAP) to form a functional signaling receptor complex that can induce the production of T helper type 2 (Th2) cytokines. The soluble IL-33R may function as a decoy receptor which can block the binding of IL-33 to the transmembrane IL-33R. The IL-33R plays roles in inflammation, immunity, and allergy.
The antibody was conjugated to BD Horizon™ BV650 which is part of the BD Horizon Brilliant™ Violet family of dyes. This dye is a tandem fluorochrome of BD Horizon BV421 with an Ex Max of 405-nm and an acceptor dye with an Em Max at 650-nm. BD Horizon BV650 can be excited by the violet laser and detected in a filter used to detect APC-like dyes (eg, 660/20-nm filter). Due to the excitation and emission characteristics of the acceptor dye, there will be spillover into the APC and Alexa Fluor® 700 detectors. However, the spillover can be corrected through compensation as with any other dye combination.