The 15-2 monoclonal antibody specifically recognizes CD206 which is also known as Macrophage mannose receptor (MMR) or C-type lectin domain family 13 member D (CLEC13D). CD206 (MMR) is a ~175 kDa type I transmembrane glycoprotein that is encoded by MRC1 (Mannose receptor C-type 1) which belongs to the mannose receptor family. The extracellular region of CD206 (MMR) is comprised of an N-terminal cysteine-rich domain, followed by a fibronectin type II domain, eight carbohydrate recognition domains (CRD), a transmembrane segment, and a short cytoplasmic tail. CD206 (MMR) is expressed on human macrophages, immature dendritic cells, and endothelial cells. It is not detected on resting monocytes. CD206 (MMR) can function as a Pattern Recognition Receptor (PRR) since it binds to glycoconjugates containing mannose, fucose, or N-acetylglucosamine that are present on the surface of many microorganisms. This receptor enables macrophages and dendritic cells to bind and internalize microbes and their products through endocytosis and phagocytosis and to participate in innate immunity as well as antigen processing related to antigen presentation for adaptive immune responses.
The antibody was conjugated to BD Horizon™ BUV661 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 with an Ex Max of 348-nm and an acceptor dye with an Em Max at 661-nm. BD Horizon Brilliant BUV661 can be excited by the ultraviolet laser (355 nm) and detected with a 670/25 filter and a 630 nm LP. Due to cross laser excitation of this dye, there may be significant spillover into channels detecting APC-like emissions (eg, 670/25-nm filter).
Due to spectral differences between labeled cells and beads, using BD™ CompBeads can result in incorrect spillover values when used with BD Horizon BUV661 reagents. Therefore, the use of BD CompBeads or BD CompBeads Plus to determine spillover values for these reagents is not recommended. Different BUV661 reagents (eg, CD4 vs. CD45) can have slightly different fluorescence spillover therefore, it may also be necessary to use clone-specific compensation controls when using these reagents.