The 9B9 monoclonal antibody specifically binds to CD368, which is also known as CLEC6 (C-type lectin-like receptor 6), CLEC4D, CLECSF8, and MCL (macrophage C-type lectin). CD368 is a 30 kDa type II transmembrane glycoprotein that belongs to the C-type Lectin Receptor family of molecules. It is primarily expressed on peripheral blood neutrophils and monocytes and weakly on several subsets of blood dendritic cells. Expression of this receptor is lost upon in vitro differentiation of monocytes into dendritic cells or macrophages. CD368 reportedly serves as an endocytic receptor that may function in antigen clearance and presentation to T lymphocytes. CD368 may also play roles in cellular adhesion, signaling and glycoprotein turnover. CD368 expression can be upregulated by cells in response to cytokines including IFN-γ, TNF, IL-6, and IL-10.
The antibody was conjugated to BD Horizon™ BUV737 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 737-nm. BD Horizon Brilliant BUV737 can be excited by the ultraviolet laser (355 nm) and detected with a 740/35 filter. Due to the excitation of the acceptor dye by other laser lines, there may be significant spillover into channels detecting Alexa Fluor® 700-like dyes (eg, 712/20-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 BUV737 reagents. Therefore, the use of BD CompBeads or BD CompBeads Plus to determine spillover values for these reagents is not recommended. Different BUV737 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.