The N418 monoclonal antibody specifically binds to CD11c, the Integrin alpha X (Integrin αX, Itgax) chain of the heterodimeric gp150, 95 (CD11c/CD18, αXβ2) integrin that forms the complement receptor 4 (CR4). CD11c is a150 kDa type I transmembrane glycoprotein that is expressed on dendritic cells, CD4-CD8+ intestinal intraepithelial lymphocytes (IEL), and some NK cells and T cells. CD11c expression is upregulated on IEL and T cells following activation. Cells of the monocyte/macrophage lineage have been reported to express low levels of CD11c. The CD11c/CD18 integrin can bind to several ligands including iC3b, fibrinogen, and CD54. This integrin reportedly plays important roles in phagocytosis and in mediating cellular interactions during inflammation.
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.