The 1A29 monoclonal antibody specifically recognizes ICAM-1 which is also known as CD54. ICAM-1 is an 85 kDa type I transmembrane glycoprotein that is encoded by Icam1 (Intercellular adhesion molecule 1). It is expressed on vascular endothelium in lymphoid tissues, thymic stromal cells, peripheral blood monocytes, peritoneal macrophages and mast cells, dendritic cells, and weakly on peripheral lymphocytes and thymocytes. ICAM-1 is a ligand for LFA-1 (CD11a/CD18) and Mac-1 (CD11b/CD18). Its expression is upregulated on activated lymphocytes and endothelial cells. 1A29 mAb inhibits Phorbol 12-Myristate 13-Acetate (PMA)-induced aggregation of phytohemagglutinin (PHA)-stimulated splenic blasts, as well as the adhesion of mitogen-stimulated blasts to high endothelial venule (HEV) cells and purified ICAM-1. The 1A29 antibody can reportedly inhibit leucocyte infiltration in in vivo systems, blocks induction of experimental allergic encephalomyelitis, and reduces NK-cell adhesion to tumor cells.
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.