The BU63 monoclonal antibody specifically recognizes CD86 which is also known as B70, B7-2, B7.2, LAB72 or CD28LG2. CD86 is a ~70-80 kDa type I transmembrane glycoprotein that belongs to the Ig gene superfamily. CD86 is expressed on monocytes, dendritic cells, Langerhans cells, activated B cells, and memory B cells. Like CD80 (B7-1), CD86 serves as a ligand for CD28 or CD152 (CTLA-4) expressed by T cells and can induce costimulatory or coinhibitory signals, respectively. The BU63 antibody can reportedly block the binding of other human CD86-specific antibodies including the 2331 (FUN-1) (complete block) or IT2.2 (partial block) antibodies. These results suggest that the BU63 antibody may bind to a similar or identical CD86 epitope as the 2331 (FUN-1) antibody but to a different, although spatially-related epitope compared with the IT2.2 antibody.
The antibody was conjugated to BD Horizon™ BUV496 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 496-nm. BD Horizon BUV496 can be excited by the ultraviolet laser (355 nm) and detected with a 515/30 nm filter with a 450LP. Due to the excitation of the acceptor dye by other laser lines, there may be significant spillover into the channel detecting BD Horizon V500 or BV510 (eg, 525/40-nm filter). However, the spillover can be corrected through compensation as with any other dye combination.