The 16-10A1 monoclonal antibody specifically recognizes CD80 (B7-1). This member of the Ig superfamily, like CD86 (B7-2), can bind to either CD28 or CD152 (CTLA-4) and provide either costimulatory or coinhibitory signals to T cells, respectively. CD80 is constitutively expressed on dendritic cells, monocytes, and peritoneal macrophages as well as by activated B cells and T cells. The 16-10A1 antibody blocks binding of CTLA-4 Ig to CD80 as well as T-cell activation by Con A-elicited peritoneal exudate cells or CD80-transfected cell lines. However, the 16-10A1 antibody alone is not able to block T-cell activation by antigen-presenting cells. The 16-10A1 antibody may reportedly block the binding of another CD80-specific antibody, clone 1G10. In addition, the 16-10A1 antibody may crossreact with an activation antigen expressed on IFN-γ-activated alveolar macrophages of the dog.
The antibody was conjugated to BD Horizon™ BUV563 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 which has an Ex Max of 348 nm and an acceptor dye. The tandem has an Em Max at 563 nm. BD Horizon BUV563 can be excited by the 355 nm ultraviolet laser. On instruments with a 561 nm Yellow-Green laser, the recommended bandpass filter is 585/15 nm with a 535 nm long pass to minimize laser light leakage. When BD Horizon BUV563 is used with an instrument that does not have a 561 nm laser, a 560/40 nm filter with a 535 nm long pass may be more optimal. Due to the excitation and emission characteristics of the acceptor dye, there may be spillover into the PE and PE-CF594 detectors. However, the spillover can be corrected through compensation as with any other dye combination.