The HP-3D9 monoclonal antibody specifically binds to CD94 which is also known as KP43. CD94 is expressed on the cell surface as a ~70 kDa, disulfide-linked, type II transmembrane glycoprotein dimer. It is encoded by KLRD1 (Killer cell lectin like receptor D1) which belongs to the C-type lectin superfamily. CD94 is expressed on natural killer (NK) cells, especially activated NK cells. It is also expressed on γ/δ TCR+ T lymphocytes, NK-T cells, and on some CD8+CD56+ α/β TCR+ cells. CD94 associates with various NKG2 receptors to form receptors for HLA class I molecules and plays a role in regulating cellular adhesion and activation. The HP-3D9 antibody can reportedly inhibit the cytolytic activity of activated NK cells.
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.