The HP-3G10 monoclonal antibody specifically recognizes human CD161 which is also known as Natural killer cell surface protein P1A (NKR-P1A or NKRP1A) or C-type lectin domain family 5 member B (CLEC5B). CD161 is expressed on the cell surface as an 80 kDa disulfide-linked homodimeric type II transmembrane glycoprotein. It is encoded by KLRB1 (Killer cell lectin-like receptor subfamily B member 1) which belongs to the Ca2+-dependent C-type lectin superfamily. CD161 is expressed on NK cells and on subsets of CD4+ and CD8+ αβ T cells, NKT cells, γδ T cells, CD3+ thymocytes, and fetal liver cells. CD161 is preferentially expressed on memory/effector T cells. CD161 can reportedly inhibit NK cell-mediated cytotoxicity and IFN-γ production. Lectin-like transcript 1 (LLT-1), encoded by CLEC2D (C-type lectin domain family 2 member D), has been described as a ligand for CD161. LLT-1 is expressed on some activated dendritic cells (DC) and B 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.