The 10/78 monoclonal antibody recognizes the rat CD161 proteins, CD161a (also known as, Klrb1a, or Nkrp1a/NKR-P1A), and CD161b (Klrb1b, Nkrp1b/NKR-P1B). These type II transmembrane glycoproteins have an extracellular C-type lectin domain and thus belong to the C-type lectin superfamily. These CD161 proteins form ~ 60 kDa homodimers that are expressed on natural killer cells and subsets of T lymphocytes, activated monocytes, and dendritic cells. The 10/78 antibody competes with the previously-described 3.2.3 antibody for binding to these CD161 proteins. CD161 molecules are C-type lectin-like receptors that can either activate (CD161a) or inhibit (CD161b) effector leucocyte responses, eg, cytotoxicity or cytokine production, against target cells which express C-type lectin-like related (Clr) molecules. Although several members of the Klrb1 gene family have been identified in the mouse and rat, only a single human KLRB1 homolog has been discovered.
The antibody was conjugated to BD Horizon™ BUV737 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 737-nm. BD Horizon Brilliant BUV737 can be excited by the ultraviolet laser (355 nm) and detected with a 740/35 filter. Due to the excitation of the acceptor dye by other laser lines, there may be significant spillover into channels detecting Alexa Fluor® 700-like dyes (eg, 712/20-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 BUV737 reagents. Therefore, the use of BD CompBeads or BD CompBeads Plus to determine spillover values for these reagents is not recommended. Different BUV737 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.