The 18d3 monoclonal antibody specifically recognizes CD94 on all NK cells, NK1.1- or DX5-positive T lymphocytes (NK-T cells), and a subset of CD8-positive T lymphocytes in most strains tested (eg, A/J, AKR/J, BALB/c, C3H/He, C57BL/6, CBA/J, DBA/1, FVB/N, 129/Sv, NOD, SWR, and most DBA/2 substrains, but not DBA/2J). DBA/2J mice do not express CD94.3 CD94 is also expressed on CD8+ T lymphocytes activated in vivo. CD94 is a type-II transmembrane protein with an extracellular lectin-like domain and a short cytoplasmic tail which is not believed to have any signalling function. Heterodimers of CD94 with NKG2A, NKG2C, or NKG2E recognize Qa-1 (a non-classical MHC class I antigen) presenting the Qdm peptide. Studies on CD94/NKG2 heterodimers on human NK cells have demonstrated that the NKG2 components mediate signal transduction for the receptor, NKG2A being inhibitory and NKG2C being stimulatory. Similarly, the mouse NKG2A molecule contains two intracytoplasmic sequences which resemble the ITIM (Immunoreceptor Tyrosine-based Inhibitory Motif) consensus sequence. CD94/NKG2 receptors appear on fetal NK cells before the Ly- 49 MHC class I receptors, suggesting that CD94/NKG2 receptors and their ligand, Qa-1, may play a role in maintenance of self-tolerance in developing NK cells.
The antibody was conjugated to BD Horizon™ BV711 which is part of the BD Horizon Brilliant™ Violet family of dyes. This dye is a tandem fluorochrome of BD Horizon BV421 with an Ex Max of 405-nm and an acceptor dye with an Em Max at 711-nm. BD Horizon BV711 can be excited by the violet laser and detected in a filter used to detect Cy™5.5 / Alexa Fluor® 700-like dyes (eg, 712/20-nm filter). Due to the excitation and emission characteristics of the acceptor dye, there may be moderate spillover into the Alexa Fluor® 700 and PerCP-Cy5.5 detectors. However, the spillover can be corrected through compensation as with any other dye combination.