The 11-5 monoclonal antibody specifically recognizes MHC class I-restricted T cell-associated molecule (CRTAM) that is also known as CD355 or Cytotoxic and regulatory T-cell molecule. CD355 (CRTAM) is encoded by Crtam which belongs to the Nectin family of cell adhesion molecules within the immunoglobulin superfamily. This type I transmembrane glycoprotein contains a V-type Ig domain, followed by a C-type Ig domain, a transmembrane region, and an intracellular region that contains a PDZ-binding motif at the C terminus. CD355 (CRTAM) is transiently expressed as a homodimer on activated NK cells, NKT cells, γδ T cells, CD8+ T cells, or CD4+ T cells. Through its V-type Ig domain, CRTAM (CD355) binds to Nectin-like molecule 2 (Necl-2) and plays important roles in adhesive interactions between different cell types and in cellular migration.
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.