The TX56 monoclonal antibody specifically recognizes CD155, which is also known as Poliovirus Receptor (PVR), Tumor-associated glycoprotein E4 (Tage4), or Tumor-associated antigen 1 (Taa1). CD155 is a type I transmembrane glycoprotein that belongs to the Ig supergene family. CD155 is an adhesion receptor that binds to different ligands including nectin-3, CD96 (Tactile), CD226 (DNAM-1), TIGIT, and the extracellular matrix protein vitronectin. It is highly expressed on double-positive thymocytes and variably expressed on mature thymocytes and T cells, including regulatory T cells and NKT cells. CD155 is also differentially expressed on subsets of B cells, plasma cells, dendritic cells, and monocytes. CD155 expression is upregulated by activated T cells, B cells, and dendritic cells. CD155 is involved in forming adherens junctions between adjacent epithelial or endothelial cells. CD155 plays roles in regulating cell growth, adhesion, motility, migration as well as NK and T cell-mediated cytotoxicity.
The antibody was conjugated to BD Horizon BUV615 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome with an Ex Max near 350 nm and an Em Max near 615 nm. BD Horizon Brilliant BUV615 can be excited by the ultraviolet laser (355 nm) and detected with a 610/20 filter and a 595 nm LP. Due to the excitation of the acceptor dye by the blue/yellow-green laser line, there may be significant spillover into channels detecting PE-CF594 like emissions (eg, 610/20-nm filter).