The DX11 monoclonal antibody specifically binds to CD226 which is also known as DNAX accessory molecule-1 (DNAM-1), Platelet and T cell activation antigen 1 (PTA1), or T lineage-specific activation antigen 1 antigen (TLiSA1). CD226 is a 65 kDa type 1 transmembrane glycoprotein consisting of 318 amino acid residues including two Ig-like domains. CD226 is expressed on the majority of T cells, NK cells, monocytes, platelets, and a subset of B cells, but not on erythrocytes. It is also present on a subset of thymocytes coexpressing high density surface CD3. CD226 is not present on normal fibroblast cell lines or tumor cell lines of epithelial or neuronal origins. CD226 is a tyrosine phosphorylated, signal-transducing molecule which participates in primary adhesion during cytotoxic T lymphocyte (CTL)- or NK cell-mediated cytotoxicity. The DX11 antibody inhibits T- and NK cell-mediated cytotoxicity against a variety of tumor cell targets, and blocks cytokine production by alloantigen-specific T 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.