The DX9 monoclonal antibody specifically binds to CD158e1, also known as NKB1. CD158e1 functions as a killer cell inhibitory receptor (KIR) and is encoded by KIR3DL1 (Killer cell immunoglobulin-like receptor, three domains, long cytoplasmic tail). CD158e1 is a 70 kDa glycoprotein that belongs to the Ig superfamily. It is expressed on a subset of natural killer cells and a small subset of T cells. Expression of CD158e1 has been observed to vary among individuals. KIR molecules specifically recognize a certain group of HLA class I antigens. Interaction of CD158e1 with specific HLA-B antigen on a target cell appears to inhibit cell-mediated cytotoxicity by delivering a negative signal that prevents lymphocyte activation. It is suggested that this MHC class I-KIR interaction works as a signaling mechanism that regulates NK and T-cell responses to antigenic challenge.
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).