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 BB700, which is part of the BD Horizon Brilliant™ Blue family of dyes. It is a polymer-based tandem dye developed exclusively by BD Biosciences. With an excitation max of 485 nm and an emission max of 693 nm, BD Horizon BB700 can be excited by the 488 nm laser and detected in a standard PerCP-Cy™5.5 set (eg, 695/40-nm filter). This dye provides a much brighter alternative to PerCP-Cy5.5 with less cross laser excitation off the 405 nm and 355 nm lasers.