Clone DX27 reacts with CD158b1 (KIR2DL2), CD158b2 (KIR2DL3), and CD158j (KIR2DS2), members of the killer immunoglobulin-like receptor (KIR) family expressed on natural killer (NK) cells and subsets of T cells.
KIRs contribute to the regulation of NK cell–mediated cytotoxicity and possess high allelic polymorphism with either 2 or 3 Ig-like extracellular domains. According to the length of their cytoplasmic tail, KIRs can be further subdivided in inhibitory KIRs (KIR2DL or KIR3DL) and activating KIRs (KIR2DS or KIR3DS). CD158b provides an inhibitory signal on NK cell lytic activity upon interaction with HLA C (e.g. alleles HLA-Cw1, HLA-Cw3, HLA-Cw7) in an antigen-independent manner.
Human peripheral blood mononuclear cells (PBMCs) were stained with CD158b (KIR2DL2/DL3) antibodies as well as with CD56 antibodies and analyzed by flow cytometry using the MACSQuant® Analyzer. The Tandem Signal Enhancer has been used to increase binding specificity of tandem-dye–conjugated antibodies. Cell debris and dead cells were excluded from the analysis based on scatter signals and propidium iodide fluorescence or 4',6-diamidino-2-phenylindole (DAPI) fluorescence, as in the case of tandems.