The CH-L monoclonal antibody specifically binds to CD158b proteins. These proteins are 50-58 kDa type I glycoproteins that belong to the Killer cell immunoglobulin-like receptor (KIR) family: (KIR2DL2/L3/S2). They are also known as CD158b1 (KIR2DL2; NKAT-6; p58.2), CD158b2 (KIR2DL3; NKAT-2; p58.2), or CD158j (KIR2DS2; NKAT-5; p50.2). The CD158b molecules are composed of two extracellular Ig-like domains, and a transmembrane region. CD158b1 and CD158b2 also possess long (84 or 76 amino acids, respectively) cytoplasmic tails with two immunoreceptor tyrosine-based inhibition motifs (ITIM) whereas CD158j has a short (39 amino acid) cytoplasmic tail that lacks the ITIM motif. CD158b molecules are expressed on NK cells and subsets of TCR αβ+ cells or TCR γδ+ cells. Ligand- or CH-L antibody-bound CD158b1 or CD158b2 can reportedly inhibit cytolytic NK and T cell responses to various stimuli including certain target cells expressing MHC class I ligands encoded by HLA-C alleles (Cw 1, 3, 7 and 8). CD158j reportedly can enhance some cellular cytolytic responses.
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).