The UP-D1 monoclonal antibody specifically binds to Immune receptor expressed on myeloid cells 1 (IREM-1). IREM-1 is encoded by CD300LF. It is also known as CD300 antigen-like family member F (CD300f), CMRF35-like molecule 1 (CLM-1/CLM1), NK inhibitory receptor (NKIR), or Immunoglobulin superfamily member 13 (IgSF13). IREM-1/CD300f is expressed on monocytes, dendritic cells, granulocytes, and mast cells. IREM-1 is a single-pass type I transmembrane glycoprotein that belongs to the CMRF family of the Ig gene superfamily. The long intracellular region of IREM-1 contains two classical immunoreceptor tyrosine-based inhibitory motifs (ITIM). Ligand-bound IREM-1 can transduce negative regulatory signals intracellularly by recruiting SHP1 or SHIP phosphatases that in turn dephosphorylate tyrosine residues within activating cell signaling molecules. CD300f may thus play a role in regulating inflammatory responses involving myeloid 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.