The ZM3.8 monoclonal antibody specifically binds to CD85k which is also known as Immunoglobulin-like transcript 3 (ILT-3) and Monocyte inhibitory receptor HM18. CD85k is encoded by LILRB4 (Leukocyte immunoglobulin-like receptor, subfamily B member 4) and is expressed as a type I transmembrane glycoprotein. CD85k is comprised of two C2-type Ig domains, a transmembrane region, and a cytoplasmic tail with three immunoreceptor tyrosine-based inhibitory motifs (ITIMs). CD85k is selectively expressed by myeloid antigen presenting cells including monocytes, macrophages, and dendritic cells. CD85k functions as an inhibitory receptor. ILT3 can also function in antigen capture and presentation. It is efficiently internalized upon cross-linking, and delivers its ligand to an intracellular compartment where it is processed and ultimately presented by APCs to T cells. Thus, ILT3 is a novel inhibitory receptor that can negatively regulate activation of APCs and can be used by APCs for antigen uptake. ILT3 expression is upregulated on tolerogenic dendritic cells that can induce regulatory T cells.
The antibody was conjugated to an oligonucleotide that contains an antibody clone-specific barcode (ABC) flanked by a poly-A tail on the 3' end and a PCR handle (PCR primer binding site) on the 5' end. The ABC for this antibody was designed to be used with other BD AbSeq oligonucleotides conjugated to other antibodies. All AbSeq ABC sequences were selected in silico to be unique from human and mouse genomes, have low predicted secondary structure, and have high Hamming distance within the BD AbSeq portfolio, to allow for sequencing error correction and unique mapping. The poly-A tail of the oligonucleotide allows the ABC to be captured by the BD Rhapsody™ system. The 5' PCR handle allows for efficient sequencing library generation for Illumina sequencing platforms.
NOTE: The BD Rhapsody Single-Cell Analysis System must be used with the BD Rhapsody Express Instrument.