The 440c monoclonal antibody specifically recognizes Siglec-H, a type I transmembrane glycoprotein that is encoded by Siglech (Sialic acid binding Ig-like lectin H). Siglec-H contains two immunoglobulin domains in its extracellular region and a cytoplasmic domain that lacks tyrosine-based signaling motifs unlike other CD33-related Siglec-like molecules. Siglec-H is expressed on progenitors of plasmacytoid dendritic cells (pDCs) and depends on DAP12 for cell surface expression and intracellular signaling function. In addition to its expression on pDC, Siglec-H may also be expressed by splenic marginal zone macrophages, medullary macrophages in lymph nodes, and microglia. Siglec-H may regulate the production of type I interferons (IFN-I) by pDCs and other cell types. There is no clear human ortholog for mouse Siglec-H.
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.