The HMPV monoclonal antibody specifically binds to CD227 which is also known as Mucin-1 (MUC1). A major form of CD227 is expressed as a type I transmembrane glycoprotein. CD227 belongs to the epithelial mucin family whose members are heavily O-glycosylated and characterized by high molecular weight, and an amino acid composition rich in serine, threonine, proline, and glycine. CD227 is variably expressed on the surfaces of normal and malignant glandular and ductal epithelial cells, and some hematopoietic cell lineages including subsets of T cells, B cells, monocytes and dendritic cells. Soluble forms of CD227 may arise by shedding from the cell surface or by secretion of forms derived from alternative RNA splicing. The HMPV antibody binds to the core peptide of the MUC1 protein. The core protein contains a domain of 20 amino-acid tandem repeats which function as multiple epitopes for this monoclonal antibody. Incomplete glycosylation of some tumor-associated mucins may lead to variable unmasking of the multiple peptide epitopes leading to the observed differences in immunostaining intensities between cells from normal and malignant tissues. CD227 plays roles in the provision of protective barrier function, the regulation of cellular adhesion, and the transduction of multiple signal pathways.
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.