The TY25 monoclonal antibody specifically binds to CD273, also known as B7-DC or PD-L2. CD273 is a 42-kDa type I membrane glycoprotein encoded by the Pdcd1lg2 gene of the B7 family of the Ig superfamily. Pdcd1lg2 mRNA is expressed selectively in dendritic cells (DC), liver, and a few transformed cell lines (hepatic, neuroblastoma, and myeloid), but not in lymphoid tissues or macrophages. The protein has not been detected on resting peripheral T and B lymphocytes, macrophages, or DC, but it is upregulated upon activation of T cells, macrophages, and DC by a variety of stimulatory factors. B7-DC's receptor, PD-1, contains an ITIM (Immunoreceptor Tyrosine-based Inhibitory Motif) on its intracytoplasmic region and is expressed on activated B and T lymphocytes, suggesting that B7-DC-PD-1 interaction may be involved in the negative regulation of immune responses. The second PD-1 ligand, B7-H1 (PD-L1), is also a member of the B7 family of the Ig superfamily. B7-DC may also participate in positive immunoregulation, or costimulation of T cells, through an additional receptor, which is not PD-1 and distinct from the alternate receptor for B7-H1. Moreover, B7-DC is the first B7 ligand that has been found to participate in bi-directional communication; ligation of B7-DC on DC stimulates those DC. The TY25 antibody blocks the binding of B7-DC to PD-1, but not to its alternate ligand.
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.