The J168-540 monoclonal antibody specifically binds to human CD272, also known as BTLA (B and T lymphocyte attenuator), an inhibitory receptor expressed in bone marrow and thymus on developing B and T cells. In the periphery, BTLA is expressed by B cells, T cells, bone marrow-derived dendritic cells, and macrophages. After T cell activation, BTLA appears to be expressed at higher levels on Th1 cell populations than in Th2 cell populations. Upon binding the herpesvirus entry mediator (HVEM/LIGHT-R/CD270), CD272 undergoes tyrosine phosphorylation and inhibits T cell proliferation in a BTLA-dependent manner. CD272 has structural similarities to two other lymphocyte inhibitory receptors, CTLA-4 and PD-1 and is a member of the CD28-like family of coreceptors. Based on these observations, CD272 is considered to be a negative regulator of lymphocyte activation and/or function.
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 or other oligo-dT-based capture systems. The 5' PCR handle allows for efficient sequencing library generation for Illumina sequencing platforms.