The 4B4-1 monoclonal antibody specifically binds to CD137 which is also known as 4-1BB, and ILA (induced by lymphocyte activation). CD137 is a type I transmembrane glycoprotein that belongs to the TNF/NGF receptor family. It is encoded by TNFRSF9 (tumor necrosis factor receptor superfamily, member 9). CD137 is expressed on activated T cells, B cells, monocytes, and follicular dendritic cells. CD137 plays roles in the costimulation, differentiation and survival of T cells and B 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 or other oligo-dT-based capture systems. The 5' PCR handle allows for efficient sequencing library generation for Illumina sequencing platforms.