The 2ST8.5H7 monoclonal antibody specifically recognizes an epitope formed by the combination of CD8 alpha and beta chains. The majority of peripheral blood CD8+ T lymphocytes expresses a CD8αβ heterodimer (32, 30 kilodaltons (kDa)), while CD8+CD16+ natural killer (NK) cells and CD8+ TCR γδ+ T lymphocytes express CD8αα homodimers. The 2ST8.5H7 antibody can therefore be used to selectively bind to CD8+ T cells while excluding CD8+ NK cells. CD8 binds to class I major histocompatibility (MHC) molecules, resulting in increased adhesion between the CD8+ T lymphocytes and target cells. Binding of CD8 to class I MHC molecules enhances the activation of resting T lymphocytes. CD8 is coupled to a protein tyrosine kinase, p56lck. The CD8:p56lck complex can play a role in T-lymphocyte activation through mediation of the interactions between CD8 and the CD3/TCR complex. The CD8β antigen is present on the human suppressor/cytotoxic T-lymphocyte subset. The CD8 antigen is expressed on 19% to 48% of normal peripheral blood lymphocytes and 60% to 85% of normal thymocytes. The 2ST8.5H7 antibody crossreacts with lymphocytes of some nonhuman primate species.
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.