Anti-CD8 (Clone: RPAT8)

CD8 membrane glycoprotein that is expressed on cytotoxic T-cells where it interacts with MHC class I processed antigens. CD8 also regulates T-cell activation and differention. CD8 has two isoforms (25 and 21 kDa) CD8 can function either as a homodimer (two alpha chains) or as a heterodimer (one alpha and one beta chain). CD8 is highly expressed in T lymphocyte, peripheral blood T-lymphocytes, thymus, spleen and lymphocyte. Protein function: Integral membrane glycoprotein that plays an essential role in the immune response and serves multiple functions in responses against both external and internal offenses. In T-cells, functions primarily as a coreceptor for MHC class I molecule:peptide complex. The antigens presented by class I peptides are derived from cytosolic proteins while class II derived from extracellular proteins. Interacts simultaneously with the T-cell receptor (TCR) and the MHC class I proteins presented by antigen presenting cells (APCs). In turn, recruits the Src kinase LCK to the vicinity of the TCR-CD3 complex. LCK then initiates different intracellular signaling pathways by phosphorylating various substrates ultimately leading to lymphokine production, motility, adhesion and activation of cytotoxic T-lymphocytes (CTLs). This mechanism enables CTLs to recognize and eliminate infected cells and tumor cells. In NK- cells, the presence of CD8A homodimers at the cell surface provides a survival mechanism allowing conjugation and lysis of multiple target cells. CD8A homodimer molecules also promote the survival and differentiation of activated lymphocytes into memory CD8 T-cells. [The UniProt Consortium]