Cluster of differentiation 8 (CD8), a type I transmembrane glycoprotein of the immunoglobulin family of receptors, plays an integral role in signal transduction, and T cell differentiation and activation. CD8 is predominantly expressed on T cells as a disulfide-linked heterodimer of CD8alpha and CD8beta, where it functions as a co-receptor, along with T cell receptor (TCR), for major histocompatibilty complex class I (MHC-I) molecules; whereas its counterpart, CD4, acts as a co-receptor for MHC-II molecules. CD8 exists on the cell surface, where the CD8alpha chain is essential for binding to MHC-I. CD8 is also expressed on a subset of T cells, NK cells, monocytes and dendritic cells as disulfide-linked homodimers of CD8alpha. Ligation of MHC-I/peptide complexes presented by antigen-presenting cells (APCs), triggers the recruitment of lymphocyte-specific protein tyrosine kinase (Lck), which leads to lymphokine production, motility and cytotoxic T lymphocyte (CTL) activation. Once activated, CTLs play a crucial role in the clearance of pathogens and tumor cells. Differentiation of naive CD8+ T cells into CTLs is strongly enhanced by IL-2, IL-12 and TGF-beta1.
BB154331; CD8; CD8 alpha; CD8 alpha chain; CD8 alpha chain precursor; CD8 antigen; CD8 antigen 32 kDa chain; CD8 antigen 37 kDa chain; CD8 antigen alpha polypeptide; CD8 antigen alpha protein; CD8 antigen alpha protein precursor; CD8 antigen alpha-chain; CD8 antigen beta polypeptide; CD8 antigen beta polypeptide precursor; CD8 antigen beta-chain; CD8 antigen, alpha chain; CD8 antigen, alpha polypeptide; CD8 antigen, alpha polypeptide (p32); CD8 antigen, alpha-chain; CD8 antigen, beta chain; CD8 antigen, beta chain 1; CD8 antigen, beta polypeptide; CD8 antigen, beta polypeptide 1 (p37); CD8 antigen, beta-chain; CD8 beta; CD8 beta chain; CD8 beta-2; CD8a; CD8A antigen alpha; CD8a molecule; CD8A; T-cell surface glycoprotein; CD8alpha; CD8B; CD8b antigen; CD8b molecule; CD8b molecule pseudogene; Cd8b1; CD8beta; CD8BP; fCD8; LEU2; Leu-2; Leu2 T-lymphocyte antigen; leu-2a; Ly-2; LY3; Ly-3; Ly-35; Ly-B; Ly-C; Lymphocyte antigen 3; Lyt2; Lyt-2; Lyt-2.1 lymphocyte differentiation antigen (AA at 100); Lyt3; Lyt-3; MAL; membrane glycoprotein; membrane protein; OKT8 T-cell antigen; OX-8 membrane antigen; p32; P37; RHACD8-4; T cell co-receptor; T lymphocyte surface glycoprotein beta chain; T8 T-cell antigen; T-cell antigen Leu2; T-cell membrane glycoprotein Ly-3; T-cell surface glycoprotein; T-cell surface glycoprotein CD8 alpha chain; T-cell surface glycoprotein CD8 beta chain; T-cell surface glycoprotein Lyt-2; T-cell surface glycoprotein Lyt-3; T-cell surface molecule; T-lymphocyte differentiation antigen T8/Leu-2; type I transmembrane glycoprotein