FIGURE: 1 / 1
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.
Protein Aliases: CD8 antigen, alpha polypeptide (p32); CD8 antigen, beta polypeptide 1 (p37); CD8a; CD8alpha; CD8b; CD8beta; fCD8; Leu-2; leu-2a; Leu2 T-lymphocyte antigen; OKT8 T-cell antigen; T cell co-receptor; T lymphocyte surface glycoprotein beta chain; T-cell antigen Leu2; T-cell surface glycoprotein CD8 alpha chain; T-cell surface glycoprotein CD8 beta chain; T-lymphocyte differentiation antigen T8/Leu-2; T8 T-cell antigen
Gene Aliases: CD8; CD8A; CD8B; CD8B1; LEU2; LY3; LYT3; MAL; p32; P37