CD8 Antibody – Rat Monoclonal

The CD8 antigen is a cell surface glycoprotein found on most cytotoxic T lymphocytes that mediates efficient cell-cell interactions within the immune system. The CD8 antigen acts as a coreceptor with the T-cell receptor on the T lymphocyte to recognize antigens displayed by an antigen presenting cell in the context of class I MHC molecules. The coreceptor functions as either a homodimer composed of two alpha chains or as a heterodimer composed of one alpha and one beta chain. Both alpha and beta chains share significant homology to immunoglobulin variable light chains. This gene encodes the CD8 alpha chain. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Nov 2011]

CD8A: Identifies cytotoxic/suppressor T-cells that interact with MHC class I bearing targets. CD8 is thought to play a role in the process of T-cell mediated killing. CD8 alpha chains binds to class I MHC molecules alpha-3 domains. In general heterodimer of an alpha and a beta chain linked by two disulfide bonds. Can also form homodimers. Shown to be expressed as heterodimer on thymocytes and as homodimer on peripheral blood T-lymphocytes. Interacts with the MHC class I HLA-A/B2M dimer. Interacts with LCK in a zinc-dependent manner. 2 isoforms of the human protein are produced by alternative splicing.

Protein type: Membrane protein, integral

Chromosomal Location of Human Ortholog: 2p12

Cellular Component: T cell receptor complex; integral to plasma membrane; plasma membrane; extracellular region; external side of plasma membrane

Molecular Function: protein binding; protein homodimerization activity; MHC class I protein binding; coreceptor activity; protein kinase binding

Biological Process: antigen processing and presentation; regulation of immune response; T cell activation; T cell mediated immunity; positive regulation of calcium-mediated signaling; cytotoxic T cell differentiation; immune response; defense response to virus; transmembrane receptor protein tyrosine kinase signaling pathway

Disease: Cd8 Deficiency, Familial