T-cell surface glycoprotein CD8 alpha chain (CD8α)

The T-cell surface glycoprotein CD8 alpha chain (CD8α) is an integral membrane glycoprotein that functions as a co-receptor on T cells, primarily cytotoxic T lymphocytes (CTLs). It enhances T-cell receptor (TCR) recognition of peptide antigens presented by MHC class I molecules on antigen-presenting cells, facilitating efficient cell–cell interactions and signal transduction. CD8α exists as a homodimer (CD8αα) or a heterodimer with a beta chain (CD8αβ). It plays crucial roles in thymocyte development, maturation, and modulation of immune responses. CD8 is widely used as an immunophenotyping marker and is a key component in engineered T-cell therapies such as CAR T-cells.

Other names

CD8 alpha chainCD8AT8Leu2MAL

Enhances T-cell receptor (TCR) signaling upon binding to MHC class I molecules presenting antigens; recruits Lck kinase for signal transduction; mediates cell-cell adhesion during immune responses.