CD8 antigen (human) (CD8)

The CD8 antigen is a transmembrane glycoprotein complex found primarily on the surface of cytotoxic T lymphocytes, serving as a co-receptor for the T-cell receptor (TCR) and mediating immune recognition of antigens presented on major histocompatibility complex class I (MHC-I) molecules. In humans, CD8 exists as a heterodimer of two chains, CD8A (alpha) and CD8B (beta), both encoded on chromosome 2. The primary function of CD8 is to enhance antigen recognition and T cell activation by binding to the invariant α3 domain of MHC-I molecules, facilitating signaling and cytotoxic activity. CD8 is widely used as a biomarker for cytotoxic T cells in research, diagnostics, and monitoring of immunotherapeutic responses. Direct pharmacological targeting of CD8 is rare, but its expression and function are central to strategies in cancer immunotherapy and infection management due to its critical roles in immune surveillance and cytotoxicity.

Other names

CD8CD8A (CD8 alpha chain)CD8B (CD8 beta chain)T-cell surface glycoprotein CD8 alpha chainT-cell surface glycoprotein CD8 beta chainCluster of Differentiation 8

Null (CD8 is a marker and co-receptor rather than a direct pharmacological target; drugs modulate CD8 function indirectly via immunotherapies or depleting antibodies)