T-cell surface glycoprotein CD8 alpha chain (CD8A) (CD8)

T-cell surface glycoprotein CD8 alpha chain (CD8A) is a transmembrane glycoprotein that serves as a critical co-receptor for the T-cell receptor (TCR) on cytotoxic T lymphocytes [5, 6]. It primarily exists as a heterodimer of alpha and beta chains, though homodimers also occur, and it functions by binding to the non-polymorphic alpha-3 domain of MHC class I molecules [6, 12]. This interaction stabilizes the TCR-MHC complex and facilitates the recruitment of the Src kinase Lck to the TCR-CD3 complex, initiating intracellular signaling pathways essential for T-cell activation and the elimination of infected or malignant cells [5, 35]. In the context of disease, CD8+ T cells are the primary effectors in anti-tumor immunity and the clearance of intracellular pathogens, but their dysfunction or exhaustion is a hallmark of cancer progression and chronic infections [1, 16]. Therapeutically, CD8 is targeted by novel immuno-PET imaging agents like crefmirlimab to monitor T-cell infiltration in tumors and by next-generation bispecific antibodies and cytokine-fusion proteins designed to selectively activate or recruit cytotoxic T cells [21, 25, 30, 37]. Safety concerns associated with modulating CD8 activity include the risk of cytokine release syndrome and the potential for inducing autoimmunity or further T-cell exhaustion [4, 22].

Other names

CD8ACD8BLeu-2T8Cluster of Differentiation 8T-lymphocyte surface antigen CD8

Selective recruitment and activation of CD8+ T cells, immuno-PET imaging of T-cell infiltration, and targeted delivery of cytokines to cytotoxic T lymphocytes.