CD8 alpha Protein, Human (HEK293, His)

CD8 alpha, an integral membrane glycoprotein, plays a pivotal role in orchestrating immune responses against both external and internal threats. In T-cells, it serves as a coreceptor for MHC class I molecule:peptide complexes, facilitating the recognition of antigens derived from cytosolic proteins. Simultaneously interacting with the T-cell receptor (TCR) and MHC class I proteins on antigen-presenting cells (APCs), CD8 alpha recruits the Src kinase LCK to the TCR-CD3 complex, initiating intracellular signaling pathways that culminate in lymphokine production, cellular motility, adhesion, and activation of cytotoxic T-lymphocytes (CTLs). This mechanism empowers CTLs to identify and eliminate infected or tumor cells. In NK-cells, CD8 alpha homodimers at the cell surface contribute to a survival mechanism, enabling the conjugation and lysis of multiple target cells. Moreover, CD8 alpha homodimers promote the survival and differentiation of activated lymphocytes into memory CD8 T-cells. The protein forms disulfide-linked heterodimers with CD8B on the cell surface and homodimers in various cell types, including NK-cells and peripheral blood T-lymphocytes. Interactions with the MHC class I HLA-A/B2M dimer and LCK, as well as its direct interaction with HLA-G, highlight the intricate network of molecular associations that underlie CD8 alpha's diverse functions in immune regulation.