Biotinylated CD8 alpha&beta (CD8A&CD8B) Heterodimer,His,Avi Tag&Tag Free Protein, Human

CD8A and CD8B encode the α and β chains, respectively, which associate via disulfide bonds to form the CD8αβ heterodimer, a transmembrane glycoprotein co-receptor expressed on the surface of cytotoxic T lymphocytes. Structurally, it comprises immunoglobulin-like V-type extracellular domains, and the incorporation of the β chain alters the binding interface and spatial conformation with MHC class I molecules, conferring higher antigen-binding affinity than the CD8αα homodimer. Functionally, CD8αβ cooperates with the T-cell receptor (TCR) to recognize MHC class I–peptide complexes presented by target cells, and initiates T-cell activation and cytotoxic signaling through the intracellular Lck kinase, serving as a central molecule in adaptive immunity. Clinically, the expression level of CD8αβ is closely associated with HIV disease progression and CD8⁺ T-cell subset differentiation; reduced heterodimer expression is observed in immunodeficiency disorders such as Wiskott–Aldrich syndrome. Moreover, as a key marker of tumor-infiltrating lymphocytes and autoimmune diseases, CD8αβ has become an important research target for immunotherapy efficacy assessment and targeted intervention.