CD8A-CD8B Heterodimer Protein, Mouse (HEK293, Flag-His)

The CD8A, an integral membrane glycoprotein, plays a critical role in the immune response, fulfilling multiple functions in responses against both external and internal threats. In T-cells, it primarily functions as a coreceptor for the MHC class I molecule:peptide complex, interacting simultaneously with the T-cell receptor (TCR) and the MHC class I proteins presented by antigen-presenting cells (APCs). This interaction leads to the recruitment of the Src kinase LCK to the vicinity of the TCR-CD3 complex. LCK, in turn, initiates diverse intracellular signaling pathways, phosphorylating various substrates and ultimately promoting lymphokine production, motility, adhesion, and activation of cytotoxic T-lymphocytes (CTLs). This mechanism enables CTLs to recognize and eliminate infected cells and tumor cells. In NK-cells, the presence of CD8A homodimers at the cell surface provides a survival mechanism allowing the conjugation and lysis of multiple target cells. CD8A homodimer molecules also contribute to the survival and differentiation of activated lymphocytes into memory CD8 T-cells. The CD8A forms disulfide-linked complexes at the cell surface and also homodimers in various cell types, including NK-cells and peripheral blood T-lymphocytes. It interacts with the MHC class I HLA-A/B2M dimer and with LCK in a zinc-dependent manner.