Anti-Mouse H-2Kd (MHC Class I) In Vivo Antibody - Low Endotoxin

H-2Kd antibody, clone A4C8.1-Do9, recognizes the major histocompatibility complex (MHC) class I H-2K haplotype d (H-2Kd). MHC class I is ubiquitously expressed on the cell surface of nucleated cells and consists of a 45-kDa type I transmembrane glycoprotein (α-chain or heavy chain) and a 12-kDa soluble protein (β2-microglobulin, β2M)1,2. The α-chain consists of three domains (α1, α2, and α3)3. α1 and α2 form the closed antigen-binding groove and bind to 8-10 aa peptides derived from cytosolic antigens4-6. β2M noncovalently associates with α3, which is essential for MHC stability. H-2Kd plays a critical role in the adaptive immune response by presenting endogenous antigens to cytotoxic CD8 T cells. MHC class I molecules can also present exogenous antigens to CD8 T cells via a process known as cross-presentation7. The T cell receptor (TCR)/CD3 complex of CD8 T cells interacts with peptide-MHC class I, which induces CD8 T cell activation and subsequent cell-killing. CD8 molecules also bind to MHC class I, which helps augment TCR signaling8. In contrast to CD8 T cells, MHC class I is an inhibitory ligand for natural killer (NK) cells, promoting self tolerance9. MHC class I also contributes to the positive selection of CD8 T cells and NK cell specificity10,11.