Major histocompatibility complex class I H-2K(b) (H-2Kb)

MHC class I H-2K^b is a murine major histocompatibility complex (MHC) class I molecule, specifically the K locus product of the 'b' haplotype, which is the standard haplotype for the C57BL/6 mouse strain (UniProt: P01901). It is a cell surface glycoprotein consisting of a polymorphic alpha heavy chain non-covalently associated with the invariant beta-2 microglobulin (PubMed: 1064840). The primary biological function of H-2K^b is to present short, endogenous peptides (typically 8 amino acids long) to the T-cell receptors (TCRs) of CD8+ cytotoxic T lymphocytes (PubMed: 7507881). This presentation is a critical step in the immune surveillance of intracellular pathogens, such as viruses, and the detection of neoantigens in cancer cells. In pharmaceutical research, H-2K^b is a pivotal target for the development and testing of peptide-based vaccines and adoptive T-cell therapies in preclinical mouse models (PubMed: 25236395). For example, the SIINFEKL peptide is a widely used experimental agent that binds H-2K^b to induce a robust CD8+ T-cell response. Challenges associated with this target include the ability of tumors to downregulate H-2K^b expression to evade immune detection, a phenomenon known as immune escape.

Other names

H-2K(b)H2-K1H-2K1MHC class I antigen K-bH-2 class I histocompatibility antigen, K-B alpha chain

Presentation of endogenous peptides to CD8+ T-cell receptors (TCRs) to trigger cytotoxic immune responses.