Keyhole limpet hemocyanin-derived peptides presented on MHC molecules (KLH-pMHC)

Keyhole limpet hemocyanin (KLH)-derived peptides presented on MHC molecules are highly immunogenic complexes formed when the KLH protein is internalized, processed, and displayed by professional antigen-presenting cells (APCs). KLH, a massive oxygen-carrying protein from the giant keyhole limpet (Megathura crenulata), is recognized as a potent foreign antigen by the human immune system, leading to the presentation of a diverse array of peptides on MHC Class I and Class II (HLA-DR) molecules. These complexes are primarily utilized as gold-standard positive controls in immunogenicity risk assessment assays, such as MHC-associated peptide proteomics (MAPPs), to validate the ability of the assay to detect presented peptides. While not a direct therapeutic target for disease treatment, they serve as essential tools for studying T-cell recruitment, evaluating the potency of bispecific T-cell engagers (BiTEs), and benchmarking the performance of TCR-like antibodies in preclinical research. Additionally, the induction of these complexes via KLH administration is used in clinical settings to assess a patient's cellular immune competence through delayed-type hypersensitivity (DTH) skin tests. In the context of cancer immunotherapy, KLH acts as an adjuvant that, through the formation of these pMHC complexes, provides the necessary T-cell help to enhance the immune response against co-administered tumor antigens.

Other names

KLH-peptide-MHC complexMHC-presented KLH peptidesKLH-derived MHC ligandsKLH-pMHC complex

Antigen processing and presentation leading to T-cell mediated immune response