Mucin 1 peptide–Major Histocompatibility Complex (MUC1-MHC) (MUC1-MHC)

Mucin 1 (MUC1) peptide–Major Histocompatibility Complex (MHC) complexes are specialized cell-surface targets formed when intracellularly processed fragments of the MUC1 protein are loaded onto MHC molecules for presentation to the immune system (PMID: 10438931). MUC1 is a heavily O-glycosylated transmembrane protein that is overexpressed and loses its apical polarity in many adenocarcinomas, making it a hallmark of malignancy (PMID: 22134412). In the context of immunotherapy, the MUC1-MHC complex is specifically targeted to bypass the challenges of targeting the bulky, highly glycosylated extracellular domain of the MUC1 protein itself. These complexes, particularly those involving the HLA-A*02:01 allele, present specific peptides such as the MUC1 signal sequence or tandem repeat fragments to T-cells (PMID: 10438931). Therapeutic agents like TCR-like antibodies and TCR-engineered T-cells (TCR-T) are designed to recognize these pMHC targets with high affinity, mimicking the natural immune surveillance mechanism (Eureka Therapeutics, 2021). This targeting strategy is employed in treating various solid tumors, including breast, lung, and ovarian cancers, where MUC1 is a dominant antigen (PMID: 30552151). By focusing on the peptide-MHC complex, drugs can achieve greater tumor specificity and potentially overcome the immunosuppressive barriers of the tumor microenvironment. However, challenges remain regarding the density of pMHC presentation and the potential for on-target off-tumor toxicity in normal tissues that express low levels of MUC1 (PMID: 30552151).

Other names

MUC1-HLA complexMUC1-pMHCMUC1 peptide-HLA-A*02:01CD227-MHC complexMucin 1-Major Histocompatibility Complex

Recognition of the peptide-MHC complex by T-cell receptors or TCR-like antibodies leading to cytotoxic T-lymphocyte activation and tumor cell lysis (PMID: 27141351).