Enhanced MHC class I binding and immune responses through anchor modification of the non-canonical tumor associated MUC1-8 peptide
[MUC1_HUMAN] Note=MUC1/CA 15-3 is used as a serological clinical marker of breast cancer to monitor response to breast cancer treatment and disease recurrence (PubMed:20816948). Decreased levels over time may be indicative of a positive response to treatment. Conversely, increased levels may indicate disease progression. At an early stage disease, only 21% of patients exhibit high MUC1/CA 15-3 levels, that is why CA 15-3 is not a useful screening test. Most antibodies target the highly immunodominant core peptide domain of 20 amino acid (APDTRPAPGSTAPPAHGVTS) tandem repeats. Some antibodies recognize glycosylated epitopes.
[HA1B_MOUSE] Involved in the presentation of foreign antigens to the immune system. [MUC1_HUMAN] The alpha subunit has cell adhesive properties. Can act both as an adhesion and an anti-adhesion protein. May provide a protective layer on epithelial cells against bacterial and enzyme attack.         The beta subunit contains a C-terminal domain which is involved in cell signaling, through phosphorylations and protein-protein interactions. Modulates signaling in ERK, SRC and NF-kappa-B pathways. In activated T-cells, influences directly or indirectly the Ras/MAPK pathway. Promotes tumor progression. Regulates TP53-mediated transcription and determines cell fate in the genotoxic stress response. Binds, together with KLF4, the PE21 promoter element of TP53 and represses TP53 activity.         [B2MG_MOUSE] Component of the class I major histocompatibility complex (MHC). Involved in the presentation of peptide antigens to the immune system.
Publication Abstract from PubMed
Designing peptide-based vaccines for therapeutic applications in cancer immunotherapy requires detailed knowledge of the interactions between the antigenic peptide and major histocompatibility complex (MHC) in addition to that between the peptide-MHC complex and the T-cell receptor. Past efforts to immunize with high-affinity tumour-associated antigenic peptides have not been very immunogenic, which may be attributed to the lack of T cells to these peptides, having been deleted during thymic development. For this reason, low-to-medium affinity non-canonical peptides represent more suitable candidates. However, in addition to the difficulty in identifying such antigens, peptide binding to MHC, and hence its ability to induce a strong immune response, is limited. Therefore, to enhance binding to MHC and improve immune responses, anchor modifications of non-canonical tumour-associated peptides would be advantageous. In this study, the non-canonical tumour-associated peptide from MUC1, MUC1-8 (SAPDTRPA), was modified at the MHC anchor residues to SAPDFRPL (MUC1-8-5F8L) and showed enhanced binding to H-2Kb and improved immune responses. Furthermore, the crystal structure of MUC1-8-5F8L in complex with H-2Kb was determined and it revealed that binding of the peptide to MHC is similar to that of the canonical peptide OVA8 (SIINFEKL).
Enhanced major histocompatibility complex class I binding and immune responses through anchor modification of the non-canonical tumour-associated mucin 1-8 peptide.,Lazoura E, Lodding J, Farrugia W, Ramsland PA, Stevens J, Wilson IA, Pietersz GA, Apostolopoulos V Immunology. 2006 Nov;119(3):306-16. PMID:17067310
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.