M-phase phosphoprotein 1-derived peptide–Human leukocyte antigen class I complex (MPHOSPH1-HLA class I complex)

M-phase phosphoprotein 1 (MPHOSPH1), also known as Kinesin family member 20B (KIF20B), is a kinesin-related motor protein that is essential for the completion of cytokinesis during the cell cycle (UniProt: O60282). While its expression is highly restricted in normal adult tissues—primarily found in the testis—it is significantly overexpressed in a wide range of human malignancies, including bladder, lung, and esophageal cancers (PMID: 21860411). Peptides derived from the MPHOSPH1 protein are processed and presented on the cell surface by Human Leukocyte Antigen (HLA) class I molecules, most commonly the HLA-A*24:02 restriction element. This peptide–HLA complex acts as a tumor-associated antigen (TAA) that is recognized by the immune system. In the context of cancer immunotherapy, the complex on antigen-presenting cells (APCs) is used to prime and activate cytotoxic T lymphocytes (CTLs). These activated CTLs then seek out and destroy cancer cells that display the same MPHOSPH1-derived peptide–HLA complex on their surface. Clinical strategies, such as peptide-based vaccines, target this complex to induce a robust and specific anti-tumor immune response while minimizing damage to healthy tissues (PMID: 17671678, 24331540).

Other names

KIF20B peptide–HLA complexMPHOSPH1-HLA-A*24:02 complexM-phase phosphoprotein 1 antigenKinesin family member 20B-derived peptide–HLA complex

The complex serves as a specific recognition site for the T-cell receptors (TCRs) of CD8+ cytotoxic T lymphocytes (CTLs). Therapeutic vaccines utilize MPHOSPH1-derived peptides to prime and expand these CTLs; once activated, the CTLs identify the peptide–HLA complex on the surface of malignant cells, triggering targeted cell lysis through the release of perforin and granzymes (PMID: 17671678, 24331540).