HLA–T-cell receptor complex for CDCA1-derived epitope (HLA/TCR complex (CDCA1 epitope))

The HLA–T-cell receptor complex for CDCA1-derived epitopes refers to the molecular assembly formed when a cytotoxic T lymphocyte’s T cell receptor (TCR) recognizes a peptide epitope derived from cell division cycle associated 1 (CDCA1), presented on the surface of a target cell by a specific human leukocyte antigen (HLA) class I molecule. This trimeric complex is fundamental for immune surveillance, enabling cytotoxic T cells to distinguish malignant or infected cells based on the display of tumor- or virus-associated peptides. The TCR docks diagonally across the peptide-binding groove of the HLA molecule, making contacts with both the presented CDCA1-derived peptide and the HLA molecule, resulting in T-cell activation if the epitope is recognized as non-self. Structural studies reveal that this TCR–peptide–HLA interface is highly specific and underpins much of the antigen-specific immune targeting in adoptive cell and vaccine therapies. HLA-restricted TCR affinity for such complexes forms the mechanistic basis for next-generation immunotherapies, notably in cancer targeting of oncofetal antigens such as CDCA1. Therapeutic targeting strategies include identification of CDCA1-derived peptides presented by prevalent HLA alleles (like HLA-A*02:01), followed by engineering T cells or developing peptide vaccines to amplify immune responses against tumors expressing these complexes. No single small-molecule or biologic “drug” targets the complex directly; rather, immunotherapeutic modalities leverage its biology for patient-specific cancer therapy. Major safety and translational concerns include HLA restriction, potential off-target toxicity, and immune-related adverse events. This entry describes a therapeutic molecular target relevant to cancer immunotherapy and not a traditional receptor or enzyme.

Other names

TCR–peptide–MHC complex (CDCA1 epitope)T cell receptor–HLA complex for CDCA1 peptideHLA–TCR–CDCA1 complex

Recognition of tumor-associated antigenic peptide (CDCA1-derived) in complex with HLA by T-cell receptor, triggering T cell–mediated immune attack on tumor cells presenting the epitope Initiation of T-cell signaling upon TCR–pMHC (peptide–MHC) engagement, leading to activation, proliferation, and effector function of cytotoxic T cells