Tumor-associated antigen–Major Histocompatibility Complex class I complex (TAA-MHC I) (TAA-MHC I)

Tumor-associated antigen (TAA)–MHC class I complexes represent a critical class of therapeutic targets in oncology, specifically for T-cell receptor (TCR)-based therapies such as the ACTL (Antigen-specific Cytotoxic T Lymphocyte) platform [Shenzhen BinDeBio, 2024]. These complexes are formed when intracellular tumor proteins are degraded by the proteasome into short peptides, which are then transported into the endoplasmic reticulum and loaded onto Major Histocompatibility Complex (MHC) class I molecules for presentation on the cell surface [Nature Reviews Drug Discovery, 2021, 20:803-824]. The ACTL technology utilizes dendritic cells to present these TAA-MHC I complexes to T cells, inducing the formation of highly specific cytotoxic T lymphocytes that can identify and eliminate tumor cells [Journal of Hematology & Oncology, 2022, 15:1]. Unlike monoclonal antibodies that target surface proteins, these complexes allow the immune system to see and attack intracellular oncogenic drivers. Therapeutic success depends on the high specificity of the TCR for the peptide-MHC complex to avoid cross-reactivity with similar peptides presented on healthy tissues [PubMed, PMID: 33574551]. Current clinical applications focus on well-characterized antigens such as NY-ESO-1, MAGE-A3, and Survivin across various solid tumors [ClinicalTrials.gov, 2024].

Other names

pMHC I complexPeptide-HLA class I complexTumor-specific MHC-peptide complexAntigen-MHC complexpMHC target

The ACTL T-cell receptor specifically recognizes the peptide-MHC complex on the tumor cell surface, leading to the formation of an immunological synapse and subsequent T-cell mediated lysis of the target cell via the release of cytotoxic granules [Shenzhen BinDeBio, 2024].