Major histocompatibility complex-Wilms' tumor 1 peptide complex (MHC-WT1)

The Major Histocompatibility Complex (MHC) class I/II – Wilms' Tumor 1 (WT1) peptide complex is a molecular assembly consisting of a peptide fragment derived from the WT1 protein bound to an MHC molecule on the cell surface (National Cancer Institute, 2023). WT1 is a transcription factor that is highly overexpressed in a variety of hematological malignancies and solid tumors, such as acute myeloid leukemia and mesothelioma, while maintaining minimal expression in healthy adult tissues (PubMed, PMID: 17634404). This differential expression makes the MHC-WT1 complex an ideal target for immunotherapy, as it allows the immune system to distinguish malignant cells from normal ones. Therapeutic strategies targeting this complex include peptide vaccines like Galinpepimut-S, which stimulate the patient's own T cells to recognize the complex, and TCR-engineered T-cell (TCR-T) therapies that provide a direct attack (ClinicalTrials.gov, 2024). Additionally, TCR-like antibodies and bispecific T-cell engagers are being developed to bind the complex with high specificity (Nature Reviews Cancer, 2021). Because MHC molecules are highly polymorphic, these therapies are typically restricted to patients with specific HLA alleles, most commonly HLA-A*02:01. Safety concerns primarily involve potential "on-target, off-tumor" toxicity in tissues like the kidneys or bone marrow where WT1 is expressed at low levels (Journal of Hematology & Oncology, 2022).

Other names

HLA-WT1 complexWT1-MHC complexWT1 peptide-HLA complexWilms tumor 1 antigen-MHC complex

T-cell receptor-mediated recognition of tumor-associated antigens presented by MHC molecules, leading to cytotoxic T-lymphocyte activation and tumor cell lysis.