Wilms' Tumor 1 (WT1) peptide-MHC complex (WT1-pMHC)

The Wilms' Tumor 1 (WT1) peptide-MHC complex is a therapeutic target formed by the presentation of intracellularly processed WT1 protein fragments on the cell surface by Major Histocompatibility Complex (MHC) molecules. WT1 is a transcription factor essential for urogenital development that becomes highly overexpressed in various hematological malignancies and solid tumors, earning it a top rank among prioritized cancer antigens (Source: PMID: 19276362). Because WT1 is an intracellular protein, it is inaccessible to standard monoclonal antibodies; however, its presentation as a peptide-MHC complex allows for recognition by T-cell receptors (TCRs). This target is utilized in several immunotherapeutic modalities, including peptide vaccines like Galinpepimut-S, TCR-engineered T-cell therapies, and TCR-mimetic bispecific antibodies (Source: ClinicalTrials.gov). These therapies aim to trigger a cytotoxic T-lymphocyte response specifically against tumor cells expressing the WT1-pMHC complex. A significant challenge in targeting this complex is HLA restriction, as the therapeutic agent must be compatible with the patient's specific MHC alleles, such as HLA-A*02:01 or HLA-A*24:02. Safety considerations involve potential "on-target, off-tumor" effects, as low levels of WT1 are present in healthy tissues like the kidney podocytes and hematopoietic stem cells (Source: UniProt P19544).

Other names

WT1-HLA complexWT1-MHC complexWT1 antigen-MHC complexWT1-derived epitope-MHC complex

T-cell receptor (TCR) mediated recognition of the peptide-MHC complex leading to T-cell activation and tumor cell lysis.