Wilms' tumor 1 (WT1) VLD peptide–HLA class I complex (WT1 VLD-HLA complex)

The Wilms' tumor 1 (WT1) VLD peptide–HLA class I complex is a specific peptide-major histocompatibility complex (pMHC) found on the surface of cells that overexpress the WT1 protein. The complex consists of the 9-amino acid peptide VLDFAPPGA (residues 37-45 of the WT1 protein) presented by the Human Leukocyte Antigen (HLA) class I molecule, most commonly the HLA-A*02:01 allele (1.2.1, 1.3.1). WT1 is a transcription factor that plays a critical role in cell growth and differentiation; while it is essential during embryonic development, its expression in healthy adults is restricted to low levels in specific tissues like the kidney and bone marrow (1.1.2, 1.3.3). However, WT1 is significantly overexpressed in many cancers, including acute myeloid leukemia (AML), myelodysplastic syndromes (MDS), and various solid tumors, making it a high-priority target for immunotherapy (1.3.4, 1.4.1). Because WT1 is an intracellular protein, it cannot be targeted by standard monoclonal antibodies. Instead, therapeutic approaches focus on the VLD peptide presented by HLA molecules, which allows the immune system to "see" the intracellular state of the cell (1.1.1, 1.3.3). Current drug development efforts include TCR-engineered T cells (TCR-T), TCR-like antibodies, and bispecific T-cell engagers (TCBs) that specifically bind to the WT1 VLD-HLA complex to trigger a potent T-cell-mediated immune response against tumor cells (1.1.3, 1.3.1). These therapies are designed to provide high specificity for cancer cells, although challenges such as HLA restriction and potential off-target effects on low-WT1-expressing normal tissues remain key considerations in clinical development (1.3.3, 1.3.5).

Other names

WT1 37-45 peptide-HLA complexVLDFAPPGA-HLA-A*02:01 complexWT1-A2 VLD complexWT1 VLD pMHCVLD/A2 complex

T-cell mediated cytotoxicity via specific recognition of the peptide-MHC complex by T-cell receptors (TCRs) or TCR-like antibodies.