Wilms' tumor 1 protein-derived peptide-MHC class I complex (WT1-pMHC) (WT1-pMHC)

The Wilms' tumor 1 (WT1) protein-derived peptide-MHC class I complex (WT1-pMHC) is a highly specific tumor-associated antigen target consisting of a processed WT1 peptide fragment bound to a Major Histocompatibility Complex (MHC) class I molecule, typically HLA-A*02:01 [Source: PubMed, PMID: 19723909]. WT1 is a zinc-finger transcription factor overexpressed in various hematological malignancies, such as acute myeloid leukemia (AML), and several solid tumors, while maintaining restricted expression in normal tissues such as kidney podocytes [Source: NIH, National Cancer Institute]. On dendritic cells, this complex is formed following the uptake and processing of WT1 antigens, serving as the essential signal for priming and activating CD8+ cytotoxic T lymphocytes (CTLs) [Source: PubMed, PMID: 23486626]. Therapeutic strategies targeting this complex include peptide vaccines like Galinpepimut-S, which utilize dendritic cells to present the WT1-pMHC complex and stimulate an endogenous immune response, as well as TCR-engineered T cells (TCR-T) and TCR-like antibodies (e.g., ESK1) that recognize the complex on malignant cells [Source: Sellas Life Sciences]. Targeting this complex allows for the recognition of intracellular proteins, expanding the range of targetable tumor antigens beyond surface proteins. However, clinical application must account for potential safety concerns such as renal toxicity due to low-level WT1 expression in the kidneys and the risk of cytokine release syndrome during T-cell activation [Source: PubMed, PMID: 26034289]. Additionally, the requirement for specific HLA genotypes in patients limits the broad applicability of certain WT1-pMHC targeted therapies.

Other names

WT1-HLA-A*02:01 complexWT1 peptide-HLA complexWT1-MHC class I complexWT1-pMHC

Induction of antigen-specific cytotoxic T-lymphocyte response through T-cell receptor recognition of the peptide-MHC complex.