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

The Wilms tumor protein 1 (WT1) peptide-MHC class I complex is a prominent target in oncology, particularly for T-cell based immunotherapies. WT1 is a transcription factor that plays a vital role in cell growth and differentiation, and it is ranked by the National Cancer Institute as a top priority tumor-associated antigen due to its high expression in various cancers and low expression in normal tissues (Cheever et al., 2009, Clinical Cancer Research). Since WT1 is an intracellular protein, it is not accessible to traditional antibodies; instead, it must be processed into short peptides and presented on the cell surface by Major Histocompatibility Complex (MHC) class I molecules (typically HLA-A*02:01 or HLA-A*24:02) for recognition by T-cell receptors (TCRs) (Sugiyama, 2010, Japanese Journal of Clinical Oncology). Therapeutic interventions targeting this complex include peptide vaccines like Galinpepimut-S, which stimulate endogenous T-cell responses, and adoptive cell therapies using TCR-engineered T-cells (TCR-T) that provide a direct cytotoxic attack against tumor cells (Dao et al., 2017, Nature Biotechnology). Additionally, TCR-like antibodies such as ESK1 have been developed to bind this specific pMHC complex with high affinity, bridging the gap between antibody-based and TCR-based therapies (Veomett et al., 2014, Clinical Cancer Research). The primary challenge in targeting this complex is ensuring high specificity to avoid on-target, off-tumor toxicity in tissues like the kidney or bone marrow where low levels of WT1 may be present.

Other names

WT1-HLA complexWT1 peptide-HLA-A*02:01Wilms tumor 1 antigen-MHC complexWT1-MHC complex

Targeting of the WT1 peptide-MHC complex via T-cell receptor (TCR) binding or TCR-mimetic antibodies, leading to the activation of cytotoxic T-lymphocytes and subsequent lysis of the target tumor cell (Dao et al., 2017, Nature Biotechnology).