Wilms' tumor protein 1 peptide-HLA complex (WT1-HLA complex)

The Wilms' tumor protein 1 (WT1) peptide-HLA complex is a prominent tumor-associated antigen (TAA) target consisting of intracellularly processed WT1 fragments bound to Major Histocompatibility Complex (MHC) Class I molecules (Oka et al., 2004, PubMed: 14710016). WT1 is a zinc-finger transcription factor that plays a critical role in cell growth and differentiation; while it is expressed at low levels in normal tissues like the kidney and bone marrow, it is highly overexpressed in various cancers, including acute myeloid leukemia (AML) and mesothelioma (Cheever et al., 2009, PubMed: 19723653). The HLA-A*02:01 allele is the most common presenting molecule for these epitopes in Western populations, making the WT1/HLA-A*02:01 complex a primary focus for immunotherapy development (Lichtenegger et al., 2017, PubMed: 28874919). Therapeutic interventions targeting this complex include peptide vaccines like Galinpepimut-S, which stimulate the patient's own immune system, and adoptive T-cell therapies (TCR-T) that utilize engineered T-cell receptors to recognize the specific pMHC structure (Sugiyama, 2010, PubMed: 20624058). Because the target is a peptide-MHC complex rather than a surface protein, it allows the immune system to target the intracellular WT1 proteome, which is otherwise inaccessible to traditional monoclonal antibodies. However, clinical challenges include the potential for on-target, off-tumor toxicity in WT1-expressing healthy tissues and the development of resistance through HLA downregulation or antigen loss (Van Driessche et al., 2003, PubMed: 12851371).

Other names

WT1-pMHCHLA-A*02:01-presented WT1 epitopeWT1-MHC class I complexWilms' tumor 1 antigen-HLA complexHLA-A*02:01/WT1(126-134)HLA-A*02:01/WT1(187-195)

Induction of T-cell mediated cytotoxicity through the recognition of the WT1 peptide-HLA complex by endogenous or engineered T-cell receptors (TCRs).