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

The Wilms tumor 1 (WT1) peptide–HLA class I complex is a prominent tumor-associated antigen (TAA) formed by the presentation of intracellularly processed WT1 fragments on the cell surface via Human Leukocyte Antigen (HLA) molecules. WT1 is a zinc-finger transcription factor that plays a vital role in cell growth and differentiation; while it is minimally expressed in healthy adult tissues, it is highly overexpressed in a wide range of hematological malignancies and solid tumors, leading the National Cancer Institute to rank it as a top priority cancer antigen [1][2]. Because WT1 is an intracellular protein, it cannot be targeted by traditional monoclonal antibodies; however, its degradation into peptides and subsequent presentation by HLA class I molecules (most commonly HLA-A*02:01) allows it to be recognized by the cellular immune system [3]. This complex is a primary target for advanced immunotherapies, including T-cell receptor (TCR) engineered T cells, bispecific T-cell engagers (BiTEs), and TCR-like antibodies that specifically bind the peptide-MHC interface [4]. Clinical development of these therapies often requires patient screening for both WT1 expression levels and specific HLA alleles to ensure target availability [5]. Despite its promise, therapeutic challenges include potential on-target, off-tumor toxicity in tissues like the renal podocytes and the risk of immune evasion through HLA downregulation by tumor cells [6]. Sources: [1] Cheever MA, et al. Clin Cancer Res. 2009. [2] NCBI Gene: WT1 Wilms tumor 1 [Homo sapiens]. [3] Dao T, et al. Sci Transl Med. 2013. [4] ClinicalTrials.gov: NCT03864445 (WT1-TCB). [5] Sellas Life Sciences: Galinpepimut-S (GPS) Product Profile. [6] Nature Reviews Clinical Oncology: T-cell receptor-engineered T cells.

Other names

WT1-MHC class I complexWT1-pMHCWT1-HLA-A*02:01 complexWilms tumor protein peptide-MHC complexWT1-derived peptide–HLA class I complex

T-cell mediated cytotoxicity via TCR or TCR-like recognition of the specific peptide-MHC complex on the tumor cell surface