Wilms' tumor 1 (WT1)-derived helper peptide–HLA class II complex (WT1-HLA class II complex)

The Wilms' tumor 1 (WT1)-derived helper peptide–HLA class II complex is a molecular assembly consisting of a specific peptide fragment from the WT1 protein bound to a Human Leukocyte Antigen (HLA) class II molecule (Oka et al., 2004). WT1 is a transcription factor that is highly overexpressed in various hematological malignancies and solid tumors, while having limited expression in normal adult tissues, making it an ideal target for cancer immunotherapy (National Cancer Institute, 2009). These complexes are primarily presented on the surface of professional antigen-presenting cells to CD4+ T helper cells. Upon recognition by the T-cell receptor (TCR), the complex triggers the activation and proliferation of helper T cells, which subsequently secrete cytokines to orchestrate a robust and sustained immune response, including the enhancement of CD8+ cytotoxic T-cell activity (Sellos-Moura et al., 2020). Therapeutic strategies targeting these complexes include peptide-based vaccines, such as Galinpepimut-S and DSP-7888, and TCR-engineered T-cell therapies designed to boost the patient's own immune system against WT1-expressing cancer cells (ClinicalTrials.gov). Clinical trials have demonstrated that inducing an immune response against these complexes can lead to improved outcomes in patients with acute myeloid leukemia and various solid tumors. The therapeutic efficacy is often dependent on the patient's specific HLA genotype, as the helper peptides must match the binding motifs of the individual's HLA class II molecules.

Other names

WT1-MHC class II complexWT1 CD4+ T cell epitope-HLA complexWilms' tumor 1 helper peptide-HLA complexWT1-derived helper peptide-MHC II

Activation of CD4+ T helper cells through T-cell receptor (TCR) recognition of the peptide-HLA complex to stimulate a multi-valent anti-tumor immune response, including cytokine secretion and enhancement of CD8+ cytotoxic T-cell activity.