Patient-specific neoantigen peptide–HLA class II complex (NeoAg-HLA-II)

Patient-specific neoantigen peptide–HLA class II complexes are molecular structures consisting of a tumor-specific mutated peptide (neoantigen) bound to a Human Leukocyte Antigen (HLA) class II molecule. These complexes are primarily presented on the surface of professional antigen-presenting cells (APCs) like dendritic cells, or occasionally on tumor cells, where they are recognized by the T-cell receptors (TCRs) of CD4+ T helper cells (Ott et al., 2017, Nature). The recognition of these complexes is a cornerstone of the adaptive immune response against cancer, as CD4+ T cells provide essential signals for the activation and memory formation of CD8+ cytotoxic T cells and B cells (Sahin et al., 2017, Nature). Because neoantigens arise from somatic mutations unique to an individual's tumor, these complexes represent highly specific targets for personalized immunotherapy, minimizing the risk of central tolerance and off-target effects on healthy tissues (Hu et al., 2021, Nature Reviews Immunology). Therapeutic strategies targeting these complexes include personalized neoantigen vaccines, such as mRNA-4157, and adoptive cell therapies using TCR-engineered T cells. However, the high polymorphism of HLA genes and the complexity of predicting HLA class II peptide binding present significant challenges in the design and efficacy of these precision therapies (Alspach et al., 2019, Nature).

Other names

Neoepitope-HLA-II complexTumor-specific neoantigen-MHC class II complexPersonalized neoantigen-MHC-II complexNeoantigen-HLA-II complexpMHC-II complex

Presentation of tumor-specific mutant peptides to CD4+ T cells to stimulate a coordinated anti-tumor immune response.