Patient-specific tumor-associated peptide-human leukocyte antigen complexes (pHLA complexes)

Patient-specific tumor-associated peptide-HLA (pHLA) complexes are unique molecular signatures found on the surface of cancer cells, consisting of a short peptide fragment derived from a tumor-specific mutation (neoantigen) or overexpressed protein bound to a Human Leukocyte Antigen (HLA) molecule. These complexes serve as the primary interface for the adaptive immune system, allowing T-cell receptors (TCRs) to distinguish malignant cells from healthy tissue (Nature, 2017). Because neoantigens arise from stochastic somatic mutations, these pHLA targets are often highly specific to an individual patient's tumor, minimizing the risk of central tolerance and systemic toxicity (Science, 2015). In the context of precision oncology, pHLA complexes are targeted by a variety of therapeutic modalities, including personalized mRNA vaccines, adoptive cell therapies using TCR-engineered T-cells (TCR-T), and TCR-mimetic antibodies or bispecific T-cell engagers. The therapeutic efficacy of targeting these complexes depends heavily on the stability of the peptide-HLA binding and the density of the complex on the cell surface (Journal of Clinical Investigation, 2019). However, challenges remain, such as the potential for tumor immune escape through the loss of HLA expression or the emergence of resistance mutations that alter peptide processing and presentation (Cell, 2017).

Other names

Neoantigen-HLA complexesTumor-specific peptide-MHC complexespMHC complexesPatient-specific neoantigen-HLA complexesTumor-associated antigen-HLA complexes

Drugs targeting these complexes typically function by presenting synthetic neoantigen peptides to the immune system via vaccines or by utilizing engineered T-cell receptors (TCRs) and bispecific molecules that specifically bind the peptide-HLA surface, triggering T-cell mediated lysis of the tumor cell (Nature Reviews Drug Discovery, 2021).