Human epidermal growth factor receptor 2-derived peptides presented on Major Histocompatibility Complex molecules (HER2-pMHC)

Human epidermal growth factor receptor 2 (HER2/neu)-derived peptides presented on dendritic cell Major Histocompatibility Complex (MHC) molecules are the fundamental units for inducing targeted T-cell immunity against HER2-positive malignancies. Dendritic cells (DCs) act as professional antigen-presenting cells that process the HER2 protein into immunogenic epitopes, such as the E75 or GP2 peptides, and display them on their surface via MHC molecules (UniProt P04626). This peptide-MHC (pMHC) complex is specifically recognized by the T-cell receptors (TCRs) of naive or memory T cells, initiating a robust cellular immune response (Brossart et al., 2000). In clinical practice, this target is utilized in dendritic cell vaccines, where autologous DCs are loaded with HER2 antigens ex vivo to prime the patient's immune system against cancer cells (Mittendorf et al., 2011). The therapeutic goal is to generate a pool of HER2-specific cytotoxic T lymphocytes capable of infiltrating tumors and inducing apoptosis in cells overexpressing the HER2 protein. While highly specific, the efficacy of targeting these pMHC complexes can be limited by tumor-mediated immune suppression or the loss of MHC expression on malignant cells (National Cancer Institute). Furthermore, the success of this approach is often dependent on the patient's specific HLA haplotype, as different MHC alleles present different HER2-derived peptides. This target represents a bridge between innate and adaptive immunity, focusing the immune system's destructive power on a specific molecular signature of cancer.

Other names

HER2/neu-derived epitopesERBB2-pMHCHER2-derived HLA-restricted peptidesHER2-pMHC complexHER2-derived peptides presented on MHC

The mechanism involves the presentation of HER2-derived antigenic peptides by dendritic cell MHC Class I and II molecules to T-cell receptors (TCRs). This interaction, accompanied by co-stimulatory signals, triggers the activation, expansion, and differentiation of HER2-specific CD8+ cytotoxic T lymphocytes and CD4+ helper T cells, which subsequently target and eliminate HER2-overexpressing tumor cells.