Human epidermal growth factor receptor 2 (HER2)-derived epitope (HER2-derived epitope)

Human epidermal growth factor receptor 2 (HER2)-derived epitope refers to specific peptide fragments originating from the HER2/neu protein (UniProt P04626), which is overexpressed in approximately 20-30% of breast cancers and other solid tumors (National Cancer Institute). These epitopes are processed intracellularly and presented on the cell surface by Major Histocompatibility Complex (MHC) molecules, making them targets for the adaptive immune system. In clinical oncology, synthetic versions of these epitopes, such as E75 (nelipepimut-S), GP2, and AE37, are developed as therapeutic vaccines to stimulate HER2-specific CD8+ cytotoxic T lymphocytes and CD4+ helper T cells (PMID: 25103457, PMID: 32544865). These vaccines are typically administered in the adjuvant setting to prevent disease recurrence by establishing long-term immunological surveillance against HER2-expressing malignant cells. By focusing the immune response on specific immunogenic regions of the HER2 protein, these therapies aim to provide a highly specific anti-tumor effect with minimal toxicity to healthy tissues (PMID: 27103119).

Other names

ErbB2-derived peptideHER2/neu epitopeHER2 peptideE75 peptideGP2 peptideAE37 peptidenelipepimut-SCD340-derived epitope

HER2-derived epitopes function as antigens that are presented by MHC class I or II molecules on the surface of tumor cells or professional antigen-presenting cells (APCs). When administered as a vaccine, these peptides are taken up by APCs and presented to naive T cells, leading to the activation and clonal expansion of HER2-specific cytotoxic T lymphocytes (CTLs) and helper T cells (PMID: 25103457). These activated T cells then circulate and recognize the same HER2-derived epitopes presented on the surface of malignant cells, triggering cell death through the release of perforins and granzymes (PMID: 32544865).