Human epidermal growth factor receptor 2 (HER2) peptide-MHC class II complex (HER2-MHC II complex)

The HER2-derived peptide epitope presented via MHC class II is a specialized molecular complex consisting of a processed fragment of the Human Epidermal Growth Factor Receptor 2 (HER2) protein bound to the cleft of a Major Histocompatibility Complex (MHC) class II molecule. While HER2 is a well-known oncogenic driver in various cancers, its presentation via MHC II is critical for the recruitment and activation of CD4+ T helper cells. These T cells play a pivotal role in orchestrating a robust and sustained anti-tumor immune response by providing necessary signals for the maturation of cytotoxic CD8+ T cells and the production of anti-HER2 antibodies by B cells. In therapeutic contexts, this complex is targeted by cancer vaccines, such as AE37, and novel TCR-engineered T cell therapies designed to overcome the immune tolerance often seen in HER2-positive malignancies. Understanding the specific peptide sequences, such as the p776–790 fragment, and their binding affinity to various HLA-DR alleles is essential for developing personalized immunotherapies that can effectively treat breast, gastric, and ovarian cancers.

Other names

HER2/neu peptide-HLA class II complexERBB2 peptide-MHC IIHER2-derived MHC II epitopepMHC II (HER2)

Activation of CD4+ T helper cells which provide essential cytokines (like IFN-gamma and IL-2) to support CD8+ cytotoxic T cell activity and B cell antibody production against HER2-expressing tumor cells.