Major histocompatibility complex class I presenting the GP2 HER2-derived peptide (HLA-A2-GP2)

The MHC class I presenting the GP2 HER2-derived peptide is a specific molecular complex formed by the human leukocyte antigen A2 (HLA-A2) and a 9-amino acid fragment (IISAVVGIL, residues 654–662) derived from the transmembrane domain of the HER2/neu protein [1]. This complex serves as a critical recognition element for the cellular immune system, specifically for CD8+ cytotoxic T lymphocytes (CTLs) [2]. In HER2-positive cancers, such as breast and ovarian malignancies, the GP2 peptide is processed and presented on the cell surface by MHC class I molecules, making it a viable target for immunotherapy [3]. Therapeutic strategies, most notably the GP2 vaccine (GLSI-100), aim to elicit a robust and specific immune response against cells displaying this complex to prevent disease recurrence [4]. By training the immune system to identify this specific epitope, these therapies seek to eliminate residual cancer cells following primary treatment [5]. The clinical utility of targeting this complex is primarily restricted to patients who are HLA-A2 positive and have tumors that overexpress the HER2 protein [6].

Other names

HLA-A*02:01-GP2 complexHER2 GP2 peptide-MHC complexGP2-HLA-A2HER2(654-662) peptide-MHCMHC class I-GP2 complex

The GP2 peptide vaccine induces a specific CD8+ cytotoxic T lymphocyte response against HER2-expressing cells by presenting the GP2 epitope via HLA-A2 molecules on antigen-presenting cells and tumor cells.