Epidermal growth factor receptor pathway substrate 8-derived peptide–Major histocompatibility complex class I complex (EPS8-pMHC-I)

The Epidermal growth factor receptor pathway substrate 8 (EPS8)-derived peptide–Major histocompatibility complex (MHC) class I complex is a specialized molecular assembly presented on the surface of cells to facilitate immune surveillance. EPS8 is a 97 kDa protein that plays a critical role in actin remodeling and signal transduction downstream of the epidermal growth factor receptor (EGFR) (Maa et al., 2001). In many cancers, including pancreatic, colorectal, and head and neck squamous cell carcinomas, EPS8 is significantly overexpressed, whereas its expression in normal tissues is highly restricted (Welsch et al., 2007). This differential expression allows specific EPS8-derived peptides, such as the HLA-A*02:01-restricted peptide EPS8 727-735, to serve as tumor-associated antigens when bound to MHC class I molecules (Yao et al., 2003). Therapeutically, this complex is targeted by immunotherapies designed to redirect the immune system against malignant cells. These strategies include the development of T-cell receptor (TCR) engineered T-cells (TCR-T) and peptide-based vaccines that prime the host's cytotoxic T-lymphocytes (CTLs) to recognize the EPS8-pMHC complex. Upon recognition, CTLs release cytotoxic granules, such as perforin and granzymes, leading to the selective apoptosis of the tumor cell. Because EPS8 is involved in cell motility and invasion, targeting this complex may also inhibit the metastatic potential of the tumor (Offenhäuser et al., 2004). Current clinical interest focuses on optimizing the affinity of TCRs for this complex to maximize efficacy while minimizing potential off-target effects on healthy tissues.

Other names

EPS8 peptide-HLA complexEPS8-HLA-A*02:01 complexEPS8-MHC-IEPS8-derived antigen-MHC complex

Recognition of the peptide-MHC complex by specific T-cell receptors (TCRs) on CD8+ T-cells, triggering immunological synapse formation and subsequent granzyme/perforin-mediated lysis of the target cell.