Epstein-Barr virus nuclear antigen 3A peptide–Major Histocompatibility Complex (EBNA3A-MHC)

The Epstein-Barr virus nuclear antigen 3A (EBNA3A) peptide–Major Histocompatibility Complex (MHC) is a cell-surface molecular assembly consisting of a processed peptide from the EBNA3A protein bound to an MHC Class I molecule, most frequently HLA-B*08:01 (UniProt P12977; PubMed 15123769). EBNA3A is a latent viral protein essential for the immortalization and transformation of B-lymphocytes during EBV infection (PubMed 10482588). In EBV-infected cells, particularly during the latency III program, EBNA3A is expressed and its degradation products are presented on the cell surface to signal the presence of the virus to the immune system (PubMed 15123769). This complex serves as a primary target for cytotoxic CD8+ T-lymphocytes (CTLs), which recognize the specific peptide-MHC combination via their T-cell receptors (TCRs) to initiate cell lysis (PubMed 7524606). In the context of EBV-associated malignancies and post-transplant lymphoproliferative disorders (PTLD), this complex is exploited as a therapeutic target for adoptive T-cell therapies (Atara Biotherapeutics, 2024). Drugs like Tabelecleucel (Ebvallo) utilize allogeneic T-cells primed to recognize these EBV-specific complexes to selectively eliminate infected or malignant cells while sparing healthy tissue (EMA, 2022).

Other names

EBNA3A-HLA complexEBNA3A-HLA-B*08:01EBV nuclear antigen 3A-MHCEBNA3A-HLA-A*03:01EBNA3A-HLA-B*35:01

T-cell receptor (TCR) mediated recognition of the peptide-MHC complex followed by cytotoxic T-lymphocyte (CTL) activation and granzyme/perforin-mediated apoptosis of the target cell.