Cytomegalovirus immediate-early protein 1 peptide-MHC class I complex (CMV IE1 pMHC-I)

The Cytomegalovirus immediate-early protein 1 (IE1) peptide-MHC class I complex is a primary immunological target on cells infected with Human Cytomegalovirus (HCMV) (UniProt: P06473). IE1, encoded by the UL123 gene, is a 491-amino acid phosphoprotein that is essential for viral replication and the evasion of host antiviral responses, such as the interferon-mediated defense (PubMed: 15956344). During infection, IE1 is processed by the proteasome into short peptides, such as the immunodominant VLEETSVML peptide, which are then loaded onto MHC class I molecules (e.g., HLA-A*02:01) for presentation to the immune system (PubMed: 10400705). These complexes are recognized by the T-cell receptors (TCRs) of CD8+ cytotoxic T lymphocytes, making them a focal point for adoptive cell therapies and vaccine design (PubMed: 25609775). Therapeutic strategies targeting this complex are particularly relevant in the context of hematopoietic stem cell transplantation (HSCT) and solid organ transplantation, where CMV reactivation is a significant cause of morbidity and mortality (PubMed: 28234343).

Other names

HCMV IE1 peptide-HLA complexUL123 peptide-MHCIE1-specific MHC-I complexCMV IE1 antigenIE1-derived pMHC

Recognition by antigen-specific T-cell receptors (TCRs) on CD8+ T cells, which triggers the release of cytotoxic granules (perforin and granzymes) and pro-inflammatory cytokines, leading to the targeted lysis of CMV-infected cells (PubMed: 10400705).