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

The Cytomegalovirus (CMV) immediate-early 1 (IE1) protein peptide-MHC class I complex is a primary immunological target for the cellular immune response against CMV. IE1 is a regulatory protein encoded by the UL123 gene, essential for initiating the viral lytic cycle and modulating host immune defenses by disrupting PML nuclear bodies (UniProt: P06473). During infection, IE1 is degraded into peptides, such as the immunodominant VLEETSVML sequence, which are presented on the cell surface by MHC class I molecules like HLA-A*02:01 (PubMed: 11836417). These peptide-MHC complexes serve as the specific ligands for the T-cell receptors (TCRs) of CD8+ cytotoxic T lymphocytes. Recognition of this target triggers T-cell activation, leading to the secretion of perforins and granzymes that destroy the infected cell. In clinical practice, this complex is the focus of adoptive T-cell therapies and TCR-engineered T-cell products designed to restore CMV immunity in immunocompromised patients, such as transplant recipients (PubMed: 31534000). It is also a key component in the development of peptide-based vaccines aimed at preventing CMV reactivation.

Other names

IE1 peptide-HLA complexUL123 peptide-MHCCMV IE1 antigen-MHC ICytomegalovirus IE1-MHC class I complex

Targeted recognition by the T-cell receptor (TCR) of CD8+ cytotoxic T lymphocytes, leading to the directed lysis of CMV-infected cells and secretion of antiviral cytokines.