Cytomegalovirus immediate-early 1 protein peptides presented by HLA class I (CMV IE-1/HLA-I)

Cytomegalovirus immediate-early 1 (IE-1) protein, encoded by the UL123 gene, is a primary regulatory protein expressed during the earliest phase of Human Cytomegalovirus (HCMV) infection or reactivation (UniProt P13202). It plays a pivotal role in initiating viral gene expression and antagonizing host antiviral responses, such as those mediated by Type I interferons and PML nuclear bodies (PMID: 16140084). Peptides derived from the IE-1 protein are processed by the proteasome and presented on the cell surface by Human Leukocyte Antigen (HLA) Class I molecules. These peptide-HLA complexes serve as critical targets for CD8+ cytotoxic T lymphocytes (CTLs), which are essential for controlling CMV latency and preventing symptomatic disease in healthy individuals. In clinical practice, IE-1/HLA complexes are targeted through adoptive T-cell therapies and vaccines, particularly in immunocompromised transplant recipients who lack sufficient endogenous CMV-specific immunity (PMID: 28232463). Therapeutic strategies include the infusion of ex vivo expanded IE-1-specific T cells or the use of viral vector vaccines designed to elicit a robust IE-1-specific cellular immune response.

Other names

HCMV IE1 antigenUL123 peptide-MHC complexCMV IE1-specific T-cell targetHuman cytomegalovirus immediate-early 1 proteinIE1-HLA complex

The target functions as a ligand for specific T-cell receptors (TCRs) on CD8+ cytotoxic T lymphocytes. Recognition of the IE-1 peptide-HLA complex triggers T-cell activation, leading to the release of perforin and granzymes that induce apoptosis in infected cells, as well as the secretion of antiviral cytokines like IFN-gamma and TNF-alpha (PMID: 15919923, 25605961).