Cytomegalovirus immediate-early 1 peptide–HLA class I complex (CMV IE-1–HLA-I complex)

The Cytomegalovirus (CMV) immediate-early 1 (IE-1) peptide–HLA class I complex is a primary immunological target for the control of CMV infection by the adaptive immune system (UniProt P06473). CMV is a beta-herpesvirus that establishes lifelong latency and can cause life-threatening disease in immunocompromised individuals, such as hematopoietic stem cell or solid organ transplant recipients (PubMed: 25605930). The IE-1 protein is expressed very early during the viral lytic cycle or reactivation, and its degradation products are presented on the cell surface by HLA class I molecules (PubMed: 15141017). These peptide-MHC complexes are recognized by the T-cell receptors (TCRs) of CD8+ cytotoxic T lymphocytes, which are essential for limiting viral spread (Schub et al., 2009). Therapeutic approaches targeting this complex include the infusion of ex vivo expanded virus-specific T cells (VSTs), such as Viralym-M, and the development of TCR-engineered T cells designed to provide immediate immunity (AlloVir, 2023). Additionally, peptide-based vaccines like Triplex utilize IE-1 epitopes to prime the endogenous immune system against CMV-related pathologies (ClinicalTrials.gov NCT04354311). This target is particularly valuable because IE-1 expression precedes viral DNA replication, allowing the immune system to intervene before significant viral progeny are produced.

Other names

CMV IE1-MHC complexIE1 pMHCVLEETSVML-HLA-A*02:01 complexCytomegalovirus IE1 peptide-MHC class I complexIE-1 pMHC complex

Recognition by antigen-specific T-cell receptors (TCRs) on CD8+ T cells, leading to the activation of cytotoxic pathways (granzyme/perforin) and lysis of CMV-infected cells (Schub et al., 2009).