Cytomegalovirus immediate-early 1 peptide-HLA complex (CMV IE1-HLA complex)

The Cytomegalovirus (CMV) immediate-early 1 (IE1) peptide-HLA complex is a molecular assembly consisting of a peptide fragment derived from the viral IE1 protein (UL123) bound to a Human Leukocyte Antigen (HLA) molecule (UniProt P06473). IE1 is one of the first proteins expressed during the lytic cycle of CMV and is crucial for viral replication and the evasion of host intrinsic immunity (Schub et al., 2015, J Vis Exp). These complexes are presented on the surface of infected cells, serving as the primary signal for recognition by the adaptive immune system, specifically CD8+ cytotoxic T lymphocytes (Class I) and CD4+ helper T cells (Class II). In clinical settings, these complexes are the primary targets for adoptive T-cell therapies, such as posoleucel, and vaccines like Triplex, which aim to prevent or treat CMV disease in immunocompromised patients, such as hematopoietic stem cell transplant recipients (NCT02396134). The specificity of the interaction depends on the patient's HLA genotype, with peptides like VLEETSVML being commonly presented by HLA-A*02:01. Therapeutic challenges include the potential for off-target toxicity if the TCRs cross-react with similar human self-peptides and the risk of cytokine release syndrome during T-cell activation.

Other names

CMV IE1 pMHCUL123 peptide-MHC complexHuman cytomegalovirus IE1-HLA complexCMV IE1-specific peptide-HLA complex

Recognition by antigen-specific T-cell receptors (TCRs) leading to the activation of cytotoxic and helper T-cell responses against CMV-infected cells.