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

Cytomegalovirus immediate-early protein 1 (IE1), encoded by the UL123 gene, is a primary viral protein expressed during the initial phase of Human Cytomegalovirus (HCMV) infection [UniProt: P13202]. Peptides derived from IE1 are processed and presented on the cell surface by Major Histocompatibility Complex (MHC) Class I molecules, where they serve as essential targets for the host's cellular immune response [PubMed: 15608363]. These peptide-MHC complexes are specifically recognized by the T-cell receptors (TCRs) of CD8+ cytotoxic T-lymphocytes, which then mediate the destruction of infected cells. In clinical practice, IE1 pMHC complexes are targeted by adoptive T-cell therapies and vaccines, such as the Triplex vaccine, to prevent or treat CMV-related diseases in immunocompromised transplant recipients [NCT02506933]. Furthermore, IE1 expression in certain tumors like glioblastoma has led to the investigation of these complexes as potential targets for cancer immunotherapy. Therapeutic approaches include the use of ex vivo expanded virus-specific T-cells (VSTs) and multi-antigen vaccines designed to stimulate a robust IE1-specific immune response. However, the effectiveness of these therapies can be challenged by viral mechanisms that downregulate MHC expression to evade immune detection [PubMed: 11248117].

Other names

Human cytomegalovirus immediate-early protein 1 peptide-HLA complexUL123 peptide-MHCIE1-derived epitopesCMV IE1 antigen

Recognition of the peptide-MHC complex by specific T-cell receptors (TCRs) on CD8+ cytotoxic T-lymphocytes, triggering the release of perforins and granzymes to induce apoptosis in CMV-infected or CMV-expressing cells [PubMed: 15608363].