Cytomegalovirus pp65 and IE-1 peptide-HLA class I complexes (CMV pp65/IE-1 pHLA)

Cytomegalovirus (CMV) pp65 and IE-1 peptide epitopes presented on HLA class I molecules are the primary targets for CD8+ cytotoxic T-lymphocyte (CTL) mediated immunity against Human Cytomegalovirus (HCMV) (PubMed: 15956288). The pp65 protein (encoded by UL83) is a major tegument protein and the most dominant target of the CMV-specific cellular immune response, while the IE-1 protein (encoded by UL123) is expressed immediately upon viral entry and is crucial for viral reactivation control (UniProt: P06725, P13202). These viral proteins are processed into short peptides and displayed on the cell surface by Human Leukocyte Antigen (HLA) class I molecules, forming a peptide-MHC complex that is specifically recognized by T-cell receptors (TCRs). In clinical settings, particularly following hematopoietic stem cell transplantation (HSCT) or solid organ transplantation, the absence of a robust T-cell response against these epitopes leads to life-threatening CMV disease. Therapeutic interventions such as adoptive cell therapy (ACT) utilize virus-specific T cells (VSTs) or TCR-engineered T cells to target these specific pHLA complexes and eliminate infected cells (PubMed: 30733317). Monitoring the frequency of T cells reactive to these epitopes serves as a critical biomarker for assessing a patient's risk of CMV reactivation and the efficacy of immunotherapy.

Other names

HCMV pp65 and IE-1 epitopesCMV UL83 and UL123 peptide-MHC complexesCMV-specific T-cell targetspp65/IE-1 peptide-HLA complexesHuman cytomegalovirus phosphoprotein 65 and immediate-early protein 1 epitopes

Recognition of the peptide-HLA complex by the T-cell receptor (TCR) of cytotoxic T-lymphocytes, triggering the release of perforin and granzymes to induce apoptosis in the CMV-infected cell.