Cytomegalovirus 65 kDa phosphoprotein (pp65) peptide-MHC class I complex (CMV pp65-MHC I)

The Cytomegalovirus 65 kDa phosphoprotein (pp65), encoded by the UL83 gene, is the most abundant tegument protein of Human Cytomegalovirus (HCMV) and serves as a primary target for the host's cell-mediated immune response (UniProt P06725). During viral infection, pp65 is processed into peptides that are presented on the surface of infected cells by Major Histocompatibility Complex (MHC) class I molecules (PubMed PMID: 15507653). This peptide-MHC complex is specifically recognized by the T-cell receptors (TCRs) of CD8+ cytotoxic T lymphocytes, which then initiate the destruction of the infected cell through the release of cytotoxins (PubMed PMID: 28923917). Because of its high immunogenicity and consistent expression during both lytic and latent phases of infection, the pp65-MHC I complex is a critical target for therapeutic interventions. Current drug development strategies include adoptive transfer of donor-derived CMV-specific T cells, TCR-engineered T-cell therapies, and viral vector-based vaccines like Triplex designed to elicit a robust pp65-specific immune response (ClinicalTrials.gov NCT02506933). These therapies are primarily aimed at preventing or treating CMV-related complications in immunocompromised patients, such as those undergoing hematopoietic stem cell or solid organ transplantation (PubMed PMID: 25605371).

Other names

UL83ppUL83Human cytomegalovirus 65 kDa phosphoproteinCMV pp65 antigenLower matrix protein pp65

Recognition of the pp65 peptide-MHC class I complex by specific T-cell receptors (TCRs) on CD8+ T cells, leading to T-cell activation, cytokine release, and targeted lysis of CMV-infected cells.