Cytomegalovirus phosphoprotein 65-derived peptide–HLA class I complex (CMV pp65–HLA-I)

The Cytomegalovirus phosphoprotein 65-derived peptide–HLA class I complex is a primary immunological target for the management of Human Cytomegalovirus (HCMV) infection [1]. The pp65 protein, encoded by the UL83 gene, is the most abundant tegument protein of HCMV and serves as a dominant antigen for CD8+ cytotoxic T-lymphocyte (CTL) responses [1][2]. During infection, pp65 is processed by the host cell's proteasome into short peptides, which are then loaded onto HLA class I molecules and presented on the cell surface [2]. These peptide-MHC (pMHC) complexes are specifically recognized by the T-cell receptors (TCRs) of CTLs, leading to the targeted destruction of the infected cell [2]. Therapeutic strategies targeting this complex include the administration of ex vivo expanded CMV-specific T cells (VSTs) and the development of TCR-engineered T-cell therapies, which are particularly vital for immunocompromised patients such as hematopoietic stem cell transplant recipients [3][4]. Additionally, vaccine candidates like Triplex utilize pp65 to elicit protective T-cell responses against these specific complexes to prevent viral reactivation [5]. Monitoring the presence of these complexes and the corresponding T-cell response is essential for assessing immune reconstitution and treatment efficacy in clinical settings [4][6].

Other names

CMV pp65-MHC class I complexUL83 peptide-HLA complexpp65-HLA-A*02:01 complexCMV-specific pMHC complexpp65-MHC complex

T-cell receptor (TCR) mediated recognition of the peptide-HLA complex, triggering cytotoxic T-lymphocyte (CTL) activation and granzyme/perforin-mediated lysis of the target cell.