Cytomegalovirus phosphoprotein 65 peptide-HLA complex (CMV pp65-pMHC)

Cytomegalovirus (CMV) phosphoprotein 65 (pp65) peptide-HLA complexes are molecular assemblies formed by the association of immunodominant peptides derived from the viral tegument protein pp65 with Human Leukocyte Antigen (HLA) Class I or Class II molecules. These complexes are presented on the surface of CMV-infected cells or certain malignancies, such as glioblastoma and medulloblastoma, where they serve as the primary recognition signal for the host's cellular immune system (NIH, 1.1.2, 1.2.2). Recognition of these complexes by the T-cell receptor (TCR) on CD8+ cytotoxic T lymphocytes or CD4+ helper T cells triggers an effector response, including the release of perforin, granzymes, and pro-inflammatory cytokines like interferon-gamma, leading to the lysis of the target cell (NIH, 1.1.1, 1.1.3). In clinical development, these complexes are targeted by various immunotherapeutic strategies, including peptide vaccines (e.g., PEP-CMV), dendritic cell vaccines, and adoptive T-cell therapies (e.g., Posoleucel) to restore CMV-specific immunity in immunocompromised transplant recipients (WUSTL, 1.1.4; NIH, 1.2.1). Furthermore, novel T-cell receptor (TCR)-like antibodies are being engineered to specifically bind these pMHC complexes, offering a highly targeted approach for treating CMV-associated diseases and pp65-expressing tumors (NIH, 1.1.2, 1.1.3). The efficacy of these therapies is highly dependent on the patient's HLA profile, as specific pp65 epitopes like NLVPMVATV are restricted to common alleles such as HLA-A*02:01 (NIH, 1.1.2).

Other names

Cytomegalovirus pp65-derived peptide–HLA class I/II complexesCMV pp65 peptide-MHC complexpp65-HLA complexCMV pp65-pMHCCytomegalovirus phosphoprotein 65 peptide-MHC complexpp65 epitope-HLA complex

Induction of antigen-specific T-cell responses through vaccine-mediated presentation or direct targeting of the complex by adoptive T-cells and TCR-like antibodies to induce cell lysis.