Peptide-major histocompatibility complex presenting Cytomegalovirus 65 kDa phosphoprotein (pp65)-derived epitopes (CMV pp65-pMHC)

Peptide-major histocompatibility complex (pMHC) complexes presenting Cytomegalovirus (CMV) 65 kDa phosphoprotein (pp65)-derived epitopes are critical immunological targets for managing CMV infection and reactivation. The pp65 protein, encoded by the UL83 gene, is the most abundant tegument protein of CMV and serves as a primary target for the host's cellular immune response, particularly CD8+ cytotoxic T lymphocytes (CTLs) [Source: UniProt P06725]. These complexes form when pp65 is processed intracellularly into short peptides, such as the immunodominant NLVPMVATV epitope, which are then loaded onto HLA Class I molecules (most commonly HLA-A*02:01) and displayed on the cell surface [Source: PubMed 10438931]. In immunocompromised individuals, such as transplant recipients, the failure of the immune system to recognize these pMHC complexes can lead to life-threatening CMV disease. Therapeutic interventions targeting these complexes include adoptive T-cell therapies (e.g., CMV-specific T cells), TCR-engineered T cells, and vaccines designed to prime the immune system to recognize pp65-presenting cells [Source: ClinicalTrials.gov NCT02390141]. By specifically binding to these pMHC targets, therapies aim to restore viral surveillance and eliminate infected cells through directed T-cell mediated lysis.

Other names

CMV pp65-HLA complexHLA-A*02:01/NLVPMVATV complexpMHC-pp65UL83-derived peptide-MHCCMV pp65 antigen-presenting complex

The primary mechanism of action involves the recognition of the peptide-MHC complex by specific T-cell receptors (TCRs) on the surface of CD8+ cytotoxic T lymphocytes. This binding event triggers a signaling cascade within the T cell, leading to the release of cytotoxic granules containing perforin and granzymes, which induce apoptosis in the CMV-infected or antigen-presenting cell [Source: PubMed 10438931].