Cytomegalovirus peptide–Major Histocompatibility Complex (CMV pMHC)

Cytomegalovirus peptide–Major Histocompatibility Complex (CMV pMHC) is a molecular assembly consisting of a viral peptide fragment bound to a host Major Histocompatibility Complex (MHC) molecule, typically HLA class I, on the surface of infected cells (Source: PubMed, PMID: 31435312). These complexes, often featuring peptides from the pp65 (UL83) or IE1 (UL123) proteins, are the primary targets for CD8+ cytotoxic T lymphocytes (CTLs) which recognize them via specific T-cell receptors (TCRs) (Source: NIH, National Institute of Allergy and Infectious Diseases). In healthy individuals, this interaction maintains viral latency, but in immunocompromised patients, such as those undergoing hematopoietic stem cell or solid organ transplantation, the absence of effective pMHC recognition leads to viral reactivation and life-threatening disease (Source: Nature Reviews Immunology). Therapeutic interventions targeting these complexes include adoptive T-cell therapies like posoleucel and investigational TCR-like antibodies designed to bind specifically to the pMHC complex to trigger cell lysis (Source: Journal of Clinical Investigation). A significant challenge in targeting CMV pMHC is the virus's sophisticated immune evasion mechanisms, which include the downregulation of MHC molecules to prevent surface presentation of viral antigens (Source: Frontiers in Immunology). Additionally, therapeutic development must account for HLA polymorphism, as pMHC complexes are highly specific to the patient's HLA genotype (Source: Blood).

Other names

CMV pMHC complexHCMV peptide-HLA complexCytomegalovirus antigen-MHC complexCMV-specific pMHC

T-cell receptor (TCR) mediated recognition and subsequent cytotoxic T-lymphocyte (CTL) activation leading to infected cell lysis.