Human cytomegalovirus peptide–major histocompatibility complex (HCMV pMHC)

Human cytomegalovirus (HCMV) peptide–major histocompatibility complex (pMHC) structures are the fundamental units for immune recognition of HCMV-infected cells. These complexes consist of viral peptides, derived from proteins like pp65 or IE1, non-covalently bound to MHC Class I or Class II molecules (Reddehase, 2002, Nature Reviews Immunology). They are presented on the surface of infected cells to be recognized by the T-cell receptors (TCRs) of CD8+ and CD4+ T cells, respectively, which is a critical step for the control of viral replication (Griffiths et al., 2015, The Lancet). In immunocompromised individuals, such as those undergoing hematopoietic stem cell or solid organ transplantation, the failure of this recognition system leads to viral reactivation and significant morbidity. Therapeutic interventions, such as adoptive virus-specific T-cell (VST) therapies, specifically target these pMHC complexes to restore cellular immunity and clear the infection (Blyth et al., 2013, Blood). However, HCMV has evolved sophisticated evasion strategies, including the production of proteins that degrade or sequester MHC molecules, thereby reducing the density of pMHC complexes on the cell surface and hindering immune detection (Hansen et al., 2010, Science).

Other names

CMV peptide-MHC complexHCMV peptide-HLA complexCytomegalovirus antigen-MHC complexHCMV pMHCCMV pMHC

T-cell receptor (TCR) mediated recognition of viral peptides presented on MHC, leading to cytotoxic T-lymphocyte (CTL) activation and apoptosis of infected cells.