Cytomegalovirus peptide–Human Leukocyte Antigen complex (CMV-HLA complex)

The Cytomegalovirus (CMV) peptide–Human Leukocyte Antigen (HLA) complex is a molecular assembly presented on the surface of cells infected with Human Cytomegalovirus (HCMV). It consists of a viral protein fragment, typically derived from immunodominant proteins like pp65 (UL83) or Immediate-Early 1 (IE1), bound within the peptide-binding groove of an HLA molecule, such as HLA-A*02:01 (UniProt P06725; PubMed 8970964). This complex is the fundamental unit recognized by the T-cell receptor (TCR) of CMV-specific T-lymphocytes, which is essential for the cellular immune response to control viral replication (PubMed 4135594). In therapeutic contexts, these complexes are targeted by adoptive cell therapies, such as donor-derived or off-the-shelf CMV-specific T cells like Posoleucel, and experimental TCR-like antibodies designed to mimic T-cell recognition (AlloVir Pipeline 2024). Targeting these complexes is particularly critical in immunocompromised patients, such as hematopoietic stem cell or solid organ transplant recipients, where CMV reactivation can lead to severe morbidity and mortality (PubMed 28235134). The efficacy of these therapies is highly dependent on the patient's HLA type and the presence of specific viral epitopes on the cell surface. Furthermore, the virus has evolved mechanisms to downregulate these complexes to evade immune detection, presenting a significant challenge for treatment (PubMed 11282483).

Other names

CMV pMHCHCMV peptide-MHC complexCMV-specific HLA-peptide complexCytomegalovirus antigen-HLA complex

Recognition of the viral peptide-MHC complex by specific T-cell receptors (TCRs) on cytotoxic T-lymphocytes, triggering the release of perforins and granzymes to induce apoptosis in the infected cell.