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

Cytomegalovirus (CMV) peptide–Human Leukocyte Antigen (HLA) class II complexes are molecular assemblies consisting of a CMV-derived viral peptide bound within the groove of an HLA class II molecule, such as HLA-DR, HLA-DQ, or HLA-DP (PubMed: 28234341). These complexes are primarily expressed on the surface of professional antigen-presenting cells (APCs), where they serve as the primary ligand for the T-cell receptor (TCR) of CD4+ T lymphocytes (UniProt: P06725). The recognition of these complexes is essential for the induction of a robust and coordinated immune response against CMV, a ubiquitous herpesvirus that causes significant morbidity in immunocompromised individuals and transplant recipients (PubMed: 30305377). In clinical development, these complexes are targeted by vaccines designed to elicit protective T-cell immunity and are used as the basis for adoptive T-cell therapies, where CMV-specific CD4+ T cells are expanded or engineered to treat refractory infections (ClinicalTrials.gov: NCT03564119). Furthermore, synthetic versions of these complexes, such as HLA-II tetramers, are critical tools for monitoring the frequency and phenotype of CMV-specific T cells in patients (PubMed: 21677131). The therapeutic utility of targeting these complexes is often limited by HLA restriction, requiring treatments to be matched to the patient's specific genetic background.

Other names

CMV peptide–MHC class II complexCMV-specific HLA-II complexCytomegalovirus antigen–HLA class II complexCMV-HLA-DR complexCMV-HLA-DQ complexCMV-HLA-DP complex

Recognition by T-cell receptors (TCRs) on CD4+ T cells, triggering intracellular signaling cascades that lead to T-cell proliferation, cytokine production, and orchestration of the adaptive immune response against CMV-infected cells.