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

The Cytomegalovirus peptide-Human Leukocyte Antigen (HLA) class I complex is a molecular assembly found on the surface of cells infected with Human Cytomegalovirus (HCMV) [PubMed: 25605962]. This complex consists of a viral peptide fragment, typically derived from highly immunogenic proteins such as pp65 (UL83) or IE1 (UL123), non-covalently bound within the groove of an HLA class I molecule [NCBI Bookshelf: NBK27156]. Its primary biological function is to signal the presence of intracellular infection to the adaptive immune system, specifically to CD8+ cytotoxic T-lymphocytes (CTLs) [PubMed: 25605962]. Upon recognition of this specific pMHC complex by a cognate T-cell receptor (TCR), the CTL is activated to destroy the infected cell, thereby controlling viral replication and spread [Blood Journal DOI: 10.1182/blood-2017-02-768630]. In clinical contexts, this complex is a critical target for adoptive T-cell therapies and vaccines aimed at treating CMV-related complications in immunocompromised patients, such as those undergoing hematopoietic stem cell or solid organ transplantation [ClinicalTrials.gov NCT04354311]. Therapeutic strategies often involve the infusion of CMV-specific T-cells or the development of TCR-based biologics that mimic natural immune recognition [Blood Journal DOI: 10.1182/blood-2017-02-768630]. However, challenges include the virus's ability to downregulate HLA expression to evade detection and the potential for T-cell-mediated toxicities like cytokine release syndrome [PubMed: 25605962, ClinicalTrials.gov NCT04354311].

Other names

CMV pMHCHCMV peptide-MHC class I complexCytomegalovirus antigen-HLA complexCMV-specific peptide-HLA complexpp65 peptide-HLA-A*02:01 complex

Recognition by T-cell receptors (TCRs) on CD8+ cytotoxic T-lymphocytes, leading to the activation of immune-mediated killing of infected cells through the release of perforin and granzymes [PubMed: 25605962, Blood Journal DOI: 10.1182/blood-2017-02-768630].