Human cytomegalovirus 65 kDa phosphoprotein peptide-major histocompatibility complex (pp65-MHC complex)

The pp65 peptide-MHC complex is a molecular assembly consisting of peptides derived from the Human Cytomegalovirus (HCMV) 65 kDa phosphoprotein (pp65, also known as UL83) bound to Major Histocompatibility Complex (MHC) molecules on the surface of infected cells [1][2]. As the most abundant tegument protein of HCMV, pp65 serves as the primary immunodominant target for the host's cellular immune response, specifically for CD8+ cytotoxic T lymphocytes (CTLs) [2][3]. In the context of disease, HCMV remains a significant cause of morbidity in immunocompromised individuals, such as transplant recipients, where viral reactivation can lead to organ failure [4]. Therapeutic interventions target this complex using virus-specific T cells (VSTs), TCR-engineered T cells, or vaccines designed to elicit a robust CTL response against pp65-presenting cells [3][5]. For instance, the NLVPMVATV peptide from pp65 is frequently targeted when presented by the HLA-A*02:01 allele [3]. Recognition of the complex by a T-cell receptor (TCR) triggers an effector response that results in the lysis of the infected target cell [2]. Despite its therapeutic potential, the virus employs mechanisms to downregulate MHC expression, potentially hindering the efficacy of these treatments [6].

Other names

HCMV pp65-HLA complexUL83 peptide-MHC complexCMV pp65 antigen-MHCpp65-HLA-A*02:01 complexCytomegalovirus pp65-MHC complex

Recognition by T-cell receptors (TCRs) leading to the activation of cytotoxic T lymphocytes and subsequent lysis of infected cells.