Cytomegalovirus phosphoprotein 65 (pp65) (CMV pp65)

Cytomegalovirus phosphoprotein 65 (pp65), encoded by the UL83 gene, is the most abundant tegument protein of Human Cytomegalovirus (HCMV) and a primary target for cell-mediated immunity (UniProt P06725). In clinical immunotherapy, particularly for glioblastoma multiforme (GBM), pp65 is utilized as an antigen presented by autologous dendritic cells to stimulate a patient's immune system (PubMed: 25705881). These dendritic cells process the pp65 protein into peptides and present them via Major Histocompatibility Complex (MHC) molecules to T cells, effectively priming a specific cytotoxic T lymphocyte (CTL) response against cells expressing CMV antigens (PubMed: 24743953). This strategy exploits the observation that CMV proteins are frequently expressed in GBM tumor cells but not in surrounding healthy brain tissue, providing a specific therapeutic window (PubMed: 25705881). Beyond oncology, pp65-targeted therapies are investigated to restore CMV-specific immunity in hematopoietic stem cell transplant recipients to prevent viral reactivation (PubMed: 11238592). The therapeutic efficacy is typically monitored by measuring the frequency of pp65-specific T cells using assays like ELISPOT or MHC tetramer staining. Safety profiles for these autologous cell therapies are generally favorable, with most adverse events being limited to injection site reactions or mild constitutional symptoms. This approach represents a convergence of virology and oncology, turning a common latent virus into a target for precision cancer immunotherapy.

Other names

UL8365 kDa tegument phosphoproteinHuman herpesvirus 5 pp65CMV matrix protein pp65ppUL83

Induction of antigen-specific T-cell mediated immunity through the presentation of viral epitopes on MHC class I and II molecules, leading to the activation and expansion of CD8+ and CD4+ T cells.