Cytomegalovirus 65 kDa phosphoprotein (pp65) (pp65)

The Cytomegalovirus 65 kDa phosphoprotein (pp65), encoded by the UL83 gene, is the most abundant tegument protein of the Human Cytomegalovirus (HCMV) (UniProt P06725). It plays a critical role in viral pathogenesis by modulating the host's innate immune response, specifically by inhibiting the induction of interferon-stimulated genes through interaction with the DNA sensor IFI16 (PubMed: 25132684). While not a traditional enzyme or receptor target for small molecule inhibition, pp65 is a highly significant target in the field of vaccinology and adoptive immunotherapy because it is the dominant protein recognized by the host's cytotoxic T-lymphocytes (CTLs) during natural infection (PubMed: 11506829). \n\nClinically, pp65 is used both as a diagnostic biomarker through the 'pp65 antigenemia assay' to monitor CMV load in immunocompromised patients and as a therapeutic target in the development of CMV vaccines and T-cell therapies (PubMed: 30206138). Research also suggests a potential association between pp65 expression and certain malignancies, such as glioblastoma, making it a target for experimental cancer immunotherapies. Its role in immune evasion and its high immunogenicity make it a cornerstone for strategies aiming to prevent or treat CMV-associated diseases in transplant recipients and neonates.

Other names

65 kDa tegument phosphoproteinUL83Tegument protein UL83HCMV pp65Human herpesvirus 5 UL83

pp65 serves as a primary antigenic target for the induction of CD8+ and CD4+ T-cell mediated immunity. Vaccines and immunotherapies utilizing pp65 aim to stimulate the host immune system to recognize and eliminate CMV-infected cells or cells expressing viral antigens.