Cytomegalovirus phosphoprotein 65 peptide–MHC complex (pp65-MHC complex)

The Cytomegalovirus phosphoprotein 65 (pp65) peptide–MHC complex is a primary immunological target formed when the human cytomegalovirus (HCMV) tegument protein pp65 (encoded by the UL83 gene) is processed and presented on the surface of infected cells by Major Histocompatibility Complex (MHC) class I molecules (UniProt P06725). This complex is highly immunodominant, serving as the principal signal for the activation and expansion of CD8+ cytotoxic T-lymphocytes (CTLs) during the host immune response to HCMV (PubMed PMID: 15507525). In immunocompromised individuals, such as hematopoietic stem cell or solid organ transplant recipients, the failure of the immune system to recognize these complexes leads to viral reactivation and severe systemic disease. Therapeutic strategies targeting this complex include the adoptive transfer of donor-derived pp65-specific T-cells and the development of TCR-like antibodies that mimic T-cell recognition to eliminate infected cells (PubMed PMID: 28438887). Additionally, pp65-based vaccines are utilized to prime the immune system to recognize these complexes, thereby preventing CMV-related complications in high-risk patient populations.

Other names

CMV pp65-HLA complexUL83 peptide-MHC complexpp65-MHC class I complexHLA-A*02:01/NLVPMVATV complexHuman cytomegalovirus phosphoprotein 65-MHC complex

Recognition by T-cell receptors (TCRs) on CD8+ T-cells leading to cytotoxic lysis of infected cells; induction of humoral and cellular immunity via vaccination; direct neutralization by TCR-like antibodies.