Adenoviral peptide–Major Histocompatibility Complex (Adenoviral pMHC)

Adenoviral peptide–Major Histocompatibility Complex (pMHC) complexes are cell-surface assemblies consisting of adenovirus-derived peptides bound to host MHC molecules. These complexes are essential for the immune system to identify and eliminate cells harboring adenoviral infections (Feuchtinger et al., 2004, British Journal of Haematology). During the viral life cycle, intracellular adenoviral proteins such as the hexon or penton base are processed by the proteasome into short peptides, which are then transported into the endoplasmic reticulum and loaded onto MHC Class I molecules for presentation on the cell surface. These pMHC complexes are the primary targets for CD8+ cytotoxic T lymphocytes (CTLs), which recognize them via specific T-cell receptors (TCRs). In therapeutic applications, particularly for immunocompromised patients like those undergoing hematopoietic stem cell transplantation, these complexes are targeted by adoptive cell therapies using virus-specific T cells (VSTs) to restore antiviral immunity (Leen et al., 2009, Biology of Blood and Marrow Transplantation). However, adenoviruses have evolved mechanisms, such as the E3-19K protein, to downregulate MHC expression and evade this recognition, making the density of these complexes a critical factor in therapeutic efficacy (UniProt P03247).

Other names

Adenovirus peptide-HLA complexAdenoviral antigen-MHC complexAdenoviral pMHC complex

Recognition of the viral peptide-MHC complex by the T-cell receptor (TCR) of a cytotoxic T lymphocyte, leading to the formation of an immunological synapse and subsequent release of cytotoxic granules (perforin/granzyme) to induce target cell apoptosis (Leen et al., 2006, Blood).