Adenoviral peptide-Human Leukocyte Antigen (HLA) complex (Adv-pHLA)

The Adenoviral peptide-Human Leukocyte Antigen (HLA) complex is the primary immunological target found on the surface of host cells infected with adenovirus (Leen et al., 2006, Nature Medicine). This complex consists of a short viral peptide, often derived from the highly conserved hexon or penton proteins, non-covalently bound to the groove of an MHC Class I molecule (Feuchtinger et al., 2008, Blood). Its biological function is to signal the presence of intracellular viral infection to the adaptive immune system, specifically to CD8+ cytotoxic T lymphocytes (UniProt, 2024). In patients with weakened immune systems, such as those post-hematopoietic stem cell transplant, the failure to recognize these complexes leads to disseminated and often fatal infection (AlloVir, 2023). Therapeutic interventions like posoleucel utilize virus-specific T cells (VSTs) that are engineered or selected to bind these specific pHLA complexes with high affinity. Upon binding, the T cells release cytotoxic granules containing perforin and granzymes, which trigger apoptosis in the infected host cell (PubMed, 2022). This target is highly specific to infected cells, which helps in reducing the risk of systemic toxicity compared to broad-spectrum antivirals. Monitoring the clearance of cells presenting these complexes is typically done by measuring viral DNA levels in the blood.

Other names

Adenovirus-specific peptide-MHC complexAdv-pMHCAdenoviral antigen-HLA complexAdenovirus-infected cell surface antigensAdenovirus-infected host cells

Recognition of the viral peptide-HLA complex by the T-cell receptor (TCR) of cytotoxic T lymphocytes, leading to targeted cell lysis via the perforin/granzyme pathway (Leen et al., 2006, Nature Medicine).