Hepatitis B virus peptide–Major Histocompatibility Complex class I (HBV pMHC-I)

Hepatitis B virus (HBV) peptide–Major Histocompatibility Complex (MHC) class I complexes are molecular assemblies found on the surface of HBV-infected hepatocytes or HBV-related hepatocellular carcinoma (HCC) cells. These complexes consist of short viral peptides, derived from proteins such as the HBV surface antigen (HBsAg) or core antigen (HBcAg), nested within the binding groove of MHC class I molecules, most commonly HLA-A*02:01 (Bertoletti & Ferrari, 2016, Nature Reviews Immunology). They serve as the primary target for CD8+ cytotoxic T lymphocytes (CTLs), which recognize the viral signature and initiate cell-mediated immunity. In chronic HBV infection, the endogenous T-cell response often becomes exhausted or deleted, allowing the virus to persist and potentially lead to oncogenesis (Qasim et al., 2015, Gastroenterology). Modern therapeutic strategies, including TCR-engineered T-cell therapies like SCG101 and LioCyx-M, specifically target these pMHC complexes to bypass natural immune tolerance and eliminate infected or malignant cells (SCG Cell Therapy, 2023; Lion TCR, 2022). This target is particularly valuable in HCC cases where HBV DNA integration into the host genome results in the continuous presentation of viral antigens even in the absence of active viral replication.

Other names

HBV peptide-HLA complexHBV pMHCHepatitis B virus antigen-MHC complexHBV-specific peptide-MHC class I complex

Redirection of T-cell cytotoxicity through specific binding of engineered T-cell receptors (TCRs) or TCR-like antibodies to viral peptide-MHC complexes, leading to the lysis of HBV-infected or HBV-integrated cells.