Hepatitis B virus peptide–Human leukocyte antigen class I complex (HBV-HLA-I complex)

The Hepatitis B virus (HBV) peptide–Human leukocyte antigen (HLA) class I complex is a molecular assembly presented on the surface of HBV-infected hepatocytes and HBV-related hepatocellular carcinoma (HCC) cells (Boni et al., 2007). It consists of short viral peptide fragments, typically 8–11 amino acids in length, derived from HBV proteins such as the surface antigen (HBsAg), core antigen (HBcAg), or polymerase, which are bound within the peptide-binding groove of HLA class I molecules (Tan et al., 2015). This complex is the fundamental unit recognized by the T-cell receptor (TCR) of CD8+ cytotoxic T lymphocytes, triggering the destruction of the infected cell (Maini & Gehring, 2016). In chronic HBV infection, the host's T-cell response is often characterized by exhaustion or deletion, leading to viral persistence and an increased risk of HCC (Ye et al., 2015). Modern therapeutic approaches, such as TCR-engineered T-cell (TCR-T) therapy and bispecific T-cell engagers, are designed to specifically target these HBV-HLA complexes to restore or bypass the defective immune response (Meng et al., 2021). These therapies, including candidates like SCG101 and LioCyx-M01, aim to achieve a functional cure for HBV or treat HBV-associated malignancies by precisely eliminating cells expressing these viral antigens (SCG Cell Therapy, 2023; Lion TCR, 2022).

Other names

HBV-pMHCHBV peptide-MHC class I complexHepatitis B virus antigen-HLA complexHBV peptide–HLA class I complexes on infected hepatocytesHBV-specific pMHC

Recognition of specific viral epitopes presented by HLA molecules to trigger T-cell receptor (TCR) mediated cytotoxicity against infected or malignant hepatocytes.