Hepatitis B virus envelope peptide-HLA-A*02:01 complex (HBV env-HLA-A*02:01)

The Hepatitis B virus (HBV) envelope peptide-HLA-A*02:01 complex is a specific molecular assembly presented on the surface of hepatocytes that are either chronically infected with HBV or have undergone malignant transformation into hepatocellular carcinoma (HCC). This complex is formed when intracellularly processed fragments of the HBV surface antigen (HBsAg), such as the immunodominant Env183-191 or Env335-343 epitopes, are loaded onto the Human Leukocyte Antigen (HLA)-A*02:01 class I molecule and transported to the cell membrane (Geiger et al., 2016, Journal of Hepatology). In healthy individuals, this complex triggers a robust CD8+ T-cell response; however, in chronic hepatitis B patients, T-cell exhaustion leads to viral persistence. Modern immunotherapeutic strategies, including TCR-engineered T-cell (TCR-T) therapies like SCG101, specifically target this complex to redirect the immune system to eliminate infected cells and tumor cells (Zhang et al., 2022, Journal of Hepatology). Because the target is expressed on the surface of hepatocytes, therapeutic intervention carries a risk of liver inflammation and transient elevation of liver enzymes as infected cells are cleared (ClinicalTrials.gov, NCT05417932). This target represents a precision medicine approach, requiring patients to be both HLA-A*02:01 positive and have confirmed HBV antigen expression.

Other names

HBsAg peptide-HLA-A*02:01 complexHBV surface antigen peptide-HLA-A*02:01 complexHBV env183-191-HLA-A*02:01HBV env335-343-HLA-A*02:01

T-cell receptor (TCR) mediated recognition of the peptide-MHC complex leading to T-cell activation and cytotoxic destruction of the target cell.