Hepatitis B Virus Surface Antigen-Presenting Hepatocyte or HCC Cell (HBsAg-Presenting Hepatocyte/HCC Cell)

Hepatitis B virus (HBV) surface antigen-presenting hepatocytes or hepatocellular carcinoma (HCC) cells are liver cells that display the hepatitis B surface antigen (HBsAg) on their plasma membrane. This presentation is a hallmark of HBV infection and is closely associated with both acute and chronic hepatitis B, as well as the development of HCC in chronically infected individuals. HBsAg is a multifunctional glycoprotein composed of three isoforms: large (LHB), middle (MHB), and small (SHB) subunits. The large HBV surface protein mediates viral attachment to hepatocytes, primarily through interaction with the sodium-taurocholate cotransporting polypeptide (NTCP), which acts as a high-affinity receptor for viral entry. After binding to NTCP via its PreS1 domain, HBV enters hepatocytes. Once inside, it releases its DNA-containing nucleocapsid into the cytoplasm. Infected hepatocytes process and present fragments of HBV proteins—including those from HBsAg—on their surface via major histocompatibility complex class I molecules. This allows recognition by CD8+ T cells. Detection of HBsAg in blood is an early indicator of acute infection and persists during chronic infection. Its presence signals active replication or carrier status. Chronic expression of HBsAg on hepatocytes correlates strongly with increased risk for cirrhosis and progression to HCC. Persistent expression helps HBV evade host immunity. The unique presence and persistence of surface antigen on infected or transformed liver cells make them attractive targets for immunotherapeutic strategies.

Other names

HBV-infected HepatocyteHepatitis B Surface Antigen expressing liver cellHBsAg-positive HepatocyteHBsAg+ HepatocyteHBV Surface Antigen on Hepatocellular Carcinoma

T-cell receptor-like antibodies recognize peptide-MHC complexes derived from HBV envelope proteins; NTCP inhibitors block viral entry.