Fig. 1.

Diagram of viral entry of HBV/HDV. HBV (left) or HDV (right) travels with blood to liver, penetrates into the space of Disse and reaches the sinusoidal side of hepatocytes. The virus is enriched on the cell surface by interaction with HSPG. The viral envelope may undergo conformational changes upon binding to HSPG. Subsequently, the preS1 region of the envelope binds to the extracellular loop(s) of NTCP with high specificity. Binding of virions to NTCP may lead to endocytosis of the receptor, and ultimately the nucleocapsid (HBV) or the ribonucleoprotein complex (HDV) is realised to the nucleus and the infection is established. NTCP, sodium taurocholate cotransporting polypeptide; Myrcludex B, a lipopeptide derived from the 2–47 residues of preS1 region of HBV; HSPG, heparan sulfate proteoglycan.