title: Hepatitis B Virus and Hepatitis D Virus Entry, Species Specificity, and Tissue Tropism.
abstract: Entry of hepatitis B (HBV) and hepatitis D viruses (HDV) into a host cell represents the initial step of infection. This process requires multiple steps, including the low-affinity attachment of the virus to the cell surface, followed by high-affinity attachment to specific receptor(s), and subsequent endocytosis-mediated internalization. Within the viral envelope, the preS1 region is involved in receptor binding. Recently, sodium taurocholate cotransporting polypeptide (NTCP) has been identified as an entry receptor of HBV and HDV by affinity purification using a preS1 peptide. NTCP is mainly or exclusively expressed in the liver, and this membrane protein is at least one of the factors determining the narrow species specificity and hepatotropism of HBV and HDV. However, there are likely other factors that mediate the species and tissue tropism of HBV. This review summarizes the current understanding of the mechanisms of HBV/HDV entry.
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Tokyo 162-8640, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Watashi
authors.affiliation: Department of Virology II, National Institute of Infectious Diseases, Tokyo 162-8640, Japan.
authors.forename: Takaji
authors.initials: T
authors.lastname: Wakita
mesh_terms: D005260:Female; D006509:Hepatitis B / Q000503:physiopathology / Q000821:virology; D006515:Hepatitis B virus / Q000472:pathogenicity* / Q000502:physiology; D003699:Hepatitis D / Q000503:physiopathology / Q000821:virology; D003698:Hepatitis Delta Virus / Q000472:pathogenicity* / Q000502:physiology; D006801:Humans; D008297:Male; D011991:Receptors, Virus / Q000378:metabolism; D013045:Species Specificity; D013656:Taurocholic Acid / Q000378:metabolism; D018523:Tropism; D014759:Viral Envelope Proteins / Q000378:metabolism; D014771:Virion / Q000378:metabolism; D053586:Virus Internalization
chemical_list: D011991:Receptors, Virus; D014759:Viral Envelope Proteins; D013656:Taurocholic Acid