HBV infection of cell culture: evidence for multivalent and cooperative attachment.
Hepadnaviruses do not infect cultured cells, therefore our knowledge of the mechanism of the early stages of virus-cell interaction is rather poor. In this study, we show that dimethylsulfoxide (DMSO)-treated HepG2 hepatoblastoma cells are infected efficiently by serum-derived hepatitis B virus (HBV) as monitored by viral gene expression and replication markers. To measure virus attachment, a variety of HBV surface proteins (HBsAgs) were conjugated to polystyrene beads and their capacity to attach cells was visualized and quantified by light microscopy at a single-cell resolution. Remarkably, DMSO increases the attachment efficiency by >200-fold. We further identify the QLDPAF sequence within preS1 as the receptor-binding viral domain epitope. Interestingly, a similar sequence is shared by several cellular, bacterial and viral proteins involved in cell adhesion, attachment and fusion. We also found that the small HBsAg contains a secondary attachment site that recognizes a distinct receptor on the cell membrane. Furthermore, we provide evidence in support of multivalent HBV attachment with synergistic interplay. Our data depict a mechanistic view of virus attachment and ingestion.
Paran
N
N
Departments of Molecular Genetics and Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel.
Geiger
B
B
Shaul
Y
Y
D000595:Amino Acid Sequence; D001665:Binding Sites; D018929:Cell Culture Techniques; D003902:Detergents / Q000494:pharmacology; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004705:Endocytosis; D006514:Hepatitis B Surface Antigens / Q000235:genetics / Q000378:metabolism*; D006515:Hepatitis B virus / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008561:Membrane Fusion / Q000502:physiology; D008969:Molecular Sequence Data; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014771:Virion
D003902:Detergents; D006514:Hepatitis B Surface Antigens; D011498:Protein Precursors; D011993:Recombinant Fusion Proteins; C050806:presurface protein 1, hepatitis B surface antigen; D004121:Dimethyl Sulfoxide