Figure 1
Characterization of novel HBV-replicating cell lines. (A) Extracellular HBs (a) as well as intracellular HBV DNA (b) and cccDNA (c) were quantified for each subclone (Hep38.2-Tet, Hep38.3-Tet, Hep38.7-Tet, and HepG2.2.15.7 cells) or the corresponding parental cells (HepAD38 and HepG2.2.15 cells) at 9 days post-seeding (the cells reached confluent at 3 days after seeding, when tetracycline was depleted from HepAD38, Hep38.2-Tet, Hep38.3-Tet, and Hep38.7-Tet cells, and continued for culturing for further 6 days). Hep38.7-Tet cells showed the highest HBV DNA and cccDNA level among the cell clones. (B) HBV in the culture supernatant of HepAD38, Hep38.7-Tet, HepG2.2.15 and HepG2.2.15.7 cells was inoculated to HepaRG cells with different amount of HBV inoculum (667, 2,000, 6,000, 18,000 GEq/cell) to examine the infectivity by monitoring HBs secreted from HepaRG cells at 12 days post-infection. (C) HepAD38 and Hep38.7-Tet cells were transfected with empty vector or an expression plasmid for HBV. After transfection, these cells were treated with or without 1 μM entecavir (ETV) for 72 h in the presence of tetracycline. Nucleocapsid-associated HBV DNA was quantified by real time PCR. Statistical significance was determined by using Student’s t test (*P < 0.05, **P < 0.01, N.S.; not significant).
