Fig. 4.

Cell lines persistently infected with DHBV. (A) (i) DVP and DVNP cells express DHBV surface antigen (red), but the ZO-1 (green) distribution indicates that only DVP cells are polarized. Bar, 5 μm. (ii) When grown on membranes, DVP cells export a much greater percentage (almost 100%) of the total virus (black bars) produced basolaterally than the nonpolarized DVNP cells, which parallels polarized albumin secretion (gray bars). (B) These cell lines export virus efficiently (ii) with low intracellular levels (i) until 24 days of culture. (C) (i) Southern blotting of lysates shows that the cell lines produce all intracellular DHBV viral replicative DNA intermediates: relaxed circular (RC), double-stranded (DS), and single-stranded (SS) DNA. (ii) Western blotting shows both L and S antigens in lysates.