Fig 7.

Effect of LHBsAg on internalization of transferrin. (A) Uptake of Alexa 594-conjugated transferrin in the presence of HBsAgs. Two days after transfection with plasmids encoding LHBsAg and MHBsAg, untreated HuS-E/2 cells were incubated with Alexa 594-conjugated transferrin (red) for 20 min and were then fixed, immunostained with mouse monoclonal anti-HBsAg antibodies and Alexa 488-conjugated goat anti-mouse IgG antibodies (green), and visualized by fluorescence microscopy. Hoechst 33258 (right) was applied at the same time as the secondary antibody to stain nuclei. Arrows, transfected cells. (B) Quantification of transferrin uptake. The intensity of the Alexa 594-conjugated transferrin signal was quantified for 10 transfected cells in each set, and the mean intensity was calculated and normalized against that of the nontransfected cells (NT). The graph shows the means and standard deviations for three independent experiments.