Cellular DNA repair cofactors affecting hepatitis B virus infection and replication

Figure 1 An ATR-dependent cellular checkpoint response activated by HBV infection. A: 10⁵ human HL7702 monolayer liver cells in a 6 cm plate were infected with 10⁶ virus particles from HBV-positive patients at 37°C in an atmosphere containing 50 mL/L CO₂. Normal serum from healthy individuals was used as non-infected control. Prior to cell harvesting, the cells were washed 8 times thoroughly to remove the excessive viral input. Whole cell lysates were prepared at various time points of infection (hours of infection, hoi) and subjected to immunoblotting assay using antibodies to the indicated proteins. Alpha-tubulin was used as the equal loading control; B: Specialized siRNA for ATR was transfected in HL7702 cells using lipofectamine 2000. At the indicated time points, cells were collected for Western blotting testing the ATR level; C: HBV-positive serum was added to ATR knockdown cells 24 h after transfection, cells were then harvested for FQ-PCR to test HBV DNA titers at the indicated time points post-infection.