Ataxia telangiectasia-mutated-Rad3-related DNA damage checkpoint signaling pathway triggered by hepatitis B virus infection

Figure 1 HBV infection activates a cellular checkpoint response dependent on ATR. A: 105 human hepatocyte HL7702 monolayer cells in a 6-cm plate were infected with 106 virus particles from HBV-positive patients at 37°C under 50 mL/L CO₂; normal serum from healthy individuals was used as a non-infected control. Prior to cell harvesting, the cells were washed eight times thoroughly to remove excess viral input. Whole-cell lysates were prepared at various times of infection (hoi) and subjected to an immunoblotting assay by using antibodies against the indicated proteins. Tubulin was used as the equal loading control; B: Primarily cultured hepatocyte cells were prepared and were harvested 3 h after HBV-positive serum addition. Whole cell lysates were prepared and subjected to immunoblotting assay by using Chk1 phosphorylation antibody; tubulin was used as the equal loading control; C: HL7702 cells were infected with HBV-positive serum for 0.5 h. Normal serum from healthy individuals was used as a non-infected control. Immunofluorescence with antibodies to Chk1 Ser-345 and ATR (green) were monitored. DNA was stained with DAPI (blue).