Uptake of hepatitis B virus into choriocarcinoma cells in the presence of proinflammatory cytokine tumor necrosis factor-α

Objective The aim of this study was to establish an in vitro experimental model that mimics the interaction of hepatitis B virus (HBV) and the trophoblastic barrier. Study design The barrier was represented by choriocarcinoma cell line, JAR cells, which were incubated with HBV in the presence or absence of tumor necrosis factor-α (TNF-α). At 12-hour intervals after a 24-hour incubation, the infection efficiency was examined by enzyme-linked immunosorbent assay of culture supernatants, immunohistochemistry of cell slides, Western blotting of cell lysates, polymerase chain reaction amplification for viral DNA of infected cells, and transmission electron microscopy for HBsAg particles in infected cells. Results In the absence of TNF-α, many JAR cell colonies showed a negative or punctate positive pattern after incubation with HBV. But when JAR cells were pretreated with TNF-α before cocultured with HBV, the infection was greatly enhanced, whereas the differences observed between the various time points in the second series of experiments did not reach a statistically significant level. Conclusion JAR cells can support HBV infection in the presence of TNF-α. Our in vitro system provides key basis on further study reflecting mechanism of in vivo HBV intrauterine infection and transfer.