Figure 7. Partial association of endogenous and overexpressed DDX3 with HCV core protein in hepatocyte lines.

(A) O cells with the HCV replicon form DDX3-containing speckles in the cytoplasm. O cells contain full-length HCV replicon, and Oc cells do not [16]. O cells were transfected with a plasmid expressing HA-tagged DDX3 (top panel). In other experiments, O cells were transfected with plasmids expressing HA-tagged DDX3 and FLAG-tagged HCV core protein (center panel). After 24 hrs, cells were stained with anti-HA or FLAG antibodies. Proteins were visualized with Alexa488 or 564 second antibodies and the LD was stained with BODIPY493/503. In the bottom panel, Oc cells (no replicon) and sO cells with the core-less subgenomic replicon [16] were transfected with a plasmid expressing HA-tagged DDX3. After 24 hrs, cells were stained with anti-HA antibodies. LD was stained with BODIPY493/503. (B) Endogenous DDX3-HCV core association in O cells. O or Oc cells were cultured to amplify the HCV replicon. Cells were stained with anti-core mAb and anti-DDX3pAb and secondary antibodies. Similar sets of experiments were performed three times to confirm the results.