Figure 4.

Bacterial AvrA protein activates STAT3 signaling. (A) AvrA activates STAT3 promoters in HCT116 cells. HCT116 cells were transiently co-transfected with a STAT3 reporter pGL3-STAT3 and a p-CMVAvrA, or pGL3-empty vector and p-CMVAvrA using a lipofectin reagent. Each experiment was assayed in triplicate. * P < .05. (B) AvrA protein increases STAT3 and p-STAT3 in the HCT116 cells. Cells were treated with purified AvrA protein for 30 minutes. Cell lysates were collected for the Western blots. (C) HCT116 cells were treated with purified AvrA protein (20 μg/ml) for 1 hour. Immunofluorescence was performed using an anti-Stat3 antibody.