Figure 4.

ER stress results in the phosphorylation and nuclear translocation of IRF3. (A–D) BX-795 and 4-PBA were respectively treated before M. bovis infection in Raw 264.7 cells and total cell lysates were subjected to Western blot for phosphorylation of IRF3. Bands corresponding to each protein were quantified, and the intensities of each protein were normalized to the intensity of tubulin. The asterisks indicate significant differences compared with untreated cells (^*P < 0.05, ^**P < 0.01). (E) 4-PBA was treated before M. bovis infection in Raw 264.7 cells. Fixed cells were incubated with anti-IRF3 monoclonal antibody followed by FITC-conjugated goat anti-rabbit antibody as the secondary antibody and visualized by immunofluorescence microscopy. Results are representative of three independent experiments, each performed in triplicate with similar results.