Fig. 4

Immunofluorescence staining of ZO-1 and occludin in Caco-2 cell monolayers incubated for 3 h with EPEC in the absence or presence of COF-SN or OMVs from the indicated bacterial strains. Analysis was performed by laser scanning confocal spectral microscope with 63x oil immersion objective lens, and images were captured with a Nikon color camera (8 bit). Images shown are representative from three independent biological experiments and are coded with Fire look-up table. Calibration bar is shown on the left. Scale bar, 20 μm