Figure 6.

Fluorescence microscopy of Caco2 monolayers labeled with ZO-1 or fluorescein-phalloidin (actin) show disruption of the tight-junction complex and the cytoskeleton at 4 h post-infection. Caco2 polarized monolayers were infected with wild-type S. Typhi (MOI 400:1) for 4 h, washed with PBS, fixed and stained along with uninfected controls. (A) ZO-1 staining in uninfected monolayers. Note the characteristic chicken wire patterning. (B) Disrupted ZO-1organization in wild-type S. Typhi -infected monolayers. Areas of cell-cell detachment are marked by arrows. (C) Actin staining of the cytoskeleton in uninfected controls. (D) Actin fibers stained in the S. Typhi -infected cells. (E) Merge of (A,C). (F) Merge of (B,D). (G) ZO-1 distribution in CVD 909 infected monolayers. (H) ZO-1 (red), actin (green) and DAPI for the nuclei (blu) merged staining of CVD 909 infected cells. Bar, 25 μm.