Figure 4.

TJ disruption is tightly associated with lipid raft-mediated C. jejuni invasion in polarized epithelial cells. (A–F) Caco-2 cells cultured for 7 days on transwells and treated with 4 mM EGTA for 20 min. Following EGTA treatment, cells were incubated in normal culture medium. During the incubation, the TER value (A) and ZO-1 localization (B–F) were evaluated every hour for 3 h. TER values were calculated as the percentage of the TER value for untreated cells. Scale bar = 10 μm. (G) Caco-2 cells treated with 4 mM EGTA for 20 min were incubated in normal culture medium for the indicated time. After incubation, cells were pretreated with 10 mM MβCD for 1 h and infected with C. jejuni for 6 h. The number of intracellular bacteria was measured using a gentamycin protection assay. Results are shown as the mean ± SD; n = 4. Significant difference from the post Ca²⁺ reintroduction 0 h group are shown: N.S.; not significant; ^*P < 0.05; ^**P < 0.01.