Figure 4

Knockdown of endogenous cortactin and N-WASP prevent C. jejuni -invasion of INT 407 cells. A. Internalization of C. jejuni in INT 407 cells transfected with siRNA to cortactin, siRNA to N-WASP or a scrambled (Scram) siRNA. Results are shown as the mean number of internalized bacteria ± SEM. B. Whole cell lysates of untreated, siRNA to cortactin, siRNA to N-WASP, and scramble siRNA-transfected cells were probed with α-cortactin and α-N-WASP antibodies. The blot was re-probed with an α-tubulin antibody to confirm equal loading. C. Internalization of C. jejuni in INT 407 cells transfected with phosphorylation null constructs of cortactin. Bacterial invasion was assessed using the gentamicin protection assay. Results are displayed as mean number of internalized bacteria ± SEM. D. Whole cell lysates of untreated and cortactin phosphorylation null transfected cells were collected and probed with an α-EGFP antibody. The blot was re-probed with an α-tubulin antibody to determine loading. The asterisks indicate a significant difference (P < 0.01) compared to the value obtained for the C. jejuni wild-type strain, as judged by one-way ANOVA followed by post-hoc Dunnett’s analysis. N.S. indicates no significant difference.