Figure 7.

FlpA and β₁-integrin are required for phosphorylation of Erk1/2 during C. jejuni infection. (A) Levels of Erk1/2 phosphorylation in INT 407 epithelial cells infected with C. jejuni treated with chloramphenicol. Cell lysates were immunoblotted with antibodies against pErk and actin (loading control). Uninfected cells treated with chloramphenicol served as a negative control. Band intensities were quantitated by densitometry (n=4, error bars indicate standard error of the mean). (B) Erk1/2 phosphorylation in epithelial cells depleted of β₁ integrin in response to C. jejuni infection. Uninfected cells treated with NT show basal levels of Erk1/2 phosphorylation, and C. jejuni-infected cells treated with NT were used as a positive control. Erk1/2 phosphorylation was measured by densitometric analysis (n=4, error bars indicate standard error of the mean) and statistical significance was determined by ANOVA using Tukey's post-test (*P<0.05). NT, non-targeting siRNA; pErk, phosphorylated Erk1/2.