Figure 6. FAK and Rac 1 are involved in the secretion of IL-18.
Caco-2 cells were pretreated for 1hr with increasing concentrations of: (A) the FAK inhibitor PF-431396 or C) the Rac 1 inhibitor NSC23766 or (E) with 5μM of PF-431396, 100μM of NSC23766, a combination of either inhibitors or the vehicle (DMSO). (A, C, E) Cells were then infected with indicated bacterial strains at an MOI of 10. ELISA determined the concentration of IL-18 in the culture media. (B) Caco-2 cells were transfected with 100nM of FAK siRNA or control siRNA for 72 hours prior to infection. Cell supernatants were analyzed for IL-18 and lysates subjected to immunoblot analysis of phospho-FAK, total-FAK and the loading control Hsp70. (D) Caco-2 cells were transfected with 0.5ug of Rac1 shRNA vector or a control vector expressing scrambled shRNA for 48 hours. Cells were infected and processed as in (B) and Rac 1 was assessed by immunoblotting. Data represents mean ± SD of three independent experiments. *p < 0.01; ***p<0.0001. See also Fig. S2.