Fig. 9. Rho GTPases are involved in N. meningitidis internalization into endothelial host cells. HBMECs were either left untreated (control) or pretreated for 18 hours with 1 ng/ml of C. difficile toxin B (ToxB) or for 2 hours with 30 µM Y27632 (Y27632). Cells were infected with the ROU strain of N. meningitidis for 4 hours in the presence of the inhibitors, and the number of adherent bacteria (A) and internalized bacteria (B) were determined as in Fig. 3. These experiments, carried out in triplicates, were performed four times independently and results from one representative experiment are shown.