Fig. 7. Activation of PI3K is required for the recruitment and phosphorylation of cortactin and bacterial internalisation. (A,B) HBMECs were pretreated or not for 2 hours with 100 ng ml^–1 wortmannin and then infected for 3 hours with the 2C43 wild-type strain of N. meningitidis. (A) Cells were triple stained for ezrin (green), cortactin (blue) and actin (red), and were analysed by confocal microscopy. (right) Merged images (overlay) of the same fields. (B) Cortactin was immunoprecipitated and immunoblotted with an anti-phosphotyrosine antibody (PY). (C) HBMECs were either left untreated (–) or pretreated for 2 hours with 100 ng ml^–1 wortmannin (+) before infection with the 2C43 wild-type strain of N. meningitidis (WT) or with the isogenic rfaC-defective mutant strain (rfaC) in the presence or absence of the inhibitor. After 3 hours, the number of internalized bacteria in relation to the number of adherent bacteria was determined. Average values (± s.e.m.) are presented from one representative experiment out of four independent experiments performed in triplicate.