Figure 6

Knockdown of endogenous cortactin and N-WASP prevent C. jejuni induced membrane ruffling. A-P. C. jejuni induced membrane ruffling in INT 407 cells transfected with scrambled (Scram) siRNA, siRNA to N-WASP, siRNA to cortactin, and cortactin S405A, S418A and S405/418A phosphorylation null constructs. Representative scanning electron microscopy images of INT 407 cells uninfected (Panel A) and cells infected with C. jejuni wild-type strain with various treatment conditions; No treatment (Panel B), Scrambled siRNA control (Panel C), siRNA to N-WASP (Panel D), siRNA to cortactin (Panel E), cortactin S405A (Panel F), cortactin S418A (Panel G), and cortactin S405/4118A (Panel H). Arrows in the higher magnification images show C. jejuni in contact with host cells (Panels I-P). Boxes indicate the area of the INT 407 cell that is shown in the 50,000× panel. INT 407 cells that display extensive membrane ruffling (Panel J and K), and INT 407 cells that display no host cell membrane ruffling (Panels L-P). Images are shown at a magnification of 7,000× with a 10 μM scale bar (Panels A-H), and 50,000× with a 2 μM scale bar (Panels I-P). Also indicated within each panel is the percent of host cell that display membrane ruffling.