FIG. 3.

Localization of IpaB in S. flexneri-infected HeLa cells by double fluorescence labeling and confocal microscopy. (A to D) HeLa cells infected with M90TS. Arrows indicate protrusions containing a dividing bacterium; arrowheads indicate nondividing bacteria in protrusions. (E to H) HeLa cells infected with Sh42. Arrows indicate protrusions containing Sh42. Other bacteria lie within the cell or on the surface. (A and E) Bacteria binding rabbit anti-Shigella LPS antiserum or goat anti-rabbit IgG conjugated with Texas red. (B and F) Localization of IpaB with mouse monoclonal antibody H16 or FITC-conjugated goat anti-mouse IgG. Panels C and G are phase-contrast images of the fields shown in panels A and B and E and F, respectively. (D and F) Overlays of A, B, and C and E, F, and G, respectively.