FIG. 5.

H. pylori invasion of AGS cells inhibits lysosomal protease activity in a VacA-dependent manner. GFP-Rab7 (green)-expressing cells were infected with vacA mutant bacteria (A and B) or wild-type (C and D) H. pylori. Following 24 h of infection, the cells were incubated with the chromogenic protease substrate DQ red-BSA (red) for a 3- to 4-h period. After this time, the cells were fixed and the bacteria were labeled with DAPI (4′,6′-diamidino-2-phenylindole). Panel E shows GFP-Rab7 (green)-expressing cells infected with wild-type H. pylori. Twenty-four hours later, the cells were incubated with a fluid-phase fluorescence marker, rhodamine dextran (0.5 mg/ml) (red), for a 3- to 4-h period, extensively washed, and then examined by confocal microscopy.