Figure 10.
Endosomal membranes cofractionate with mitochondria in cells intoxicated with VacA. Wt MEF cells were incubated for 2 h and 30 min with H. pylori CS, either wt or P9A mutant, before being processed for immunoelectron microscopy. (a) anti-LBPA antibody was used to label late endosomal membranes in cells exposed to P9A mutant (left panel) or to wt CS (right panel) respectively. N, nucleus; arrowheads point to mitochondria; gold particles identify late endosomes. Scale bar corresponds to 0.84 μm for the left panel and to 0.47 μm for the right panel. (b) Morphometry analysis of MEF treated and processed as in a. The number of mitochondria located within 5.25 μm from the endosomal surface was counted (22.37±1.1 in untreated cells, 46.74±2.33 in 326 P9A-treated cells and 90.63±4.53 in 326 wt treated cells). Numbers refer to mitochondria identified in a total area of 65 μm2 around endosomes. (c) Morphometry analysis of MEF cells treated and processed as in a. The total cell area occupied by late endosomes was measured (an average of 12 endosomes were considered for each condition)