Figure 1.

Concomitant Size Regulation of the Salmonella-Containing Vacuole (SCV)

(A) Time-lapse microscopy of HeLa cells transfected with GFP-2xFYVE (in green) and infected with fluorescent Salmonella (in red). Scale bars: 10 μm. Blue arrowheads designate fusion events; yellow arrowheads designate tubular structures. See also Video S1A.

(B) Time-lapse microscopy of HeLa cells transfected with GFP-SNX1 (in green) and infected with fluorescent Salmonella (in red). Scale bars: 10 μm. Yellow arrowheads designate tubular structures. See also Video S1B and Figure S1A.

(C) Characterization of SopB intracellular localization by super-resolution SIM microscopy. Scale bars: 10 μm. Yellow arrowheads designate tubular structures.

(D) Quantification of the percentage of SopB-positive SCVs, IAMs, and SVATs over more than 150 intracellular salmonellae (3 independent experiments—manual counting based on confocal images). Error bars: ±SEM. Above-bar annotations: mean values.

(E) Time-lapse microscopy of HeLa cells transfected with GFP-2xFYVE (in green) and infected with fluorescent ΔsopB Salmonella (in red). Scale bars: 10 μm. Blue arrowheads designate fusion events. See also Video S1C.

(F) Quantification of dextran uptake over 30 min of incubation with WT or ΔsopB Salmonella.

(G) Fixed microscopy of HeLa cells infected with fluorescent Salmonella (in red) in the presence of fluorescent Dextran (in white) for 30 min. Extracellular bacteria (in green) are labeled by staining the samples without permeabilization. Left panel: untreated cells (Ctrl). Right panel: cells incubated with the allosteric pan-Akt inhibitor MK-2206 for 3 h before infection and during bacterial infection. Dashed circle: infection sites defined as circles with a diameter of 18 μm used for quantification in (F) and (H). Scale bars: 10 μm.

(H) Quantification of dextran uptake over 30 min of incubation with WT Salmonella in untreated cells (Ctrl) or cells treated with MK-2206.

(F and H) Each dot represent the mean fluorescence intensity of the dextran channel normalized by the mean fluorescence intensity of the bacteria channel over an infection site. A total of 100 infection sites were measured per experiment (n = 3 independent experiments). Graphs display all measured infection sites. Error-bars: ±SD. p values were obtained after t test.