Figure 3.

EspG reduces the amount of surface-localized TfR.

A. Surface-localized TfR on HeLa cells infected with the indicated EHEC strains was assessed by addition of Tf-647 at the indicated time-points post infection. The median fluorescence intensity (MFI) of surface-bound Tf-647 is expressed as a percentage of the MFI of uninfected cells. Results are expressed as the mean ± SEM of two independent experiments. *P < 0.05; **P < 0.01.

B. Localization of the TfR was determined by immunofluorescence of infected HeLa cells before (TfR surface) and after (TfR total) permeabilization.C. Total TfR levels in all infected cell lysates was detected by immunoblot (actin serves as a loading control).

D and E. (D) Surface-localized TfR was assessed on HeLa cells infected for 5 h with and without cycloheximide (20 μg ml⁻¹) treatment throughout the infection to inhibit new TfR synthesis. The MFI of surface-bound Tf-647 is expressed as a percentage of the MFI of uninfected cells and the mean ± SEM of three independent experiments plotted and representative histograms of fluorescence intensity shown in (E).

*P < 0.05; **P < 0.01; ****P < 0.0001.