The Type III Effectors NleE and NleB from Enteropathogenic E. coli and OspZ from Shigella Block Nuclear Translocation of NF-κB p65
Figure 4
Effect of NleE on nuclear translocation of STAT1 and STAT2.
A. Representative immunofluorescence fields and quantification of nuclear exclusion using antibodies to STAT1 (A) or STAT2 (B) (red) of HeLa cells transfected with pEGFP-C2 (GFP only) or pGFP-NleE (green), stimulated with IFNα for 30 min and stained for nucleic acid with DAPI (blue). Results are expressed as the percentage of GFP-positive cells that exclude STAT1 or STAT2 and are the mean ± SEM of three independent experiments performed in duplicate. At least 100 GFP-positive cells were counted per test. C. Fold increase in STAT1/2 dependent luciferase activity in HeLa cells transfected with pEGFP-C2 (GFP), pGFP-NleE or pGFP-OspZ. Results are the mean ± SEM of 3 independent experiments performed in triplicate. Differences between GFP and GFP-NleE or GFP-OspZ were not significant (P>0.05, one way ANOVA).