Figure 1  .

Transactivation of SRE by Helicobacter pylori. Transactivation of SRE in TMK1 (A) and MKN45 (B) cells induced by H pylori was measured by luciferase assay using pSRE-Luc. The TN2 strain was positive for two known virulence factors, CagA and VacA, and had intact cag pathogenicity island (PAI). The T68 strain, isolated from a Japanese patient at our institution, was negative for the above two virulence factors and lacked cag PAI. An isogenic cagE negative mutant (TN2-ΔcagE) was constructed by inserting a kanamycin resistant gene cassette into the cagE locus of cag PAI of TN2. The isogenic vacA negative mutant (TN2-ΔvacA) was constructed by disrupting the vacA gene of TN2. Luciferase activity is presented as a fold induction relative to basal levels measured in untreated cells. Mean (SD) values of four independent experiments are shown. *p<0.05 compared with TN2 by Dunnett's multiple comparison.