Table 1

Effect of different preparations of H. pylori SS1 and SS1 rocFaphA3 on NO2 generation by RAW 264.7 macrophages

Preparation[NO2], μM Fold increaseP
SS1SS1 rocFaphA3
Bacteria, untreated2.5  ± 1.117.3  ± 1.86.8<0.0001
Bacteria in Transwell5.9  ± 1.9*19.1  ± 1.53.20.0002
Boiled bacteria26.3  ± 4.630  ± 4.81.1NS
Water extract19.6  ± 1.217  ± 2.11.1NS
French press lysate22.3  ± 3.321.3  ± 3.80.9NS
  • RAW 264.7 macrophages were cocultured with intact H. pylori SS1 WT or rocFaphA3 or with the preparations of bacteria listed. H. pylori were also separated from macrophages by a filter support. Experiments were performed with an moi of 100, at 0.4 mM l-arginine in the medium. [NO2] in culture supernatants was measured after 24 h. Results are the mean ± SEM of three separate experiments performed in duplicate. Statistical comparison of values for SS1 WT vs. SS1 rocFaphA3 were performed by the unpaired t test. 

  • * No significant difference vs. untreated bacteria by unpaired t test. NS, not significant.