Helicobacter felis does not stimulate human neutrophil oxidative burst in contrast to ‘ Gastrospirillum hominis’ and Helicobacter pylori

Abstract

Helicobacte pylori is a human pathogen, whereas the natural hosts for ‘ Gastrospirillum hominis’ and Helicobacter felis are animals. ‘ G. hominis’ is occasionally found to cause infection in humans, whereas H. felis only rarely infects humans. The pathogenesis of H. pylori infection is not completely understood and in order to reveal differences in immune response to the three Helicobacter species, the upregulation of adherence molecule CD11b/CD18, chemotactic activity and oxidative burst response of neutrophils after stimulation with H. pylori, ‘ G. hominis’ and H. felis sonicates, were compared. Like H. pylori, ‘ G. hominis’ and H. felis induced upregulation of CD11b/CD18 and chemotaxis of neutrophils. ‘ G. hominis’ demonstrated a more pronounced upregulation of CD11b/CD18, whereas H. felis was the strongest stimulant of neutrophil chemotaxis. H. felis was unable to stimulate neutrophils to oxidative burst response, whereas ‘ G. hominis’ activated neutrophils in a dose-dependent way similar to H. pylori. ‘ G. hominis’ and H. felis were both able to prime neutrophils for oxidative burst response similar to H. pylori. In conclusion, we observed clear differences in neutrophil responses to different Helicobacter species, which indicates that bacterial virulence factors may be important for the diversity in the pathogenetic outcome of Helicobacter infections.