Activation of human neutrophils with Helicobacter pylori and the role of Toll‐like receptors 2 and 4 in the response

The innate immune response to Helicobacter pylori infection is beginning to be understood and recent works support a role for Toll‐like receptors (TLRs). Our aim was to study the response of human neutrophils to H. pylori and to elucidate the role of TLR2 and TLR4. Neutrophils from healthy H. pylori ‐negative volunteers were cocultured with H. pylori 26695 strain. The release of IL‐8, IL‐1β, tumor necrosis factor (TNF)‐α and IL‐10 was measured. The role of TLR2 and TLR4 was investigated with blocking assays using monoclonal antibodies against TLRs. Neutrophils produced a significant increase of IL‐8, IL‐1β and TNF‐α after 3, 6 and 24 h of H. pylori challenge, respectively, whereas IL‐10 increased after 24 h. Helicobacter pylori challenge increased TLR2 and TLR4 expression; and antibodies against TLR2 and TLR4 diminished significantly the H. pylori ‐induced production of IL‐8 and IL‐10. In human neutrophils, H. pylori induces an early inflammatory response, partially mediated via TLR2 and TLR4 activation.