Helicobacter pylori binds human Annexins via Lipopolysaccharide to interfere with Toll-like Receptor 4 signaling

PLoS Pathog. 2022 Feb 17;18(2):e1010326. doi: 10.1371/journal.ppat.1010326. eCollection 2022 Feb.

Abstract

Helicobacter pylori colonizes half of the global population and causes gastritis, peptic ulcer disease or gastric cancer. In this study, we were interested in human annexin (ANX), which comprises a protein family with diverse and partly unknown physiological functions, but with a potential role in microbial infections and possible involvement in gastric cancer. We demonstrate here for the first time that H. pylori is able to specifically bind ANXs. Binding studies with purified H. pylori LPS and specific H. pylori LPS mutant strains indicated binding of ANXA5 to lipid A, which was dependent on the lipid A phosphorylation status. Remarkably, ANXA5 binding almost completely inhibited LPS-mediated Toll-like receptor 4- (TLR4) signaling in a TLR4-specific reporter cell line. Furthermore, the interaction is relevant for gastric colonization, as a mouse-adapted H. pylori increased its ANXA5 binding capacity after gastric passage and its ANXA5 incubation in vitro interfered with TLR4 signaling. Moreover, both ANXA2 and ANXA5 levels were upregulated in H. pylori-infected human gastric tissue, and H. pylori can be found in close association with ANXs in the human stomach. Furthermore, an inhibitory effect of ANXA5 binding for CagA translocation could be confirmed. Taken together, our results highlight an adaptive ability of H. pylori to interact with the host cell factor ANX potentially dampening innate immune recognition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Annexins / metabolism
  • Gastric Mucosa
  • Helicobacter Infections* / metabolism
  • Helicobacter pylori* / metabolism
  • Humans
  • Lipid A
  • Lipopolysaccharides / metabolism
  • Mice
  • Stomach Neoplasms* / metabolism
  • Toll-Like Receptor 4 / genetics
  • Toll-Like Receptor 4 / metabolism

Substances

  • Annexins
  • Lipid A
  • Lipopolysaccharides
  • Toll-Like Receptor 4

Grants and funding

The work was funded by research grants from the Deutsche Forschungsgemeinschaft (SFB914, Project B5 and DFG HA2697/16-2 for RH and SFB914, Project Z01 for HI-A) and by the Förderung von Forschung und Lehre (FöFoLe) Program of the LMU Munich (Reg.-Nr. 54/2014) to RH and LFJS. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.