Bacillus cereus non-haemolytic enterotoxin activates the NLRP3 inflammasome

Nat Commun. 2020 Feb 6;11(1):760. doi: 10.1038/s41467-020-14534-3.

Abstract

Inflammasomes are important for host defence against pathogens and homeostasis with commensal microbes. Here, we show non-haemolytic enterotoxin (NHE) from the neglected human foodborne pathogen Bacillus cereus is an activator of the NLRP3 inflammasome and pyroptosis. NHE is a non-redundant toxin to haemolysin BL (HBL) despite having a similar mechanism of action. Via a putative transmembrane region, subunit C of NHE initiates binding to the plasma membrane, leading to the recruitment of subunit B and subunit A, thus forming a tripartite lytic pore that is permissive to efflux of potassium. NHE mediates killing of cells from multiple lineages and hosts, highlighting a versatile functional repertoire in different host species. These data indicate that NHE and HBL operate synergistically to induce inflammation and show that multiple virulence factors from the same pathogen with conserved function and mechanism of action can be exploited for sensing by a single inflammasome.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacillus cereus / pathogenicity*
  • Bacterial Proteins / toxicity
  • Cell Line
  • Enterotoxins / chemistry
  • Enterotoxins / toxicity*
  • Female
  • Hemolysin Proteins / toxicity
  • Host Microbial Interactions
  • Host Specificity
  • Humans
  • Inflammasomes / drug effects
  • Inflammasomes / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • NLR Family, Pyrin Domain-Containing 3 Protein / metabolism*
  • Pyroptosis / drug effects
  • Virulence Factors / toxicity

Substances

  • Bacterial Proteins
  • Enterotoxins
  • Hemolysin Proteins
  • Inflammasomes
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Virulence Factors
  • enterotoxin, Bacillus cereus
  • hemolysin BL protein, Bacillus