title: Artefactual nanoparticle activation of the inflammasome platform: in vitro evidence with a nano-formed calcium phosphate.
abstract: OBJECTIVE
  To determine whether in vitro experimental conditions dictate cellular activation of the inflammasome by apatitic calcium phosphate nanoparticles.
  
  
  METHODS
  The responses of blood-derived primary human cells to in situ-formed apatite were investigated under different experimental conditions to assess the effect of aseptic culture, cell rest and duration of particle exposure. Cell death and particle uptake were assessed, while IL-1β and caspase 1 responses, with and without lipopolysaccharide prestimulation, were evaluated as markers of inflammasome activation.
  
  
  RESULTS
  Under carefully addressed experimental conditions, apatitic nanoparticles did not induce cell death or engage the inflammasome platform, although both could be triggered through artefacts of experimentation.
  
  
  CONCLUSIONS
  In vitro studies often predict that engineered nanoparticles, such as synthetic apatite, are candidates for inflammasome activation and, hence, are toxic. However, the experimental setting must be very carefully considered as it may promote false-positive outcomes.
authors.affiliation: 1Medical Research Council - Human Nutrition Research, Elsie Widdowson Laboratory, Fulbourn Road, Cambridge, CB1 9NL, UK.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Pele
authors.affiliation: 1Medical Research Council - Human Nutrition Research, Elsie Widdowson Laboratory, Fulbourn Road, Cambridge, CB1 9NL, UK.
authors.forename: Carolin T
authors.initials: CT
authors.lastname: Haas
authors.affiliation: 1Medical Research Council - Human Nutrition Research, Elsie Widdowson Laboratory, Fulbourn Road, Cambridge, CB1 9NL, UK.
authors.forename: Rachel
authors.initials: R
authors.lastname: Hewitt
authors.affiliation: 1Medical Research Council - Human Nutrition Research, Elsie Widdowson Laboratory, Fulbourn Road, Cambridge, CB1 9NL, UK.
authors.forename: Nuno
authors.initials: N
authors.lastname: Faria
authors.affiliation: 2Institute for Materials Research, SPEME, University of Leeds, Leeds, LS2 9JT, UK.
authors.forename: Andy
authors.initials: A
authors.lastname: Brown
authors.affiliation: 1Medical Research Council - Human Nutrition Research, Elsie Widdowson Laboratory, Fulbourn Road, Cambridge, CB1 9NL, UK.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Powell
mesh_terms: D001031:Apatites / Q000494:pharmacology*; D016477:Artifacts; D006801:Humans; D066298:In Vitro Techniques; D058847:Inflammasomes / Q000187:drug effects*; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles
chemical_list: D001031:Apatites; D058847:Inflammasomes
keywords: IL-1β; apatite; caspase 1; experimental conditions; inflammasome; nanoparticle