title: Activation of the inflammasome by amorphous silica and TiO2 nanoparticles in murine dendritic cells.
abstract: Nanomaterials are increasingly used in various food applications. In particular, nanoparticulate amorphous SiO2 is already contained, e.g., in spices. Since intestinal dendritic cells (DC) could be critical targets for ingested particles, we compared the in vitro effects of amorphous silica nanoparticles with fine crystalline silica, and micron-sized with nano-sized TiO2 particles on DC. TiO2- and SiO2-nanoparticles, as well as crystalline silica led to an upregulation of MHC-II, CD80, and CD86 on DC. Furthermore, these particles activated the inflammasome, leading to significant IL-1β-secretion in wild-type (WT) but not Caspase-1- or NLRP3-deficient mice. Silica nanoparticles and crystalline silica induced apoptosis, while TiO2 nanoparticles led to enhanced production of reactive oxygen species (ROS). Since amorphous silica and TiO2 nanoparticles had strong effects on the activation-status of DC, we suggest that nanoparticles, used as food additives, should be intensively studied in vitro and in vivo, to ensure their safety for the consumer.
authors.affiliation: Molecular Immunology, Institut für Umweltmedizinische Forschung at the Heinrich-Heine University , Düsseldorf , Germany.
authors.forename: Meike
authors.initials: M
authors.lastname: Winter
authors.forename: Hans-Dietmar
authors.initials: HD
authors.lastname: Beer
authors.forename: Veit
authors.initials: V
authors.lastname: Hornung
authors.forename: Ursula
authors.initials: U
authors.lastname: Krämer
authors.forename: Roel P F
authors.initials: RP
authors.lastname: Schins
authors.forename: Irmgard
authors.initials: I
authors.lastname: Förster
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D003713:Dendritic Cells / Q000187:drug effects*; D005786:Gene Expression Regulation; D007249:Inflammation / Q000139:chemically induced* / Q000378:metabolism; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; D010316:Particle Size; D012822:Silicon Dioxide / Q000737:chemistry / Q000633:toxicity*; D014025:Titanium / Q000737:chemistry / Q000633:toxicity*
chemical_list: D002352:Carrier Proteins; D000071199:NLR Family, Pyrin Domain-Containing 3 Protein; C492716:Nlrp3 protein, mouse; C009495:titanium dioxide; D012822:Silicon Dioxide; D014025:Titanium