Anda R. Gliga,ab Jessica De Loma, ORCID logo a Sebastiano Di Bucchianico, ORCID logo a Sara Skoglund, ORCID logo c Sandeep Keshavan,b Inger Odnevall Wallinder, ORCID logo c Hanna L. Karlsson*a and Bengt Fadeel ORCID logo *b
* Corresponding authors
a Division of Biochemical Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
b Division of Molecular Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
c Department of Chemistry, Surface and Corrosion Science, KTH Royal Institute of Technology, Stockholm, Sweden
Silver (Ag) nanoparticles are commonly used in consumer products due to their antimicrobial properties. Here we studied the impact of Ag nanoparticles on immune responses by using cell lines of monocyte/macrophage and lung epithelial cell origin, respectively. Short-term experiments (24 h) showed that Ag nanoparticles reduced the lipopolysaccharide (LPS)-induced secretion of pro-inflammatory cytokines in THP-1 cells under serum-free conditions. ICP-MS analysis revealed that cellular uptake of Ag was higher under these conditions. Long-term exposure (up to 6 weeks) of BEAS-2B cells to Ag nanoparticles also suppressed pro-inflammatory cytokine production following a brief challenge with LPS. Experiments using reporter cells revealed that Ag nanoparticles as well as AgNO3 inhibited LPS-triggered Toll-like receptor (TLR) signaling. Furthermore, RNA-sequencing of BEAS-2B cells indicated that Ag nanoparticles affected TLR signaling pathways. In conclusion, Ag nanoparticles reduced the secretion of pro-inflammatory cytokines in response to LPS, likely as a result of the release of silver ions leading to an interference with TLR signaling. This could have implications for the use of Ag nanoparticles as antibacterial agents. Further in vivo studies are warranted to study this.
Complete paper available here: https://pubs.rsc.org/en/content/articlel...1k#!divAbstract