title: Lipopolysaccharide and Lipoteichoic Acid Virulence Deactivation by Stannous Fluoride.
abstract: OBJECTIVE
  Oral bacterial pathogens promote gingivitis and periodontal disease. Bacterial endotoxins, also known as lipopolysaccharides (LPSs) and lipoteichoic acids (LTAs), are known to enhance bacterial pathogenicity through binding with Toll-like receptors (TLRs), a group of pattern recognition receptors critical to the activation of innate immunity, that are expressed on host cells. Both LPS and LTA contain lipophilic domains and anionic charges that may be susceptible to reactivity with stannous fluoride, a commonly used ingredient clinically proven for the treatment and prevention of gingivitis. This study examined the effects of stannous fluoride on Toll-like receptor activation in response to bacterially derived LPS and LTA in select cell lines and secretion of inflammatory cytokines from human primary peripheral monocytes likewise exposed to LPS.
  
  
  METHODS
  TLR4 and TLR2 transfected HEK293 cells and THP1-Dual™ cells were exposed to bacterial LPS and LTA in the presence of increasing concentrations of stannous fluoride. Gene expression was assessed by measurement of secreted embryonic alkaline phosphatase (SEAP) reporter gene for HEK293 cells and SEAP and luciferase for THP-1 cells. Cell viability was confirmed using PrestoBlue. Human primary monocytes were treated with LPS with various concentrations of supplemented stannous fluoride, and cytokine expression was directly measured.
  
  
  RESULTS
  Stannous fluoride inhibited gene expression response of TLR4 and TLR2 in HEK293 cells and THP1-Dual™ cells in a dose response fashion, producing complete inhibition at micromolar concentrations. The addition of stannous fluoride suppressed production of TNF-a, IFN-g, IL12p70, IL10, IL-1b, IL2, and IL-6, and also increased secretion of Il-8 in dose response fashion. Viability assays confirmed no effects of LPS or stannous fluoride on viability of HEK293, THP-1, and primary human monocytes.
  
  
  CONCLUSIONS
  These results support the potential for stannous fluoride to provide clinical gingivitis benefits by directly decreasing the pathogenicity of plaque biofilms by blocking reactivity of LPS and LTA ligands with tissue receptors associated with inflammation. These learnings may influence recommendations for patients at risk for plaque-related diseases.
authors.affiliation: The Procter & Gamble Company, Mason, OH, USA.
authors.forename: Chris
authors.initials: C
authors.lastname: Haught
authors.affiliation: The Procter & Gamble Company, Mason, OH, USA.
authors.forename: Sancai
authors.initials: S
authors.lastname: Xie
authors.affiliation: The Procter & Gamble Company, Mason, OH, USA.
authors.forename: Ben
authors.initials: B
authors.lastname: Circello
authors.affiliation: The Procter & Gamble Company, Mason, OH, USA.
authors.forename: Cheryl S
authors.initials: CS
authors.lastname: Tansky
authors.affiliation: The Procter & Gamble Company, Mason, OH, USA.
authors.forename: Deepa
authors.initials: D
authors.lastname: Khambe
authors.affiliation: The Procter & Gamble Company, Mason, OH, USA.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Klukowska
authors.affiliation: The Procter & Gamble Company, Mason, OH, USA.
authors.forename: Tom
authors.initials: T
authors.lastname: Huggins
authors.affiliation: The Procter & Gamble Company, Mason, OH, USA.
authors.forename: Donald J
authors.initials: DJ
authors.lastname: White
mesh_terms: D001419:Bacteria; D018441:Biofilms; D003773:Dental Plaque; D057809:HEK293 Cells; D006801:Humans; D008070:Lipopolysaccharides; D009055:Mouth / Q000382:microbiology; D013682:Teichoic Acids; D014002:Tin Fluorides / Q000494:pharmacology*; D051195:Toll-Like Receptor 2 / Q000378:metabolism; D051197:Toll-Like Receptor 4 / Q000378:metabolism; D014774:Virulence
chemical_list: D008070:Lipopolysaccharides; D013682:Teichoic Acids; D014002:Tin Fluorides; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; C009900:lipoteichoic acid
keywords: Antimicrobials; Lipopolysaccharide; Lipoteichoic acid; Oral care