title: The allergy-protective properties of Acinetobacter lwoffii F78 are imparted by its lipopolysaccharide.
abstract: BACKGROUND
  An increasing number of epidemiological studies show that exposure to farming environment during early childhood strongly influences the development of allergic reactions later in life ('hygiene hypothesis'). Also, it had been shown that certain bacteria from this environment may have allergy-protective properties. In the present study, we further characterized one of these bacteria, namely Acinetobacter lwoffii F78, with regard to the bacteria-induced signaling and possible mechanisms of allergy protection.
  
  
  METHODS
  The impact of A. lwoffii F78 on human monocyte-derived dendritic cells especially with respect to their T(Helper) cell polarization capacity was investigated by ELISA and real-time PCR experiments as well as confocal microscopy. The responsible molecule for these effects was further characterized and identified using blocking experiments.
  
  
  RESULTS
  It was shown that A. lwoffii F78 induced a T(H)1-polarizing program in human dendritic cells which led to T(H)1 differentiation. In addition, a positive influence on the TBet/GATA3 level could be detected. Blocking experiments revealed that the lipopolysaccharide (LPS) of A. lwoffii F78 was the responsible molecule promoting these effects.
  
  
  CONCLUSIONS
  We found evidence that the allergy-protecting effects of A. lwoffii F78 are because of the activation of a T(H)1-polarizing program in human dendritic cells, and that the LPS of A. lwoffii F78 is responsible for these beneficial effects.
authors.affiliation: Division of Innate Immunity, Research Center Borstel, Leibniz-Center for Medicine and Biosciences, Parkallee 22, Borstel, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Debarry
authors.forename: A
authors.initials: A
authors.lastname: Hanuszkiewicz
authors.forename: K
authors.initials: K
authors.lastname: Stein
authors.forename: O
authors.initials: O
authors.lastname: Holst
authors.forename: H
authors.initials: H
authors.lastname: Heine
mesh_terms: D000150:Acinetobacter / Q000276:immunology*; D001691:Biological Therapy / Q000379:methods; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000187:drug effects / Q000276:immunology; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology / Q000517:prevention & control*; D008070:Lipopolysaccharides / Q000276:immunology* / Q000494:pharmacology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
chemical_list: D008070:Lipopolysaccharides