title: Induction of nitric oxide production in RAW264.7 cells under serum-free conditions by O-antigen polysaccharide of lipopolysaccharide.
abstract: BACKGROUND
  Lipopolysaccharide derived from Pantoea agglomerans (LPSp) mainly consists of two aggregates, the high-molecular aggregate (HMM-LPSp) and the low-molecular aggregate (LMM-LPSp). The structural differences between HMM-LPSp and LMM-LPSp seem to depend on the length of the O-antigen polysaccharide because the lipid A regions of the two fractions are quite similar. In this study, we examined the biological activity of LPSp focusing on the O-antigen polysaccharide using HMM-LPSp and LMM-LPSp under serum-free conditions.
  
  
  METHODS
  The binding of LPSp to RAW264.7 cells under serum-free conditions was analyzed by flow cytometry using LPSp-conjugated fluorescein isothiocyanate (FITC-LPSp). The biological activities of HMM-LPSp and LMM-LPSp under serum-free conditions were evaluated by the nitric oxide production.
  
  
  RESULTS
  FITC-LPSp showed higher fluorescence intensity under serum-free than serum-containing conditions. HMM-LPSp induced higher nitric oxide production than LMM-LPSp under serum-free conditions.
  
  
  CONCLUSIONS
  The present study indicates that the reactivity of LPSp is affected by the O-antigen polysaccharide under serum-free conditions.
authors.affiliation: Department of Integrated and Holistic Immunology, Faculty of Medicine, Kagawa University, Kagawa, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kadowaki
authors.forename: Shiho
authors.initials: S
authors.lastname: Ohno
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Taniguchi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Inagawa
authors.forename: Chie
authors.initials: C
authors.lastname: Kohchi
authors.forename: Gen-Ichiro
authors.initials: G
authors.lastname: Soma
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D005434:Flow Cytometry; D008070:Lipopolysaccharides / Q000276:immunology / Q000494:pharmacology*; D008264:Macrophages / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D009569:Nitric Oxide / Q000378:metabolism*; D019081:O Antigens / Q000276:immunology* / Q000378:metabolism; D020636:Pantoea / Q000378:metabolism*
chemical_list: D016895:Culture Media, Serum-Free; D008070:Lipopolysaccharides; D019081:O Antigens; D009569:Nitric Oxide
keywords: HMM; LMM; LPS; LPSp; O-antigen polysaccharide; Pantoea agglomerans; serum-free