title: Functional characterization of lipopolysaccharide derived from symbiotic bacteria in rice as a macrophage-activating substance.
abstract: OBJECTIVE
  Lipopolysaccharide derived from a symbiotic bacterium in wheat (Pantoea agglomerans, LPSp) has shown multiple positive effects, such as prophylactic, antiallergic and antitumour effects, without serious side-effects. LPSp has differential biological activities in comparison to other LPS, such as those from Escherichia coli (LPSe). The only difference between LPSp and LPSe is in the O-antigen polysaccharide structure (O-PS). This led us to the hypothesis that the O-PS structure would seem to participate in biological activities. Thus, the characterization of properties of O-PS in LPS is of the utmost importance for understanding cell activation in the maintenance of homeostasis. However, little is known about the correlation between the O-PS structure of LPS and its biological activities. In this study, we extracted LPS derived from a symbiotic bacterium in rice (strain A46, related species of Pantoea), which has a long history of use in foods, and investigated its putative structures and functions.
  
  
  METHODS
  LPS derived from strain A46 was prepared using a hot phenol extraction method. The properties of LPS-A46 were analysed by thin-layer chromatography, Tricine SDS-PAGE and Western blotting. The function of LPS-A46 was analyzed by quantative real-time PCR and flow cytometry using THP-1 cells and Peripheral blood mononuclear cell (PBMC) derived macrophages.
  
  
  RESULTS
  In Tricine SDS-PAGE, high molecular mass LPS-A46 had a molecular mass lower than that of LPSp. In Western blotting, LPS-A46 reacted with lipid A antibody but did not react with an O-PS antibody of LPSp. In comparison to other LPS, LPS-A46 induced a differential cytokine gene expression profile in THP-1 cells and PBMC-derived macrophages.
  
  
  CONCLUSIONS
  The present study suggests that LPS derived from symbiotic bacterium in rice is a bioactive functional LPS which may have different functional activities compared to other types of LPS.
authors.affiliation: Department of Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kida-gun, Kagawa-ken, 761-0793, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kadowaki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Inagawa
authors.forename: Chie
authors.initials: C
authors.lastname: Kohchi
authors.forename: Mitsuomi
authors.initials: M
authors.lastname: Hirashima
authors.forename: Gen-Ichiro
authors.initials: G
authors.lastname: Soma
mesh_terms: D015153:Blotting, Western; D002460:Cell Line / Q000187:drug effects / Q000378:metabolism; D002855:Chromatography, Thin Layer; D003429:Cross Reactions; D016207:Cytokines / Q000096:biosynthesis / Q000235:genetics; D004353:Drug Evaluation, Preclinical; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008033:Limulus Test; D008050:Lipid A / Q000276:immunology; D008070:Lipopolysaccharides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D008213:Lymphocyte Activation / Q000187:drug effects; D008262:Macrophage Activation / Q000187:drug effects*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D008823:Micelles; D015394:Molecular Structure; D008970:Molecular Weight; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism; D019081:O Antigens / Q000737:chemistry*; D012275:Oryza / Q000382:microbiology*; D020636:Pantoea / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D016207:Cytokines; D008050:Lipid A; D008070:Lipopolysaccharides; D008823:Micelles; D019081:O Antigens