title: Molecular identification of potential Th1/Th2 responses-modulating bacterial genes using suppression subtractive DNA hybridization.
abstract: OBJECTIVE
  We characterized the immunomodulating potential of a number of lactobacilli isolated from an African fermented food by co-incubation with peripheral blood mononuclear cells (PBMCs). Two strains with different immune modulating properties were genetically compared by suppression subtractive hybridization (SSH).
  
  
  METHODS
  From 48 Lactobacillus strains isolated from Kimere, African fermented pearl millet dough, 10 were selected based on their bile salt tolerance. Their effects on secretion by PBMCs of the T-helper cells Th1- and Th2-cytokines IFN-γ and IL-4, respectively, in the presence or absence of staphylococcal enterotoxin A (SEA) were assessed. To study the genetic basis of different immune-modulating properties, a subtracted cDNA library for L. fermentum strains K1-Lb1 (Th1 inducer) and K8-Lb1 (Th1 and Th2 suppressor) was constructed using SSH. Finally, adhesion of these strains to hydrocarbons (relative hydrophobicity) and to human HT-29 colonic epithelial cell line was assessed.
  
  
  RESULTS
  Two strains, K1-Lb1 and K4-Lb6, induced basal IFN-γ secretion. Four strains, K1-Lb6, K6-Lb2, K7-Lb1, and K8-Lb1 diminished INF-γ secretion by SEA-stimulated PBMCs. All strains, except K1-Lb1, K2-Lb4, and K9-Lb3, inhibited SEA-stimulated IL-4 secretion. Comparing the genomes of K1-Lb1 and K8-Lb1 by SSH indicated that K1-Lb1 is able to synthetize polysaccharides, for the synthesis of which K1-Lb8 appears to lack enzymes. A difference in the hydrophobicity properties of the surfaces of both strains indicated that this has impact on their surface.
  
  
  CONCLUSIONS
  The K1-Lb1-specific sequences encoding putative glycosyltransferases and enzymes for polysaccharides synthesis may account for the observed differences in immunomodulation and surface properties between the two strains and for mediating potential probiotic effects.
authors.affiliation: Department of Microbiology and Biotechnology, Max Rubner-Institut, Hermann-Weigmann-Str. 1, D-24103 Kiel, Germany. Electronic address: darab.ghadimi@mri.bund.de.
authors.forename: Darab
authors.initials: D
authors.lastname: Ghadimi
authors.affiliation: Department of Physiology and Biochemistry of Nutrition, Max Rubner-Institut, Hermann-Weigmann-Str. 1, D-24103 Kiel, Germany.
authors.forename: Patrisio Njiru
authors.initials: PN
authors.lastname: Njeru
authors.affiliation: Department of Microbiology and Biotechnology, Max Rubner-Institut, Haid-und-Neu-Str. 9, D-76131 Karlsruhe, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Guigas
authors.affiliation: Department of Physiology and Biochemistry of Nutrition, Max Rubner-Institut, Hermann-Weigmann-Str. 1, D-24103 Kiel, Germany.
authors.forename: Mohammed Hassan
authors.initials: MH
authors.lastname: Farghaly
authors.affiliation: Clinic of Dermatology, University Hospital Schleswig-Holstein, Schittenhelmstr. 7, D-24105 Kiel, Germany.
authors.forename: Regina
authors.initials: R
authors.lastname: Fölster-Holst
authors.affiliation: Department of Microbiology and Biotechnology, Max Rubner-Institut, Hermann-Weigmann-Str. 1, D-24103 Kiel, Germany.
authors.forename: Arnold
authors.initials: A
authors.lastname: Geis
authors.affiliation: Department of Microbiology and Biotechnology, Max Rubner-Institut, Hermann-Weigmann-Str. 1, D-24103 Kiel, Germany; Department of Physiology and Biochemistry of Nutrition, Max Rubner-Institut, Hermann-Weigmann-Str. 1, D-24103 Kiel, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: de Vrese
authors.affiliation: Department of Physiology and Biochemistry of Nutrition, Max Rubner-Institut, Hermann-Weigmann-Str. 1, D-24103 Kiel, Germany; Clinical Research Center, Schauenburgerstr. 116, D-24118 Kiel, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schrezenmeir
authors.affiliation: Department of Microbiology and Biotechnology, Max Rubner-Institut, Hermann-Weigmann-Str. 1, D-24103 Kiel, Germany.
authors.forename: Knut J
authors.initials: KJ
authors.lastname: Heller
mesh_terms: D001652:Bile Ducts / Q000382:microbiology*; D002478:Cells, Cultured; D015342:DNA Probes; D004768:Enterotoxins / Q000276:immunology; D015723:Gene Library; D005798:Genes, Bacterial / Q000235:genetics; D016695:Glycosyltransferases / Q000235:genetics; D006801:Humans; D056747:Immunomodulation; D007371:Interferon-gamma / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D007777:Lactobacillaceae / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D007963:Leukocytes, Mononuclear / Q000276:immunology* / Q000382:microbiology; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis; D019936:Probiotics; D018417:Th1 Cells / Q000276:immunology*; D058408:Th1-Th2 Balance; D018418:Th2 Cells / Q000276:immunology*
chemical_list: D015342:DNA Probes; D004768:Enterotoxins; D011135:Polysaccharides, Bacterial; D015847:Interleukin-4; C026066:enterotoxin A, Staphylococcal; D007371:Interferon-gamma; D016695:Glycosyltransferases
keywords: CFU; Cytokine; EPS; GTF; LTA; Lactobacillus fermentum; MAMPs; N-acetylglucosamine; N-acetylmuramic acid; NAG; NAM; OD; Optical density; PBMCs; PBS; PGN; PPT; Probiotics; SEA; Suppression subtractive hybridization; T helper cell type 1; T helper cell type 2; Th1; Th2; WTA; colony-forming units; exopolysaccharide; glucosyltransferase; lipoteichoic acid; microbe-associated molecular patterns; optical density; peptidoglycan; peripheral blood mononuclear cells; phosphate-buffered saline; pyruvyltransferase; staphylococcal enterotoxin A; wall teichoic acid