title: Ex vivoresponse to mucosal bacteria and muramyl dipeptide in inflammatory bowel disease.
abstract: OBJECTIVE
  To evaluate how mucosal bacteria impact on the spontaneous and muramyl dipeptide (MDP)-induced inflammation in Crohn's disease (CD) and ulcerative colitis (UC).
  
  
  METHODS
  Colonic mucosal biopsies were collected from children with active or remissive CD, UC and controls. Two tissue samples were taken from inflamed mucosal segments (in patients with active disease) or from non-inflamed mucosa [in patients in remission or in healthy controls (HC)]. Experiments were performed in the presence or absence of antibiotics, to assess whether the disease-associated microbiota can modulate the cytokine responseex vivo. For this purpose, each specimen was half-cut to compare spontaneous and MDP-induced inflammation in the presence of live bacteria (LB) or antibiotics. After 24 h of culture, an array of 17 cytokines was assessed in supernatants. Statistical analyses were performed to find significant differences in single cytokines or in patterns of cytokine response in the different groups.
  
  
  RESULTS
  We demonstrated that subjects with CD display a spontaneous production of inflammatory cytokines including granulocyte-colony stimulating factor (G-CSF), interleukin (IL) 6, IL8, IL10 and IL12, that was not significantly influenced by the addition of antibiotics. UC specimens also displayed a trend of increased spontaneous secretion of several cytokines, which however was not significant due to broader variability among patients. After the addition of antibiotics, spontaneous IL8 secretion was significantly higher in UC than in controls. In HC, a trend towards the weakening of spontaneous IL8 production was observed in the presence of live mucosal bacteria with respect to the presence of antibiotics. In contrast, in the presence of LB UC showed an increasing trend of spontaneous IL8 production, while MDP stimulation resulted in lower IL8 production in the presence of antibiotics. We also showed that subjects with CD seem to have a lowered production of IL8 in response to MDP in the presence of LB. Only with the addition of antibiotics, likely reducing the contribution of LB, multivariate statistical analysis could identify the combination of measures of G-CSF, tumor necrosis factor alpha, IL4 and IL17 as a good discriminator between CD and UC.
  
  
  CONCLUSIONS
  We showed that the presence of LB or antibiotics can significantly influence the inflammatory responseex vivoin inflammatory bowel diseases.
authors.affiliation: Claudia Loganes, Elisa Marini, Samuele Naviglio, Tarcisio Not, Annalisa Marcuzzi, Department of Medicine, Surgery, and Health Sciences, University of Trieste, Strada di Fiume, 447 Trieste, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Loganes
authors.affiliation: Claudia Loganes, Elisa Marini, Samuele Naviglio, Tarcisio Not, Annalisa Marcuzzi, Department of Medicine, Surgery, and Health Sciences, University of Trieste, Strada di Fiume, 447 Trieste, Italy.
authors.forename: Erica
authors.initials: E
authors.lastname: Valencic
authors.affiliation: Claudia Loganes, Elisa Marini, Samuele Naviglio, Tarcisio Not, Annalisa Marcuzzi, Department of Medicine, Surgery, and Health Sciences, University of Trieste, Strada di Fiume, 447 Trieste, Italy.
authors.forename: Alessia
authors.initials: A
authors.lastname: Pin
authors.affiliation: Claudia Loganes, Elisa Marini, Samuele Naviglio, Tarcisio Not, Annalisa Marcuzzi, Department of Medicine, Surgery, and Health Sciences, University of Trieste, Strada di Fiume, 447 Trieste, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Marini
authors.affiliation: Claudia Loganes, Elisa Marini, Samuele Naviglio, Tarcisio Not, Annalisa Marcuzzi, Department of Medicine, Surgery, and Health Sciences, University of Trieste, Strada di Fiume, 447 Trieste, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Martelossi
authors.affiliation: Claudia Loganes, Elisa Marini, Samuele Naviglio, Tarcisio Not, Annalisa Marcuzzi, Department of Medicine, Surgery, and Health Sciences, University of Trieste, Strada di Fiume, 447 Trieste, Italy.
authors.forename: Samuele
authors.initials: S
authors.lastname: Naviglio
authors.affiliation: Claudia Loganes, Elisa Marini, Samuele Naviglio, Tarcisio Not, Annalisa Marcuzzi, Department of Medicine, Surgery, and Health Sciences, University of Trieste, Strada di Fiume, 447 Trieste, Italy.
authors.forename: Luigina
authors.initials: L
authors.lastname: De Leo
authors.affiliation: Claudia Loganes, Elisa Marini, Samuele Naviglio, Tarcisio Not, Annalisa Marcuzzi, Department of Medicine, Surgery, and Health Sciences, University of Trieste, Strada di Fiume, 447 Trieste, Italy.
authors.forename: Tarcisio
authors.initials: T
authors.lastname: Not
authors.affiliation: Claudia Loganes, Elisa Marini, Samuele Naviglio, Tarcisio Not, Annalisa Marcuzzi, Department of Medicine, Surgery, and Health Sciences, University of Trieste, Strada di Fiume, 447 Trieste, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Monasta
authors.affiliation: Claudia Loganes, Elisa Marini, Samuele Naviglio, Tarcisio Not, Annalisa Marcuzzi, Department of Medicine, Surgery, and Health Sciences, University of Trieste, Strada di Fiume, 447 Trieste, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Tommasini
authors.affiliation: Claudia Loganes, Elisa Marini, Samuele Naviglio, Tarcisio Not, Annalisa Marcuzzi, Department of Medicine, Surgery, and Health Sciences, University of Trieste, Strada di Fiume, 447 Trieste, Italy.
authors.forename: Annalisa
authors.initials: A
authors.lastname: Marcuzzi
mesh_terms: D000119:Acetylmuramyl-Alanyl-Isoglutamine / Q000494:pharmacology*; D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D019540:Area Under Curve; D016022:Case-Control Studies; D002648:Child; D003093:Colitis, Ulcerative / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D003106:Colon / Q000187:drug effects* / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D003424:Crohn Disease / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D016207:Cytokines / Q000378:metabolism; D005260:Female; D000069196:Gastrointestinal Microbiome / Q000187:drug effects; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D012372:ROC Curve; D046509:Tissue Culture Techniques
chemical_list: D000900:Anti-Bacterial Agents; D016207:Cytokines; D018836:Inflammation Mediators; D000119:Acetylmuramyl-Alanyl-Isoglutamine
keywords: Crohn’s disease; Cytokines; Gut-microbiota; Inflammation; Ulcerative colitis