Sa.128. Simultaneous Oral Gluten and Microbial Exposure Increases Systemic Cytokine Suppression in a...
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Sa.126. FTY720 Ameliorates Pathogen Driven Ileitis in C57BL/6 Mice by Impeding Lymphocyte Trafficking Daniel Mielcarz, 1 David Foureau, 1 Laurence Menard, 1 Javier Ochoa-Repáraz, 1 Dominique Buzoni-Gatel, 2 Lloyd Kasper. 1 1 Dartmouth Medical School, Lebanon, NH; 2 Institut Pasteur- INRA, Paris, France We investigated the effect of impeding lymphocyte trafficking with FTY720 in the immune regulation of an experimental model of pathogen-driven inflammatory bowel disease (IBD). Inbred B6 mice develop an acute necrotizing ileitis 7-9 days following oral infection with Toxoplasma gondii. A hallmark of this ileitis is a massive infiltration of lymphocytes and subsequent production of Th1 cytokines. The parasite driven ileitis has both morphologic and immunologic features consistent with human Crohn's dis- ease. FTY720 is a sphingosine-1-phosphate (S1P) analogue that binds to S1P receptors. Lymphocytes require signaling through S1P1 to leave the lymph node following encounter with antigen. Treatment with FTY720 reduced clinical signs of ileitis in T. gondii infected mice, as demonstrated by reduced weight loss as well as fewer morphologic and pathologic changes associated with inflammation in the small intestine. Chimeric mice were generated in which the hematopoietic cells were GFP+ in order to visualize the trafficking of lymphocytes following infection and treat- ment. FTY720 treated mice showed reduced numbers of CD4+ lymphocytes in both the small intestinal lamina propria and in the brain following infection. Reduced Th1 cytokine expression as well as an increased parasite burden in the small intestine was observed in the FTY720 treated group. Interestingly, the brain parasite burden of treated mice showed a lower parasite burden indicating an inhibition of lymphotcyte trafficking by FTY720. These results indicate that FTY720 may be a promising treatment for IBD. doi:10.1016/j.clim.2008.03.347 Sa.127. Expression of FOXP3+CD4+CD25+ Regulatory T Cells in Patients with Inflammatory Bowel Disease Sara Ciullini Mannurita, Eleonora Gambineri, Lucia Bianchi, Gloria Serena, Paolo Lionetti, Anna Maria Gelli, Chiara Azzari, Maurizio de Martino. University of Florence, Florence, Italy FOXP3+CD4+CD25+ regulatory T cells play a key role in regulation of immune responses. To date there are few studies that describes their potential function in human inflammatory bowel disease (IBD), although it has been demonstrated that this T cells subset can prevent experimental murine colitis. In this study 14 patients affected by IBD (9 patients with Ulcerative Colitis and 5 with Crohn's disease), and 8 healthy subjects were enrolled. Peripheral blood mononuclear cells (PBMCs) were analysed by flow cytometry to evaluate FOXP3+ CD4+CD25+ regulatory T cells. First the frequency of CD4+ CD25+bright lymphocytes subset was examined, then we evaluated FOXP3 expression calculating the mean fluores- cence intensity (MFI). Statistic analysis was performed by Student's t-test. We observed a higher CD4+CD25+bright expression in IBD patients than in healthy subjects (3,13± 1,26% vs 1,50 ± 0.53%, p = 0,002), but a lower FOXP3 expression both in CD4+CD25+ total population (MFI =5,19±1,8 vs 7,20± 1,79 p b 0.05) and in CD4+CD25+bright subset (MFI = 9,56 ± 2,83 vs 13,80±3,96 p b 0.02) in IBD patients compared to healthy subjects. Moreover this analysis was performed comparing each group of patients affected by the same disease with the normal subjects and similar results were obtained. Although patients with IBD showed an increased number of CD4+CD25+ bright, probably due to a steady-state activation, lower FOXP3 levels were found in this cell subset compared to healthy subjects, suggesting that impaired expression of FOXP3 may be responsible of the immune imbalance in IBD. Further studies to confirm these preliminary findings and to test FOXP3 function both on peripheral blood and mucosal lymphocytes are currently ongoing. doi:10.1016/j.clim.2008.03.348 Sa.128. Simultaneous Oral Gluten and Microbial Exposure Increases Systemic Cytokine Suppression in a MHC Class II Dependent Manner Susan Barton, Eric Marietta, Marshall Behrens, Melissa Jacobson, Kerryl Piper, Joseph Murray, Chella David. Mayo Clinic, Rochester, MN Celiac disease (CD) is an autoimmune enteropathy of the proximal small bowel that is strongly associated with DQ2/ DQ8 HLA genotypes. Prevotella organisms have been identi- fied in increased numbers in the stool of celiac patients. In an attempt to develop a murine model of enteropathy for CD, Prevotella species (PS) and Prevotella melaninogenica (PM) cultured from the proximal small bowel of celiac disease patients were introduced via oral gavages into AeoDQ8 transgenic mice with or without the introduction of oral gluten feeding. All the mice had been weaned and maintained on a gluten free diet. The three experimental groups were: no bacteria and no dietary gluten (control group), bacteria alone, and bacteria plus initiation of a gluten-containing diet. No enteropathy developed. Rather there was high level suppres- sion of the following cytokines in the sera in both series after the administration of both dietary gluten and bacteria (mean reduction): IFNγ (↓51%), IL-12p70 (↓56%), IL-17 (↓64%), TNFa (↓62%), IL-6 (↓61%), IL-10 (↓61%), IL-13 (↓64%). In comparison, Aeo-/- mice had decreased suppression of serum cytokines when co-administered gluten and bacteria. This would suggest a role for MHC class II. Feeding PS or PM bacteria with dietary gluten resulted in an increase in splenic CD4+CD25-FoxP3+ T- cells. These findings suggest that there is systemic cytokine suppression generated in response to simultaneous gluten and microbial antigen exposure in the context of the gluten sensitive associated MHC genotype DQ8 that may reflect a gluten augmented probiotic effect. doi:10.1016/j.clim.2008.03.349 S122 Abstracts
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Transcript of Sa.128. Simultaneous Oral Gluten and Microbial Exposure Increases Systemic Cytokine Suppression in a...
Sa.126. FTY720 Ameliorates Pathogen DrivenIleitis in C57BL/6 Mice by Impeding LymphocyteTraffickingDaniel Mielcarz,1 David Foureau,1 Laurence Menard,1 JavierOchoa-Repáraz,1 Dominique Buzoni-Gatel,2 Lloyd Kasper.11Dartmouth Medical School, Lebanon, NH; 2Institut Pasteur-INRA, Paris, France
We investigated the effect of impeding lymphocytetrafficking with FTY720 in the immune regulation of anexperimental model of pathogen-driven inflammatory boweldisease (IBD). Inbred B6 mice develop an acute necrotizingileitis 7-9 days following oral infection with Toxoplasmagondii. A hallmark of this ileitis is a massive infiltration oflymphocytes and subsequent production of Th1 cytokines.The parasite driven ileitis has both morphologic andimmunologic features consistent with human Crohn's dis-ease. FTY720 is a sphingosine-1-phosphate (S1P) analoguethat binds to S1P receptors. Lymphocytes require signalingthrough S1P1 to leave the lymph node following encounterwith antigen. Treatment with FTY720 reduced clinical signsof ileitis in T. gondii infected mice, as demonstrated byreduced weight loss as well as fewer morphologic andpathologic changes associated with inflammation in thesmall intestine. Chimeric mice were generated in which thehematopoietic cells were GFP+ in order to visualize thetrafficking of lymphocytes following infection and treat-ment. FTY720 treated mice showed reduced numbers ofCD4+ lymphocytes in both the small intestinal lamina propriaand in the brain following infection. Reduced Th1 cytokineexpression as well as an increased parasite burden in thesmall intestine was observed in the FTY720 treated group.Interestingly, the brain parasite burden of treated miceshowed a lower parasite burden indicating an inhibition oflymphotcyte trafficking by FTY720. These results indicatethat FTY720 may be a promising treatment for IBD.
doi:10.1016/j.clim.2008.03.347
Sa.127. Expression of FOXP3+CD4+CD25+Regulatory T Cells in Patients with InflammatoryBowel DiseaseSara Ciullini Mannurita, Eleonora Gambineri, Lucia Bianchi,Gloria Serena, Paolo Lionetti, Anna Maria Gelli, ChiaraAzzari, Maurizio de Martino. University of Florence,Florence, Italy
FOXP3+CD4+CD25+ regulatory T cells play a key role inregulation of immune responses. To date there are few studiesthat describes their potential function in human inflammatorybowel disease (IBD), although it has been demonstrated thatthis T cells subset can prevent experimental murine colitis. Inthis study 14 patients affected by IBD (9 patients withUlcerative Colitis and 5 with Crohn's disease), and 8 healthysubjects were enrolled. Peripheral blood mononuclear cells(PBMCs) were analysed by flow cytometry to evaluate FOXP3+CD4+CD25+ regulatory T cells. First the frequency of CD4+CD25+bright lymphocytes subset was examined, then we
evaluated FOXP3 expression calculating the mean fluores-cence intensity (MFI). Statistic analysis was performed byStudent's t-test. We observed a higher CD4+CD25+brightexpression in IBD patients than in healthy subjects (3,13±1,26% vs 1,50±0.53%, p=0,002), but a lower FOXP3 expressionboth in CD4+CD25+ total population (MFI=5,19±1,8 vs 7,20±1,79 pb0.05) and in CD4+CD25+bright subset (MFI=9,56±2,83vs 13,80±3,96 pb0.02) in IBD patients compared to healthysubjects. Moreover this analysis was performed comparingeach group of patients affected by the same disease with thenormal subjects and similar results were obtained. Althoughpatients with IBD showed an increased number of CD4+CD25+bright, probably due to a steady-state activation, lower FOXP3levels were found in this cell subset compared to healthysubjects, suggesting that impaired expression of FOXP3 maybe responsible of the immune imbalance in IBD. Furtherstudies to confirm these preliminary findings and to testFOXP3 function both on peripheral blood and mucosallymphocytes are currently ongoing.
doi:10.1016/j.clim.2008.03.348
Sa.128. Simultaneous Oral Gluten and MicrobialExposure Increases Systemic Cytokine Suppressionin a MHC Class II Dependent MannerSusan Barton, Eric Marietta, Marshall Behrens, MelissaJacobson, Kerryl Piper, Joseph Murray, Chella David. MayoClinic, Rochester, MN
Celiac disease (CD) is an autoimmune enteropathy of theproximal small bowel that is strongly associated with DQ2/DQ8 HLA genotypes. Prevotella organisms have been identi-fied in increased numbers in the stool of celiac patients. In anattempt to develop a murine model of enteropathy for CD,Prevotella species (PS) and Prevotella melaninogenica (PM)cultured from the proximal small bowel of celiac diseasepatients were introduced via oral gavages into AeoDQ8transgenic mice with or without the introduction of oralgluten feeding. All the mice had been weaned and maintainedon a gluten free diet. The three experimental groups were: nobacteria and no dietary gluten (control group), bacteria alone,and bacteria plus initiation of a gluten-containing diet. Noenteropathy developed. Rather there was high level suppres-sion of the following cytokines in the sera in both series afterthe administration of both dietary gluten and bacteria (meanreduction): IFNγ (↓51%), IL-12p70 (↓56%), IL-17 (↓64%), TNFa(↓62%), IL-6 (↓61%), IL-10 (↓61%), IL-13 (↓64%). In comparison,Aeo-/- mice had decreased suppression of serum cytokineswhen co-administered gluten and bacteria. This would suggesta role for MHC class II. Feeding PS or PM bacteria with dietarygluten resulted in an increase in splenic CD4+CD25-FoxP3+ T-cells. These findings suggest that there is systemic cytokinesuppression generated in response to simultaneous gluten andmicrobial antigen exposure in the context of the glutensensitive associated MHC genotype DQ8 that may reflect agluten augmented probiotic effect.
doi:10.1016/j.clim.2008.03.349
S122 Abstracts
