Intestinal Microflora and Immunoregulation Monica Boirivant Istituto Superiore di Sanità Roma
Microflora-immune cells interactions Ethanol AT 12 T
Effect of ir Ethanol 5% administration 115 weight (% of day ) 11 15 1 95 9 85 * * * * Untreated Eth 5% *= p<.5 8 2 4 6 8 1 12 Days
Effect of ir Ethanol 5% administration Increased intestinal permeability Serum Fitc-Dextran (μg/ml) 8 6 4 2 * * * * Day 1 Day 3 Day 5 Day 7 1 2 3 4 5 6 7 8 *p<.5 vs day Days
Effect of ir Ethanol 5% administration Increased LPMC production of IFN-γ and IL-1 IFN-γ (pg/ml) 8 6 4 2 p=.2 IL-1 (pg/ml) 12 1 8 6 4 2.7 p=.3 Unstim αcd3/28 Untreated Eth5% Untreated Eth 5%
Effect of ir Ethanol 5% administration Increased % of CD25+ and LAP+ cells in CD4+LPC 14 14 CD25+ T cells (%) 12 1 8 6 p=.2 LAP+ T cells (%) 12 1 8 6 p=.2 4 4 2 2 Untreated Eth 5% Untreated Eth 5%
Foxp3+ cells (%) 9 8 7 6 5 4 3 2 1 Untreated Eth 5% CD25+ cells LAP+ cells
Effect of ir Ethanol 5% pre-administration Protection from TNBS-colitis 15 weight (% of day ) 1 95 9 * * * Eth 5%/TNBS TNBS TNBS 35 3 p=.3 Eth 5%/TNBS 85 8 1 2 3 4 Days IFN-γ (ng/ml) 25 2 15 1 5 Unstim αcd3/28 *= p<.5 Eth/TNBS TNBS
AT 12 Hexapeptide representing the active domain of zonula occludens toxin from Vibrio cholerae Acting as mammalian zonulin, causing disassembling of tight junctions AT12 intraluminal administration is associated with transient increase of intestinal permeability without epitelial damage Katouzian F et al. J pediatr Gastroenterol Nutr 25; 4:632 Mottlekar NA et al. J Drug Target 26; 14:321-9
Effect of ir AT 12 administration Increased LPMC production of IFN-γ and IL-1 Increased % of CD25+ and LAP+ cells in CD4+LPC 14 12 Unstim α CD3/28 1 pg/ml 8 6 IL-1 IFN-γ 4 Untreated 2 Untreated AT 12 Untreated AT 12 7 6 p=.2 5 % 4 3 Untreated AT12 2 1 AT 12 treated CD25 LAP
Effect of ir AT12 pre-administration Protection from TNBS-colitis weight (% of day ) 15 1 95 9 85 8 75 AT12/ TNBS TNBS * * * * 7 1 2 3 4 *= p<.5 Days TNBS AT12/ TNBS 1 2 3 4 5 Colitis score
Summary I Specific induction of increased mucosal permeability is associated with an increased production of IFN-γ and IL-1 as well as with an increase in the number of CD4+T cells expressing CD25 and/or LAP This condition is associated with resistance to induction of TNBS colitis
Effect of ir Ethanol 5% pre-administration Protection from TNBS-colitis is dependent on LAP+Tcells 15 Recipients of: weight (% of day ) 1 95 9 85 8 75 7 1 2 3 4 5 Days LPMC from ethanol treated mice (A) LAP depleted LPMC from ethanol treated Mice (B) LPMC fromtnbs treated mice (C) TNBS(D) IFN-γ (ng/ml) 1 9 8 7 6 5 4 3 2 1 Unstim α CD3/28 Recipients Recipients of LPMC of LAP+depleted LPMC TNBS
1 4.28 Control ETOH ETOH(LAP depleted) 1 3 1 4 7.27 1 3 1 4 24.8 1 3 1 4 12.3 1 3 GoatIgG 1 2 1 1 LAP 1 2 1 1 1 2 1 1 1 2 1 1 1 1 4 1 1 1 1 2 1 3 1 4 1 1 1 1 4 1 1 1 1 2 1 3 1 4 1 1 4 1 1 1 2 1 3 1 4 1 1 4 1 1 1 2 1 3 1 4 RatIgG 1 3 1 2.75 Foxp3 1 3 1 2 6.7 1 3 1 2 9.3 1 3 1 2 9.31 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 3 1 4 CD4 1 1 1 1 1 1 1 2 1 3 1 4 1 1 1 1 2 1 3 1 4 1 1 1 1 2 1 3 1 4 CD4
CD4+LAP+ cells expansion is dependent on the presence of an intact bacterial flora Ampicillin:1g/L Vancomycin: 5 mg/l 4 weeks Neomycin: 1g/L 15 Metronidazole: 1g/L weight (% of day ) 1 95 9 85 8 75 7 Eth 5% Antibiotics/Eth 5% 1 2 3 4 5 % 3 25 2 15 1 5 Eth 5% Antibiotics/Eth5% Untreated CD25+ LAP+ Days
Summary II CD4+LAP+ cells are responsible for the protection from TNBS colitis CD4+LAP+ expansion is dependent on the presence of an intact bacterial flora
Plasmacytoid dendritic cells do not play a role in the expansion of regulatory cells causing increased resistance to TNBS colitis 12G8 /Eth /TNBS Eth/ TNBS 12G8/TNBS αgr-1/eth/tnbs Eth/TNBS αgr-1/tnbs 15 TNBS 15 TNBS weight (% of day ) 1 95 9 85 8 weight (% of day ) 1 95 9 85 8 75 75 1 2 3 4 1 2 3 4 Days
Myeloid dendritic cells induce IL-1 dependent expansion of CD4+LAP+T cells 16 14 LAP+ cells % 12 1 8 6 4 2 LP CD4+ cells untreated mice CD11c+ cells untreated mice CD11c+ cells ethanol treated mice anti -IL-1R + + + + + + + + + + +
TLR2 signaling is critical for the generation of LAP+ Regulatory cells Weight (% of day ) Eth 5% 8 sirna Control /Eth 5% 115 7 11 sirna TLR2/Eth 5% 6 15 5 1 4 95 3 9 2 85 1 8 1 2 3 4 5 6 7 8 Days LAP+ cells (%) Eth5% p=.1 p=.5 sictr/eth5% sitlr2/eth5% pg/ml 12 11 1 9 8 7 6 5 4 3 2 1 IFN-γ - Eth5% sictr/eth5% sitlr2/eth5% IL-1
TLR2 signaling is critical for the generation of LAP+ regulatory cells weight (% of day ) 15 1 95 9 85 8 75 Eth 5%/ TNBS (A) sirna Control /Eth 5%/ TNBS (B) sirna TLR2/Eth 5%/TNBS (C) TNBS(D) 1 2 3 4 Days
Summary III Myeloid dendritic cells induce an IL-1 dependent expansion of CD4+LAP+T cells TLR2 signaling is critical for the generation of LAP+ regulatory cells
Conclusions Transient loss of epithelial cell barrier function increases the resistance of the mucosa to inflammation via the induction of regulatory T cells Limited exposure of the mucosal immune system to the microflora might represent an important mechanism of tolerance induction and gut homeostasis
Antonello Amendola Alessia Butera Monica Boirivant Immune-mediated Diseases Section. Department of Infectious, Parasitic and Immune-mediated Diseases. Istituto Superiore di Sanità. Roma. Italy Ivan Fuss Warren Strober Mucosal Immunity Section. Laboratory of host defences. NIAID. NIH. USA
IL-1 production of LPMC before and after LAP depletion pg/m 16 14 12 1 8 6 4 2 IL-1 TGF-b Untreated Eth 5% Eth 5% LAP depleted
25 2 IL-1 (pg/ml) 15 1 5 LP CD4+ cells untreated mice CD11c+ cells untreated mice CD11c+ cells ethanol treated mice anti-il-1r + + + + + + + + + + +
9 NA : Not available 8 IL-12 p7 (pg/ml) 7 6 5 4 3 2 1 NA LP CD4+ cells untreated mice CD11c+ cells untreated mice CD11c+ cells ethanol treated mice anti-il-1r + + + + + + + + + + +
ND: not detectable 12 1 IL-1 (pg/ml) 8 6 4 2 ND LP CD4+ cells untreated mice CD11c+ cells untreated mice CD11c+ cells ethanol treated mice anti-il-1r + + + + + + + + + + +
ND: not detectable 3 25 IL-12 p7 (pg/ml) 2 15 1 5 LP CD4+ cells untreated mice CD11c+ cells untreated mice CD11c+ cells ethanol treated mice anti-il-1r ND ND ND + + + + + + + + + + +
ND: not detectable pg/ml 5 45 4 35 3 25 2 15 1 IL-12 IL-1 5 ND CD11c+cells untreated CD11c+cells Eth 5% IL-12 15.58 IL-1 8.5 475
Microflora-immune cells interactions B MФ DC T