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Toll-like receptor-4 differentially mediates intestinal and extra-intestinal immune responses upon multi-drug resistant Pseudomonas aeruginosa association of IL10(−/−) mice with chronic colitis
BACKGROUND: Infections with multi-drug resistant (MDR) Gram-negative bacteria including Pseudomonas aeruginosa (PA) have become a serious threat particularly in hospitalized patients with immunopathological co-morbidities. The well-balanced interplay between immune cells, pattern recognition recepto...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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BioMed Central
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5678768/ https://www.ncbi.nlm.nih.gov/pubmed/29151895 http://dx.doi.org/10.1186/s13099-017-0211-z |
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author | Grunau, Anne Escher, Ulrike Kühl, Anja A. Bereswill, Stefan Heimesaat, Markus M. |
author_facet | Grunau, Anne Escher, Ulrike Kühl, Anja A. Bereswill, Stefan Heimesaat, Markus M. |
author_sort | Grunau, Anne |
collection | PubMed |
description | BACKGROUND: Infections with multi-drug resistant (MDR) Gram-negative bacteria including Pseudomonas aeruginosa (PA) have become a serious threat particularly in hospitalized patients with immunopathological co-morbidities. The well-balanced interplay between immune cells, pattern recognition receptors such as Toll-like receptor (TLR)-4 sensing lipopolysaccharide from Gram-negative bacteria including PA, and evolving pathways is crucial to prevent the host from invading (opportunistic) pathogens. Information regarding the molecular mechanisms underlying the interactions between intestinal carriage of MDR PA and host immunity during chronic large intestinal inflammation is scarce, however. METHODS AND RESULTS: We therefore perorally challenged conventionally colonized TLR4-deficient IL10(−/−) mice and IL10(−/−) counterparts displaying comparably severe chronic colitis with a clinical MDR PA strain. PA could more sufficiently establish in the intestinal tract of TLR4-deficient IL10(−/−) mice until day 14 postinfection (p.i.), whereas within 48 h the majority of IL10(−/−) mice had already expelled the opportunistic pathogen from their guts. Intestinal colonization properties of PA in TLR4-deficient IL10(−/−) mice were associated with distinct genotype-dependent differences in gut microbiota compositions before challenge given that TLR4-deficient IL10(−/−) mice harbored more fecal enterobacteria and enterococci, but lower Clostridium/Eubacterium burdens. At day 14 p.i., PA-induced increases in colonic immune cells such as macrophages, monocytes and T-lymphocytes could be observed in TLR4-deficient IL10(−/−) mice, but not IL10(−/−) counterparts, that were accompanied by a more distinct secretion of IFN-γ in the colon and TNF in the mesenteric lymph nodes (MLN) of the former as compared to the latter. Conversely, splenic TNF levels were lower in TLR4-deficient IL10(−/−) mice as compared to IL10(−/−) controls at day 14 p.i. Interestingly, more pronounced apoptotic responses could be assessed in colonic epithelia of PA-challenged IL10(−/−) mice only. This was paralleled by enhanced pro-inflammatory cytokine secretion not only in the intestines, but also in extra-intestinal compartments of IL10(−/−) mice as indicated by increased concentrations of nitric oxide in the colon, IFN-γ in the MLN and IL-12p70 in the spleen at day 14 p.i. CONCLUSIONS: Under chronic intestinal inflammatory conditions including IL10(−/−) colitis MDR PA-association results in well-orchestrated TLR4-dependent immune responses both in intestinal and extra-intestinal compartments. Further studies should unravel the underlying molecular mechanisms in more detail. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13099-017-0211-z) contains supplementary material, which is available to authorized users. |
format | Online Article Text |
id | pubmed-5678768 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-56787682017-11-17 Toll-like receptor-4 differentially mediates intestinal and extra-intestinal immune responses upon multi-drug resistant Pseudomonas aeruginosa association of IL10(−/−) mice with chronic colitis Grunau, Anne Escher, Ulrike Kühl, Anja A. Bereswill, Stefan Heimesaat, Markus M. Gut Pathog Research BACKGROUND: Infections with multi-drug resistant (MDR) Gram-negative bacteria including Pseudomonas aeruginosa (PA) have become a serious threat particularly in hospitalized patients with immunopathological co-morbidities. The well-balanced interplay between immune cells, pattern recognition receptors such as Toll-like receptor (TLR)-4 sensing lipopolysaccharide from Gram-negative bacteria including PA, and evolving pathways is crucial to prevent the host from invading (opportunistic) pathogens. Information regarding the molecular mechanisms underlying the interactions between intestinal carriage of MDR PA and host immunity during chronic large intestinal inflammation is scarce, however. METHODS AND RESULTS: We therefore perorally challenged conventionally colonized TLR4-deficient IL10(−/−) mice and IL10(−/−) counterparts displaying comparably severe chronic colitis with a clinical MDR PA strain. PA could more sufficiently establish in the intestinal tract of TLR4-deficient IL10(−/−) mice until day 14 postinfection (p.i.), whereas within 48 h the majority of IL10(−/−) mice had already expelled the opportunistic pathogen from their guts. Intestinal colonization properties of PA in TLR4-deficient IL10(−/−) mice were associated with distinct genotype-dependent differences in gut microbiota compositions before challenge given that TLR4-deficient IL10(−/−) mice harbored more fecal enterobacteria and enterococci, but lower Clostridium/Eubacterium burdens. At day 14 p.i., PA-induced increases in colonic immune cells such as macrophages, monocytes and T-lymphocytes could be observed in TLR4-deficient IL10(−/−) mice, but not IL10(−/−) counterparts, that were accompanied by a more distinct secretion of IFN-γ in the colon and TNF in the mesenteric lymph nodes (MLN) of the former as compared to the latter. Conversely, splenic TNF levels were lower in TLR4-deficient IL10(−/−) mice as compared to IL10(−/−) controls at day 14 p.i. Interestingly, more pronounced apoptotic responses could be assessed in colonic epithelia of PA-challenged IL10(−/−) mice only. This was paralleled by enhanced pro-inflammatory cytokine secretion not only in the intestines, but also in extra-intestinal compartments of IL10(−/−) mice as indicated by increased concentrations of nitric oxide in the colon, IFN-γ in the MLN and IL-12p70 in the spleen at day 14 p.i. CONCLUSIONS: Under chronic intestinal inflammatory conditions including IL10(−/−) colitis MDR PA-association results in well-orchestrated TLR4-dependent immune responses both in intestinal and extra-intestinal compartments. Further studies should unravel the underlying molecular mechanisms in more detail. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13099-017-0211-z) contains supplementary material, which is available to authorized users. BioMed Central 2017-11-07 /pmc/articles/PMC5678768/ /pubmed/29151895 http://dx.doi.org/10.1186/s13099-017-0211-z Text en © The Author(s) 2017 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. |
spellingShingle | Research Grunau, Anne Escher, Ulrike Kühl, Anja A. Bereswill, Stefan Heimesaat, Markus M. Toll-like receptor-4 differentially mediates intestinal and extra-intestinal immune responses upon multi-drug resistant Pseudomonas aeruginosa association of IL10(−/−) mice with chronic colitis |
title | Toll-like receptor-4 differentially mediates intestinal and extra-intestinal immune responses upon multi-drug resistant Pseudomonas aeruginosa association of IL10(−/−) mice with chronic colitis |
title_full | Toll-like receptor-4 differentially mediates intestinal and extra-intestinal immune responses upon multi-drug resistant Pseudomonas aeruginosa association of IL10(−/−) mice with chronic colitis |
title_fullStr | Toll-like receptor-4 differentially mediates intestinal and extra-intestinal immune responses upon multi-drug resistant Pseudomonas aeruginosa association of IL10(−/−) mice with chronic colitis |
title_full_unstemmed | Toll-like receptor-4 differentially mediates intestinal and extra-intestinal immune responses upon multi-drug resistant Pseudomonas aeruginosa association of IL10(−/−) mice with chronic colitis |
title_short | Toll-like receptor-4 differentially mediates intestinal and extra-intestinal immune responses upon multi-drug resistant Pseudomonas aeruginosa association of IL10(−/−) mice with chronic colitis |
title_sort | toll-like receptor-4 differentially mediates intestinal and extra-intestinal immune responses upon multi-drug resistant pseudomonas aeruginosa association of il10(−/−) mice with chronic colitis |
topic | Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5678768/ https://www.ncbi.nlm.nih.gov/pubmed/29151895 http://dx.doi.org/10.1186/s13099-017-0211-z |
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