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Mucosal Macrophages in Intestinal Homeostasis and Inflammation

Intestinal macrophages are essential for local homeostasis and in keeping a balance between commensal microbiota and the host. However, they also play essential roles in inflammation and protective immunity, when they change from peaceful regulators to powerful aggressors. As a result, activated mac...

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Detalles Bibliográficos
Autores principales: Mowat, Allan McI, Bain, Calum C.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: S. Karger AG 2011
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3224516/
https://www.ncbi.nlm.nih.gov/pubmed/22025201
http://dx.doi.org/10.1159/000329099
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author Mowat, Allan McI
Bain, Calum C.
author_facet Mowat, Allan McI
Bain, Calum C.
author_sort Mowat, Allan McI
collection PubMed
description Intestinal macrophages are essential for local homeostasis and in keeping a balance between commensal microbiota and the host. However, they also play essential roles in inflammation and protective immunity, when they change from peaceful regulators to powerful aggressors. As a result, activated macrophages are important targets for treatment of inflammatory bowel diseases such as Crohn's disease. Until recently, the complexity and heterogeneity of intestinal macrophages have been underestimated and here we review current evidence that there are distinct populations of resident and inflammatory macrophages in the intestine. We describe the mechanisms that ensure macrophages remain partially inert in the healthy gut and cannot promote inflammation despite constant exposure to bacteria and other stimuli. This may be because the local environment ‘conditions’ macrophage precursors to become unresponsive after they arrive in the gut. Nevertheless, this permits some active, physiological functions to persist. A new population of pro-inflammatory macrophages appears in inflammation and we review the evidence that this involves recruitment of a distinct population of fully responsive monocytes, rather than alterations in the existing cells. A constant balance between these resident and inflammatory macrophages is critical for maintaining the status quo in healthy gut and ensuring protective immunity when required.
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spelling pubmed-32245162012-04-10 Mucosal Macrophages in Intestinal Homeostasis and Inflammation Mowat, Allan McI Bain, Calum C. J Innate Immun Review Intestinal macrophages are essential for local homeostasis and in keeping a balance between commensal microbiota and the host. However, they also play essential roles in inflammation and protective immunity, when they change from peaceful regulators to powerful aggressors. As a result, activated macrophages are important targets for treatment of inflammatory bowel diseases such as Crohn's disease. Until recently, the complexity and heterogeneity of intestinal macrophages have been underestimated and here we review current evidence that there are distinct populations of resident and inflammatory macrophages in the intestine. We describe the mechanisms that ensure macrophages remain partially inert in the healthy gut and cannot promote inflammation despite constant exposure to bacteria and other stimuli. This may be because the local environment ‘conditions’ macrophage precursors to become unresponsive after they arrive in the gut. Nevertheless, this permits some active, physiological functions to persist. A new population of pro-inflammatory macrophages appears in inflammation and we review the evidence that this involves recruitment of a distinct population of fully responsive monocytes, rather than alterations in the existing cells. A constant balance between these resident and inflammatory macrophages is critical for maintaining the status quo in healthy gut and ensuring protective immunity when required. S. Karger AG 2011-10 2011-09-19 /pmc/articles/PMC3224516/ /pubmed/22025201 http://dx.doi.org/10.1159/000329099 Text en Copyright © 2011 by S. Karger AG, Basel http://creativecommons.org/licenses/by-nc/3.0/ This article is distributed under the terms of the Creative Commons Attribution-Noncommercial License (http://creativecommons.org/licenses/by-nc/3.0/). Users may download, print and share this work on the Internet for noncommercial purposes only, provided the original work is properly cited, and a link to the original work on http://www.karger.com and the terms of this license are included in any shared versions.
spellingShingle Review
Mowat, Allan McI
Bain, Calum C.
Mucosal Macrophages in Intestinal Homeostasis and Inflammation
title Mucosal Macrophages in Intestinal Homeostasis and Inflammation
title_full Mucosal Macrophages in Intestinal Homeostasis and Inflammation
title_fullStr Mucosal Macrophages in Intestinal Homeostasis and Inflammation
title_full_unstemmed Mucosal Macrophages in Intestinal Homeostasis and Inflammation
title_short Mucosal Macrophages in Intestinal Homeostasis and Inflammation
title_sort mucosal macrophages in intestinal homeostasis and inflammation
topic Review
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3224516/
https://www.ncbi.nlm.nih.gov/pubmed/22025201
http://dx.doi.org/10.1159/000329099
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