Macrophages Maintain Epithelium Integrity by Limiting Fungal Product Absorption.

TitleMacrophages Maintain Epithelium Integrity by Limiting Fungal Product Absorption.
Publication TypeJournal Article
Year of Publication2020
AuthorsChikina, AS, Nadalin, F, Maurin, M, San-Roman, M, Thomas-Bonafos, T, Li, XV, Lameiras, S, Baulande, S, Henri, S, Malissen, B, Mariano, LLacerda, Barbazan, J, J Blander, M, Iliev, ID, Vignjevic, DMatic, Lennon-Duménil, A-M
JournalCell
Date Published2020 Sep 23
ISSN1097-4172
Abstract

The colon is primarily responsible for absorbing fluids. It contains a large number of microorganisms including fungi, which are enriched in its distal segment. The colonic mucosa must therefore tightly regulate fluid influx to control absorption of fungal metabolites, which can be toxic to epithelial cells and lead to barrier dysfunction. How this is achieved remains unknown. Here, we describe a mechanism by which the innate immune system allows rapid quality check of absorbed fluids to avoid intoxication of colonocytes. This mechanism relies on a population of distal colon macrophages that are equipped with "balloon-like" protrusions (BLPs) inserted in the epithelium, which sample absorbed fluids. In the absence of macrophages or BLPs, epithelial cells keep absorbing fluids containing fungal products, leading to their death and subsequent loss of epithelial barrier integrity. These results reveal an unexpected and essential role of macrophages in the maintenance of colon-microbiota interactions in homeostasis. VIDEO ABSTRACT.

DOI10.1016/j.cell.2020.08.048
Alternate JournalCell
PubMed ID32970988
Grant ListR01 DK113136 / DK / NIDDK NIH HHS / United States
R01 DK121977 / DK / NIDDK NIH HHS / United States