Innate imprinting of murine resident alveolar macrophages by allergic bronchial inflammation causes a switch from hypoinflammatory to hyperinflammatory reactivity

15Citations
Citations of this article
46Readers
Mendeley users who have this article in their library.

Abstract

Resident alveolar macrophages (rAMs) residing in the bronchoalveolar lumen of the airways play an important role in limiting excessive inflammatory responses in the respiratory tract. High phagocytic activity along with hyporesponsiveness to inflammatory insults and lack of autonomous IFN-β production are crucial assets in this regulatory function. Using a mouse model of asthma, we analyzed the fate of rAMs both during and after allergic bronchial inflammation. Although nearly indistinguishable phenotypically from naïve rAMs, postinflammation rAMs exhibited a strongly reduced basal phagocytic capacity, accompanied by a markedly increased inflammatory reactivity to Toll-like receptors TLR-3 (poly I:C), TLR-4 [lipopolysaccharide (LPS)], and TLR-7 (imiquimod). Importantly, after inflammation, rAMs exhibited a switch from an IFN-β-defective to an IFN-β-competent phenotype, thus indicating the occurrence of a new, inflammatory-released rAM population in the postallergic lung. Analysis of rAM turnover revealed a rapid disappearance of naïve rAMs after the onset of inflammation. This inflammation-induced rAM turnover is critical for the development of the hyperinflammatory rAM phenotype observed after clearance of bronchial inflammation. These data document a novel mechanism of innate imprinting in which noninfectious bronchial inflammation causes alveolar macrophages to acquire a highly modified innate reactivity. The resulting increase in secretion of inflammatory mediators on TLR stimulation implies a role for this phenomenon of innate imprinting in the increased sensitivity of postallergic lungs to inflammatory insults. Copyright © 2012 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Cite

CITATION STYLE

APA

Naessens, T., Vander Beken, S., Bogaert, P., Van Rooijen, N., Lienenklaus, S., Weiss, S., … Grooten, J. (2012). Innate imprinting of murine resident alveolar macrophages by allergic bronchial inflammation causes a switch from hypoinflammatory to hyperinflammatory reactivity. American Journal of Pathology, 181(1), 174–184. https://doi.org/10.1016/j.ajpath.2012.03.015

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free