Dynamic changes in macrophage metabolism modulate induction and suppression of Type I inflammatory responses. (December 2021)

• Record Type: Journal Article
• Authors: Luan, Haoming; Horng, Tiffany
• Is Part Of: Current opinion in immunology. Volume 73(2021)
• Page Start: 9
• Page End: 15
• Publication Date: 2021-12
• Subjects: Immunology -- Periodicals; Allergy -- Periodicals; Immunology -- Abstracts -- Periodicals; Allergy -- Abstracts -- Periodicals; 616.079
• DOI: 10.1016/j.coi.2021.07.012
• Languages: English
• ISSNs: 0952-7915

Abstract

Highlights: Induction and suppression of inflammatory responses must be regulated to balance beneficial and detrimental effects. A dynamic shift from anabolic to catabolic metabolism modulates the shift from induction to suppression of inflammatory responses. Induction of inflammatory responses is fueled by a high-energy anabolic state and enhanced oxidative metabolism. Suppression of inflammatory responses is facilitated by a decreased oxidative metabolism and a catabolic state. Abstract : During microbial infection, macrophages link recognition of microbial stimuli to the induction of Type I inflammatory responses. Such inflammatory responses coordinate host defense and pathogen elimination but induce significant tissue damage if sustained, so macrophages are initially activated to induce inflammatory responses but then shift to a tolerant state to suppress inflammatory responses. Macrophage tolerance is regulated by induction of negative regulators of TLR signaling, but its metabolic basis was not known. Here, we review recent studies that indicate that macrophage metabolism changes dynamically over the course of microbial exposure to influence a shift in the inflammatory response. In particular, an initial increase in oxidative metabolism boosts the induction of inflammatory responses, but is followed by a shutdown of oxidative metabolism that contributes to suppression of inflammatory responses. We propose a unifying model for how dynamic changes to oxidative metabolism influences regulation of macrophage inflammatory responses during microbial exposure.