Innate immunity champions: The diverse functions of macrophages

Abstract

Macrophages are instrumental in maintaining tissue homeostasis, modulating inflammation, and driving regeneration. The advent of omics techniques has led to the identification of numerous tissue-specific macrophage subtypes, thereby introducing the concept of the “macrophage niche”. This paradigm underscores the ability of macrophages to adapt their functions based on environmental cues, such as tissue-specific signals. This adaptability is closely linked to their metabolic states, which are crucial for their function and role in health and disease. Macrophage metabolism is central to their ability to switch between proinflammatory and anti-inflammatory states. In this regard, environmental factors, including the extracellular matrix, cellular interactions, and microbial metabolites, profoundly influence macrophage behavior. Moreover, diet and gut microbiota significantly impact macrophage function, with nutrients and microbial metabolites influencing their activity and contributing to conditions like inflammatory bowel disease. Targeting specific macrophage functions and their metabolic processes is leading to the development of novel treatments for a range of chronic inflammatory conditions. The exploration of macrophage biology enriches our understanding of immune regulation and holds the promise of innovative approaches to managing diseases marked by inflammation and immune dysfunction, offering a frontier for scientific and clinical advancement.