Editorial: Sentinels of the immune system: tissue-resident macrophages in the battle against infection and autoimmunity

Macrophages are an integral component of innate immunity and serve as the first line of defense against tissue damage and infection. Tissue-resident macrophages (TRMs) originate from embryonic precursor cells and differentiate into Microglia (brain), alveolar macrophages (lung), Kupffer cells (liver), Langerhans cells (skin), Lamina propria (intestine), red pulp/white pulp/marginal zonal (spleen), peritoneal macrophages (peritoneal cavity) (1). TRMs are seeded into the tissues and maintained throughout lifespan by local self-renewal. TRMs are highly specialized tissue-resident cells with diverse functions and play an important role in maintaining homeostasis by preventing infections, controlling inflammation, and regulating autoimmunity (2) . This research topic was conceived to bring together studies that address current challenges and bridge the existing gaps in TRMs biology, including mechanism underlying tissues heterogeneity, interaction between TRMs and other immune cells in controlling pathogenic infections and autoimmune responses, and the development of novel macrophage-targeted therapeutic approaches. The five published articles cover a broad range of topics, including macrophage-mediated immune regulation, disease development, polarization, and emerging therapeutic approaches using both preclinical models and clinical settings. Here, we summarize their key findings, highlighting advances and new insights in TRMs research.