Macrophage heterogeneity in autoimmune diseases

The pathogenesis of autoimmune diseases (AIDs) is complex and their etiology remains unclear, with multiple cell types involved in the disease progression. Macrophages, as a crucial immune cell population in AIDs, play a pivotal role in maintaining immune homeostasis. In traditional research, macrophages are frequently oversimplified into the M1 and M2 polarized subtypes. The advent of single-cell RNA sequencing (scRNA-seq) technology has significantly advanced high-throughput research in the life sciences, enabling in-depth investigations at the cellular and molecular levels. This technology has revealed the significant heterogeneity of macrophages, further enhancing our understanding of their development, phenotypic diversity, and functional plasticity. Additionally, it provides a novel perspective for exploring the molecular mechanisms underlying various diseases. In this review, we comprehensively explore the heterogeneity of macrophages across different AIDs, and summarize potential therapeutic targets for macrophage-directed interventions, aiming to provide valuable theoretical insights and novel research directions to advance precision therapy and related studies in AIDs.