Published online Mar 27, 2017. doi: 10.5411/wji.v7.i1.1
Peer-review started: September 11, 2016
First decision: November 14, 2016
Revised: November 18, 2016
Accepted: December 7, 2016
Article in press: December 9, 2016
Published online: March 27, 2017
Macrophages are key players in various immune responses. In addition to functions in innate immunity such as antigen phagocytosis and cytokine production, antigen presentation by macrophage represents a link between innate and acquired immunity. During inflammatory processes, naïve monocytes differentiate into pro-inflammatory M1 and anti-inflammatory M2 macrophages. Resident monocytes/macrophages contribute to immune response that maintains tissue-specific homeostasis. In the target organs of autoimmune diseases, macrophages have dual functions in both the induction and suppression of autoimmune responses, which are mediated by production of various cytokines and chemokines, or by interaction with other immune cells. This review focuses on selected autoimmune diseases, such as systemic lupus erythematosus, multiple sclerosis, rheumatoid arthritis, and Sjögren’s syndrome, to illustrate the key roles of macrophages in the cellular or molecular pathogenesis of autoimmunity. In addition, the contribution of macrophages to each autoimmune disease is compared.
Core tip: Macrophages are well known as phagocytic cells and the source of cytokines and other immunomodulators of the innate immune system. There are many reviews of macrophage function, but not many that focus on their role in autoimmunity and autoimmune disease. This review focuses on the role of tissue resident macrophages in autoimmunity both in general and several selected autoimmune diseases, develops a novel context for evaluation and a slightly different way of thinking of the complex interactions involved in “mistaken self-identity”.