Understanding the Mysterious M2 Macrophage through Activation Markers and Effector Mechanisms

作者：Tamás Rőszer · 发表于：Mediators of Inflammation · 年份：2015 · DOI：10.1155/2015/816460 · 被引用次数：1782 · 研究领域：Immune cells in cancer、Tryptophan and brain disorders、Immune Cell Function and Interaction

The alternatively activated or M2 macrophages are immune cells with high phenotypic heterogeneity and are governing functions at the interface of immunity, tissue homeostasis, metabolism, and endocrine signaling. Today the M2 macrophages are identified based on the expression pattern of a set of M2 markers. These markers are transmembrane glycoproteins, scavenger receptors, enzymes, growth factors, hormones, cytokines, and cytokine receptors with diverse and often yet unexplored functions. This review discusses whether these M2 markers can be reliably used to identify M2 macrophages and define their functional subdivisions. Also, it provides an update on the novel signals of the tissue environment and the neuroendocrine system which shape the M2 activation. The possible evolutionary roots of the M2 macrophage functions are also discussed.