Macrophages: Development and Tissue Specialization

作者：Chen Varol, Alexander Mildner, Steffen Jung · 发表于：Annual Review of Immunology · 年份：2015 · DOI：10.1146/annurev-immunol-032414-112220 · 被引用次数：977 · 研究领域：Immune cells in cancer、Neuroinflammation and Neurodegeneration Mechanisms、Phagocytosis and Immune Regulation

Macrophages are myeloid immune cells that are strategically positioned throughout the body tissues, where they ingest and degrade dead cells, debris, and foreign material and orchestrate inflammatory processes. Here we review two major recent paradigm shifts in our understanding of tissue macrophage biology. The first is the realization that most tissue-resident macrophages are established prenatally and maintained through adulthood by longevity and self-renewal. Their generation and maintenance are thus independent from ongoing hematopoiesis, although the cells can be complemented by adult monocyte-derived macrophages. Second, aside from being immune sentinels, tissue macrophages form integral components of their host tissue. This entails their specialization in response to local environmental cues to contribute to the development and specific function of their tissue of residence. Factors that govern tissue macrophage specialization are emerging. Moreover, tissue specialization is reflected in discrete gene expression profiles of macrophages, as well as epigenetic signatures reporting actual and potential enhancer usage.