Monocytes and macrophages: developmental pathways and tissue homeostasis.
Monocytes and macrophages have crucial and distinct roles in tissue homeostasis and immunity, but they also contribute to a broad spectrum of pathologies and are thus attractive therapeutic targets. Potential intervention strategies that aim to manipulate these cells will require an in-depth understanding of their origins and the mechanisms that ensure their homeostasis. Recent evidence shows that monocytes do not substantially contribute to most tissue macrophage populations in the steady state or during certain types of inflammation. Rather, most tissue macrophage populations in mice are derived from embryonic precursors, are seeded before birth and can maintain themselves in adults by self-renewal. In this Review, we discuss the evidence that has dramatically changed our understanding of monocyte and macrophage development, and the maintenance of these cells in the steady state.
Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), 138648 Singapore.
Florent
F
Ginhoux
Department of Immunology, The Weizmann Institute of Science, Rehovot 76100, Israel.
Steffen
S
Jung
D000818:Animals; D001717:Birds / Q000276:immunology; D001854:Bone Marrow Cells / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology; D006410:Hematopoiesis / Q000276:immunology*; D006706:Homeostasis / Q000276:immunology*; D006801:Humans; D007249:Inflammation / Q000276:immunology; D008264:Macrophages / Q000276:immunology*; D051379:Mice; D009000:Monocytes / Q000276:immunology*; D015027:Zebrafish / Q000276:immunology