Focus on Macrophages

New data redefine macrophages as diverse, polyfunctional and plastic cells that respond to the needs of the tissue at steady state and during disturbed homeostasis.

Gomez Perdiguero and Geissmann discuss the origin of tissue macrophages as a layered system composed of resident macrophages originating mostly from yolk-sac progenitor cells and transitory myeloid cells that originate and renew from bone marrow hematopoietic stem cells.

Macrophages are essential components of mammalian tissues. In this Review, Okabe and Medzhitov discuss the emerging views of macrophage biology from evolutionary, developmental and homeostatic perspectives.

In addition to their role in systemic innate immunity, macrophages have important tissue-specific roles. In this Review, Jung and colleagues discuss how differentiation and tissue-specific activation of macrophages are regulated.

Glass and Natoli review recent advances in the understanding of mechanisms underlying priming and signal-dependent activation of macrophages, and discuss the impact of genetic variation on these processes.

Ginhoux and colleagues discuss how recent advances in macrophage development and functional diversity indicate a multidimensional concept of macrophage ontogeny, activation and function.