Macrophages (and their precursors, monocytes) are the 'big eaters' of the immune system. These cells reside in every tissue of the body, albeit in different guises — such as microglia, Kupffer cells and osteoclasts — where they engulf apoptotic cells and pathogens and produce immune effector molecules. Upon tissue damage or infection, monocytes are rapidly recruited to the tissue, where they differentiate into tissue macrophages. Macrophages are remarkably plastic and can change their functional phenotype depending on the environmental cues they receive. Through their ability to clear pathogens and instruct other immune cells, these cells have a central role in protecting the host but also contribute to the pathogenesis of inflammatory and degenerative diseases.

The Review articles in this Focus on Monocytes and macrophages, together with recent Research Highlights and an accompanying Web Library of the most relevant recent publications from Nature Publishing Group, describe our current understanding of this ancient field.

All of the articles in this Focus are available free to registered users until December 2011.

Research Highlights

Immunotherapy: Stopping monocytes in their tracks


Nature Reviews Immunology, 11, 715 (2011)

Therapeutic targeting of inflammatory monocyte migration attenuates disease severity.

In brief

Macrophages: Arteriogenic macrophages protect against ischaemia | PDF (124 KB)

p716 | doi:10.1038/nri3097

Nature Reviews Immunology, 11, 716 (2011)

Monocytes: How a high-fat diet results in monocytosis | PDF (124 KB)

p716 | doi:10.1038/nri3104

Nature Reviews Immunology, 11, 716 (2011)

Technique: Recapitulating human TB in vitro | PDF (124 KB)

p716 | doi:10.1038/nri3105

Nature Reviews Immunology, 11, 716 (2011)


Protective and pathogenic functions of macrophage subsets

Peter J. Murray & Thomas A. Wynn


Nature Reviews Immunology 11, 723-737 (2011)

Macrophages exhibit remarkable plasticity and adopt pro- or anti-inflammatory phenotypes in response to environmental signals. This Review article by Murray and Wynn discusses the different macrophage subsets and their contribution to tissue homeostasis and disease pathogenesis.

Macrophage-mediated inflammation in metabolic disease

Ajay Chawla, Khoa D. Nguyen & Y. P. Sharon Goh


Nature Reviews Immunology 11, 738-749 (2011)

Inflammation in adipose tissue is known to mediate insulin resistance in obesity, and macrophages are thought to have a central role in mediating this inflammatory response. But adipose tissue macrophages are not all bad: alternative activation of these cells promotes insulin sensitivity.

Transcriptional regulation of macrophage polarization: enabling diversity with identity

Toby Lawrence & Gioacchino Natoli


Nature Reviews Immunology 11, 750-761 (2011)

This Review describes the key transcription factors that enable the polarization of macrophages in response to the microenvironment in the context of a regulatory landscape that determines macrophage identity.

Monocyte recruitment during infection and inflammation

Chao Shi & Eric G. Pamer


Nature Reviews Immunology 11, 762-774 (2011)

Monocytes serve as precursors for various tissue macrophage and dendritic cell populations and contribute to both protective and pathological immune responses. Here, the authors describe the mechanisms that are involved in mobilizing monocytes to distinct tissue sites, both during steady-state conditions and in response to infection.

Microglial cell origin and phenotypes in health and disease

Kaoru Saijo & Christopher K. Glass


Nature Reviews Immunology 11, 775-787 (2011)

Microglia are brain-resident macrophages with a distinct origin. This Review discusses the development and function of microglia, and describes the association between the different microglia phenotypes and disease.

Studying the mononuclear phagocyte system in the molecular age

Andrew Chow, Brian D. Brown & Miriam Merad


Nature Reviews Immunology 11, 788-798 (2011)

Immunologists are making good progress in unravelling the intricacies of the mononuclear phagocyte system, and this is largely due to recent technological advances. This article describes the current tools that exist for studying the origins and functions of mononuclear phagocytes and discusses the future technologies that will enable further progress in the field.


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