. Author manuscript; available in PMC: 2014 Jun 4.

Published in final edited form as: Nat Immunol. 2013 Sep 18;14(10):986–995. doi: 10.1038/ni.2705

Table 1. Distinct locations and functions of tissue macrophages.

Tissue	^aCell type	^bFunctions & notes	Phenotypic markers (^cTissue-selective transcriptional regulators)
Adipose tissue	‘Adipose-associated macrophages’	Involved in control of insulin sensitivity⁹⁶ and adaptive thermogenesis⁹⁹.	F4/80⁺, CD45⁺ (white and brown adipose tissue)⁹⁹ (PPARγ⁹⁶)

Blood	Ly-6C^lo monocytes	These monocytes function analogously as “intravascular housekeepers” clearing endothelial cell debris¹¹⁵.	CX3CR1⁺, Ly-6C^lo, F4/80⁺, CSF1R^{+ 115} (Nr4a1¹¹⁵)

Bone	Osteoclasts	Multinucleated cells formed by fusion that resorb bone by disruption of the mineralized matrix³⁶.	Calcitonin receptor⁺ (multinucleate)¹¹⁷
	Bone marrow macrophages	Supporting erythropoeisis^{87, 88}. Maintenance of hematopoietic stem cells in stem cell niches¹¹⁶. An independent self-renewing population³⁰.	CD169⁺, F4/80⁺, ER-HR3^{+ 118}

Central nervous system	Microglia	Promotes neuronal survival, front-line immune-surveillance cell, removal of dead neurons, synaptic remodelling^{76, 119}. Derived from yolk sac and maintained and during inflammation independently of the bone marrow ^{15, 26, 65}.	F4/80⁺, CD11b⁺, CD45^{lo 120}
	Perivascular macrophages	Immune surveillance.	F4/80⁺, CD11b⁺, CD163⁺, CD45^{hi 120}
	Meningeal macrophages	Immune surveillance¹²⁰.	F4/80⁺, CD11b⁺, CD45^{hi 120}

Gastrointestinal tract	Intestinal macrophages	Maintenance of intestinal homeostasis and regulation of immune responses to commensals^{23, 121}.	CX3CR1^hi, F4/80⁺, CD11b⁺, CD11c⁺, CD64^{+ 121}

Liver	Kupffer cells (sessile)	Clearance of microorganisms and cell debris from the blood. Clearance of aged erythrocytes^{91, 122}. Pre-natal origins²². Maintained in the adult independently of the bone marrow¹⁷	F4/80^hi, CD11b^lo, CD169⁺, CD68⁺, Galectin-3⁺¹²³,^dCD80^{lo/− 122} (PPARδ⁹⁸)
	Motile liver macrophages	Immune surveilance¹²²	F4/80⁺, CD11b⁺, CD80^{hi 122}

Lung	Alveolar macrophages	Immune-surveillance of the lung for inhaled pathogens⁵¹, homeostatic regulation of tissue function^{72, 124}, for example clearance of surfactant. Prenatal origins²². Maintained in adult and during inflammation independently of the bone marrow^{30, 125}.	F4/80^lo, CD11b^lo, CD11c^hi, CD68⁺, Siglec F⁺, MARCO⁺, CD206⁺, Dectin-1⁺¹²⁷, Galectin-3^{+ 123} (PPARγ⁷²)
	Interstitial macrophages	Regulates DC maturation/activation¹²⁶.	F4/80⁺, CD11c⁻, CD68⁺, MHCII^{+ 126}

Serosal tissues	Peritoneal macrophages: F4/80^hi majority	Immune surveillance and regulation of homeostatic environment^{50, 128}. Apoptotic cell clearance⁸⁰. Pre-natal origins²². Maintained in adult and during inflammation independently of the bone marrow^{22, 29}.	F4/80^hi, CD11b^hi, ^dTim4^{+ 83} MHCII^lo
	F4/80^lo Pleural macrophages:	Immune surveillance¹²⁹.	F4/80^lo, CD11b⁺, Tim4⁻, MHCII^hi, CD11c^+/− (This population is most likely heterogeneous, mixed with dendritic cells)
	F4/80^hi majority	Maintained in adult and can expand during T_H2 inflammation independently of the bone marrow⁴¹	F4/80^hi, CD11b^hi, dTim4⁺
	F4/80^lo		F4/80^lo, CD11b⁺, Tim4⁻ (Dendritic cell-macrophage content undetermined, unpublished phenotypic observations)

Skin	Dermal macrophages	Immune surveillance¹³⁰.	F4/80⁺, CD11b⁺, CD11c^lo, CD206⁺, MHCII^lo, CD169⁺ (In the deep dermis)¹²³, Dectin-1⁺, CD301^{+ 132}, Dectin-2^{+ 133}
	Langerhans cells	Interaction with T lymphocytes¹³¹. Derived from yolk sac and/or fetal liver and maintained independently of the bone marrow^{14, 16}.	F4/80⁺, CD11b⁺, CD11c⁺, Langerin^{+ 14} (Id2¹³⁴, Runx3¹³⁵)

Spleen	Marginal zone macrophages	Immune surveillance of the circulation¹⁰².	CD68⁺, CD209b⁺, MARCO⁺, Dectin-2^{+ 133}, Tim4^{+ 109}. (LXRα¹⁰⁹)
	Metallophilic macrophages	Immune surveillance¹⁰².	CD68⁺, CD169^{+ 102} (LXRα¹⁰⁹)
	Red-pulp macrophages	Erythrocyte clearance and iron metabolism¹⁰³. Pre-natal origins^{17, 22}. Maintained in adult independently of the bone marrow³⁰.	F4/80⁺, CD206⁺, Dectin-2^{+ 133} (Spi-C¹⁰³)
	White pulp (tingible body) macrophages	Clearance of apoptotic cells resulting during the germinal center reaction¹⁰⁰.	CD68^{+ 102}

This table represents a simplification and marked heterogeneity is evident in many tissues (for example, bone marrow, peritoneum, lung and liver) highlighted through fate mapping studies and phenotypic variation^{17, 22, 33, 122, 128.}

Origin indicated only where experimentally established.

Select examples of tissue selective transcriptional regulators involved in cellular development or function are indicated.

Marker is expressed by the majority of the indicated cells. Subsets are only listed where distinct anatomical localization, function or origins are reported, and not those that are simply defined by variation in select receptor/antigen expression.