Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2018 Aug:330:5-15.
doi: 10.1016/j.cellimm.2018.01.001. Epub 2018 Jan 12.

Fetal monocytes and the origins of tissue-resident macrophages

Affiliations
Review

Fetal monocytes and the origins of tissue-resident macrophages

Guillaume Hoeffel et al. Cell Immunol. 2018 Aug.

Abstract

Tissue-resident macrophages have pivotal functions for tissue defense and homeostasis. Two main discoveries have changed our current understanding of macrophage development: Their embryonic origin and their ability to self-renew throughout the lifespan. It is now well accepted that most tissue-resident macrophages are long-lived cells derived from a transient hematopoietic wave of erythro-myeloid progenitors (EMPs) emerging in the yolk sac. At least two distinct pathways derived from EMPs have been implicated in macrophage development. The first one, c-Myb-independent is giving rise to yolk sac macrophages also called primitive macrophages, and bypassing the classical monocytic intermediates. The second requires c-Myb expression and start once EMPs seed the fetal liver where they generate fetal monocytes. Sequentially, primitive macrophages seed every tissue and will ultimately give rise to microglia in the brain, rapidly isolated by the blood brain barrier, while EMP-derived fetal monocytes infiltrate every other tissues and gradually generate the major pool of adult tissue-resident macrophages by diluting the initial primitive macrophage contribution. A third wave of hematopoietic stem cells (HSC)-derived monocytes is also emerging from the fetal liver to contribute to the long-lived macrophage pool established at birth while the adult hematopoiesis is only starting in the bone marrow. We propose here to review recent insights about the different embryonic hematopoietic programs responsible for the generation of long-lived tissue-resident macrophages and their maintenance after birth.

Keywords: EMP; Erythro-myeloid progenitors; Fetal liver; HSC; Hematopoiesis; Hematopoietic stem cells; Macrophage; Monocyte; Ontogeny; Yolk sac.

PubMed Disclaimer

Similar articles

Cited by

Publication types

Substances