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Updated: Sep 16, 2025

Characterization of Thymic Settling Progenitors in the Mouse Embryo Using In Vivo and In Vitro Assays
Published on: June 9, 2015
Innate lymphoid cells originate from fetal liver-derived tissue-resident progenitors
Xianwei Wang1, Jiarui Li1, Lucas Rebuffet2
1State Key Laboratory of Immune Response and Immunotherapy, the Institute of Immunology, Biomedical Sciences and Health Laboratory of Anhui Province, Center for Advanced Interdisciplinary Science and Biomedicine of IHM, School of Basic Medical Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China.
Innate lymphoid cell (ILC) development differs between fetal and adult origins. Fetal liver-derived precursors establish extramedullary ILCs independently of adult bone marrow hematopoiesis.
Area of Science:
- Immunology
- Developmental Biology
- Hematopoiesis
Background:
- Committed progenitors for innate lymphoid cells (ILCs) exist in fetal and adult bone marrow (BM).
- The temporal and spatial contributions of fetal and BM hematopoiesis to ILC pools are not fully understood.
Purpose of the Study:
- To elucidate the distinct origins and developmental pathways of extramedullary and intramedullary ILCs in mice during ontogeny.
- To provide a comprehensive framework for ILC developmental dynamics.
Main Methods:
- Investigated ILC development in mice during ontogeny.
- Tracked fetal liver-derived PD-1+ ILC precursors (ILCPs) seeding fetal organs.
- Analyzed organ niche-specific commitment of ILCPs to downstream precursors.
- Differentiated contributions of fetal vs. BM hematopoiesis to ILC pools.
Main Results:
- ILC-restricted hematopoiesis initiates in the fetal liver (FL).
- FL-derived ILCPs seed fetal lung and intestine, with organ niches dictating commitment to ILC1-ILC3 precursors (ILC1/3Ps) or ILC2 precursors (ILC2Ps).
- These extramedullary precursors contribute to adult ILC pools independently of BM hematopoiesis.
- Intramedullary ILC2Ps and ILC2s depend on BM hematopoiesis.
Conclusions:
- Extramedullary and intramedullary ILCs possess distinct origins.
- A comprehensive framework for ILC developmental dynamics, highlighting fetal vs. BM contributions, has been established.
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