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Updated: Aug 12, 2026

Characterization of Thymic Settling Progenitors in the Mouse Embryo Using In Vivo and In Vitro Assays
Published on: June 9, 2015
Circulating macrophages as well as developing thymocytes are enclosed within thymic nurse cells
M Samms1, M Martinez, S Fousse
1Department of Biology, The City College of New York, 138th Street at Convent Avenue, New York, NY 10031, USA.
Thymic nurse cells (TNCs) and macrophages interact directly in the thymus, with macrophages entering TNCs to support antigen presentation. This study reveals a novel collaboration between these immune cells in thymocyte selection.
Area of Science:
- Immunology
- Cell Biology
Background:
- Thymic nurse cells (TNCs) and macrophages are known antigen-presenting cells involved in thymocyte selection.
- TNCs internalize viable thymocytes, while macrophages engulf apoptotic ones.
Purpose of the Study:
- To investigate the direct interaction between peripheral macrophages and TNCs in mice.
- To explore the functional relationship between TNCs and macrophages in the thymus.
Main Methods:
- Isolation and examination of freshly isolated TNCs from C57BL/6 mice.
- In vitro co-culture of thymocytes and macrophages with the tsTNC-1 cell line.
- In vivo tracking of fluorescently labeled peritoneal macrophages in the mouse thymus.
Main Results:
- Approximately 1.7% of isolated TNCs contained macrophages within their cytoplasm.
- A total of 4.6% of TNCs showed association with macrophages (internalized or bound).
- In vitro and in vivo experiments confirmed dynamic interactions and thymus infiltration by macrophages.
Conclusions:
- This study provides the first evidence of direct interaction between peripheral macrophages and TNCs.
- TNCs and macrophages collaborate dynamically in the thymus, likely enhancing antigen presentation during thymocyte selection.
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