1. T Cell Zone Resident Macrophages Silently Dispose of Apoptotic Cells in the Lymph Node.
- Author
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Baratin M, Simon L, Jorquera A, Ghigo C, Dembele D, Nowak J, Gentek R, Wienert S, Klauschen F, Malissen B, Dalod M, and Bajénoff M
- Subjects
- Animals, Antigen Presentation, Apoptosis, CD4-Positive T-Lymphocytes immunology, CX3C Chemokine Receptor 1, Cell Differentiation, Cell Lineage, Cells, Cultured, Dendritic Cells immunology, Immune Tolerance, Lymphocyte Activation, Mice, Mice, Inbred C57BL, Mice, Knockout, Proto-Oncogene Proteins metabolism, Receptor Protein-Tyrosine Kinases metabolism, Receptors, Chemokine metabolism, c-Mer Tyrosine Kinase, Lymph Nodes immunology, Macrophages immunology, Phagocytosis
- Abstract
In lymph nodes (LNs), dendritic cells (DCs) are thought to dispose of apoptotic cells, a function pertaining to macrophages in other tissues. We found that a population of CX3CR1
+ MERTK+ cells located in the T cell zone of LNs, previously identified as DCs, are efferocytic macrophages. Lineage-tracing experiments and shield chimeras indicated that these T zone macrophages (TZM) are long-lived macrophages seeded in utero and slowly replaced by blood monocytes after birth. Imaging the LNs of mice in which TZM and DCs express different fluorescent proteins revealed that TZM-and not DCs-act as the only professional scavengers, clearing apoptotic cells in the LN T cell zone in a CX3CR1-dependent manner. Furthermore, similar to other macrophages, TZM appear inefficient in priming CD4 T cells. Thus, efferocytosis and T cell activation in the LN are uncoupled processes designated to macrophages and DCs, respectively, with implications to the maintenance of immune homeostasis., (Copyright © 2017 Elsevier Inc. All rights reserved.)- Published
- 2017
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