Thymic macrophages consist of two populations with distinct localization and origin

  1. Tyng-An Zhou
  2. Hsuan-Po Hsu
  3. Yueh-Hua Tu
  4. Hui-Kuei Cheng
  5. Chih-Yu Lin
  6. Nien-Jung Chen
  7. Jin-Wu Tsai
  8. Ellen A Robey
  9. Hsuan-Cheng Huang
  10. Chia-Lin Hsu
  11. Ivan L Dzhagalov  Is a corresponding author
  1. National Yang Ming Chiao Tung University, Taiwan
  2. Academia Sinica, Taiwan
  3. University of California, Berkeley, United States

Abstract

Tissue-resident macrophages are essential to protect from pathogen invasion and maintain organ homeostasis. The ability of thymic macrophages to engulf apoptotic thymocytes is well appreciated, but little is known about their ontogeny, maintenance, and diversity. Here, we characterized the surface phenotype and transcriptional profile of these cells and defined their expression signature. Thymic macrophages were most closely related to spleen red pulp macrophages and Kupffer cells and shared the expression of the transcription factor SpiC with these cells. Single-cell RNA sequencing showed that the macrophages in the adult thymus are composed of two populations distinguished by the expression of Timd4 and Cx3cr1. Remarkably, Timd4+ cells were located in the cortex, while Cx3cr1+ macrophages were restricted to the medulla and the cortico-medullary junction. Using shield chimeras, transplantation of embryonic thymuses, and genetic fate mapping, we found that the two populations have distinct origins. Timd4+ thymic macrophages are of embryonic origin, while Cx3cr1+ macrophages are derived from adult hematopoietic stem cells. Aging has a profound effect on the macrophages in the thymus. Timd4+ cells underwent gradual attrition, while Cx3cr1+ cells slowly accumulated with age and, in older mice, were the dominant macrophage population in the thymus. Altogether, our work defines the phenotype, origin, and diversity of thymic macrophages.

Data availability

The RNA Sequencing data of thymic macrophages and thymic dendritic cells are available at NCBI Gene Expression Omnibus (GEO) as part of GSE122108 and at www.immgen.org. The single cell RNA sequencing data is deposited at NCBI GEO under accession number GSE185460. The source data underlying Fig. 1G and H, Fig. 3B, D, and G, Fig. 5C, F, and I, Fig. 6B, E, G, and I, Fig. 7B, C, D, and G, Fig. 8B, D, E, and F, Fig. 1S4, Fig. 2S1, Fig. 2S2, Fig. 2S3, Fig. 5S1, and Fig. 5S2 are provided in the Source Data files. All other data supporting the findings of this study are available within the article.

The following data sets were generated
The following previously published data sets were used

Article and author information

Author details

  1. Tyng-An Zhou

    Institute of Microbiology and Immunology, National Yang Ming Chiao Tung University, Taipei, Taiwan
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4031-4947
  2. Hsuan-Po Hsu

    Institute of Microbiology and Immunology, National Yang Ming Chiao Tung University, Taipei, Taiwan
    Competing interests
    The authors declare that no competing interests exist.
  3. Yueh-Hua Tu

    Institute of Information Science, Academia Sinica, Taipei, Taiwan
    Competing interests
    The authors declare that no competing interests exist.
  4. Hui-Kuei Cheng

    Institute of Microbiology and Immunology, National Yang Ming Chiao Tung University, Taipei, Taiwan
    Competing interests
    The authors declare that no competing interests exist.
  5. Chih-Yu Lin

    Institute of Microbiology and Immunology, National Yang Ming Chiao Tung University, Taipei, Taiwan
    Competing interests
    The authors declare that no competing interests exist.
  6. Nien-Jung Chen

    Institute of Microbiology and Immunology, National Yang Ming Chiao Tung University, Taipei, Taiwan
    Competing interests
    The authors declare that no competing interests exist.
  7. Jin-Wu Tsai

    Brain Research Center, National Yang Ming Chiao Tung University, Taipei, Taiwan
    Competing interests
    The authors declare that no competing interests exist.
  8. Ellen A Robey

    Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-3630-5266
  9. Hsuan-Cheng Huang

    Institute of Biomedical Informatics, National Yang Ming Chiao Tung University, Taipei, Taiwan
    Competing interests
    The authors declare that no competing interests exist.
  10. Chia-Lin Hsu

    Institute of Microbiology and Immunology, National Yang Ming Chiao Tung University, Taipei, Taiwan
    Competing interests
    The authors declare that no competing interests exist.
  11. Ivan L Dzhagalov

    Institute of Microbiology and Immunology, National Yang Ming Chiao Tung University, Taipei, Taiwan
    For correspondence
    ivan.dzhagalov@nycu.edu.tw
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-9209-4582

Funding

Ministry of Science and Technology, Taiwan (107-2320-B-010 -016 -MY3)

  • Ivan L Dzhagalov

Ministry of Science and Technology, Taiwan (110-2320-B-A49A-521 -)

  • Ivan L Dzhagalov

Ministry of Science and Technology, Taiwan (111-2320-B-A49 -031 -MY3)

  • Ivan L Dzhagalov

Yen Tjing Ling Medical Foundation (CI-111-6)

  • Ivan L Dzhagalov

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Ethics

Animal experimentation: All experimental procedures involving animals were approved by the Institutional Animal Care and Use Committee (IACUC) of National Yang Ming Chiao Tung University (animal protocols #1070506, and 1090301). All surgery was performed under Ketamine + Xylazine anesthesia, and every effort was made to minimize suffering.

Copyright

© 2022, Zhou et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 2,743
    views
  • 396
    downloads
  • 16
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Tyng-An Zhou
  2. Hsuan-Po Hsu
  3. Yueh-Hua Tu
  4. Hui-Kuei Cheng
  5. Chih-Yu Lin
  6. Nien-Jung Chen
  7. Jin-Wu Tsai
  8. Ellen A Robey
  9. Hsuan-Cheng Huang
  10. Chia-Lin Hsu
  11. Ivan L Dzhagalov
(2022)
Thymic macrophages consist of two populations with distinct localization and origin
eLife 11:e75148.
https://doi.org/10.7554/eLife.75148

Share this article

https://doi.org/10.7554/eLife.75148

Further reading

    1. Developmental Biology
    2. Stem Cells and Regenerative Medicine
    Thi Thom Mac, Teddy Fauquier ... Thierry Brue
    Research Article

    Deficient Anterior pituitary with common Variable Immune Deficiency (DAVID) syndrome results from NFKB2 heterozygous mutations, causing adrenocorticotropic hormone deficiency (ACTHD) and primary hypogammaglobulinemia. While NFKB signaling plays a crucial role in the immune system, its connection to endocrine symptoms is unclear. We established a human disease model to investigate the role of NFKB2 in pituitary development by creating pituitary organoids from CRISPR/Cas9-edited human induced pluripotent stem cells (hiPSCs). Introducing homozygous TBX19K146R/K146R missense pathogenic variant in hiPSC, an allele found in congenital isolated ACTHD, led to a strong reduction of corticotrophs number in pituitary organoids. Then, we characterized the development of organoids harboring NFKB2D865G/D865G mutations found in DAVID patients. NFKB2D865G/D865G mutation acted at different levels of development with mutant organoids displaying changes in the expression of genes involved on pituitary progenitor generation (HESX1, PITX1, LHX3), hypothalamic secreted factors (BMP4, FGF8, FGF10), epithelial-to-mesenchymal transition, lineage precursors development (TBX19, POU1F1) and corticotrophs terminal differentiation (PCSK1, POMC), and showed drastic reduction in the number of corticotrophs. Our results provide strong evidence for the direct role of NFKB2 mutations in the endocrine phenotype observed in patients leading to a new classification of a NFKB2 variant of previously unknown clinical significance as pathogenic in pituitary development.

    1. Developmental Biology
    2. Genetics and Genomics
    Debashish U Menon, Prabuddha Chakraborty ... Terry Magnuson
    Research Article

    We present evidence implicating the BAF (BRG1/BRM Associated Factor) chromatin remodeler in meiotic sex chromosome inactivation (MSCI). By immunofluorescence (IF), the putative BAF DNA binding subunit, ARID1A (AT-rich Interaction Domain 1 a), appeared enriched on the male sex chromosomes during diplonema of meiosis I. Germ cells showing a Cre-induced loss of ARID1A arrested in pachynema and failed to repress sex-linked genes, indicating a defective MSCI. Mutant sex chromosomes displayed an abnormal presence of elongating RNA polymerase II coupled with an overall increase in chromatin accessibility detectable by ATAC-seq. We identified a role for ARID1A in promoting the preferential enrichment of the histone variant, H3.3, on the sex chromosomes, a known hallmark of MSCI. Without ARID1A, the sex chromosomes appeared depleted of H3.3 at levels resembling autosomes. Higher resolution analyses by CUT&RUN revealed shifts in sex-linked H3.3 associations from discrete intergenic sites and broader gene-body domains to promoters in response to the loss of ARID1A. Several sex-linked sites displayed ectopic H3.3 occupancy that did not co-localize with DMC1 (DNA meiotic recombinase 1). This observation suggests a requirement for ARID1A in DMC1 localization to the asynapsed sex chromatids. We conclude that ARID1A-directed H3.3 localization influences meiotic sex chromosome gene regulation and DNA repair.