Deletional Tolerance Mediated by Extrathymic Aire-Expressing Cells
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE12388 | GEO | 2008/08/08
SECONDARY ACCESSION(S): PRJNA113139
REPOSITORIES: GEO
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Project description:Adaptive immunity requires multiple complementary mechanisms to maintain self-tolerance. Dedicated tolerogenic lymphoid populations and their key transcriptional regulators have been well characterized, but while recent evidence suggests some myeloid populations, particularly migratory dendritic cells (migDCs), may have similar functions, the identity of these populations and the transcriptional circuits regulating them remain obscure. The Autoimmune Regulator (Aire), well defined in medullary thymic epithelial cells (mTECs), is also expressed in extrathymic Aire-expressing cells (eTACs) in the secondary lymphoid organs. eTACs have been shown to have tolerogenic capabilities (ref), and recently work has shown them to be required for normal immune homeostasis in pregnancy (ref). But the precise identity and function of these cells remain unclear. Here using high-dimensional single-cell multiomics (scRNAseq/ASAPseq), we define the identity and biology of the principal extrathymic Aire-expressing populations at the transcriptional, genomic, and proteomic level, resulting in two related populations: CCR7+ Aire-regulated migratory dendritic cells (ArmDCs) and a novel population co-expressing RAR-related orphan receptor gamma-t (ROR-γt), with significant transcriptional and genomic homology to both migDCs and mTECs, which we termed Janus cells (JCs). We demonstrate these eTAC populations share a distinct transcriptional and genomic homology to medullary epithelium and, like mTECs, depend on RANK-RANK-ligand interactions to drive Aire expression. Lineage-tracing experiments suggest JCs are not a precursor population to the majority of ArmDCs. Further, self-antigen display by eTACs is sufficient to mediate negative selection of T cells that escape thymic selection. This remarkable central and peripheral homology suggests that a core Aire-associated transcriptional program may drive immune tolerance in both the thymus and periphery, and suggests a remarkable convergence of transcriptional programs in two disparate cell lineages in the thymus and periphery.
2021-12-15 | GSE176282 | GEO
Project description:Thymic B cells have been recently shown the ability to be licensed to express Aire, a critical transcription factor involved in the expression of self-antigens in the thymus which are critical for clonal deletion of autoreactive T cells and maintenance of self-tolerance. Mutations in AIRE cause systemic autoimmunity in humans and autoimmunity with varying degrees of severity in different mouse strains. Thymic B cells have been studied in young animals, but studies of this population with age are lacking. Given the thymus undergoes age-associated atrophy in its stromal compartment, we hypothesized that aged thymic B cells may under go changes with age which may impact their ability to mediate clonal deletion of autoreactive T cells and may contribute to age-associated increases in autoimmune prevalence. By comparing the transcriptome of young and aged thymic B cells we find that Aire and transcriptional activators of Aire are signficantly decreased with age.
2018-01-30 | GSE107110 | GEO
Project description:Thymic B cells have been recently shown the ability to be licensed to express Aire, a critical transcription factor involved in the expression of self-antigens in the thymus which are critical for clonal deletion of autoreactive T cells and maintenance of self-tolerance. Mutations in AIRE cause systemic autoimmunity in humans and autoimmunity with varying degrees of severity in different mouse strains. Thymic B cells have been studied in young animals, but studies of this population with age are lacking. Given the thymus undergoes age-associated atrophy in its stromal compartment, we hypothesized that aged thymic B cells may under go changes with age which may impact their ability to mediate clonal deletion of autoreactive T cells and may contribute to age-associated increases in autoimmune prevalence. By comparing the transcriptome of young and aged thymic B cells we find that Aire and transcriptional activators of Aire are signficantly decreased with age.
2018-01-30 | GSE107111 | GEO
Project description:Thymic central tolerance is essential to preventing autoimmunity. In medullary thymic epithelial cells (mTECs), the Autoimmune regulator (Aire) gene plays an essential role in this process by driving the expression of a diverse set of tissue-specific antigens (TSAs), which are presented and help tolerize self-reactive thymocytes. Interestingly, Aire has a highly tissue-restricted pattern of expression, with only mTECs and peripheral extrathymic Aire-expressing cells (eTACs) known to express detectable levels in adults. Despite this high level of tissue specificity, the cis-regulatory elements that control Aire expression have remained obscure. We used sequence conservation analysis and ChIP-seq against the enhancer-associated histone mark H3K27ac to identify a candidate Aire cis-regulatory element. There is enrichment of H3K27ac near this element, ACNS1, in mTECs and the element also has characteristics of being NF-κB-responsive. Finally, we find that this element is essential for Aire expression in vivo and necessary to prevent spontaneous autoimmunity, reflecting the importance of this regulatory DNA element in promoting immune tolerance. Two experimental groups (GFP neg mTECs and GFP pos mTECs), each with three samples, and one control sample (D10 Th2 cells).
2015-10-23 | E-GEOD-74257 | biostudies-arrayexpress
Project description:Thymic central tolerance is essential to preventing autoimmunity. In medullary thymic epithelial cells (mTECs), the Autoimmune regulator (Aire) gene plays an essential role in this process by driving the expression of a diverse set of tissue-specific antigens (TSAs), which are presented and help tolerize self-reactive thymocytes. Interestingly, Aire has a highly tissue-restricted pattern of expression, with only mTECs and peripheral extrathymic Aire-expressing cells (eTACs) known to express detectable levels in adults. Despite this high level of tissue specificity, the cis-regulatory elements that control Aire expression have remained obscure. We used sequence conservation analysis and ChIP-seq against the enhancer-associated histone mark H3K27ac to identify a candidate Aire cis-regulatory element. There is enrichment of H3K27ac near this element, ACNS1, in mTECs and the element also has characteristics of being NF-κB-responsive. Finally, we find that this element is essential for Aire expression in vivo and necessary to prevent spontaneous autoimmunity, reflecting the importance of this regulatory DNA element in promoting immune tolerance.
2015-10-23 | GSE74257 | GEO
Project description:Mutations in the gene encoding the transcription factor AutoImmune REgulator (AIRE) are responsible for the ‘Autoimmune PolyEndocrinopathy Candidiasis Ecodermal Dystrophy’ syndrome. AIRE directs expression of tissue restricted antigens in the thymic medulla and in lymph node stromal cells and thereby substantially contributes to induction of immunological tolerance to self-antigens. Data from experimental mouse models showed that AIRE-deficiency leads to impaired deletion of autospecific T cell precursors. However, a potential role for AIRE in the function of regulatory T cell populations, which are known to play a central role in prevention of immunopathology, has remained elusive. Regulatory T cells of CD8+CD28low phenotype efficiently control immune responses in experimental autoimmune and colitis models in mice. We here show that CD8+CD28low Treg from AIRE-deficient mice are transcriptionally and phenotypically normal, exert efficient suppression of in vitro immune responses, but completely fail to prevent experimental colitis in vivo. Our data therefore demonstrate that AIRE plays an important role in the in vivo function of a naturally occurring regulatory T cell population. Total RNA was extracted from CD8+CD28low regulatory T lymphocytes isolated from wildtype and Aire-deficient C57BL/6 mice for comparison of gene expression profiles.
2011-06-22 | E-GEOD-30129 | biostudies-arrayexpress
Project description:Tolerance to self- or innocuous foreign antigens is vital for preservation of organismal health. Within the thymus, medullary thymic epithelial cells (mTECs) expressing AutoImmune Regulator, Aire, play a critical role in self-tolerance through deletion of autoreactive T cells and promotion of thymic regulatory T (Treg) cell development. A second wave of Treg cell differentiation occurs in the periphery, upon exposure to dietary and commensal microbiota derived antigens within the first few weeks of life, yet the cell types responsible for the generation of peripheral Treg (pTreg) cells are not known. Here we identified a new lineage of tolerogenic RORγt+ antigen-presenting cells (APC) with a hybrid dendritic cell (DC)-mTEC phenotype, dubbed Thetis cells (TCs), comprising 4 major sub-groups (TC I-IV), We uncovered a developmental wave of TCs within intestinal lymph nodes during a critical early life window, coincident with the wave of pTreg cell differentiation. While Aire+ TC I and III bore remarkable homology with Aire+ mTECs, including expression of tissue restricted self-antigens, TC IV lacked Aire expression and were enriched for molecules required for pTreg generation, including the TGF-β activating integrin αvβ8. Loss of either MHCII or Itgb8 expression by TCs led to a profound impairment in intestinal pTreg differentiation, with onset of intestinal inflammation. In contrast, MHCII expression by RORγt+ group 3 innate lymphoid cells (ILC3) and classical DCs was neither sufficient nor required for pTreg generation, further implicating TCs as the critical tolerogenic RORγt+ APC. Our studies reveal parallel pathways for establishment of tolerance to self and foreign antigen within the thymus and periphery, marked by involvement of shared cellular and transcriptional programs.
2022-09-06 | GSE174405 | GEO
Project description:Tolerance to self- or innocuous foreign antigens is vital for preservation of organismal health. Within the thymus, medullary thymic epithelial cells (mTECs) expressing AutoImmune Regulator, Aire, play a critical role in self-tolerance through deletion of autoreactive T cells and promotion of thymic regulatory T (Treg) cell development. A second wave of Treg cell differentiation occurs in the periphery, upon exposure to dietary and commensal microbiota derived antigens within the first few weeks of life, yet the cell types responsible for the generation of peripheral Treg (pTreg) cells are not known. Here we identified a new lineage of tolerogenic RORγt+ antigen-presenting cells (APC) with a hybrid dendritic cell (DC)-mTEC phenotype, dubbed Thetis cells (TCs), comprising 4 major sub-groups (TC I-IV), We uncovered a developmental wave of TCs within intestinal lymph nodes during a critical early life window, coincident with the wave of pTreg cell differentiation. While Aire+ TC I and III bore remarkable homology with Aire+ mTECs, including expression of tissue restricted self-antigens, TC IV lacked Aire expression and were enriched for molecules required for pTreg generation, including the TGF-β activating integrin αvβ8. Loss of either MHCII or Itgb8 expression by TCs led to a profound impairment in intestinal pTreg differentiation, with onset of intestinal inflammation. In contrast, MHCII expression by RORγt+ group 3 innate lymphoid cells (ILC3) and classical DCs was neither sufficient nor required for pTreg generation, further implicating TCs as the critical tolerogenic RORγt+ APC. Our studies reveal parallel pathways for establishment of tolerance to self and foreign antigen within the thymus and periphery, marked by involvement of shared cellular and transcriptional programs.
2022-09-06 | GSE205066 | GEO
Project description:Tolerance to self- or innocuous foreign antigens is vital for preservation of organismal health. Within the thymus, medullary thymic epithelial cells (mTECs) expressing AutoImmune Regulator, Aire, play a critical role in self-tolerance through deletion of autoreactive T cells and promotion of thymic regulatory T (Treg) cell development. A second wave of Treg cell differentiation occurs in the periphery, upon exposure to dietary and commensal microbiota derived antigens within the first few weeks of life, yet the cell types responsible for the generation of peripheral Treg (pTreg) cells are not known. Here we identified a new lineage of tolerogenic RORγt+ antigen-presenting cells (APC) with a hybrid dendritic cell (DC)-mTEC phenotype, dubbed Thetis cells (TCs), comprising 4 major sub-groups (TC I-IV), We uncovered a developmental wave of TCs within intestinal lymph nodes during a critical early life window, coincident with the wave of pTreg cell differentiation. While Aire+ TC I and III bore remarkable homology with Aire+ mTECs, including expression of tissue restricted self-antigens, TC IV lacked Aire expression and were enriched for molecules required for pTreg generation, including the TGF-β activating integrin αvβ8. Loss of either MHCII or Itgb8 expression by TCs led to a profound impairment in intestinal pTreg differentiation, with onset of intestinal inflammation. In contrast, MHCII expression by RORγt+ group 3 innate lymphoid cells (ILC3) and classical DCs was neither sufficient nor required for pTreg generation, further implicating TCs as the critical tolerogenic RORγt+ APC. Our studies reveal parallel pathways for establishment of tolerance to self and foreign antigen within the thymus and periphery, marked by involvement of shared cellular and transcriptional programs.
2022-09-06 | GSE205065 | GEO
Project description:Tolerance to self- or innocuous foreign antigens is vital for preservation of organismal health. Within the thymus, medullary thymic epithelial cells (mTECs) expressing AutoImmune Regulator, Aire, play a critical role in self-tolerance through deletion of autoreactive T cells and promotion of thymic regulatory T (Treg) cell development. A second wave of Treg cell differentiation occurs in the periphery, upon exposure to dietary and commensal microbiota derived antigens within the first few weeks of life, yet the cell types responsible for the generation of peripheral Treg (pTreg) cells are not known. Here we identified a new lineage of tolerogenic RORγt+ antigen-presenting cells (APC) with a hybrid dendritic cell (DC)-mTEC phenotype, dubbed Thetis cells (TCs), comprising 4 major sub-groups (TC I-IV), We uncovered a developmental wave of TCs within intestinal lymph nodes during a critical early life window, coincident with the wave of pTreg cell differentiation. While Aire+ TC I and III bore remarkable homology with Aire+ mTECs, including expression of tissue restricted self-antigens, TC IV lacked Aire expression and were enriched for molecules required for pTreg generation, including the TGF-β activating integrin αvβ8. Loss of either MHCII or Itgb8 expression by TCs led to a profound impairment in intestinal pTreg differentiation, with onset of intestinal inflammation. In contrast, MHCII expression by RORγt+ group 3 innate lymphoid cells (ILC3) and classical DCs was neither sufficient nor required for pTreg generation, further implicating TCs as the critical tolerogenic RORγt+ APC. Our studies reveal parallel pathways for establishment of tolerance to self and foreign antigen within the thymus and periphery, marked by involvement of shared cellular and transcriptional programs.
2022-09-06 | GSE174403 | GEO