Runx3 instructs Aire+ mTEC development, TSA gene expression, and central tolerance
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE310103 | GEO | 2026/04/23
REPOSITORIES: GEO
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Project description:The zinc-finger transcription factor Ikaros (Ikzf1) modulates key gene expression programs important for hematopoietic development, and coding mutations in IKZF1 are found in patients with immunodeficiency, leukemia, and autoimmunity. While Ikaros has a well-established function in hematopoiesis, its role in other cell types is less well defined. Here, we uncover new functions for Ikaros in thymic epithelial lineage development and show that Ikzf1 expression in medullary thymic epithelial cells (mTECs) is required for both Autoimmune Regulator positive (Aire+) mTEC development and tissue-specific antigen (TSA) gene expression. Accordingly, TEC-specific deletion of Ikzf1 in mice results in a profound decrease in Aire+ mTECs, a global loss of TSA gene expression, and the development of autoimmunity. Moreover, Ikaros shapes thymic mimetic cell diversity and its deletion results in a dramatic expansion of thymic tuft cells and muscle-like mTECs and a loss of other Aire-dependent mimetic populations. Single-cell analysis reveals Ikaros modulates core transcriptional programs in TECs that correlate with the observed cellular changes. Our findings highlight a previously undescribed role for Ikaros in regulating epithelial lineage development and function, and suggest that failed thymic central tolerance could contribute to the autoimmunity seen in humans with IKZF1 mutations.
2023-10-25 | GSE238149 | GEO
Project description:The zinc-finger transcription factor Ikaros (Ikzf1) modulates key gene expression programs important for hematopoietic development, and coding mutations in IKZF1 are found in patients with immunodeficiency, leukemia, and autoimmunity. While Ikaros has a well-established function in hematopoiesis, its role in other cell types is less well defined. Here, we uncover new functions for Ikaros in thymic epithelial lineage development and show that Ikzf1 expression in medullary thymic epithelial cells (mTECs) is required for both Autoimmune Regulator positive (Aire+) mTEC development and tissue-specific antigen (TSA) gene expression. Accordingly, TEC-specific deletion of Ikzf1 in mice results in a profound decrease in Aire+ mTECs, a global loss of TSA gene expression, and the development of autoimmunity. Moreover, Ikaros shapes thymic mimetic cell diversity and its deletion results in a dramatic expansion of thymic tuft cells and muscle-like mTECs and a loss of other Aire-dependent mimetic populations. Single-cell analysis reveals Ikaros modulates core transcriptional programs in TECs that correlate with the observed cellular changes. Our findings highlight a previously undescribed role for Ikaros in regulating epithelial lineage development and function, and suggest that failed thymic central tolerance could contribute to the autoimmunity seen in humans with IKZF1 mutations.
2023-10-25 | GSE238148 | GEO
Project description:The zinc-finger transcription factor Ikaros (Ikzf1) modulates key gene expression programs important for hematopoietic development, and coding mutations in IKZF1 are found in patients with immunodeficiency, leukemia, and autoimmunity. While Ikaros has a well-established function in hematopoiesis, its role in other cell types is less well defined. Here, we uncover new functions for Ikaros in thymic epithelial lineage development and show that Ikzf1 expression in medullary thymic epithelial cells (mTECs) is required for both Autoimmune Regulator positive (Aire+) mTEC development and tissue-specific antigen (TSA) gene expression. Accordingly, TEC-specific deletion of Ikzf1 in mice results in a profound decrease in Aire+ mTECs, a global loss of TSA gene expression, and the development of autoimmunity. Moreover, Ikaros shapes thymic mimetic cell diversity and its deletion results in a dramatic expansion of thymic tuft cells and muscle-like mTECs and a loss of other Aire-dependent mimetic populations. Single-cell analysis reveals Ikaros modulates core transcriptional programs in TECs that correlate with the observed cellular changes. Our findings highlight a previously undescribed role for Ikaros in regulating epithelial lineage development and function, and suggest that failed thymic central tolerance could contribute to the autoimmunity seen in humans with IKZF1 mutations.
2023-10-25 | GSE237988 | GEO
Project description:The zinc-finger transcription factor Ikaros (Ikzf1) modulates key gene expression programs important for hematopoietic development, and coding mutations in IKZF1 are found in patients with immunodeficiency, leukemia, and autoimmunity. While Ikaros has a well-established function in hematopoiesis, its role in other cell types is less well defined. Here, we uncover new functions for Ikaros in thymic epithelial lineage development and show that Ikzf1 expression in medullary thymic epithelial cells (mTECs) is required for both Autoimmune Regulator positive (Aire+) mTEC development and tissue-specific antigen (TSA) gene expression. Accordingly, TEC-specific deletion of Ikzf1 in mice results in a profound decrease in Aire+ mTECs, a global loss of TSA gene expression, and the development of autoimmunity. Moreover, Ikaros shapes thymic mimetic cell diversity and its deletion results in a dramatic expansion of thymic tuft cells and muscle-like mTECs and a loss of other Aire-dependent mimetic populations. Single-cell analysis reveals Ikaros modulates core transcriptional programs in TECs that correlate with the observed cellular changes. Our findings highlight a previously undescribed role for Ikaros in regulating epithelial lineage development and function, and suggest that failed thymic central tolerance could contribute to the autoimmunity seen in humans with IKZF1 mutations.
2023-10-25 | GSE241742 | GEO
Project description:Forkhead Box P1 (Foxp1) is a transcription factor critical for the proper development of multiple tissues. While Foxp1 has a well-described role in regulating adaptive immunity through modulation of T and B cells, a function in medullary thymic epithelial cells (mTECs) has not been reported. Here, we show that Foxp1 is expressed in mTECs and deletion of Foxp1 in TECs results in significant changes to mTEC populations. Surprisingly, Foxp1-deletion results in an expansion of neuroendocrine mTECs and Ccl21a-expressing mTECs and a loss of Aire+ mTECs, tuft cells, and microfold mTECs. With these changes in mimetic mTECs there are alterations to the thymus with enhanced thymic size, shifts in thymic innate lymphocyte populations, and loss of thymic B cell class switching. Mechanistically, scRNA-seq gene expression analysis of mTECs reveals decreased Fezf2 expression with loss of Foxp1 in mTECs resulting in loss of Fezf2-induced tissue specific antigen gene expression and autoimmunity in aged mice. Altogether, our studies reveal that Foxp1 is an important regulator of mimetic mTECs and Fezf2-dependent gene expression resulting in significant changes to mTEC population diversity.
2026-05-22 | GSE329877 | GEO
Project description:Medullary thymic epithelial cells (mTECs) play a critical role in central immune tolerance by mediating negative selection of autoreactive T cells through the collective expression of the peripheral self-antigen compartment, including tissue-specific antigens (TSAs). Recent work has shown that gene expression patterns within the mTEC compartment are remarkably heterogenous and include multiple differentiated cell states. To further define mTEC development and medullary epithelial lineage relationships, we combined lineage tracing and recovery from transient in vivo mTEC ablation with single cell RNA-sequencing in Mus musculus. The combination of bioinformatic and experimental approaches revealed a non-stem transit-amplifying population of cycling mTECs that preceded Aire expression. Based on our findings, we propose a branching model of mTEC development wherein a heterogeneous pool of transit-amplifying cells gives rise to Aire- and Ccl21a-expressing mTEC subsets. We further use experimental techniques to show that within the Aire-expressing developmental branch, TSA expression peaked as Aire expression decreased, implying Aire expression must be established before TSA expression can occur. Collectively, these data provide a higher order roadmap of mTEC development and demonstrate the power of combinatorial approaches leveraging both in vivo models and high-dimensional datasets.
2020-11-24 | GSE137699 | GEO
Project description:Thymic epithelial cells (TECs) govern thymic T lymphocyte differentiation and selection. Medullary TECs are distinctive for their "promiscuous" gene expression, transcribing thousands of peripheral tissue genes (PTG) that are otherwise only expressed highly in one or two other organs. Much of this PTG expression by mTECs is controlled by the autoimmune regulator, AIRE. This experiment was part of a larger study in which we examined the impact of Kat7 loss on AIRE-mediated PTG expression. Despite the apparently normal differentiation of AIRE+ TECs in Kat7-knockout mice, it was possible that the defect in AIRE-mediated PTG expression was secondary to the developmental loss of this histone acetyltransferase. To address this hypothesis, we employed fetal thymic organ cultures (FTOC) depleted of thymocytes where AIRE+ mTEC and PTG expression was induced by an agonist anti-RANK antibody. We then used two different approaches to acutely block KAT7 function and subsequently sort purified TECs for RNA-seq analysis to assess the impact on AIRE-mediated PTG transcription. AIRE+ mTECs exhibit relatively low turnover in organ culture; therefore, this approach uncouples KAT7 impacts on AIRE function from potential influences on TEC differentiation. Our first approach employed a new small molecule inhibitor of KAT7 function, WM-3835. The second approach was an inducible genetic deletion system. FTOC established with thymi from control (Kat7fl/fl) or RosaCre-ERT2 Kat7fl/fl mice were treated with tamoxifen to activate CRE-mediated deletion of Kat7.
2021-12-21 | GSE188869 | GEO
Project description:Fezf2 has been implicated in shaping tissue-restricted antigen (TRA) expression and as an “Aire-like” factor in the thymus. Here we demonstrate loss of Fezf2 results primarily in a developmental block in mTEC development with pronounced expansion of Ccl21a-expressing mTECs at the expense of thymic tuft cells and most Aire-high and recently described post-Aire “mimetic” populations. While loss of either Aire or Fezf2 leads to a loss of post-Aire mimetic subtypes, their transcriptional programs are distinct; whereas Aire positively regulates the expression of thousands of genome-wide targets, Fezf2 orchestrates a restricted transcriptional program balanced between induction and repression that largely impacts TEC development. Strikingly, most Fezf2-repressed genes map to Ccl21a-expressing mTECs, suggesting Fezf2 maintains a cellular state conducive to the development of Aire-expressing mTECs and downstream access to terminally differentiated mimetic programs. At least some mimetic cell programs appear to have functions beyond simply serving as antigen reservoirs; thymic microfold cells (M cells) organize the medullary B cell niche in a Ccr6-dependent manner and promote IgA class-switching, analogous to Peyer’s Patches. In Aire and Fezf2 KO mice, where development of thymic M cells is impaired, B cell class-switching is similarly disrupted. Therefore, our data reveal Fezf2 as a gatekeeper of mTEC terminal development which cooperates with Aire to allow the full program of medullary epithelial diversity, supporting unexpected layers of mimetic cell function that impact thymic homeostasis beyond antigen diversity.
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Project description:Thymic epithelial cells (TECs) support T cell development in the thymus. Cortical thymic epithelial cells (cTECs) facilitate positive selection of developing thymocytes whereas medullary thymic epithelial cells (mTECs) facilitate the deletion of self-reactive thymocytes in order to prevent autoimmunity. The mTEC compartment is highly dynamic with continuous maturation and turnover, but the genetic regulation of these processes remains poorly understood. MicroRNAs (miRNAs) are important regulators of TEC genetic programs since miRNA-deficient TECs are severely defective. However, the individual miRNAs important for TEC maintenance and function and their mechanisms of action remain unknown. Here, we demonstrate that miR-205 is highly and preferentially expressed in mTECs during both thymic ontogeny and in the postnatal thymus. This distinct expression is suggestive of functional importance for TEC biology. Genetic ablation of miR-205 in TECs, however, neither revealed a role for miR-205 in TEC function during homeostatic conditions nor during recovery from thymic stress conditions. Thus, despite its distinct expression, miR-205 on its own is largely dispensable for mTEC biology. In order to identify miRNAs differentially expressed in mTECs, we purified cortical thymic epithelial cells (cTECs), mTECs and CD45+ cells as three distinct populations and prepared RNA for microarray analysis. Thymic subsets were FACS-purified from 4-week old NOD wildtype mice. Thymi from 10-12 female mice were pooled together for stromal cell isolation for a total of 3 CD45+, 2 cTEC and 3 mTEC biologic replicates.
2015-07-28 | E-GEOD-68674 | biostudies-arrayexpress
Project description:Medullary thymic epithelial cells (mTECs) contribute to self-tolerance through the ectopic expression of peripheral tissue antigens (PTAs) in the thymus. PTA expression in mTECs is largely dependent on the autoimmune regulator (Aire) gene. Here we used a Mus musculus mTEC cell line (3.10 mTEC line, which constitutively express Aire in culture) to knockdown Aire gene by means of siRNA transfection. Aire knockdown was confirmed by means of qRT-PCR and RNA-FISH (for Aire mRNA levels), immunofluorescence and western blot (for AIRE protein levels).The Agilent oligo microarrays were used to determine the large scale transcriptional expression profiles of control or Aire-knockdown 3.10 mTECs.
2015-12-31 | E-MTAB-3879 | biostudies-arrayexpress