Ndfip1 restricts mTORC1 signalling and glycolysis in regulatory T cells to prevent autoinflammatory disease
ABSTRACT: Project abstract: Foxp3+ T regulatory (Treg) cells have important functions in suppressing immune cell activation and establishing normal immune homeostasis. How Treg cells maintain their identity is not completely understood. Here we show that Ndfip1, a co-activator of Nedd4-family E3 ubiquitin ligases, is required for Treg cell stability and function. Ndfip1 deletion in Treg cells disrupts immune homeostasis and results in autoinflammatory disease. Ndfip1-deficient Treg cells are highly proliferative and are more likely to lose Foxp3 expression to become IL-4-producing TH2 effector cells. Proteomic analyses indicate that Ndfip1 deficiency alters the metabolic signature of Treg cells. Metabolic profiling reveals elevated glycolysis and increased mTORC1 signalling. Additional data suggest that Ndfip1 restricts Treg cell metabolic capacity and IL-4 production via distinct mechanisms. Thus, Ndfip1 preserves Treg lineage stability by preventing the expansion of highly proliferative and metabolically active cells that can cause immunopathology via secretion of IL-4.
Project description:The interplay between effector and regulatory T (Treg) cells is crucial for adaptive immunity, but how Treg control effector cell flexibility is elusive. We found that the phosphatase PTEN links Treg stability to the repression of TH1 and TFH (follicular helper) responses. Depletion of PTEN in Treg resulted in excessive TFH and germinal center responses and spontaneous inflammatory disease. These defects are considerably blocked by deletion of Interferon-γ, indicating coordinated control of TH1 and TFH responses. Mechanistically, PTEN maintains Treg stability and proper metabolic balance between glycolysis and mitochondrial fitness. Moreover, PTEN deficiency markedly upregulates mTORC2-Akt activity, and loss of this activity restores PTEN-deficient Treg function. Our studies establish a PTEN-mTORC2 axis that actively maintains Treg stability and coordinates Treg-mediated control of effector cell flexibility. We used microarrays to explore the gene expression profiles differentially expressed in CD4+CD25+Foxp3-YFP+ Treg cells from wild-type (WT; C57BL/6 crossed with Foxp3-Cre) and Ptenfl/flFoxp3-Cre (Ptenfl/fl mice crossed with Foxp3-Cre) mice
Project description:Graft-versus-Host Disease (GvH) is the excessive inflammatory response by mature T cells contained in the graft during bone marrow transplantation. The allogeneic T cells recognize self-antigens as foreign and systemically attack multiple organs mostly with epithelial structures such as the skin, liver and gastrointestinal tract. We could show that IL-33 administration during allogeneic hematopoietic cell transplantation (alloHCT) increased regulatory T cell (Treg) numbers and ameliorated the outcome of GvHD. Furthermore, it is known that IL-33 also has an impact on myeloid cell compartments and we showed that IL-33 delivery together with a loss of FoxP3 positive Treg led to a massive expansion of myeloid cells. With the underlying experiment we wanted to further characterize the myeloid cells when Treg are lost, therefore mice were treated with IL-33 and one group had a loss in FoxP3 cells. CD11b+F4/80+Gr-1lo myeloid cells were sorted and analyzed in the microarray. The examined myeloid cell population shows strong activation of the IFNg transcriptome and are prone to M1 macrophage polarization. Therefore, Treg restrain myeloid cell expansion and polarization during IL-33 delivery.
Project description:Regulatory T cells (Tregs) are responsible for limiting autoimmunity and chronic inflammation. Foxp3 is a transcription factor that acts as a master regulator of Treg development and function. A serendipitous observation led to the realization that a well-characterized Foxp3gfp reporter mouse, which expresses an N-terminal GFP-Foxp3 fusion protein, is a hypomorph that causes profoundly accelerated autoimmune diabetes on a NOD background. Although natural Treg development and in vitro function is not significantly altered in Foxp3gfp NOD and C57BL/6 mice, Treg fitness function in inflammatory environments is perturbed and TGFβ-induced Treg development reduced. Foxp3gfpis unable to interact with the histone acetyltransferase Tip60, the histone deacetylase HDAC7, and the Ikaros family zinc finger 4, Eos, which leads to reduced Foxp3 acetylation and enhanced K48-linked polyubiquitylation. Collectively this leads to an altered transcriptional landscape and reduced Foxp3-mediated gene repression, notably at the hallmark IL-2 promoter. Loss of controlled Foxp3-driven epigenetic modification leads to Treg insufficiency that causes autoimmunity in prone environments. 16 samples overall split between 2 genotypes (wild type and Foxp3 knock in) and two cell types (Tregs and Tconv)
Project description:The gene expression profile of peripheral Foxp3+ natural regulatory T cells isolated from Foxp3/EGFP bicistronic mice was compared to that of in vitro-induced regulatory T cells and to CD4+ conventional (Foxp3-) T cells. The role of the regulatory T cell transcription factor Foxp3 in shaping the transcriptosomes of natural and induced regulatory T cells was analyzed using mice expressing a mutant FOXP3-EGFP fusion protein (Foxp3deltaEGFP). We used gene expression microarrays to examine the transcriptional programs of natural and induced regulatory T cells and the function of Foxp3 in organizing the transcriptosomes of the respective cell type Experiment Overall Design: Conventional T cells and natural and induced regulatory T cells were derived from Foxp3/EGFP bicistronic mice and analyzed for their gene expression profile. Conventional T cells, regulatory T cell precursors (CD4+Foxp3deltaEGFP+) and induced regulatory T cell precursors (CD4+Foxp3deltaEGFP+) cells were deriv ed from Foxp3deltaEGFP mice
Project description:The tumor microenvironment contains high frequencies of inflammatory regulatory T (Treg) cells. These Treg exhibit superior regulatory function compared with those from other environments such as the spleen, partially due to expression of anti-inflammatory interleukin-10. In order to gain insight into the origins and functional roles of different Treg subsets, we used whole genome microarray analysis to characterize tumor IL-10+ and tumor IL-10- Treg subsets obtained from VERT-X reporter mice bearing transplantable tumors, along with total tumor Treg and spleen Treg from FoxP3-EGFP reporter mice. Few genes were found to differ between IL-10+ and IL-10- tumor Treg subsets (29 upregulated, 88 downregulated), suggesting a common origin of each Treg subset. The specific gene expression profile of IL-10+ tumor Treg was associated with the tumor microenvironment and absent from spleen Treg, suggesting it to be driven by components of the inflammatory tumor microenvironment. The IL-10+ tumor Treg gene expression profile displayed upregulation of genes associated with a higher activation state and greater effector function. Pooled MC38 tumor tissue from VERT-X or FoxP3-EGFP reporter mice were used to obtain IL10+ tumor Treg (VERT-X), IL10- tumor Treg (VERT-X) and total tumor Treg (FoxP3-EGFP). Spleens from tumor-free FoxP3-EGFP mice were used for spleen Treg. Three experiments for each population gave a total 12 RNA samples.
Project description:Regulatory T (Treg) cells play an important role in the induction and maintenance of peripheral tolerance. Treg cells also suppress a variety of other immune responses, including anti-tumor and alloimmune responses. We have previously reported that tumor-activated Treg cells express granzyme B and that granzyme B is important for Treg cell-mediated suppression of anti-tumor immune responses (GSE13409). Here, we report that allogeneic mismatch also induces the expression of granzyme B. Granzyme B-deficient mice challenged with fully mismatched allogeneic P815 mastocytoma cells have markedly improved survival compared to WT and other granzyme- or perforin-deficient mice, suggesting an immunoregulatory role for granzyme B in this setting. Treg cells harvested from the tumor environment of P815-challenged mice express granzyme B. Treg cells also express granzyme B in vitro during mixed lymphocyte reactions and in vivo in a mouse model of graft-versus-host disease (GVHD). However, in contrast to findings from our previously published tumor model, granzyme B is not required for the suppression of effector T cell (Teff) proliferation in in vitro Treg suppression assays stimulated by either Concanavalin A or allogeneic antigen presenting cells. Additionally, in an ex vivo assay, sort-purified in vivo-activated CD4+Foxp3+ Treg cells from mice with active GVHD -- under conditions known to induce granzyme B expression in Treg cells -- suppressed Teff cell proliferation in a granzyme B-independent manner. Adoptive transfer of naive granzyme B-deficient CD4+CD25+ Treg cells into a mouse model of GVHD rescued hosts from lethatlity equivalently to naive wild-type Treg cells. Serum analysis of GVHD-associated cytokine production in these recipients also demonstrated that Treg cells suppressed production of IL-2, IL-4, IL-5, GM-CSF, and IFN-gamma in a granzyme B-independent manner. In order to determine whether the context in which Treg cells are activated alters the intrinsic properties of Treg cells, we used Foxp3 reporter mice to obtain gene expression profiles of CD4+Foxp3+ Treg cells purifed from naive resting spleens, spleens from mice with acute GVHD, and from ascites fluid of mice challenged intraperitoneally with allogeneic P815 tumor cells. Unsupervised analyses revealed distinct activation signatures of Treg cells among the 3 experimental groups. Taken together, these findings demonstrate that granzyme B is not required for Treg cell-mediated suppression of GVHD, which is in contrast to what we have previously reported for Treg cell function in the setting of tumor challenge. Cell intrinsic differences could partially account for these differential phenotypes. These data also suggest the therapeutic potential of targeting specific Treg cell suppressive functions in order to segregate GVHD and graft-versus-tumor effector functions. Experiment Overall Design: Six replicates of Naive CD4+Foxp3+ Treg cells were purified from resting spleens, five replicates of allogeneic tumor-activated Treg cells and three samples of GVHD-activated Treg cells. Experiment Overall Design: Naive reps 1-3 are controls for the GVHD-activated samples. Experiment Overall Design: Naive reps 4-6 are controls for the Allogeneic tumor-activated samples.
Project description:Regulatory T cells have been shown to adopt a catabolic metabolic programme with increased capacity for fatty acid oxidation fuelled oxidative phosphorylation (OXPHOS). The role of Foxp3 in this metabolic shift is poorly understood. Here we show that Foxp3 was sufficient to induce a significant increase in the spare respiratory capacity of the cell, the extra OXPHOS capacity available to a cell to increased demands on energy in response to work. Foxp3-expressing cells were enhanced in their ability to utilise palmitate for respiration and in addition the activity of electron transport complexes I, II and IV were enhanced following Foxp3 expression. ATP was secreted by both T effector and regulatory T cells and was reduced by mitochondrial respiration inhibitors. Thus Foxp3 imparts a selective advantage in ATP generation capacity to the cell and may exploit this as a source of adenosine for functional immunomodulation. In order to explore possible mechanisms for these differences in metabolism we conducted a comparative quantitative proteomics study to compare the contribution of TGFβ and the transcription factor Foxp3 to the Treg proteome. We used quantitative mass spectrometry to examine differences between proteomes of nuclear and cytoplasmic Foxp3-containing T cells and Foxp3 positive iTreg and Foxp3 negative activated CD4 T cells in addition to human peripheral blood natural Treg. Gene set enrichment analysis of our proteomic datasets demonstrated that Foxp3 drives a significant up regulation of several members of the mitochondrial electron transport chain.
Project description:Regulatory T cells (Treg) have been shown to adopt a catabolic metabolic programme with increased capacity for fatty acid oxidation fuelled oxidative phosphorylation (OXPHOS). The role of Foxp3 in this metabolic shift is poorly understood. Here we show that Foxp3 was sufficient to induce a significant increase in the spare respiratory capacity of the cell, the extra OXPHOS capacity available to a cell to meet increased demands on energy in response to work. Foxp3-expressing cells were enhanced in their ability to utilise palmitate for respiration and, in addition, the activity of electron transport complexes I, II and IV were enhanced following Foxp3 expression. Foxp3 also imparts a selective advantage in ATP generation capacity, one that might be exploited as a source of adenosine for functional immunomodulation. In order to explore possible mechanisms for these differences in metabolism we conducted a quantitative proteomics study to compare the contribution of TGFβ and the transcription factor Foxp3 to the Treg proteome. We used quantitative mass spectrometry to examine differences between proteomes of nuclear and cytoplasmic Foxp3-containing CD4+ T cells from various sources with Foxp3- activated CD4 T cells, as well as Treg from human peripheral blood. Gene set enrichment analysis of our proteomic datasets demonstrated that Foxp3 expression is associated with a significant up regulation of several members of the mitochondrial electron transport chain. Not only does Foxp3 influence genes directly concerned with immune function, but also with the energy generating functions of Treg.
Project description:CD4+CD25+FOXP3+ regulatory T cells (Treg) are pivotal for peripheral self-tolerance. They prevent immune responses to auto- and alloantigens and are thus under close scrutiny as cellular therapeutics for autoimmune diseases and the prevention or treatment of alloresponses after organ or stem cell transplantation. We previously showed that human Treg cells with a memory cell phenotype, but not those with a naïve phenotype, rapidly down-regulate expression of the lineage-defining transcription factor forkhead box P3 (FOXP3) upon in vitro expansion. We now compared the transcriptomes of stable FOXP3+ Treg and converted FOXP3- 'ex-Treg' cells by applying a newly developed intranuclear staining protocol that permits the isolation of intact mRNA from fixed, permeabilized and FACS-purified cell populations. Whole genome microarray analysis revealed strong and selective upregulation of Th2 signature genes, including GATA-3, IL-4, IL-5 and IL-13, upon downregulation of FOXP3. Th2 differentiation of converted, FOXP3- ex-Treg cells occurred even under non-polarizing conditions and could not be prevented by IL-4 signaling blockade. Thus, our studies identify Th2 differentiation as the default developmental program of human Treg cells after downregulation of FOXP3. RNA preparations from FOXP3 stained in vitro expanded CD4+CD25highCD45RA- “memory” Treg cells from five independent donors were analyzed using Whole Human Genome Oligo Microarrays (Agilent). An adapted FOXP3 staining procedure to stain FOXP3 in human regulatory T cells to isolate intact RNA for microarray hybridization was developed (see extract protocol).
Project description:Understanding human regulatory T cells (Tregs) heterogeneity may identify markers of disease pathogenesis and facilitate the development of optimized cellular therapeutics. To better elucidate human Treg subsets, we conducted direct transcriptional profiling of CD4+FOXP3+Helios+ thymic-derived Treg (tTreg) and CD4+FOXP3+Helios- peripherally-induced Treg (pTreg), followed by comparison to CD4+FOXP3-Helios- T conventional (Tconv) cells. This analysis revealed that the coinhibitory receptor T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) was highly expressed on tTreg. In this study CD4 T cells were stained for the Treg-associated transcription factors FOXP3 and Helios, and subsequently FACS sorted to yield three populations: tTreg (CD4+FOXP3+Helios+), pTreg (CD4+FOXP3+Helios–) and the reference population Tconv (CD4+FOXP3–Helios–). A direct transcriptional profile was obtained from the recovered RNA from the populations defined as tTreg, pTreg, and Tconv.