Control of regulatory T cell function by the non-oxidative pentose phosphate pathway [RNA-Seq]
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE171675 | GEO | 2022/03/31
REPOSITORIES: GEO
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Project description:Non-oxidative pentose phosphate pathway (PPP) is a crucial gatekeeper of glucose catabolism in metabolic tissues. However, its role in regulatory T cells (Tregs) remains unknown. Here we report deleting transketolase (TKT), an indispensable enzyme of non-oxidative PPP, in Tregs caused a fatal auto-immune disease in mice. TKT deletion impaired suppressive capability without disturbing Treg cell number. Mechanistically, TKT deficiency caused Treg metabolic remodeling with decreased glucose catabolism, activated fatty acid and amino acid catabolism and uncontrolled oxidative phosphorylation. Moreover, excessive ammonia from deregulated amino acid catabolism impaired mitochondrial fitness while reduced α-ketoglutarate/succinate ratio led to DNA hypermethylation, limiting functional gene expression and suppressive activity of TKT-deficient Tregs. Therefore, our study identifies non-oxidative PPP as a new pathway for controlling Treg function.
2022-03-31 | GSE172047 | GEO
Project description:Regulatory T cells (Tregs) are critical for maintaining immune homeostasis and preventing autoimmunity. Here, we show that the non-oxidative pentose phosphate pathway (PPP) regulates Treg function to prevent autoimmunity. Deletion of transketolase (TKT), an indispensable enzyme of non-oxidative PPP, in Tregs causes a fatal autoimmune disease in mice, with impaired Treg suppressive capability despite regular Treg numbers and normal Foxp3 expression levels. Mechanistically, reduced glycolysis and enhanced oxidative stress induced by TKT deficiency triggers excessive fatty acid and amino acid catabolism, resulting in uncontrolled oxidative phosphorylation and impaired mitochondrial fitness. Reduced -KG levels as a result of reductive TCA cycle activity leads to DNA hypermethylation, thereby limiting functional gene expression and suppressive activity of TKT-deficient Tregs. We also find that TKT levels are frequently downregulated in Tregs of patients with autoimmune disorders. Our study identifies the non-oxidative PPP as an integrator of metabolic and epigenetic processes that control Treg function.
2022-03-31 | GSE198995 | GEO
Project description:The Pentose Phosphate Pathway (PPP), a metabolic offshoot of the glycolytic pathway, provides protective metabolites and molecules essential for cell redox balance and survival. Transketolase (TKT) is the critical enzyme that controls the extent of “traffic flow” through the PPP. Here, we explored the role of TKT in maintaining the health of the human retina. We found that Müller cells were the primary retinal cell type expressing TKT in the human retina. We further explored the role of TKT in human Müller cells by knocking down its expression in primary cultured Müller cells (huPMCs), isolated from the human retina (11 human donors in total), under lightinduced oxidative stress. TKT knockdown and light stress reduced TKT enzymatic activities and the overall metabolic activities of huPMCs with no detectable cell death. TKT knockdown restrained the PPP traffic flow, reduced the expression of NAD(P)H Quinone Dehydrogenase 1 (NQO1) and impaired the antioxidative response of NRF2 to light stress. TKT knockdown also inhibited overall glucose intake, reduced expression of Dihydrolipoamide dehydrogenase (DLD) and impaired the energy supply of huPMCs. In summary, Müller cell-mediated TKT activity plays a critical protective role in the stressed retina. Knockdown of TKT disrupted the PPP and impaired overall glucose utilisation by huPMCs and rendered huPMCs more vulnerable to light stress by impairing energy supply and antioxidative NRF2 responses.
2022-06-26 | GSE198554 | GEO
Project description:The human genome encodes two proteins closely related to transketolase (TKT), transketolase-like protein 1 and 2 (TKTL1 and TKTL2). TKTL1 shares 61% amino acid sequence identity with TKT. More and more evidence suggests a role for TKTL1 in proliferation or cell cycle regulation. Indeed, TKTL1 is overexpressed in various cancers and is correlated with poor prognosis in colon, urothelial, gastric, and lung cancers as well as in ocular adnexa carcinomas, rectum carcinomas, and laryngeal squamous cell carcinomas. Increased TKTL1 levels also correlate with esophageal squamous cell carcinoma metastasis and increased resistance against cisplatin chemotherapy in nasopharyngeal carcinomas. Moreover, TKTL1 overexpression promotes cell proliferation and enhanced tumor growth; in contrast, TKTL1 down regulation attenuates the proliferation of various types of cancer cells. However, the cellular functions and regulatory machineries of TKTL1 are still largely unknown. Through this proteomic analysis, we defined the protein-protein interaction map for the TKTL1 and uncovered the novel regulating function of TKTL1 in regulating TKT transketolase activity.
2019-11-12 | PXD013309 | Pride
Project description:Regulatory T cells (Tregs) are known to maintain survival and suppressive function in the presence of high levels of extracellular lactic acid. However, the effect of lactic acid on Treg induction is not known. We therfore evaluated the effect of lactic acid on Treg induction and observed an increased induction of Tregs in the presence of lactic acid. This increase occurred in a glycolysis-independent, acidity-dependent manner.
2023-03-23 | GSE217536 | GEO
Project description:The proposed use of Foxp3+ T-regulatory (Treg) cells as potential cellular therapy in patients with autoimmune diseases, or post-hemopoietic stem cell or organ transplantation, requires a sound understanding of the transcriptional regulation of Foxp3 expression. Conserved CpG dinucleotides in the Treg-specific demethylated region (TSDR) upstream of Foxp3 are demethylated only in stable, thymic-derived Foxp3+ Tregs. Since methyl-binding domain (Mbd) proteins recruit histone-modifying and chromatin-remodeling complexes to methylated sites, we tested whether targeting of Mbd2 might promote demethylation of Foxp3 and thereby promote Treg numbers or function. Surprisingly, while ChIP analysis showed Mbd2 binding to the Foxp3-associated TSDR site in Tregs, Mbd2 targeting by homologous recombination or siRNA decreased Treg numbers and impaired Treg suppressive function in vitro and in vivo. Moreover, we found complete TSDR demethylation in WT Tregs but >75% methylation in Mbd2-/- Tregs, whereas re-introduction of Mbd2 into Mbd2-null Tregs restored TSDR demethylation, Foxp3 gene expression and Treg suppressive function. Lastly, Mbd2-/- Tregs had markedly binding of the DNA demethylase enzyme, Tet2, in the TSDR region. These data show that Mbd2 has a key role in promoting TSDR demethylation, Foxp3 expression and Treg suppressive function. RNA from three independent samples from magnetically separated CD4+CD25+ Treg of MBD2–/– mice, compared to wild type control (all Balb/c background).
2013-09-01 | E-GEOD-48653 | biostudies-arrayexpress
Project description:Foxp3 expressing regulatory T cells (Tregs) are the central regulator of immune homeostasis and tolerance. As it is believed that proper Treg function is compromised under inflammatory conditions, exploring a pathway that enhances Treg function is of great importance. In this study, we report that IL-27, an IL-12 family cytokine known to play both pro- and anti-inflammatory role in T cells, plays a pivotal role in Treg function to control T cell-induced colitis. Unlike WT Tregs capable of inhibiting colitogenic T cell expansion and inflammatory cytokine expression, IL-27R-deficient Tregs were unable to downregulate inflammatory T cell responses. Tregs stimulated with IL-27 expressed substantially enhanced suppressive function both in vitro and in vivo. IL-27 stimulation of Tregs induced expression of LAG3, a surface molecule implicated in negatively regulating immune responses. LAG3 expression in IL-27-stimulated Tregs was critical to mediate suppressive Treg function. Finally, human Tregs also displayed enhanced suppressive function and LAG3 expression in response to IL-27 stimulation. Taken together, our results highlight a novel function of the IL-27/LAG3 axis in Treg regulation of inflammatory responses in the intestine. FACS purified Foxp3+ Tregs were stimulated in the presence of media or IL-27 to compare IL-27 induced gene profiles. Four samples (media stimulated or IL-27-stimulated) were collected from four independent experiments. Genes altered by IL-27 treatment were compared to those of media stimulated Tregs.
2015-11-01 | E-GEOD-63455 | biostudies-arrayexpress
Project description:The mechanistic target of rapamycin (mTOR) pathway integrates diverse environmental inputs, including immune signals and metabolic cues, to direct T cell fate decisions1. Activation of mTOR, comprised of mTORC1 and mTORC2 complexes, delivers an obligatory signal for proper activation and differentiation of effector CD4+ T cells2,3, whereas in the regulatory T cell (Treg) compartment, the Akt-mTOR axis is widely acknowledged as a crucial negative regulator of Treg de novo differentiation4-8 and population expansion9. However, whether mTOR signaling affects the homeostasis and function of Tregs remains largely unexplored. Here we show that mTORC1 signaling is a pivotal positive determinant of Treg function. Tregs have elevated steady-state mTORC1 activity compared to naïve T cells. Signals via T cell receptor (TCR) and IL-2 provide major inputs for mTORC1 activation, which in turn programs suppressive function of Tregs. Disruption of mTORC1 through Treg-specific deletion of the essential component Raptor leads to a profound loss of Treg suppressive activity in vivo and development of a fatal early-onset inflammatory disorder. Mechanistically, Raptor/mTORC1 signaling in Tregs promotes cholesterol/lipid metabolism, with the mevalonate pathway particularly important for coordinating Treg proliferation and upregulation of suppressive molecules CTLA-4 and ICOS to establish Treg functional competency. In contrast, mTORC1 does not directly impact the expression of Foxp3 or anti- and pro-inflammatory cytokines in Tregs, suggesting a non-conventional mechanism for Treg functional regulation. Lastly, we provide evidence that mTORC1 maintains Treg function partly through inhibiting the mTORC2 pathway. Our results demonstrate that mTORC1 acts as a fundamental ‘rheostat’ in Tregs to link immunological signals from TCR and IL-2 to lipogenic pathways and functional fitness, and highlight a central role of metabolic programming of Treg suppressive activity in immune homeostasis and tolerance. We used microarrays to explore the gene expression profiles differentially expressed in regulatory T-cells from wild-type and CD4(cre) x Raptor(fl/fl) mice
2013-06-24 | E-GEOD-46693 | biostudies-arrayexpress
Project description:The PI3K pathway has emerged as a key regulator of regulatory T cell (Treg) development and homeostasis and is required for full Treg-mediated suppression. To identify new genes involved in PI3K-dependent suppression we compared the transcriptome of WT and p110delta D910A Tregs. Among the genes that were differentially expressed was CD38. Here we show that CD38 is expressed mainly by a subset of Foxp3+CD25+CD4+ T cells originating in the thymus and on Tregs in the spleen. CD38high WT Tregs showed superior suppressive activity and CD38low Tregs failed to upregulate CD73, a surface protein which is important for suppression. However, Tregs from heterozygous CD38+/- mice were unimpaired despite their lower levels of CD38 expression. Therefore, CD38 can be used as a marker for Tregs with high suppressive activity and the impaired Treg function in p110delta D910A mice can in part be explained by the failure of CD38high cells to develop.
2011-04-01 | E-MEXP-2955 | biostudies-arrayexpress
Project description:The therapeutic use of regulatory T cells (Tregs) in patients with autoimmune disorders has been hampered by the biological variability of memory Treg populations in the peripheral blood. In this study, we reveal through a combination of quantitative proteomic, multiparametric flow cytometry, RNA-seq data analysis and functional assays, that CD49f is heterogeneously expressed among human Tregs and impacts their immunomodulatory function. High expression of CD49f defines a subset of dysfunctional Tregs in the human blood characterized by a Th17-like phenotype and impaired suppressive capacity. CD49f is similarly distributed between naïve and memory Tregs and impacts the expression of CD39, CTLA-4, FoxP3 and CCR6 specifically in the memory compartment. Accumulation of CD49f high memory Tregs in the blood of ulcerative colitis patients correlates with disease severity. Our results highlight important considerations for Treg immunotherapy design in patients with inflammatory bowel disease which could possibly extend to other autoimmune disorders.
2021-08-06 | PXD022095 | Pride