Project description:BATF3 has been shown to inhibit FOXP3 expression in differentiating CD4 T cells, however, the role of IRF4 in this inhibition is unexplored. IRF4 binds DNA weakly on its own and requires interactions with other transcription factors. We investigated how BATF3/IRF4 interactions are necessary for IRF4 binding and BATF3-mediated FOXP3 inhibition.
Project description:Treg cell therapy is a promising curative approach for a variety of immune-mediated conditions. CRISPR-based genome editing allows precise insertion of transgenes through homology-directed repair, but its use in human Tregs has been limited. We report an optimized protocol for CRISPR-mediated gene knock-in in human Tregs with high-yield expansion. To establish a benchmark of human Treg dysfunction, we target the master transcription factor FOXP3 in naive and memory Tregs. Although FOXP3-ablated Tregs upregulate cytokine expression, effects on suppressive capacity in vitro manifest slowly and primarily in memory Tregs. Moreover, FOXP3-ablated Tregs retain their characteristic protein, transcriptional, and DNA methylation profile. Instead, FOXP3 maintains DNA methylation at regions enriched for AP-1 binding sites. Thus, while FOXP3 is important for human Treg development, it has a limited role in maintaining mature Treg identity. Optimized gene knock-in with human Tregs will enable mechanistic studies and the development of tailored, next-generation Treg cell therapies.
Project description:Treg cell therapy is a promising curative approach for a variety of immune-mediated conditions. CRISPR-based genome editing allows precise insertion of transgenes through homology-directed repair, but its use in human Tregs has been limited. We report an optimized protocol for CRISPR-mediated gene knock-in in human Tregs with high-yield expansion. To establish a benchmark of human Treg dysfunction, we target the master transcription factor FOXP3 in naive and memory Tregs. Although FOXP3-ablated Tregs upregulate cytokine expression, effects on suppressive capacity in vitro manifest slowly and primarily in memory Tregs. Moreover, FOXP3-ablated Tregs retain their characteristic protein, transcriptional, and DNA methylation profile. Instead, FOXP3 maintains DNA methylation at regions enriched for AP-1 binding sites. Thus, while FOXP3 is important for human Treg development, it has a limited role in maintaining mature Treg identity. Optimized gene knock-in with human Tregs will enable mechanistic studies and the development of tailored, next-generation Treg cell therapies.
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.
Project description:Objectives. Immune homeostasis in the intestinal tract is tightly controlled by FOXP3+ regulatory T cells (Tregs), with loss of this Treg-mediated control linked to development of chronic conditions, such as inflammatory bowel disease (IBD). As a mechanism of immune evasion, several species of intestinal parasites strengthen intestinal Treg activity, leading to the notion that parasite-derived products could be harnessed and used as an immunoregulatory therapy for IBD. It has been previously demonstrated that the parasite Heligmosomoides polygyrus secretes a molecule (Hp-TGM) which mimics the ability of TGF-β to induce FOXP3 expression in CD4+ T cells. Our aim was to investigate whether Hp-TGM could induce human FOXP3+ Tregs as a potential therapeutic approach. Methods. Human CD4+ T cells from healthy volunteers were expanded in the presence of Hp-TGM or mammalian TGF-β. The induction of Tregs was measured by flow cytometric detection of FOXP3 and other Treg markers, such as CTLA-4 and CD25. Epigenetic changes were detected using ChIP-Seq and pyrosequencing of FOXP3. Treg phenotype stability was assessed following inflammatory cytokine challenge and Treg function was assessed by cellular co-culture suppression assays and secreted cytokines measured by cytometric bead array. Results. Hp-TGM efficiently induced FOXP3 expression (>60%), in addition to another Treg functional marker CTLA-4. Hp-TGM caused epigenetic modification of the FOXP3 loci to a greater extent than did TGF-β. Hp-TGM-induced Tregs also had superior suppressive function compared to TGF--induced Tregs, and retained their phenotype following exposure to inflammatory cytokines. Hp-TGM also induced a Treg phenotype in in vivo differentiated Th17 cells, indicating its potential to re-program memory cells to enhance immune tolerance. Conclusion. These data indicate Hp-TGM has the potential to be used to generate stable human FOXP3+ Tregs to treat IBD.
Project description:The transcription factor FoxP3 partakes dominantly in the specification and function of FoxP3+ CD4+ T regulatory cells (Tregs), but is neither strictly necessary nor sufficient to determine the characteristic Treg transcriptional signature. Computational network inference and experimental testing assessed the contribution of several other transcription factors (TFs). Enforced expression of Helios or Xbp1 elicited specific signatures, but Eos, Irf4, Satb1, Lef1 and Gata1 elicited exactly the same outcome, synergizing with FoxP3 to activate most of the Treg signature, including key TFs, and enhancing FoxP3 occupancy at its genomic targets. Conversely, the Treg signature was robust to inactivation of any single cofactor. A redundant genetic switch thus locks-in the Treg phenotype, a model which accounts for several aspects of Treg physiology, differentiation and stability. To study the impact of deficiency of candidate FoxP3 cofactors (Xbp1, Eos, Gata1) on the expression of the Treg transcriptional signature, gene expression profiles were generated from purified splenic CD4+CD25hi Tregs of these mutant or knockout mice and their wildtype littermates.
Project description:The transcription factor FoxP3 partakes dominantly in the specification and function of FoxP3+ CD4+ T regulatory cells (Tregs), but is neither strictly necessary nor sufficient to determine the characteristic Treg transcriptional signature. Computational network inference and experimental testing assessed the contribution of several other transcription factors (TFs). Enforced expression of Helios or Xbp1 elicited specific signatures, but Eos, Irf4, Satb1, Lef1 and Gata1 elicited exactly the same outcome, synergizing with FoxP3 to activate most of the Treg signature, including key TFs, and enhancing FoxP3 occupancy at its genomic targets. Conversely, the Treg signature was robust to inactivation of any single cofactor. A redundant genetic switch thus locks-in the Treg phenotype, a model which accounts for several aspects of Treg physiology, differentiation and stability. To study the impact of FoxP3 and its candidate cofactors (Eos, Gata1, Helios, Irf4, Lef1, Satb1, Xbp1) on the expression of the Treg transcriptional signature, CD4+ conventional T cells (Tconv) activated with anti-CD3+CD28 beads were retrovirally transduced with cDNAs encoding FOXP3, candidate TFs, or a combination of FOXP3 and candidate TFs. After 3 days in culture, the transduced cells were sorted into Trizol, and RNA was purified, labeled and hybridized to Affymetrix arrays.
Project description:TIGIT+ Tregs suppress Th1 and Th17 responses while sparing Th2 responses. Analysis of global gene expression of TIGIT+ vs. TIGIT- Tregs from naive mice reveled that TIGIT+ Tregs display an activated phenotype and are enriched for Treg signature genes including the Treg effector molecule Fgl2 which enables them to selectively spare Th2 responses. TIGIT+ and TIGIT- Tregs were sorted from naïve Foxp3-GFP KI mice (pooled spleen and lymph nodes) TIGIT: T cell immunoreceptor with Ig and ITIM domains
Project description:The transcription factor FoxP3 partakes dominantly in the specification and function of FoxP3+ CD4+ T regulatory cells (Tregs), but is neither strictly necessary nor sufficient to determine the characteristic Treg transcriptional signature. Computational network inference and experimental testing assessed the contribution of several other transcription factors (TFs). Enforced expression of Helios or Xbp1 elicited specific signatures, but Eos, Irf4, Satb1, Lef1 and Gata1 elicited exactly the same outcome, synergizing with FoxP3 to activate most of the Treg signature, including key TFs, and enhancing FoxP3 occupancy at its genomic targets. Conversely, the Treg signature was robust to inactivation of any single cofactor. A redundant genetic switch thus locks-in the Treg phenotype, a model which accounts for several aspects of Treg physiology, differentiation and stability. To study the impact of FOXP3 alone or together with GATA1 on the expression of the Treg transcriptional signature, we sorted and profiled matched bins of FOXP3-transduced cells bearing various levels of FOXP3, alone or co-transduced with GATA1, chosen as a representative of the quintet factors.
Project description:Overall, we show that IL-34 induced the differentiation of human monocytes with a particular transcriptional profile and these cells favor the development of potent suppressor CD4+ and CD8+ FOXP3+ Tregs.