Project description:Genetic variants at the PTPN2 locus, which encodes the tyrosine phosphatase PTPN2, cause reduced gene expression and are linked to rheumatoid arthritis (RA) and other autoimmune diseases. PTPN2 inhibits signaling through the T cell and cytokine receptors and loss of PTPN2 promotes T cell expansion and CD4 and CD8-driven autoimmunity. However, it remains unknown whether loss of PTPN2 in FoxP3+ regulatory T cells (Treg) plays a role in autoimmunity. Here we show that a reduction in Ptpn2 expression, comparable to that reported in human carriers of autoimmune-predisposing PTPN2 variants, unexpectedly enhances the severity of autoimmune arthritis through a Treg-intrinsic mechanism. Mechanistically, we found that through dephosphorylation of STAT3, Ptpn2 inhibits IL-6-driven pathogenic loss of FoxP3 after Tregs have acquired RORgt expression, at a stage when chromatin accessibility for STAT3-targeted IL-17 associated transcription factors is maximized. We conclude that PTPN2 promotes FoxP3 stability in RORgt+ Treg and that loss of function of PTPN2 in Treg contributes to the association between PTPN2 and autoimmunity.
Project description:Genetic variants at the PTPN2 locus, which encodes the tyrosine phosphatase PTPN2, cause reduced gene expression and are linked to rheumatoid arthritis (RA) and other autoimmune diseases. PTPN2 inhibits signaling through the T cell and cytokine receptors and loss of PTPN2 promotes T cell expansion and CD4 and CD8-driven autoimmunity. However, it remains unknown whether loss of PTPN2 in FoxP3+ regulatory T cells (Treg) plays a role in autoimmunity. Here we show that a reduction in Ptpn2 expression, comparable to that reported in human carriers of autoimmune-predisposing PTPN2 variants, unexpectedly enhances the severity of autoimmune arthritis through a Treg-intrinsic mechanism. Mechanistically, we found that through dephosphorylation of STAT3, Ptpn2 inhibits IL-6-driven pathogenic loss of FoxP3 after Tregs have acquired RORgt expression, at a stage when chromatin accessibility for STAT3-targeted IL-17 associated transcription factors is maximized. We conclude that PTPN2 promotes FoxP3 stability in RORgt+ Treg and that loss of function of PTPN2 in Treg contributes to the association between PTPN2 and autoimmunity.
Project description:Treg cells bearing a diverse antigen receptor repertoire suppress pathogenic T cells and maintain immune homeostasis during their long lifespan. How their robust function is determined genetically remains elusive. Here, we investigate the regulatory space of the cis-regulatory elements of Treg lineage–specifying factor Foxp3. Foxp3 enhancers are known as distinct readers for environmental cues in promoting Treg cell induction or lineage stability. However, their single deficiencies cause mild, if any, immune dysregulation, leaving the key transcriptional mechanisms determining Foxp3 expression and thereby Treg suppressive capacity uncertain. We examined the collective activities of Foxp3 enhancers and found that they coordinate to maximize Treg cell induction, Foxp3 expression level, or lineage stability through distinct modes and that ablation of synergistic enhancers led to lethal autoimmunity in young mice. Thus, the induction and maintenance of a diverse, stable Treg cell repertoire rely on combinatorial Foxp3 enhancers, suggesting broad, stage-specific, synergistic activities of cell-intrinsic factors and -extrinsic cues in determining Treg suppressive capacity.
Project description:Analysis of Foxp3(+)epigenetics(-) T cells, Foxp3(-)epigenetics(+) T cells, and Foxp3(+)epigenetics(+) T cells. Results indicate regulatory T cell (Treg) ontogenesis requires two independent processes, expression of the transcription factor Foxp3 and establishment of Treg epigenetic programs induced by T cell receptor (TCR) stimulation.
Project description:The active form of vitamin D (1,25(OH)2D) suppresses experimental models of inflammatory bowel disease in part by regulating the microbiota. In this study, the role of vitamin D in the regulation of microbe induced RORgt/FoxP3+ T regulatory (reg) cells in the colon was determined. Vitamin D sufficient (D+) mice had significantly higher frequencies of FoxP3+ and RORgt/FoxP3+ T reg cells in the colon compared to vitamin D deficient (D-) mice. The higher frequency of RORgt/FoxP3+ T reg cells in D+ colon correlated with higher numbers of bacteria from the Clostridium XIVa and Bacteroides in D+ compared to D- cecum. D- mice with fewer RORgt/FoxP3+ T reg cells were significantly more susceptible to colitis than D+ mice. Transfer of the cecal bacteria from D+ or D- mice to germfree recipients phenocopied the higher numbers of RORgt/FoxP3+ cells and reduced susceptibility to colitis in D+ versus D- recipient mice. 1,25(OH)2D treatment of the D- mice beginning at 3 weeks of age did not completely recover RORgt/FoxP3+ T reg cells or the Bacteriodes, Bacteriodes thetaiotaomicron, and Clostridium XIVa numbers to D+ values. Early vitamin D status shapes the microbiota to optimize the population of colonic RORgt/FoxP3+ T reg cells important for resistance to colitis.
Project description:Analysis of Foxp3(+)epigenetics(-) T cells, Foxp3(-)epigenetics(+) T cells, and Foxp3(+)epigenetics(+) T cells. Results indicate regulatory T cell (Treg) ontogenesis requires two independent processes, expression of the transcription factor Foxp3 and establishment of Treg epigenetic programs induced by T cell receptor (TCR) stimulation. GFP+CD4+ and GFP-CD4+ splenocytes were sorted from DEREG and DEREG/Scurfy mice. These cells were activated with anti-CD3/CD28 antibodies, and then transduced with Foxp3-expressing retrovirus (pGCSamIN, NGFR marker). NGFR+ T cells sorted were subjected to microarray analysis (Affymetrix, mouse genome 430 2.0 array). To normalize the experimental conditions, Tregs (GFP+ T cells from DEREG) and Tconv (GFP- T cells from DEREG) were also activated and transduced with empty vector. Two replicates each.
Project description:Single cell transcriptomic analysis (InDrops) of FoxP3+ regulatory CD4+ T cells isolated from the spleen and visceral adipose tissue of wild-type and VAT-TCR transgenic mice
Project description:The aim of this study was to analyze the global transcriptional profiles of small intestine (SI) Innate Lymphoid Cells (ILCs) expressing the NK cell marker NKp46. Based on differential expression of the RORgt transcription factor SI NKp46+ ILCs can be divided in NKp46+RORgt- and NKp46+RORgt+ cells. While NKp46+RORgt- cells produce IFN-g, like conventional Natural Killer (NK) cells, NKp46+RORgt+ cells secrete IL-22, like Lymphoid Tissue inducer (LTi) cells. We compared the global transcriptional profiles of both NKp46+RORgt- and NKp46+RORgt+ cells to conventional splenic NK cells and to SI NKp46-RORgt+ cells, which contain adult LTi cells. By following this approach, we showed that SI NKp46+RORγt- ILCs correspond to SI NK cells. We also identified a transcriptional program conserved in adult SI NKp46+RORγt+, NKp46-RORγt+ ILCs and fetal LTi. The various ILC cell populations analyzed in this study were isolated from C57BL/6 RORc(gt)+/GFP reporter mice. SI NKp46+RORγt- (NKp46+GFP-) cells, SI NKp46+RORγt+ cells (NKp46+GFPlow and NKp46+GFPhigh cells) and NKp46-RORγt+ ILCs, including adult LTi cells , were sorted by flow cytometry from CD3- lamina propria cells of small intestine (SI) of RORc(γt)+/GFP reporter mice . Splenic NKp46+RORγt- (NKp46+GFP-) cells were also sorted as the reference for conventional NK cells. Two replicates of each populations were produced and analyzed.
Project description:The aim of this study was to analyze the global transcriptional profiles of small intestine (SI) Innate Lymphoid Cells (ILCs) expressing the NK cell marker NKp46. Based on differential expression of the RORgt transcription factor SI NKp46+ ILCs can be divided in NKp46+RORgt- and NKp46+RORgt+ cells. While NKp46+RORgt- cells produce IFN-g, like conventional Natural Killer (NK) cells, NKp46+RORgt+ cells secrete IL-22, like Lymphoid Tissue inducer (LTi) cells. We compared the global transcriptional profiles of both NKp46+RORgt- and NKp46+RORgt+ cells to conventional splenic NK cells and to SI NKp46-RORgt+ cells, which contain adult LTi cells. By following this approach, we showed that SI NKp46+RORγt- ILCs correspond to SI NK cells. We also identified a transcriptional program conserved in adult SI NKp46+RORγt+, NKp46-RORγt+ ILCs and fetal LTi.