Project description:Regulatory T cells (Tregs) are immune cells that play a crucial role in maintaining tolerance to harmless antigens, including commensal microbes. In the intestine, Tregs can be classified into subsets based on their expression of transcription factors Helios, Rorg, Gata3 and cMaf. The exact functions of the intestinal Treg subsets and their role in maintaining tolerance to intestinal microbes is not fully understood. Here, we generated conditional knockout mice of each Treg subset and profiled the composition of their intestinal microbiota by performing 16S rRNA sequencing of stool from conditional knockouts and matched littermate controls.
Project description:Foxp3+ regulatory T cells (Tregs) in the colon are key to promoting peaceful co-existence with symbiotic microbes. Differentiated in either thymic or peripheral locations, and modulated by microbes and other cellular influencers, colonic Treg subsets have been identified through key transcription factors (TF; Helios, Rorg, Gata3, cMaf), but their inter-relationships are unclear. Here, we perform genomic analysis of colonic lamina propria Tregs with conditional KOs of each of these TFs to better understand how each TF contributes to colonic Treg identity and function.
Project description:Instability in the composition of gut bacterial communities, referred as dysbiosis, has been associated with important human intestinal disorders such as Crohn’s disease and colorectal cancer. Our data showed that Nod2-mediated risk of intestinal inflammation in colitis model is communicable to WT mice by cohousing. Here, we investigated if Nod2-deficient mice microbiota is able to change transcript profiles in Nod2-immunocompetent mice (C57Bl6/J mice) independently of colitis. Analysis used RNA extracted from colonic mucosa of C57Bl/6J mice co-housed with Nod2-deficient mice and C57Bl/6J mice alone. Direct comparisons of 4 biologicals replicates of C57Bl/6J mice cohoused with Nod2-deficient mice vs C57Bl/6J mice were performed.
Project description:Instability in the composition of gut bacterial communities, referred as dysbiosis, has been associated with important human intestinal disorders such as CrohnM-bM-^@M-^Ys disease and colorectal cancer. Here, we show that dysbiosis coupled to Nod2 or Rip2 deficiency suffices to cause an increased risk for intestinal inflammation and colitis-associated carcinogenesis in mice. Aggravated epithelial lesions and dysplasia upon chemical-induced injury associated with loss of Nod2 or Rip2 can be prevented by antibiotics or anti-IL6R treatment. Nod2-mediated risk for intestinal inflammation and colitis-associated tumorigenesis is communicable through maternally-transmitted microbiota even to wild-type hosts. Disease progression was identified to drive complex NOD2-dependent changes of the colonic-associated microbiota. Reciprocal microbiota transplantation rescues the vulnerability of Nod2-deficient mice to colonic injury. Altogether, our results unveil an unexpected function for NOD2 in shaping a protective assembly of gut microbial communities, providing a rationale for intentional manipulation of genotype-dependent dysbiosis as a causative therapeutic principle in chronic intestinal inflammation. Analysis used RNA extracted from colonic mucosa of untreated, antibiotics-treated or metronidazole-treated C57Bl/6J and Nod2-deficient mice in CAC model. Direct comparisons were performed as follow: C57Bl/6J untreated mice vs Nod2-deficient untreated mice, C57Bl/6J antibiotics-treated mice vs Nod2-deficient antibiotics-treated mice, C57Bl/6J metronidazole-treated mice vs Nod2-deficient metronidazole-treated mice, C57Bl/6J untreated mice vs C57Bl/6J antibiotics-treated mice, C57Bl/6J untreated mice vs C57Bl/6J metronidazole-treated mice, Nod2-deficient untreated mice vs Nod2-deficient antibiotics-treated mice, Nod2-deficient untreated mice vs Nod2-deficient metronidazole-treated mice. Indirect comparisons with control data were made across multiple arrays with raw data pulled from different channels for data analysis.
Project description:The colonic lamina propria contains a distinct population of Foxp3+ T regulatory cells (Tregs) that modulate responses to commensal microbes. Analysis of gene expression revealed that the transcriptome of colonic Tregs is distinct from splenic and other tissue Tregs. Rorγ and Helios in colonic Tregs mark distinct populations: Rorγ+Helios- or Rorγ-Helios+ Tregs. We uncovered an unanticipated role for Rorγ, a transcription factor generally considered to be antagonistic to Foxp3. Rorγ in colonic Tregs accounts for a small but specific part of the colon-specific Treg signature. (1) Total colonic and splenic Foxp3+ Treg comparison: Lymphocytes were isolated from colonic lamina propria and spleens of Foxp3-ires-GFP mice, where GFP reports Foxp3 expression. TCRb+CD4+GFP+ cells were double sorted into Trizol. (2) Colonic Rorγ+ and Rorγ- Treg comparison: Foxp3-ires-Thy1.1 reporter mice were crossed to Rorc-GFP reporter mice to generate mice that report both Foxp3 and Rorγ expression. Rorγ+Foxp3+ Tregs (TCRb+CD4+Thy1.1+GFP+) and Rorγ-Foxp3+ Tregs (TCRb+CD4+Thy1.1+GFP-) from colonic lamina propria were double sorted into Trizol.To reduce variability and increase cell number, cells from multiple mice were pooled for sorting and at least three replicates were generated for all groups. RNA from 1.5-3.0 x104 cells was amplified, labeled and hybridized to Affymetrix Mouse Gene 1.0 ST Arrays.
Project description:Inflammation markedly alters the microenvironment of intestinal tissue. To explore alterations in the cell composition and transcription of intestinal tissue during colitis, we conducted single-cell RNA sequencing analysis of the colonic tissues obtained from the mice treated with 3% DSS for 6 days.
Project description:Foxp3-expressing regulatory T (Treg) cells are critical mediators of immunological tolerance to both self and microbial antigens. Tregs activate context-dependent transcriptional programs to adapt effector function to specific tissues; however, the factors controlling tissue-specific gene expression in Tregs remain unclear. Here, we find that the AP-1 transcription factor JunB regulates the intestinal adaptation of Tregs by controlling select gene expression programs in multiple Treg subsets. Treg-specific ablation of JunB results in immune dysregulation characterized by enhanced colonic T helper cell accumulation and cytokine production. However, in contrast to its classical binding-partner BATF, JunB is dispensable for maintenance of effector Tregs as well as most specialized Treg subsets. In the Peyer’s patches, JunB activates a transcriptional program facilitating the maintenance of CD25- Tregs, leading to the complete loss of T follicular regulatory cells in the absence of JunB. This defect is compounded by loss of a separate effector program found in both major colonic Treg subsets that includes the cytolytic effector molecule granzyme B. Therefore, JunB is an essential regulator of intestinal Treg effector function through pleiotropic effects on gene expression.
Project description:T cells that express the transcription factor RORg, regulatory (Treg) or conventional (Th17), are strongly influenced by intestinal symbionts. In a genetic approach to mechanisms underlying this influence, we performed a screen for microbial genes implicated, in germfree mice monocolonized with E.coli Nissle. The loss of capsule-synthesis genes impaired clonal expansion and differentiation of intestinal RORg+ T cells. Mechanistic exploration revealed that the capsule-less mutants remained able to induce specific IgA and were highly IgA-coated. They could still trigger myeloid cells, and more effectively damaged epithelial cells in vitro. Unlike wild-type microbes, capsule-less mutants were mostly engulfed in intraluminal casts, large agglomerates composed of myeloid cells extravasated into the gut lumen. We speculate that sequestration in luminal casts of potentially harmful microbes reduces the immune system’s actual exposure, preserving host-microbe equilibrium. The variable immunostimulation by microbes charted in recent years may not solely be conditioned by triggering molecules or metabolites, but also by physical limits to immunocyte exposure.
Project description:The colonic lamina propria contains a distinct population of Foxp3+ T regulatory cells (Tregs) that modulate responses to commensal microbes. Analysis of gene expression revealed that the transcriptome of colonic Tregs is distinct from splenic and other tissue Tregs. Rorγ and Helios in colonic Tregs mark distinct populations: Rorγ+Helios- or Rorγ-Helios+ Tregs. We uncovered an unanticipated role for Rorγ, a transcription factor generally considered to be antagonistic to Foxp3. Rorγ in colonic Tregs accounts for a small but specific part of the colon-specific Treg signature. Nrp1- Tregs were sorted from Foxp3-cre.Rorcfl/fl mice, which have a Treg-selective deletion of Rorc, or paired WT littermates. For low-input RNAseq, 1,000 TCRb+CD4+YFP(Foxp3)+Nrp1- cells were double-sorted into Trizol, RNA extracted and reverse-transcribed using ArrayScript (Ambion). To reduce variability at least three replicates were generated.