The lipid metabolism enzyme DGAT1 mediates Treg control of type 2 immunity at barrier sites
Ontology highlight
ABSTRACT: Regulatory T cells were sorted from the colon of mice under steady state conditions from mice that were either wild type or Dgat1 knockout. To gain enough cells for sequencing samples from the same group were pooled (n=5/pool).
Project description:Primary cilia (PC) are important signaling hubs in cells and we explored their role in colorectal cancer (CRC) and colitis. In the colon we found PC to be mostly present on different subtypes of fibroblasts and exposure of mice to either chemically induced colitis-associated colon carcinogenesis (CAC) or dextran sodium sulfate (DSS)-induced acute colitis decreased PC numbers. We employed conditional knock-out strains for the PC essential genes, Kif3A and Ift88, to generate mice with reduced numbers of PC on colonic fibroblasts. These mice showed an increased susceptibility in the CAC model as well as in DSS-induced colitis. Secretome and immunohistochemical analyses of DSS-treated mice displayed an elevated production of the pro-inflammatory cytokine IL-6 in PC-deficient colons. An inflammatory environment diminished PC presence in primary fibroblast cultures. This was triggered by IL-6 as identified by RNAseq analysis together with blocking experiments, suggesting an activation loop between IL-6 production and PC loss. Notably, an analysis of PC presence on biopsies of patients with ulcerative colitis as well as CRC patients revealed decreased numbers of PC on colonic fibroblasts in pathological versus surrounding normal tissue. Taken together, we provide evidence that a decrease in colonic PC numbers promotes colitis and CRC.
Project description:We wanted to assess the role of a specific smooth muscle protein (MMP17) in two different intestinal compartments, the epithelium (crypts) and the smooth muscle. To do that we isolate intestinal crypts from wild-type (WT) and knockout (KO, Mmp17-/-) mice, and obtained clean strips of smooth muscle. After muscle dissociation, we obtained RNA directly from crypts and muscle, and it was used for RNA-seq. By comparing WT and KO samples we observed a higher impact in gene expression affecting crypts, even though MMP17 is only expressed in muscle. This helped us to identify altered signaling pathways in KO crypts that linked MMP17 with SMAD4 and BMP signaling.
Project description:Non-lymphoid tissues (NLTs) harbour a pool of adaptive immune cells distinct from their counterparts in lymphoid tissues, and their development and phenotype remains largely unexplored. We used scRNA-seq to survey CD4+ T regulatory (Treg) and memory T (Tmem) cells in spleen, lymph nodes, skin and colon in an unbiased way, in mouse and human. This cross-tissues, cross-species comparison allows us to obtain marker genes for immune populations in specific locations with likely relevance for human studies. Additionally, a continuous phenotype of Treg migration can be modelled from the mouse data, unravelling the transcriptional stages through which these cells transition between tissues.
Project description:The human colon contains an extensively diverse microbial ecosystem and one of the most numerous communities of immune cells. Studies have highlighted dynamic crosstalk between immune cells and commensals. While studies have demonstrated increasing diversity of microbiota from stomach to stool, whether and how immune cell heterogeneity and microbiota diversity change across the colon is undefined. Furthermore, whether these changes are co-depended in the healthy colon is unknown. Here, tissue samples are collected from caecum, transverse colon, sigmoid colon and mLN of cadaveric donors by the Cambridge Biorepository of Translational Medicine (CBTM). We use single cell RNA sequencing (10X genomics) to assess the dynamics of immune cell populations across the colon and in matching lymph nodes. Associated microbiome 16S sequencing data is available.
Project description:The human colon contains an extensively diverse microbial ecosystem and one of the most numerous communities of immune cells. Studies have highlighted dynamic crosstalk between immune cells and commensals. While studies have demonstrated increasing diversity of microbiota from stomach to stool, whether and how immune cell heterogeneity and microbiota diversity change across the colon is undefined. Furthermore, whether these changes are co-depended in the healthy colon is unknown. Here, tissue samples are collected from caecum, transverse colon, sigmoid colon and mLN of cadaveric donors by the Cambridge Biorepository of Translational Medicine (CBTM). We use single cell RNA sequencing (10X genomics) to assess the dynamics of immune cell populations across the colon and in matching lymph nodes. Associated microbiome 16S sequencing data is available.
Project description:The metabolic pathways that underlie the association between folate deficiency and increased risk for colorectal cancer (CRC) remain unclear. We have studied the effect of C1THF synthase (encoded by the Mthfd1 gene) and dietary folate and choline on intestinal tumor development in Apcmin/+ mice and azoxymethane (AOM)-induced colon cancer in mice. Mthfd1 deficiency did not alter tumor number or load in Apcmin/+ mice, but did result in a decreased incidence of colon tumors. Conversely, Mthfd1 deficiency increased tumor number 3.5-fold and tumor load 2-fold in AOM-treated mice. Here we tested colons isolated from wildtype and Mthfd1-deficient animals for alterations in gene expression. Keywords: genetic modification RNA was isolated from proximal colons of MTHFD heterozygous and wild-type mice raised on a control diet. Three colon samples were isolated from each genotype to provide biological replication.
Project description:Folate-mediated one-carbon metabolism is required for purine, thymidylate, and S-adenosylmethionine synthesis. Impairments in folate metabolism diminish cellular methylation potential and genome stability. Cytoplasmic serine hydroxymethyl transferase (cSHMT) regulates partitioning between thymidylate and SAM biosynthesis. These experiments were designed to determine if mutations in cSHMT led to alterations in gene expression. Keywords: genetic modification RNA was isolated from proximal colons of cSHMT mutant, heterozygous, and wild-type mice raised on a folate-deficient diet. Three colon samples were isolated from each genotype to provide biological replication. Mutant and heterozygous data were then compared pair-wise against wild-type expression data.
Project description:Retinoic-acid receptor-related orphan receptor-γt-positive (RORγt+) innate lymphoid cells (ILCs) produce interleukin (IL)-22 and IL-17, which are critical for protective immunity against enteric pathogens. The molecular mechanism underlying the development and survival of RORγt+ ILCs is not thoroughly understood. Here we show that Dedicator of cytokinesis 8 (DOCK8), a scaffolding protein involved in cytoskeletal rearrangement and cell migration, is essential for the protective immunity against Citrobacter rodentium. A comparative RNA sequencing-based analysis reveals an impaired induction of antimicrobial peptides in the colon of DOCK8-deficient mice, which correlates with high susceptibility to infection and a very low number of IL-22-producing RORγt+ ILCs in their GI tract. Furthermore, DOCK8-deficient RORγt+ ILCs are less responsive to IL-7 mediated signaling, more prone to apoptosis and produce less IL-22 due to a defect in IL-23-mediated STAT3 phosphorylation. Our studies reveal an unsuspected role of DOCK8 for the function, generation and survival of RORγt+ ILCs. Control and DOCK8 KO mice were infected with 2X109 CFU of Citrobacter rodentium and day 8 post infection mice were sacrificed and their colons were harvested (n=5) . Total RNA was purified from the infected colons with RNeasy mini kit (Qiagen). RNA sequencing was performed (pooled RNA sample from five mice in each group) at Genomic Core Facility Southwestern Medical Center, University of Texas.
Project description:To study the impact of influenza infection on gene expression changes in the colon, mice were intra-nasally infected with 30 plaque forming units of the mouse-adapted H3N2 IAV strain Scotland/20/1974. PBS-treated mice served as controls. The colons were collected 7 days post-infection. The 4 samples presented here are \\"pair feed\\" controls of the samples presented in E-MTAB-6707. To provide the pair-fed group with only as much food daily as is consumed by IAV-infected mice, we restricted the food access during the last three days for 15% (day 4), 35% (day 5) and 85% (day 6), respectively (sacrifice at day 7). Mice were anesthetized at day 0. Food was supplied twice a day to pair-fed animals and water was available at all times. The ad libitum (normally nourished) group mice were allowed unrestricted access to food and water. At the sacrifice, paired-fed mice lost ~15% of body mass.