ABSTRACT
Gut inflammation involves contributions from immune and non-immune cells, whose interactions are shaped by the spatial organization of the healthy gut and its remodeling during inflammation. The crosstalk between fibroblasts and immune cells is an important axis in this process, but our understanding has been challenged by incomplete cell-type definition and biogeography. To address this challenge, we used multiplexed error-robust fluorescence in situ hybridization (MERFISH) to profile the expression of 940 genes in 1.35 million cells imaged across the onset and recovery from a mouse colitis model. We identified diverse cell populations, charted their spatial organization, and revealed their polarization or recruitment in inflammation. We found a staged progression of inflammation-associated tissue neighborhoods defined, in part, by multiple inflammation-associated fibroblasts, with unique expression profiles, spatial localization, cell-cell interactions, and healthy fibroblast origins. Similar signatures in ulcerative colitis suggest conserved human processes. Broadly, we provide a framework for understanding inflammation-induced remodeling in the gut and other tissues.
Subject(s)
Colitis, Ulcerative , Colitis , Animals , Humans , Mice , Colitis/metabolism , Colitis/pathology , Colitis, Ulcerative/metabolism , Colitis, Ulcerative/pathology , Fibroblasts/metabolism , Fibroblasts/pathology , In Situ Hybridization, Fluorescence/methods , Inflammation/metabolism , Inflammation/pathology , Cell Communication , Gastrointestinal Tract/metabolism , Gastrointestinal Tract/pathologyABSTRACT
Interleukin (IL)-23 and IL-17 are well-validated therapeutic targets in autoinflammatory diseases. Antibodies targeting IL-23 and IL-17 have shown clinical efficacy but are limited by high costs, safety risks, lack of sustained efficacy, and poor patient convenience as they require parenteral administration. Here, we present designed miniproteins inhibiting IL-23R and IL-17 with antibody-like, low picomolar affinities at a fraction of the molecular size. The minibinders potently block cell signaling in vitro and are extremely stable, enabling oral administration and low-cost manufacturing. The orally administered IL-23R minibinder shows efficacy better than a clinical anti-IL-23 antibody in mouse colitis and has a favorable pharmacokinetics (PK) and biodistribution profile in rats. This work demonstrates that orally administered de novo-designed minibinders can reach a therapeutic target past the gut epithelial barrier. With high potency, gut stability, and straightforward manufacturability, de novo-designed minibinders are a promising modality for oral biologics.
Subject(s)
Colitis , Interleukin-17 , Th17 Cells , Animals , Administration, Oral , Mice , Humans , Rats , Colitis/drug therapy , Interleukin-17/metabolism , Interleukin-17/antagonists & inhibitors , Th17 Cells/immunology , Receptors, Interleukin/metabolism , Receptors, Interleukin/antagonists & inhibitors , Mice, Inbred C57BL , Male , Interleukin-23/metabolism , Interleukin-23/antagonists & inhibitors , Tissue Distribution , Female , Rats, Sprague-DawleyABSTRACT
Human gut commensals are increasingly suggested to impact non-communicable diseases, such as inflammatory bowel diseases (IBD), yet their targeted suppression remains a daunting unmet challenge. In four geographically distinct IBD cohorts (n = 537), we identify a clade of Klebsiella pneumoniae (Kp) strains, featuring a unique antibiotics resistance and mobilome signature, to be strongly associated with disease exacerbation and severity. Transfer of clinical IBD-associated Kp strains into colitis-prone, germ-free, and colonized mice enhances intestinal inflammation. Stepwise generation of a lytic five-phage combination, targeting sensitive and resistant IBD-associated Kp clade members through distinct mechanisms, enables effective Kp suppression in colitis-prone mice, driving an attenuated inflammation and disease severity. Proof-of-concept assessment of Kp-targeting phages in an artificial human gut and in healthy volunteers demonstrates gastric acid-dependent phage resilience, safety, and viability in the lower gut. Collectively, we demonstrate the feasibility of orally administered combination phage therapy in avoiding resistance, while effectively inhibiting non-communicable disease-contributing pathobionts.
Subject(s)
Bacteriophages , Colitis , Gastrointestinal Microbiome , Inflammatory Bowel Diseases , Animals , Colitis/therapy , Humans , Inflammation/therapy , Inflammatory Bowel Diseases/therapy , Klebsiella pneumoniae , MiceABSTRACT
Neuroepithelial crosstalk is critical for gut physiology. However, the mechanisms by which sensory neurons communicate with epithelial cells to mediate gut barrier protection at homeostasis and during inflammation are not well understood. Here, we find that Nav1.8+CGRP+ nociceptor neurons are juxtaposed with and signal to intestinal goblet cells to drive mucus secretion and gut protection. Nociceptor ablation led to decreased mucus thickness and dysbiosis, while chemogenetic nociceptor activation or capsaicin treatment induced mucus growth. Mouse and human goblet cells expressed Ramp1, receptor for the neuropeptide CGRP. Nociceptors signal via the CGRP-Ramp1 pathway to induce rapid goblet cell emptying and mucus secretion. Notably, commensal microbes activated nociceptors to control homeostatic CGRP release. In the absence of nociceptors or epithelial Ramp1, mice showed increased epithelial stress and susceptibility to colitis. Conversely, CGRP administration protected nociceptor-ablated mice against colitis. Our findings demonstrate a neuron-goblet cell axis that orchestrates gut mucosal barrier protection.
Subject(s)
Colitis , Goblet Cells , Mice , Humans , Animals , Goblet Cells/metabolism , Nociceptors/metabolism , Calcitonin Gene-Related Peptide/metabolism , Colitis/metabolism , Mucus/metabolism , Receptor Activity-Modifying Protein 1/metabolismABSTRACT
Hundreds of microbiota genes are associated with host biology/disease. Unraveling the causal contribution of a microbiota gene to host biology remains difficult because many are encoded by nonmodel gut commensals and not genetically targetable. A general approach to identify their gene transfer methodology and build their gene manipulation tools would enable mechanistic dissections of their impact on host physiology. We developed a pipeline that identifies the gene transfer methods for multiple nonmodel microbes spanning five phyla, and we demonstrated the utility of their genetic tools by modulating microbiome-derived short-chain fatty acids and bile acids in vitro and in the host. In a proof-of-principle study, by deleting a commensal gene for bile acid synthesis in a complex microbiome, we discovered an intriguing role of this gene in regulating colon inflammation. This technology will enable genetically engineering the nonmodel gut microbiome and facilitate mechanistic dissection of microbiota-host interactions.
Subject(s)
Gastrointestinal Microbiome/genetics , Genes, Bacterial , Animals , Bile Acids and Salts/metabolism , CRISPR-Cas Systems/genetics , Clostridium/genetics , Colitis/chemically induced , Colitis/microbiology , Colitis/pathology , Dextran Sulfate , Drug Resistance, Microbial/genetics , Female , Gene Expression Regulation, Bacterial , Gene Transfer Techniques , Germ-Free Life , Inflammation/pathology , Intestines/pathology , Male , Metabolome/genetics , Metagenomics , Mice, Inbred C57BL , Mice, Knockout , Mutagenesis, Insertional/genetics , Mutation/genetics , RNA, Ribosomal, 16S/genetics , Transcription, GeneticABSTRACT
The immunological mechanisms underlying chronic colitis are poorly understood. T follicular helper (TFH) cells are critical in helping B cells during germinal center reactions. In a T cell transfer colitis model, a lymphoid structure composed of mature dendritic cells (DCs) and TFH cells was found within T cell zones of colonic lymphoid follicles. TFH cells were required for mature DC accumulation, the formation of DC-T cell clusters and colitis development. Moreover, DCs promoted TFH cell differentiation, contributing to colitis development. A lineage-tracing analysis showed that, following migration to the lamina propria, TFH cells transdifferentiated into long-lived pathogenic TH1 cells, promoting colitis development. Our findings have therefore demonstrated the reciprocal regulation of TFH cells and DCs in colonic lymphoid follicles, which is critical in chronic colitis pathogenesis.
Subject(s)
Cell Differentiation , Colitis , Dendritic Cells , T Follicular Helper Cells , Animals , Dendritic Cells/immunology , Colitis/immunology , Colitis/pathology , T Follicular Helper Cells/immunology , Mice , Cell Differentiation/immunology , Mice, Inbred C57BL , Disease Models, Animal , Th1 Cells/immunology , Colon/immunology , Colon/pathology , Mice, Knockout , Germinal Center/immunology , Mice, TransgenicABSTRACT
Intestinal immune responses to microbes are controlled by the cytokine IL-10 to avoid immune pathology. Here, we use single-cell RNA sequencing of colon lamina propria leukocytes (LPLs) along with RNA-seq and ATAC-seq of purified CD4+ T cells to show that the transcription factors Blimp-1 (encoded by Prdm1) and c-Maf co-dominantly regulate Il10 while negatively regulating proinflammatory cytokines in effector T cells. Double-deficient Prdm1fl/flMaffl/flCd4Cre mice infected with Helicobacter hepaticus developed severe colitis with an increase in TH1/NK/ILC1 effector genes in LPLs, while Prdm1fl/flCd4Cre and Maffl/flCd4Cre mice exhibited moderate pathology and a less-marked type 1 effector response. LPLs from infected Maffl/flCd4Cre mice had increased type 17 responses with increased Il17a and Il22 expression and an increase in granulocytes and myeloid cell numbers, resulting in increased T cell-myeloid-neutrophil interactions. Genes over-expressed in human inflammatory bowel disease showed differential expression in LPLs from infected mice in the absence of Prdm1 or Maf, revealing potential mechanisms of human disease.
Subject(s)
Colitis , Helicobacter hepaticus , Mice, Knockout , Positive Regulatory Domain I-Binding Factor 1 , Proto-Oncogene Proteins c-maf , Animals , Positive Regulatory Domain I-Binding Factor 1/genetics , Positive Regulatory Domain I-Binding Factor 1/metabolism , Mice , Proto-Oncogene Proteins c-maf/genetics , Colitis/immunology , Colitis/genetics , Humans , Helicobacter hepaticus/immunology , Helicobacter Infections/immunology , Mice, Inbred C57BL , Intestinal Mucosa/immunology , Intestinal Mucosa/pathology , Intestinal Mucosa/microbiology , Inflammatory Bowel Diseases/immunology , Inflammatory Bowel Diseases/genetics , Gene Expression Regulation , Disease Models, AnimalABSTRACT
Increasing evidence indicates that the brain regulates peripheral immunity, yet whether and how the brain represents the state of the immune system remains unclear. Here, we show that the brain's insular cortex (InsCtx) stores immune-related information. Using activity-dependent cell labeling in mice (FosTRAP), we captured neuronal ensembles in the InsCtx that were active under two different inflammatory conditions (dextran sulfate sodium [DSS]-induced colitis and zymosan-induced peritonitis). Chemogenetic reactivation of these neuronal ensembles was sufficient to broadly retrieve the inflammatory state under which these neurons were captured. Thus, we show that the brain can store and retrieve specific immune responses, extending the classical concept of immunological memory to neuronal representations of inflammatory information.
Subject(s)
Immunity , Insular Cortex/physiology , Neurons/physiology , Animals , Colitis/chemically induced , Colitis/complications , Colitis/immunology , Colon/pathology , Dextran Sulfate , Female , Inflammation/pathology , Male , Mice , Mice, Inbred C57BL , Peritoneum/pathology , Peritonitis/complications , Peritonitis/immunology , Peritonitis/pathology , Synapses/metabolism , ZymosanABSTRACT
Polyamine synthesis represents one of the most profound metabolic changes during T cell activation, but the biological implications of this are scarcely known. Here, we show that polyamine metabolism is a fundamental process governing the ability of CD4+ helper T cells (TH) to polarize into different functional fates. Deficiency in ornithine decarboxylase, a crucial enzyme for polyamine synthesis, results in a severe failure of CD4+ T cells to adopt correct subset specification, underscored by ectopic expression of multiple cytokines and lineage-defining transcription factors across TH cell subsets. Polyamines control TH differentiation by providing substrates for deoxyhypusine synthase, which synthesizes the amino acid hypusine, and mice in which T cells are deficient for hypusine develop severe intestinal inflammatory disease. Polyamine-hypusine deficiency caused widespread epigenetic remodeling driven by alterations in histone acetylation and a re-wired tricarboxylic acid (TCA) cycle. Thus, polyamine metabolism is critical for maintaining the epigenome to focus TH cell subset fidelity.
Subject(s)
Cell Lineage , Polyamines/metabolism , T-Lymphocytes, Helper-Inducer/cytology , T-Lymphocytes, Helper-Inducer/metabolism , Animals , Cell Differentiation/drug effects , Cell Lineage/drug effects , Cell Polarity/drug effects , Cell Proliferation/drug effects , Chromatin/metabolism , Citric Acid Cycle/drug effects , Colitis/immunology , Colitis/pathology , Cytokines/metabolism , Disease Models, Animal , Enzyme Inhibitors/pharmacology , Epigenome , Histones/metabolism , Inflammation/immunology , Inflammation/pathology , Lymphocyte Subsets/drug effects , Lymphocyte Subsets/metabolism , Lysine/analogs & derivatives , Lysine/metabolism , Mice , Mice, Inbred C57BL , Ornithine Decarboxylase/metabolism , T-Lymphocytes, Helper-Inducer/drug effects , Th17 Cells/drug effects , Th17 Cells/immunology , Transcription Factors/metabolismABSTRACT
Aberrant differentiation of progenitor cells in the hematopoietic system is known to severely impact host immune responsiveness. Here we demonstrate that NOD1, a cytosolic innate sensor of bacterial peptidoglycan, also functions in murine hematopoietic cells as a major regulator of both the generation and differentiation of lymphoid progenitors as well as peripheral T lymphocyte homeostasis. We further show that NOD1 mediates these functions by facilitating STAT5 signaling downstream of hematopoietic cytokines. In steady-state, loss of NOD1 resulted in a modest but significant decrease in numbers of mature T, B and natural killer cells. During systemic protozoan infection this defect was markedly enhanced, leading to host mortality. Lack of functional NOD1 also impaired T cell-dependent anti-tumor immunity while preventing colitis. These findings reveal that, in addition to its classical role as a bacterial ligand receptor, NOD1 plays an important function in regulating adaptive immunity through interaction with a major host cytokine signaling pathway.
Subject(s)
Immunity, Innate , Lymphopoiesis , Animals , Mice , Colitis , Ligands , Signal TransductionABSTRACT
Checkpoint blockade with antibodies specific for the PD-1 and CTLA-4 inhibitory receptors can induce durable responses in a wide range of human cancers. However, the immunological mechanisms responsible for severe inflammatory side effects remain poorly understood. Here we report a comprehensive single-cell analysis of immune cell populations in colitis, a common and severe side effect of checkpoint blockade. We observed a striking accumulation of CD8 T cells with highly cytotoxic and proliferative states and no evidence of regulatory T cell depletion. T cell receptor (TCR) sequence analysis demonstrated that a substantial fraction of colitis-associated CD8 T cells originated from tissue-resident populations, explaining the frequently early onset of colitis symptoms following treatment initiation. Our analysis also identified cytokines, chemokines, and surface receptors that could serve as therapeutic targets for colitis and potentially other inflammatory side effects of checkpoint blockade.
Subject(s)
CD8-Positive T-Lymphocytes/cytology , CTLA-4 Antigen/immunology , Colitis/metabolism , Immune Checkpoint Inhibitors/adverse effects , Immunotherapy/adverse effects , Myeloid Cells/metabolism , Receptors, Chemokine/metabolism , CD4-Positive T-Lymphocytes/cytology , CD4-Positive T-Lymphocytes/metabolism , CD4-Positive T-Lymphocytes/pathology , CD8-Positive T-Lymphocytes/metabolism , CD8-Positive T-Lymphocytes/pathology , CTLA-4 Antigen/metabolism , Chemokines/metabolism , Colitis/drug therapy , Colitis/genetics , Colitis/immunology , Cytokines/metabolism , Flow Cytometry , Gene Expression Regulation/genetics , Gene Expression Regulation/immunology , Humans , Inflammation/drug therapy , Inflammation/genetics , Inflammation/metabolism , Melanoma/genetics , Melanoma/immunology , Melanoma/metabolism , Multigene Family , Myeloid Cells/cytology , RNA-Seq , Receptors, Antigen, T-Cell/genetics , Receptors, Antigen, T-Cell/metabolism , Receptors, CXCR3/genetics , Receptors, CXCR3/metabolism , Receptors, CXCR6/genetics , Receptors, CXCR6/metabolism , Receptors, Chemokine/genetics , Single-Cell Analysis , T-Lymphocytes, Regulatory/cytology , T-Lymphocytes, Regulatory/metabolismABSTRACT
The precise mechanism by which oral infection contributes to the pathogenesis of extra-oral diseases remains unclear. Here, we report that periodontal inflammation exacerbates gut inflammation in vivo. Periodontitis leads to expansion of oral pathobionts, including Klebsiella and Enterobacter species, in the oral cavity. Amassed oral pathobionts are ingested and translocate to the gut, where they activate the inflammasome in colonic mononuclear phagocytes, triggering inflammation. In parallel, periodontitis results in generation of oral pathobiont-reactive Th17 cells in the oral cavity. Oral pathobiont-reactive Th17 cells are imprinted with gut tropism and migrate to the inflamed gut. When in the gut, Th17 cells of oral origin can be activated by translocated oral pathobionts and cause development of colitis, but they are not activated by gut-resident microbes. Thus, oral inflammation, such as periodontitis, exacerbates gut inflammation by supplying the gut with both colitogenic pathobionts and pathogenic T cells.
Subject(s)
Colitis/pathology , Enterobacter/physiology , Gastrointestinal Microbiome , Klebsiella/physiology , Mouth/microbiology , Animals , Colitis/microbiology , Colon/microbiology , Colon/pathology , Disease Models, Animal , Enterobacter/isolation & purification , Female , Inflammasomes/metabolism , Interleukin-10/deficiency , Interleukin-10/genetics , Interleukin-1beta/metabolism , Klebsiella/isolation & purification , Leukocytes, Mononuclear/cytology , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Periodontitis/microbiology , Periodontitis/pathology , Th17 Cells/cytology , Th17 Cells/immunology , Th17 Cells/metabolismABSTRACT
Gastrointestinal enterochromaffin cells regulate bone and gut homeostasis via serotonin (5-hydroxytryptamine [5-HT]) production. A recent report suggested that gut microbes regulate 5-HT levels; however, the precise underlying molecular mechanisms are unexplored. Here, we reveal that the cation channel Piezo1 in the gut acts as a sensor of single-stranded RNA (ssRNA) governing 5-HT production. Intestinal epithelium-specific deletion of mouse Piezo1 profoundly disturbed gut peristalsis, impeded experimental colitis, and suppressed serum 5-HT levels. Because of systemic 5-HT deficiency, conditional knockout of Piezo1 increased bone formation. Notably, fecal ssRNA was identified as a natural Piezo1 ligand, and ssRNA-stimulated 5-HT synthesis from the gut was evoked in a MyD88/TRIF-independent manner. Colonic infusion of RNase A suppressed gut motility and increased bone mass. These findings suggest gut ssRNA as a master determinant of systemic 5-HT levels, indicating the ssRNA-Piezo1 axis as a potential prophylactic target for treatment of bone and gut disorders.
Subject(s)
Bone and Bones/metabolism , Colon/metabolism , Gastrointestinal Motility/genetics , Ion Channels/metabolism , RNA/metabolism , Serotonin/biosynthesis , Serotonin/metabolism , Adaptor Proteins, Vesicular Transport/metabolism , Animals , Bone and Bones/cytology , Calcium/metabolism , Colitis/genetics , Colitis/metabolism , Colitis/prevention & control , Colon/physiology , Feces/chemistry , Female , Gastrointestinal Motility/physiology , HEK293 Cells , Humans , Immunohistochemistry , Intestinal Mucosa/drug effects , Intestinal Mucosa/metabolism , Ion Channels/genetics , Ligands , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Microbiota/drug effects , Myeloid Differentiation Factor 88/metabolism , Osteoclasts/metabolism , Pyrazines/pharmacology , RNA/pharmacology , Ribonuclease, Pancreatic/administration & dosage , Serotonin/blood , Serotonin/deficiency , Thiadiazoles/pharmacologyABSTRACT
Inflammatory bowel disease (IBD) is a chronic inflammatory disease associated with increased risk of gastrointestinal cancers. We whole-genome sequenced 446 colonic crypts from 46 IBD patients and compared these to 412 crypts from 41 non-IBD controls from our previous publication on the mutation landscape of the normal colon. The average mutation rate of affected colonic epithelial cells is 2.4-fold that of healthy colon, and this increase is mostly driven by acceleration of mutational processes ubiquitously observed in normal colon. In contrast to the normal colon, where clonal expansions outside the confines of the crypt are rare, we observed widespread millimeter-scale clonal expansions. We discovered non-synonymous mutations in ARID1A, FBXW7, PIGR, ZC3H12A, and genes in the interleukin 17 and Toll-like receptor pathways, under positive selection in IBD. These results suggest distinct selection mechanisms in the colitis-affected colon and that somatic mutations potentially play a causal role in IBD pathogenesis.
Subject(s)
Clonal Evolution/genetics , Colitis/genetics , Inflammatory Bowel Diseases/genetics , Mutation Rate , Adult , Aged , Aged, 80 and over , Aging/genetics , Clonal Evolution/immunology , Colitis/metabolism , Colitis, Ulcerative/genetics , Colitis, Ulcerative/metabolism , Crohn Disease/genetics , Crohn Disease/metabolism , DNA-Binding Proteins/genetics , Epithelial Cells/metabolism , Epithelial Cells/pathology , F-Box-WD Repeat-Containing Protein 7/genetics , Female , Humans , INDEL Mutation , Inflammatory Bowel Diseases/immunology , Inflammatory Bowel Diseases/metabolism , Inflammatory Bowel Diseases/pathology , Interleukin-17/metabolism , Intestinal Mucosa/metabolism , Intestinal Mucosa/pathology , Male , Middle Aged , Phylogeny , Point Mutation , Receptors, Cell Surface/genetics , Ribonucleases/genetics , Toll-Like Receptors/genetics , Transcription Factors/genetics , Whole Genome SequencingABSTRACT
Naive T cells undergo radical changes during the transition from dormant to hyperactive states upon activation, which necessitates de novo protein production via transcription and translation. However, the mechanism whereby T cells globally promote translation remains largely unknown. Here, we show that on exit from quiescence, T cells upregulate transfer RNA (tRNA) m1A58 'writer' proteins TRMT61A and TRMT6, which confer m1A58 RNA modification on a specific subset of early expressed tRNAs. These m1A-modified early tRNAs enhance translation efficiency, enabling rapid and necessary synthesis of MYC and of a specific group of key functional proteins. The MYC protein then guides the exit of naive T cells from a quiescent state into a proliferative state and promotes rapid T cell expansion after activation. Conditional deletion of the Trmt61a gene in mouse CD4+ T cells causes MYC protein deficiency and cell cycle arrest, disrupts T cell expansion upon cognate antigen stimulation and alleviates colitis in a mouse adoptive transfer colitis model. Our study elucidates for the first time, to our knowledge, the in vivo physiological roles of tRNA-m1A58 modification in T cell-mediated pathogenesis and reveals a new mechanism of tRNA-m1A58-controlled T cell homeostasis and signal-dependent translational control of specific key proteins.
Subject(s)
Colitis , RNA, Transfer , Adoptive Transfer , Animals , Cell Proliferation/genetics , Colitis/genetics , Mice , Protein Biosynthesis , RNA, Transfer/genetics , RNA, Transfer/metabolism , T-Lymphocytes/metabolismABSTRACT
Extracellular acidification occurs in inflamed tissue and the tumor microenvironment; however, a systematic study on how pH sensing contributes to tissue homeostasis is lacking. In the present study, we examine cell type-specific roles of the pH sensor G protein-coupled receptor 65 (GPR65) and its inflammatory disease-associated Ile231Leu-coding variant in inflammation control. GPR65 Ile231Leu knock-in mice are highly susceptible to both bacterial infection-induced and T cell-driven colitis. Mechanistically, GPR65 Ile231Leu elicits a cytokine imbalance through impaired helper type 17 T cell (TH17 cell) and TH22 cell differentiation and interleukin (IL)-22 production in association with altered cellular metabolism controlled through the cAMP-CREB-DGAT1 axis. In dendritic cells, GPR65 Ile231Leu elevates IL-12 and IL-23 release at acidic pH and alters endo-lysosomal fusion and degradation capacity, resulting in enhanced antigen presentation. The present study highlights GPR65 Ile231Leu as a multistep risk factor in intestinal inflammation and illuminates a mechanism by which pH sensing controls inflammatory circuits and tissue homeostasis.
Subject(s)
Colitis , Receptors, G-Protein-Coupled , Animals , Colitis/metabolism , Hydrogen-Ion Concentration , Inflammation/metabolism , Lysosomes/metabolism , Mice , Receptors, G-Protein-Coupled/genetics , Receptors, G-Protein-Coupled/metabolism , Th17 Cells/metabolismABSTRACT
We report a pleiotropic disease due to loss-of-function mutations in RHBDF2, the gene encoding iRHOM2, in two kindreds with recurrent infections in different organs. One patient had recurrent pneumonia but no colon involvement, another had recurrent infectious hemorrhagic colitis but no lung involvement and the other two experienced recurrent respiratory infections. Loss of iRHOM2, a rhomboid superfamily member that regulates the ADAM17 metalloproteinase, caused defective ADAM17-dependent cleavage and release of cytokines, including tumor-necrosis factor and amphiregulin. To understand the diverse clinical phenotypes, we challenged Rhbdf2-/- mice with Pseudomonas aeruginosa by nasal gavage and observed more severe pneumonia, whereas infection with Citrobacter rodentium caused worse inflammatory colitis than in wild-type mice. The fecal microbiota in the colitis patient had characteristic oral species that can predispose to colitis. Thus, a human immunodeficiency arising from iRHOM2 deficiency causes divergent disease phenotypes that can involve the local microbial environment.
Subject(s)
ADAM17 Protein/genetics , Carrier Proteins/genetics , Primary Immunodeficiency Diseases/genetics , A549 Cells , Animals , Child , Child, Preschool , Citrobacter rodentium/pathogenicity , Colitis/genetics , Cytokines/genetics , Enterobacteriaceae Infections/genetics , Female , HEK293 Cells , Humans , Infant, Newborn , Macrophages/metabolism , Male , Mice , Mice, Inbred C57BL , Mutation/genetics , Pseudomonas Infections/genetics , Pseudomonas aeruginosa/pathogenicity , Signal Transduction/geneticsABSTRACT
The colonic epithelium can undergo multiple rounds of damage and repair, often in response to excessive inflammation. The responsive stem cell that mediates this process is unclear, in part because of a lack of in vitro models that recapitulate key epithelial changes that occur in vivo during damage and repair. Here, we identify a Hopx+ colitis-associated regenerative stem cell (CARSC) population that functionally contributes to mucosal repair in mouse models of colitis. Hopx+ CARSCs, enriched for fetal-like markers, transiently arose from hypertrophic crypts known to facilitate regeneration. Importantly, we established a long-term, self-organizing two-dimensional (2D) epithelial monolayer system to model the regenerative properties and responses of Hopx+ CARSCs. This system can reenact the "homeostasis-injury-regeneration" cycles of epithelial alterations that occur in vivo. Using this system, we found that hypoxia and endoplasmic reticulum stress, insults commonly present in inflammatory bowel diseases, mediated the cyclic switch of cellular status in this process.
Subject(s)
Cell Culture Techniques/methods , Colon/pathology , Stem Cells/pathology , 3T3 Cells , Animals , Colitis/pathology , Epithelial Cells/drug effects , Epithelial Cells/pathology , Homeodomain Proteins/metabolism , Mice , Models, Biological , Oxygen/pharmacology , Regeneration/drug effects , Stem Cells/drug effects , Stress, Physiological/drug effectsABSTRACT
Intestinal epithelial cell (IEC) damage by T cells contributes to graft-versus-host disease, inflammatory bowel disease and immune checkpoint blockade-mediated colitis. But little is known about the target cell-intrinsic features that affect disease severity. Here we identified disruption of oxidative phosphorylation and an increase in succinate levels in the IECs from several distinct in vivo models of T cell-mediated colitis. Metabolic flux studies, complemented by imaging and protein analyses, identified disruption of IEC-intrinsic succinate dehydrogenase A (SDHA), a component of mitochondrial complex II, in causing these metabolic alterations. The relevance of IEC-intrinsic SDHA in mediating disease severity was confirmed by complementary chemical and genetic experimental approaches and validated in human clinical samples. These data identify a critical role for the alteration of the IEC-specific mitochondrial complex II component SDHA in the regulation of the severity of T cell-mediated intestinal diseases.
Subject(s)
Colitis/enzymology , Colon/enzymology , Cytotoxicity, Immunologic , Electron Transport Complex II/metabolism , Epithelial Cells/enzymology , Graft vs Host Disease/enzymology , Intestinal Mucosa/enzymology , Mitochondria/enzymology , T-Lymphocytes/immunology , Animals , Case-Control Studies , Cell Communication , Cells, Cultured , Colitis/genetics , Colitis/immunology , Colitis/pathology , Colon/immunology , Colon/ultrastructure , Disease Models, Animal , Electron Transport Complex II/genetics , Epithelial Cells/immunology , Epithelial Cells/ultrastructure , Female , Graft vs Host Disease/genetics , Graft vs Host Disease/immunology , Graft vs Host Disease/pathology , Humans , Immunity, Mucosal , Intestinal Mucosa/immunology , Intestinal Mucosa/ultrastructure , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Transgenic , Mitochondria/immunology , Mitochondria/ultrastructure , Oxidative Phosphorylation , Succinic Acid/metabolism , T-Lymphocytes/metabolismABSTRACT
It is increasingly recognized that immune development within mucosal tissues is under the control of environmental factors during early life. However, the cellular mechanisms that underlie such temporally and regionally restrictive governance of these processes are unclear. Here, we uncover an extrathymic pathway of immune development within the colon that is controlled by embryonic but not bone marrow-derived macrophages, which determines the ability of these organs to receive invariant natural killer T (iNKT) cells and allow them to establish local residency. Consequently, early-life perturbations of fetal-derived macrophages result in persistent decreases of mucosal iNKT cells and is associated with later-life susceptibility or resistance to iNKT cell-associated mucosal disorders. These studies uncover a host developmental program orchestrated by ontogenically distinct macrophages that is regulated by microbiota, and they reveal an important postnatal function of macrophages that emerge in fetal life.