RESUMO
The intestinal microbiota plays a crucial role in influencing the development of host immunity, and in turn the immune system also acts to regulate the microbiota through intestinal barrier maintenance and immune exclusion. Normally, these interactions are homeostatic, tightly controlled, and organized by both innate and adaptive immune responses. However, a combination of environmental exposures and genetic defects can result in a break in tolerance and intestinal homeostasis. The outcomes of these interactions at the mucosal interface have broad, systemic effects on host immunity and the development of chronic inflammatory or autoimmune disease. The underlying mechanisms and pathways the microbiota can utilize to regulate these diseases are just starting to emerge. Here, we discuss the recent evidence in this area describing the impact of microbiota-immune interactions during inflammation and autoimmunity, with a focus on barrier function and CD4+ T cell regulation.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Diabetes Mellitus Tipo 1/microbiologia , Microbioma Gastrointestinal/imunologia , Inflamação/microbiologia , Doenças Inflamatórias Intestinais/microbiologia , Mucosa Intestinal/microbiologia , Animais , Autoimunidade , Diabetes Mellitus Tipo 1/imunologia , Homeostase , Humanos , Tolerância Imunológica , Imunomodulação , Inflamação/imunologia , Doenças Inflamatórias Intestinais/imunologia , Mucosa Intestinal/imunologiaRESUMO
Inflammatory bowel disease (IBD) defines a spectrum of complex disorders. Understanding how environmental risk factors, alterations of the intestinal microbiota, and polygenetic and epigenetic susceptibility impact on immune pathways is key for developing targeted therapies. Mechanistic understanding of polygenic IBD is complemented by Mendelian disorders that present with IBD, pharmacological interventions that cause colitis, autoimmunity, and multiple animal models. Collectively, this multifactorial pathogenesis supports a concept of immune checkpoints that control microbial-host interactions in the gut by modulating innate and adaptive immunity, as well as epithelial and mesenchymal cell responses. In addition to classical immunosuppressive strategies, we discuss how resetting the microbiota and restoring innate immune responses, in particular autophagy and epithelial barrier function, might be key for maintaining remission or preventing IBD. Targeting checkpoints in genetically stratified subgroups of patients with Mendelian disorder-associated IBD increasingly directs treatment strategies as part of personalized medicine.
Assuntos
Suscetibilidade a Doenças/imunologia , Doenças Inflamatórias Intestinais/etiologia , Doenças Inflamatórias Intestinais/terapia , Animais , Biomarcadores , Doença Crônica , Gerenciamento Clínico , Modelos Animais de Doenças , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Disbiose , Microbioma Gastrointestinal , Predisposição Genética para Doença , Humanos , Doenças Inflamatórias Intestinais/prevenção & controle , Terapia de Alvo Molecular , Pesquisa Translacional BiomédicaRESUMO
The cellular degradative pathway of autophagy has a fundamental role in immunity. Here, we review the function of autophagy and autophagy proteins in inflammation. We discuss how the autophagy machinery controls the burden of infectious agents while simultaneously limiting inflammatory pathologies, which often involves processes that are distinct from conventional autophagy. Among the newly emerging processes we describe are LC3-associated phagocytosis and targeting by autophagy proteins, both of which require many of the same proteins that mediate conventional autophagy. We also discuss how autophagy contributes to differentiation of myeloid and lymphoid cell types, coordinates multicellular immunity, and facilitates memory responses. Together, these functions establish an intimate link between autophagy, mucosal immunity, and chronic inflammatory diseases. Finally, we offer our perspective on current challenges and barriers to translation.
Assuntos
Autofagia , Suscetibilidade a Doenças , Inflamação/etiologia , Animais , Biomarcadores , Regulação da Expressão Gênica , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Sistema Imunitário/citologia , Sistema Imunitário/imunologia , Sistema Imunitário/metabolismo , Imunomodulação , Inflamação/diagnóstico , Inflamação/metabolismo , Transdução de SinaisRESUMO
Human lectins are integral to maintaining microbial homeostasis on the skin, in the blood, and at mucosal barriers. These proteins can recognize microbial glycans and inform the host about its microbial status. In accordance with their roles, their production can vary with tissue type. They also can have unique structural and biochemical properties, and they can influence microbial colonization at sites proximal and distal to their tissue of origin. In line with their classification as innate immune proteins, soluble lectins have long been studied in the context of acute infectious disease, but only recently have we begun to appreciate their roles in maintaining commensal microbial communities (i.e., the human microbiota). This review provides an overview of soluble lectins that operate at host-microbe interfaces, their glycan recognition properties, and their roles in physiological and pathological mechanisms.
Assuntos
Imunidade Inata , Lectinas , Polissacarídeos , Humanos , Lectinas/metabolismo , Lectinas/química , Lectinas/genética , Polissacarídeos/metabolismo , Polissacarídeos/química , Microbiota , Animais , Interações Hospedeiro-Patógeno , Interações entre Hospedeiro e Microrganismos/imunologiaRESUMO
The gut fungal community represents an essential element of human health, yet its functional and metabolic potential remains insufficiently elucidated, largely due to the limited availability of reference genomes. To address this gap, we presented the cultivated gut fungi (CGF) catalog, encompassing 760 fungal genomes derived from the feces of healthy individuals. This catalog comprises 206 species spanning 48 families, including 69 species previously unidentified. We explored the functional and metabolic attributes of the CGF species and utilized this catalog to construct a phylogenetic representation of the gut mycobiome by analyzing over 11,000 fecal metagenomes from Chinese and non-Chinese populations. Moreover, we identified significant common disease-related variations in gut mycobiome composition and corroborated the associations between fungal signatures and inflammatory bowel disease (IBD) through animal experimentation. These resources and findings substantially enrich our understanding of the biological diversity and disease relevance of the human gut mycobiome.
Assuntos
Fungos , Microbioma Gastrointestinal , Micobioma , Animais , Humanos , Masculino , Camundongos , Fezes/microbiologia , Fungos/genética , Fungos/classificação , Fungos/isolamento & purificação , Genoma Fúngico/genética , Genômica , Doenças Inflamatórias Intestinais/microbiologia , Doenças Inflamatórias Intestinais/genética , Metagenoma , Filogenia , Feminino , Adulto , Pessoa de Meia-IdadeRESUMO
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.
Assuntos
Colite , Interleucina-17 , Células Th17 , Animais , Administração Oral , Camundongos , Humanos , Ratos , Colite/tratamento farmacológico , Interleucina-17/metabolismo , Interleucina-17/antagonistas & inibidores , Células Th17/imunologia , Receptores de Interleucina/metabolismo , Receptores de Interleucina/antagonistas & inibidores , Camundongos Endogâmicos C57BL , Masculino , Interleucina-23/metabolismo , Interleucina-23/antagonistas & inibidores , Distribuição Tecidual , Feminino , Ratos Sprague-DawleyRESUMO
Plasmids are extrachromosomal genetic elements that often encode fitness-enhancing features. However, many bacteria carry "cryptic" plasmids that do not confer clear beneficial functions. We identified one such cryptic plasmid, pBI143, which is ubiquitous across industrialized gut microbiomes and is 14 times as numerous as crAssphage, currently established as the most abundant extrachromosomal genetic element in the human gut. The majority of mutations in pBI143 accumulate in specific positions across thousands of metagenomes, indicating strong purifying selection. pBI143 is monoclonal in most individuals, likely due to the priority effect of the version first acquired, often from one's mother. pBI143 can transfer between Bacteroidales, and although it does not appear to impact bacterial host fitness in vivo, it can transiently acquire additional genetic content. We identified important practical applications of pBI143, including its use in identifying human fecal contamination and its potential as an alternative approach to track human colonic inflammatory states.
Assuntos
Bactérias , Trato Gastrointestinal , Metagenoma , Plasmídeos , Humanos , Bactérias/genética , Bacteroidetes/genética , Fezes/microbiologia , Plasmídeos/genéticaRESUMO
How mis-regulated chromatin directly impacts human immune disorders is poorly understood. Speckled Protein 140 (SP140) is an immune-restricted PHD and bromodomain-containing epigenetic "reader," and SP140 loss-of-function mutations associate with Crohn's disease (CD), multiple sclerosis (MS), and chronic lymphocytic leukemia (CLL). However, the relevance of these mutations and mechanisms underlying SP140-driven pathogenicity remains unexplored. Using a global proteomic strategy, we identified SP140 as a repressor of topoisomerases (TOPs) that maintains heterochromatin and macrophage fate. In humans and mice, SP140 loss resulted in unleashed TOP activity, de-repression of developmentally silenced genes, and ultimately defective microbe-inducible macrophage transcriptional programs and bacterial killing that drive intestinal pathology. Pharmacological inhibition of TOP1/2 rescued these defects. Furthermore, exacerbated colitis was restored with TOP1/2 inhibitors in Sp140-/- mice, but not wild-type mice, in vivo. Collectively, we identify SP140 as a TOP repressor and reveal repurposing of TOP inhibition to reverse immune diseases driven by SP140 loss.
Assuntos
Doença de Crohn , Animais , Humanos , Camundongos , Antígenos Nucleares , Doença de Crohn/genética , Doença de Crohn/patologia , Epigênese Genética , Regulação da Expressão Gênica , Macrófagos/patologia , Proteômica , Fatores de TranscriçãoRESUMO
Intestinal mucus forms the first line of defense against bacterial invasion while providing nutrition to support microbial symbiosis. How the host controls mucus barrier integrity and commensalism is unclear. We show that terminal sialylation of glycans on intestinal mucus by ST6GALNAC1 (ST6), the dominant sialyltransferase specifically expressed in goblet cells and induced by microbial pathogen-associated molecular patterns, is essential for mucus integrity and protecting against excessive bacterial proteolytic degradation. Glycoproteomic profiling and biochemical analysis of ST6 mutations identified in patients show that decreased sialylation causes defective mucus proteins and congenital inflammatory bowel disease (IBD). Mice harboring a patient ST6 mutation have compromised mucus barriers, dysbiosis, and susceptibility to intestinal inflammation. Based on our understanding of the ST6 regulatory network, we show that treatment with sialylated mucin or a Foxo3 inhibitor can ameliorate IBD.
Assuntos
Microbioma Gastrointestinal , Doenças Inflamatórias Intestinais , Sialiltransferases/genética , Animais , Homeostase , Humanos , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Camundongos , Muco/metabolismo , Sialiltransferases/metabolismo , SimbioseRESUMO
Gasdermins are a family of structurally related proteins originally described for their role in pyroptosis. Gasdermin B (GSDMB) is currently the least studied, and while its association with genetic susceptibility to chronic mucosal inflammatory disorders is well established, little is known about its functional relevance during active disease states. Herein, we report increased GSDMB in inflammatory bowel disease, with single-cell analysis identifying epithelial specificity to inflamed colonocytes/crypt top colonocytes. Surprisingly, mechanistic experiments and transcriptome profiling reveal lack of inherent GSDMB-dependent pyroptosis in activated epithelial cells and organoids but instead point to increased proliferation and migration during in vitro wound closure, which arrests in GSDMB-deficient cells that display hyper-adhesiveness and enhanced formation of vinculin-based focal adhesions dependent on PDGF-A-mediated FAK phosphorylation. Importantly, carriage of disease-associated GSDMB SNPs confers functional defects, disrupting epithelial restitution/repair, which, altogether, establishes GSDMB as a critical factor for restoration of epithelial barrier function and the resolution of inflammation.
Assuntos
Células Epiteliais/metabolismo , Células Epiteliais/patologia , Doenças Inflamatórias Intestinais/metabolismo , Doenças Inflamatórias Intestinais/patologia , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Piroptose , Sequência de Bases , Estudos de Casos e Controles , Adesão Celular/efeitos dos fármacos , Adesão Celular/genética , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Células Epiteliais/efeitos dos fármacos , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Células HEK293 , Células HT29 , Humanos , Doenças Inflamatórias Intestinais/genética , Metotrexato/farmacologia , Mutação/genética , Fosforilação/efeitos dos fármacos , Polimorfismo de Nucleotídeo Único/genética , Piroptose/efeitos dos fármacos , Piroptose/genética , Reprodutibilidade dos Testes , Transcriptoma/efeitos dos fármacos , Transcriptoma/genética , Regulação para Cima/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Cicatrização/genéticaRESUMO
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.
Assuntos
Colite/patologia , Enterobacter/fisiologia , Microbioma Gastrointestinal , Klebsiella/fisiologia , Boca/microbiologia , Animais , Colite/microbiologia , Colo/microbiologia , Colo/patologia , Modelos Animais de Doenças , Enterobacter/isolamento & purificação , Feminino , Inflamassomos/metabolismo , Interleucina-10/deficiência , Interleucina-10/genética , Interleucina-1beta/metabolismo , Klebsiella/isolamento & purificação , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Periodontite/microbiologia , Periodontite/patologia , Células Th17/citologia , Células Th17/imunologia , Células Th17/metabolismoRESUMO
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.
Assuntos
Evolução Clonal/genética , Colite/genética , Doenças Inflamatórias Intestinais/genética , Taxa de Mutação , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/genética , Evolução Clonal/imunologia , Colite/metabolismo , Colite Ulcerativa/genética , Colite Ulcerativa/metabolismo , Doença de Crohn/genética , Doença de Crohn/metabolismo , Proteínas de Ligação a DNA/genética , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Proteína 7 com Repetições F-Box-WD/genética , Feminino , Humanos , Mutação INDEL , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/metabolismo , Doenças Inflamatórias Intestinais/patologia , Interleucina-17/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Masculino , Pessoa de Meia-Idade , Filogenia , Mutação Puntual , Receptores de Superfície Celular/genética , Ribonucleases/genética , Receptores Toll-Like/genética , Fatores de Transcrição/genética , Sequenciamento Completo do GenomaRESUMO
Lymphoid cells that produce interleukin (IL)-17 cytokines protect barrier tissues from pathogenic microbes but are also prominent effectors of inflammation and autoimmune disease. T helper 17 (Th17) cells, defined by RORγt-dependent production of IL-17A and IL-17F, exert homeostatic functions in the gut upon microbiota-directed differentiation from naive CD4+ T cells. In the non-pathogenic setting, their cytokine production is regulated by serum amyloid A proteins (SAA1 and SAA2) secreted by adjacent intestinal epithelial cells. However, Th17 cell behaviors vary markedly according to their environment. Here, we show that SAAs additionally direct a pathogenic pro-inflammatory Th17 cell differentiation program, acting directly on T cells in collaboration with STAT3-activating cytokines. Using loss- and gain-of-function mouse models, we show that SAA1, SAA2, and SAA3 have distinct systemic and local functions in promoting Th17-mediated inflammatory diseases. These studies suggest that T cell signaling pathways modulated by the SAAs may be attractive targets for anti-inflammatory therapies.
Assuntos
Síndrome do Intestino Irritável/metabolismo , Proteína Amiloide A Sérica/metabolismo , Células Th17/metabolismo , Adulto , Animais , Doenças Autoimunes/metabolismo , Diferenciação Celular/imunologia , Citocinas/metabolismo , Encefalomielite Autoimune Experimental/metabolismo , Feminino , Humanos , Inflamação/metabolismo , Interleucina-17/metabolismo , Síndrome do Intestino Irritável/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Células Th1 , Células Th17/imunologiaRESUMO
Throughout a 24-h period, the small intestine (SI) is exposed to diurnally varying food- and microbiome-derived antigenic burdens but maintains a strict immune homeostasis, which when perturbed in genetically susceptible individuals, may lead to Crohn disease. Herein, we demonstrate that dietary content and rhythmicity regulate the diurnally shifting SI epithelial cell (SIEC) transcriptional landscape through modulation of the SI microbiome. We exemplify this concept with SIEC major histocompatibility complex (MHC) class II, which is diurnally modulated by distinct mucosal-adherent SI commensals, while supporting downstream diurnal activity of intra-epithelial IL-10+ lymphocytes regulating the SI barrier function. Disruption of this diurnally regulated diet-microbiome-MHC class II-IL-10-epithelial barrier axis by circadian clock disarrangement, alterations in feeding time or content, or epithelial-specific MHC class II depletion leads to an extensive microbial product influx, driving Crohn-like enteritis. Collectively, we highlight nutritional features that modulate SI microbiome, immunity, and barrier function and identify dietary, epithelial, and immune checkpoints along this axis to be potentially exploitable in future Crohn disease interventions.
Assuntos
Doença de Crohn/microbiologia , Células Epiteliais/metabolismo , Microbioma Gastrointestinal , Antígenos de Histocompatibilidade Classe II/metabolismo , Intestino Delgado/imunologia , Intestino Delgado/microbiologia , Transcriptoma/genética , Animais , Antibacterianos/farmacologia , Relógios Circadianos/fisiologia , Doença de Crohn/imunologia , Doença de Crohn/metabolismo , Dieta , Células Epiteliais/citologia , Células Epiteliais/imunologia , Citometria de Fluxo , Microbioma Gastrointestinal/efeitos dos fármacos , Microbioma Gastrointestinal/genética , Perfilação da Expressão Gênica , Antígenos de Histocompatibilidade Classe II/genética , Homeostase , Hibridização in Situ Fluorescente , Interleucina-10/metabolismo , Interleucina-10/farmacologia , Intestino Delgado/fisiologia , Linfócitos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Periodicidade , Linfócitos T/imunologia , Transcriptoma/fisiologiaRESUMO
Clinical benefits of cytokine blockade in ileal Crohn's disease (iCD) are limited to a subset of patients. Here, we applied single-cell technologies to iCD lesions to address whether cellular heterogeneity contributes to treatment resistance. We found that a subset of patients expressed a unique cellular module in inflamed tissues that consisted of IgG plasma cells, inflammatory mononuclear phagocytes, activated T cells, and stromal cells, which we named the GIMATS module. Analysis of ligand-receptor interaction pairs identified a distinct network connectivity that likely drives the GIMATS module. Strikingly, the GIMATS module was also present in a subset of patients in four independent iCD cohorts (n = 441), and its presence at diagnosis correlated with failure to achieve durable corticosteroid-free remission upon anti-TNF therapy. These results emphasize the limitations of current diagnostic assays and the potential for single-cell mapping tools to identify novel biomarkers of treatment response and tailored therapeutic opportunities.
Assuntos
Doença de Crohn/terapia , Citocinas/imunologia , Intestinos/patologia , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Doença de Crohn/imunologia , Doença de Crohn/patologia , Humanos , Imunoterapia/métodos , Fagócitos/patologia , Análise de Célula Única , Células Estromais/patologia , Linfócitos T/patologiaRESUMO
Genome-wide association studies (GWAS) have revealed risk alleles for ulcerative colitis (UC). To understand their cell type specificities and pathways of action, we generate an atlas of 366,650 cells from the colon mucosa of 18 UC patients and 12 healthy individuals, revealing 51 epithelial, stromal, and immune cell subsets, including BEST4+ enterocytes, microfold-like cells, and IL13RA2+IL11+ inflammatory fibroblasts, which we associate with resistance to anti-TNF treatment. Inflammatory fibroblasts, inflammatory monocytes, microfold-like cells, and T cells that co-express CD8 and IL-17 expand with disease, forming intercellular interaction hubs. Many UC risk genes are cell type specific and co-regulated within relatively few gene modules, suggesting convergence onto limited sets of cell types and pathways. Using this observation, we nominate and infer functions for specific risk genes across GWAS loci. Our work provides a framework for interrogating complex human diseases and mapping risk variants to cell types and pathways.
Assuntos
Colite Ulcerativa/patologia , Colo/metabolismo , Adulto , Idoso , Anticorpos Monoclonais/uso terapêutico , Bestrofinas/metabolismo , Antígenos CD8/metabolismo , Estudos de Casos e Controles , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/metabolismo , Colo/patologia , Enterócitos/citologia , Enterócitos/metabolismo , Feminino , Loci Gênicos , Estudo de Associação Genômica Ampla , Humanos , Interleucina-17/metabolismo , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Linfócitos T/citologia , Linfócitos T/metabolismo , Trombospondinas/metabolismo , Fator de Necrose Tumoral alfa/imunologia , Fator de Necrose Tumoral alfa/metabolismo , Adulto JovemRESUMO
Intestinal mesenchymal cells play essential roles in epithelial homeostasis, matrix remodeling, immunity, and inflammation. But the extent of heterogeneity within the colonic mesenchyme in these processes remains unknown. Using unbiased single-cell profiling of over 16,500 colonic mesenchymal cells, we reveal four subsets of fibroblasts expressing divergent transcriptional regulators and functional pathways, in addition to pericytes and myofibroblasts. We identified a niche population located in proximity to epithelial crypts expressing SOX6, F3 (CD142), and WNT genes essential for colonic epithelial stem cell function. In colitis, we observed dysregulation of this niche and emergence of an activated mesenchymal population. This subset expressed TNF superfamily member 14 (TNFSF14), fibroblastic reticular cell-associated genes, IL-33, and Lysyl oxidases. Further, it induced factors that impaired epithelial proliferation and maturation and contributed to oxidative stress and disease severity in vivo. Our work defines how the colonic mesenchyme remodels to fuel inflammation and barrier dysfunction in IBD.
Assuntos
Doenças Inflamatórias Intestinais/fisiopatologia , Mesoderma/fisiologia , Animais , Proliferação de Células , Colite/genética , Colite/fisiopatologia , Colo/fisiologia , Células Epiteliais/metabolismo , Fibroblastos/fisiologia , Heterogeneidade Genética , Homeostase , Humanos , Inflamação , Mucosa Intestinal/imunologia , Mucosa Intestinal/fisiologia , Intestinos/imunologia , Intestinos/fisiologia , Células-Tronco Mesenquimais/fisiologia , Mesoderma/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Miofibroblastos , Pericitos , Células RAW 264.7 , Fatores de Transcrição SOXD/fisiologia , Análise de Célula Única/métodos , Tromboplastina/fisiologia , Membro 14 da Superfamília de Ligantes de Fatores de Necrose Tumoral/genética , Via de Sinalização Wnt/fisiologiaRESUMO
Genome-wide association studies have identified risk loci associated with the development of inflammatory bowel disease, while epidemiological studies have emphasized that pathogenesis likely involves host interactions with environmental elements whose source and structure need to be defined. Here, we identify a class of compounds derived from dietary, microbial, and industrial sources that are characterized by the presence of a five-membered oxazole ring and induce CD1d-dependent intestinal inflammation. We observe that minimal oxazole structures modulate natural killer T cell-dependent inflammation by regulating lipid antigen presentation by CD1d on intestinal epithelial cells (IECs). CD1d-restricted production of interleukin 10 by IECs is limited through activity of the aryl hydrocarbon receptor (AhR) pathway in response to oxazole induction of tryptophan metabolites. As such, the depletion of the AhR in the intestinal epithelium abrogates oxazole-induced inflammation. In summary, we identify environmentally derived oxazoles as triggers of CD1d-dependent intestinal inflammatory responses that occur via activation of the AhR in the intestinal epithelium.
Assuntos
Colite/patologia , Dieta , Intestinos/patologia , Oxazóis/farmacologia , Receptores de Hidrocarboneto Arílico/metabolismo , Transdução de Sinais/efeitos dos fármacos , Animais , Antígenos CD1d/genética , Antígenos CD1d/metabolismo , Colite/induzido quimicamente , Colite/metabolismo , Modelos Animais de Doenças , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Interleucina-10/metabolismo , Intestinos/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células T Matadoras Naturais/imunologia , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Receptores de Hidrocarboneto Arílico/antagonistas & inibidores , Receptores de Hidrocarboneto Arílico/genética , Triptofano/metabolismoRESUMO
Extensive studies demonstrate the importance of the STING1 (also known as STING) protein as a signaling hub that coordinates immune and autophagic responses to ectopic DNA in the cytoplasm. Here, we report a nuclear function of STING1 in driving the activation of the transcription factor aryl hydrocarbon receptor (AHR) to control gut microbiota composition and homeostasis. This function was independent of DNA sensing and autophagy and showed competitive inhibition with cytoplasmic cyclic guanosine monophosphate (GMP)-AMP synthase (CGAS)-STING1 signaling. Structurally, the cyclic dinucleotide binding domain of STING1 interacted with the AHR N-terminal domain. Proteomic analyses revealed that STING1-mediated transcriptional activation of AHR required additional nuclear partners, including positive and negative regulatory proteins. Although AHR ligands could rescue colitis pathology and dysbiosis in wild-type mice, this protection was abrogated by mutational inactivation of STING1. These findings establish a key framework for understanding the nuclear molecular crosstalk between the microbiota and the immune system.
Assuntos
Proteômica , Receptores de Hidrocarboneto Arílico , Animais , Camundongos , DNA , Homeostase , Intestinos , Receptores de Hidrocarboneto Arílico/genética , Receptores de Hidrocarboneto Arílico/metabolismoRESUMO
Crohn's disease (CD) is a chronic gastrointestinal disease that is increasing in prevalence worldwide. CD is multifactorial, involving the complex interplay of genetic, immune, and environmental factors, necessitating a system-level understanding of its etiology. To characterize cell-type-specific transcriptional heterogeneity in active CD, we profiled 720,633 cells from the terminal ileum and colon of 71 donors with varying inflammation status. Our integrated datasets revealed organ- and compartment-specific responses to acute and chronic inflammation; most immune changes were in cell composition, whereas transcriptional changes dominated among epithelial and stromal cells. These changes correlated with endoscopic inflammation, but small and large intestines exhibited distinct responses, which were particularly apparent when focusing on IBD risk genes. Finally, we mapped markers of disease-associated myofibroblast activation and identified CHMP1A, TBX3, and RNF168 as regulators of fibrotic complications. Altogether, our results provide a roadmap for understanding cell-type- and organ-specific differences in CD and potential directions for therapeutic development.