RESUMEN
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.
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Células Epiteliales/metabolismo , Células Epiteliales/patología , Enfermedades Inflamatorias del Intestino/metabolismo , Enfermedades Inflamatorias del Intestino/patología , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Piroptosis , Secuencia de Bases , Estudios de Casos y Controles , Adhesión Celular/efectos de los fármacos , Adhesión Celular/genética , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Movimiento Celular/efectos de los fármacos , Movimiento Celular/genética , Proliferación Celular/efectos de los fármacos , Proliferación Celular/genética , Células Epiteliales/efectos de los fármacos , Proteína-Tirosina Quinasas de Adhesión Focal/metabolismo , Células HEK293 , Células HT29 , Humanos , Enfermedades Inflamatorias del Intestino/genética , Metotrexato/farmacología , Mutación/genética , Fosforilación/efectos de los fármacos , Polimorfismo de Nucleótido Simple/genética , Piroptosis/efectos de los fármacos , Piroptosis/genética , Reproducibilidad de los Resultados , Transcriptoma/efectos de los fármacos , Transcriptoma/genética , Regulación hacia Arriba/efectos de los fármacos , Cicatrización de Heridas/efectos de los fármacos , Cicatrización de Heridas/genéticaRESUMEN
How commensals influence intestinal immunity is incompletely understood. In this issue of Immunity, Eshleman et al. demonstrate that microbiota-derived butyrate restrains tuft cell development via HDAC3 modulation in intestinal epithelial cells, showing how microbial metabolites impact intestinal type 2 immunity.
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Mucosa Intestinal , Microbiota , Amor , Intestinos , Células EpitelialesRESUMEN
Gasdermin D (GSDMD)-mediated pyroptotic cell death drives inflammatory cytokine release and downstream immune responses upon inflammasome activation, which play important roles in host defense and inflammatory disorders. Upon activation by proteases, the GSDMD N-terminal domain (NTD) undergoes oligomerization and membrane translocation in the presence of lipids to assemble pores. Despite intensive studies, the molecular events underlying the transition of GSDMD from an autoinhibited soluble form to an oligomeric pore form inserted into the membrane remain incompletely understood. Previous work characterized S-palmitoylation for gasdermins from bacteria, fungi, invertebrates, as well as mammalian gasdermin E (GSDME). Here, we report that a conserved residue Cys191 in human GSDMD was S-palmitoylated, which promoted GSDMD-mediated pyroptosis and cytokine release. Mutation of Cys191 or treatment with palmitoyltransferase inhibitors cyano-myracrylamide (CMA) or 2-bromopalmitate (2BP) suppressed GSDMD palmitoylation, its localization to the membrane and dampened pyroptosis or IL-1ß secretion. Furthermore, Gsdmd-dependent inflammatory responses were alleviated by inhibition of palmitoylation in vivo. By contrast, coexpression of GSDMD with palmitoyltransferases enhanced pyroptotic cell death, while introduction of exogenous palmitoylation sequences fully restored pyroptotic activities to the C191A mutant, suggesting that palmitoylation-mediated membrane localization may be distinct from other molecular events such as GSDMD conformational change during pore assembly. Collectively, our study suggests that S-palmitoylation may be a shared regulatory mechanism for GSDMD and other gasdermins, which points to potential avenues for therapeutically targeting S-palmitoylation of gasdermins in inflammatory disorders.
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Cisteína , Péptidos y Proteínas de Señalización Intracelular , Lipoilación , Proteínas de Unión a Fosfato , Piroptosis , Proteínas de Unión a Fosfato/metabolismo , Proteínas de Unión a Fosfato/genética , Humanos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Péptidos y Proteínas de Señalización Intracelular/genética , Cisteína/metabolismo , Animales , Ratones , Citocinas/metabolismo , Células HEK293 , Inflamasomas/metabolismo , GasderminasRESUMEN
BACKGROUND: Several randomised clinical trials (RCTs) performing faecal microbiota transplantation (FMT) for the management of inflammatory bowel disease (IBD), particularly for ulcerative colitis, have recently been published, but with major variations in study design. These include differences in administered dose, route and frequency of delivery, type of placebo and evaluated endpoints. Although the overall outcomes appear to be promising, they are highly dependent on both donor and recipient factors. OBJECTIVE: To develop concensus-based statements and recommendations for the evaluation, management and potential treatment of IBD using FMT in order to move towards standardised practices. DESIGN: An international panel of experts convened several times to generate evidence-based guidelines by performing a deep evaluation of currently available and/or published data. Twenty-five experts in IBD, immunology and microbiology collaborated in different working groups to provide statements on the following key issues related to FMT in IBD: (A) pathogenesis and rationale, (B) donor selection and biobanking, (C) FMT practices and (D) consideration of future studies and perspectives. Statements were evaluated and voted on by all members using an electronic Delphi process, culminating in a plenary consensus conference and generation of proposed guidelines. RESULTS AND CONCLUSIONS: Our group has provided specific statements and recommendations, based on best available evidence, with the end goal of providing guidance and general criteria required to promote FMT as a recognised strategy for the treatment of IBD.
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Colitis Ulcerosa , Microbioma Gastrointestinal , Enfermedades Inflamatorias del Intestino , Humanos , Trasplante de Microbiota Fecal/métodos , Ciudad de Roma , Enfermedades Inflamatorias del Intestino/terapia , Enfermedades Inflamatorias del Intestino/microbiología , Colitis Ulcerosa/terapia , Resultado del TratamientoRESUMEN
BACKGROUND: Metabolic syndrome (MetS) is a cluster of atherosclerotic risk factors that increases cardiovascular risk. MetS has been associated with periodontitis, but the contribution of single MetS components and any possible sexual dimorphism in this relation remain undetermined. METHODS: Using the third National Health and Nutrition Examination Survey (NHANES III), we performed a nested cross-sectional study to test whether individuals aged > 30 years undergoing periodontal evaluation (population) exposed to ≥ 1 MetS component (exposure) were at increased risk of bleeding/non-bleeding periodontal diseases (outcome) compared to nonexposed individuals, propensity score matched for sex, age, race/ethnicity, and income (controls). The association between MetS components combinations and periodontal diseases was explored overall and across subgroups by sex and smoking. Periodontal health status prediction based on MetS components was assessed. RESULTS: In total, 2258 individuals (n. 1129/group) with nested clinical-demographic features were analyzed. Exposure was associated with gingival bleeding (+ 18% risk for every unitary increase in MetS components, and triple risk when all five were combined), but not with stable periodontitis; the association was specific for women, but not for men, irrespective of smoking. The only MetS feature with significant association in men was high BP with periodontitis. CRP levels significantly increased from health to disease only among exposed women. MetS components did not substantially improve the prediction of bleeding/non-bleeding periodontal disease. CONCLUSION: The observed women-specific association of gingival bleeding with single and combined MetS components advances gender and precision periodontology. Further research is needed to validate and expand these findings.
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Síndrome Metabólico , Enfermedades Periodontales , Periodontitis , Masculino , Humanos , Femenino , Síndrome Metabólico/complicaciones , Estudios Transversales , Encuestas Nutricionales , Periodontitis/complicaciones , Enfermedades Periodontales/complicaciones , Factores de RiesgoRESUMEN
Signaling of 17ß-estradiol (estrogen) through its two nuclear receptors, α and ß (ERα, ERß), is an important mechanism of transcriptional regulation. Although ERs are broadly expressed by cells of the immune system, the mechanisms by which they modulate immune responses remain poorly understood. ERß-specific signaling is reduced in patients with chronic inflammatory diseases, including systemic lupus erythematosus and inflammatory bowel disease, and our previous work suggests that dysregulation of ERß-specific signaling contributes to enhanced intestinal inflammation in female SAMP/YitFC mice, a spontaneous model of Crohn's disease-like ileitis. The present study builds on these prior observations to identify a nonredundant, immunoprotective role for ERß-specific signaling in TGF-ß-dependent regulatory T cell (Treg) differentiation. Using a strain of congenic SAMP mice engineered to lack global expression of ERß, we observed dramatic, female-specific exacerbation of intestinal inflammation accompanied by significant reductions in intestinal Treg frequency and function. Impaired Treg suppression in the absence of ERß was associated with aberrant overexpression of Tsc22d3 (GILZ), a glucocorticoid-responsive transcription factor not normally expressed in mature Tregs, and ex vivo data reveal that forced overexpression of GILZ in mature Tregs inhibits their suppressive function. Collectively, our findings identify a pathway of estrogen-mediated immune regulation in the intestine, whereby homeostatic expression of ERß normally functions to limit Treg-specific expression of GILZ, thereby maintaining effective immune suppression. Our data suggest that transcriptional cross-talk between glucocorticoid and steroid sex hormone signaling represents an important and understudied regulatory node in chronic inflammatory disease.
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Receptor beta de Estrógeno/metabolismo , Estrógenos/metabolismo , Inflamación/inmunología , Intestinos/inmunología , Transducción de Señal/fisiología , Linfocitos T Reguladores/inmunología , Adolescente , Adulto , Animales , Enfermedad de Crohn/inmunología , Modelos Animales de Enfermedad , Receptor alfa de Estrógeno/genética , Receptor alfa de Estrógeno/metabolismo , Receptor beta de Estrógeno/genética , Femenino , Glucocorticoides/metabolismo , Humanos , Ileítis/patología , Enfermedades Inflamatorias del Intestino/inmunología , Intestinos/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Persona de Mediana Edad , Factores de Transcripción/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Adulto JovenRESUMEN
BACKGROUND & AIMS: Interleukin (IL)33/IL1F11 is an important mediator for the development of type 2 T-helper cell (Th2)-driven inflammatory disorders and has also been implicated in the pathogenesis of gastrointestinal (GI)-related cancers, including gastric carcinoma. We therefore sought to mechanistically determine IL33's potential role as a critical factor linking chronic inflammation and gastric carcinogenesis using gastritis-prone SAMP1/YitFc (SAMP) mice. METHODS: SAMP and (parental control) AKR mice were assessed for baseline gastritis and progression to metaplasia. Expression/localization of IL33 and its receptor, ST2/IL1R4, were characterized in corpus tissues, and activation and neutralization studies were both performed targeting the IL33/ST2 axis. Dissection of immune pathways leading to metaplasia was evaluated, including eosinophil depletion studies using anti-IL5/anti-CCR3 treatment. RESULTS: Progressive gastritis and, ultimately, intestinalized spasmolytic polypeptide-expressing metaplasia (SPEM) was detected in SAMP stomachs, which was absent in AKR but could be moderately induced with exogenous, recombinant IL33. Robust peripheral (bone marrow) expansion of eosinophils and local recruitment of both eosinophils and IL33-expressing M2 macrophages into corpus tissues were evident in SAMP. Interestingly, IL33 blockade did not affect bone marrow-derived expansion and local infiltration of eosinophils, but markedly decreased M2 macrophages and SPEM features, while eosinophil depletion caused a significant reduction in both local IL33-producing M2 macrophages and SPEM in SAMP. CONCLUSIONS: IL33 promotes metaplasia and the sequelae of eosinophil-dependent downstream infiltration of IL33-producing M2 macrophages leading to intestinalized SPEM in SAMP, suggesting that IL33 represents a critical link between chronic gastritis and intestinalizing metaplasia that may serve as a potential therapeutic target for preneoplastic conditions of the GI tract.
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Gastritis/etiología , Gastritis/patología , Interleucina-33/fisiología , Neoplasias Gástricas/etiología , Neoplasias Gástricas/patología , Animales , Enfermedad Crónica , Modelos Animales de Enfermedad , Eosinófilos , Mucosa Gástrica/patología , Metaplasia , RatonesRESUMEN
Crohn's disease and ulcerative colitis are chronic and progressive inflammatory bowel diseases (IBDs) that are attributed to dysregulated interactions between the gut microbiome and the intestinal mucosa-associated immune system. There are limited studies investigating the role of either IL-1α or IL-1ß in mouse models of colitis, and no clinical trials blocking either IL-1 have yet to be performed. In the present study, we show that neutralization of IL-1α by a specific monoclonal antibody against murine IL-1α was highly effective in reducing inflammation and damage in SAMP mice, mice that spontaneously develop a Crohn's-like ileitis. Anti-mouse IL-1α significantly ameliorated the established, chronic ileitis and also protected mice from developing acute DSS-induced colitis. Both were associated with taxonomic divergence of the fecal gut microbiome, which was treatment-specific and not dependent on inflammation. Anti-IL-1α administration led to a decreased ratio of Proteobacteria to Bacteroidetes, decreased presence of Helicobacter species, and elevated representation of Mucispirillum schaedleri and Lactobacillus salivarius. Such modification in flora was functionally linked to the antiinflammatory effects of IL-1α neutralization, as blockade of IL-1α was not effective in germfree SAMP mice. Furthermore, preemptive dexamethasone treatment of DSS-challenged SAMP mice led to changes in flora composition without preventing the development of colitis. Thus, neutralization of IL-1α changes specific bacterial species of the intestinal microbiome, which is linked to its antiinflammatory effects. These functional findings may be of significant value for patients with IBD, who may benefit from targeted IL-1α-based therapies.
RESUMEN
Patients with inflammatory bowel disease (IBD) are particularly susceptible to behavioral diagnoses, and the microbiome has been repeatedly implicated in the pathogenesis of IBD. The intestinal microbiome's ability to affect behavior has become increasingly recognized and studied. The so-called 'psychobiome' has been linked to a plethora of neurological and psychological diagnoses, including autism and Parkinson's disease. Despite the ability of many bacterial species within the human intestinal microbiome to synthesize neurotransmitters, it has never been previously reported that a single bacterial species is sufficient to induce depression. Here, we demonstrate that our mouse model of Crohn's disease (CD)-like ileitis, the SAMP1/YitFc (SAMP1), does not exhibit baseline behavioral abnormalities. By comparison, SAMP6 mice develop depressive-like behavior that is associated with a rise in the GABA-producing bacterial genus Parabacteroides. We finally demonstrate that administration of Parabacteroides distasonis into our SAMP1 mice induces depressive-like behavior. Colonization with P. distasonis was not associated with increased intestinal inflammation or alterations in other measures of behavior. The intestinal environment of CD may be particularly conducive to colonization with P. distasonis and subsequent induction of depressive-like behavior. To our knowledge, this is the first report of a bacterial species specifically inducing depressive-like behavior.
Asunto(s)
Enfermedad de Crohn , Ileítis , Animales , Bacteroidetes , Modelos Animales de Enfermedad , Humanos , RatonesRESUMEN
Defective and/or delayed wound healing has been implicated in the pathogenesis of several chronic inflammatory disorders, including inflammatory bowel disease (IBD). The resolution of inflammation is particularly important in mucosal organs, such as the gut, where restoration of epithelial barrier function is critical to reestablish homeostasis with the interfacing microenvironment. Although IL-33 and its receptor ST2/ILRL1 are known to be increased and associated with IBD, studies using animal models of colitis to address the mechanism have yielded ambiguous results, suggesting both pathogenic and protective functions. Unlike those previously published studies, we focused on the functional role of IL-33/ST2 during an extended (2-wk) recovery period after initial challenge in dextran sodium sulfate (DSS)-induced colitic mice. Our results show that during acute, resolving colitis the normal function of endogenous IL-33 is protection, and the lack of either IL-33 or ST2 impedes the overall recovery process, while exogenous IL-33 administration during recovery dramatically accelerates epithelial restitution and repair, with concomitant improvement of colonic inflammation. Mechanistically, we show that IL-33 stimulates the expression of a network of microRNAs (miRs) in the Caco2 colonic intestinal epithelial cell (IEC) line, especially miR-320, which is increased by >16-fold in IECs isolated from IL-33-treated vs. vehicle-treated DSS colitic mice. Finally, IL-33-dependent in vitro proliferation and wound closure of Caco-2 IECs is significantly abrogated after specific inhibition of miR-320A. Together, our data indicate that during acute, resolving colitis, IL-33/ST2 plays a crucial role in gut mucosal healing by inducing epithelial-derived miR-320 that promotes epithelial repair/restitution and the resolution of inflammation.
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Colitis/metabolismo , Enfermedades Inflamatorias del Intestino/metabolismo , Interleucina-33/metabolismo , Mucosa Intestinal/fisiología , MicroARNs/metabolismo , Regeneración , Enfermedad Aguda , Animales , Células CACO-2 , Colitis/inducido químicamente , Colitis/genética , Colitis/patología , Sulfato de Dextran/toxicidad , Humanos , Enfermedades Inflamatorias del Intestino/inducido químicamente , Enfermedades Inflamatorias del Intestino/genética , Enfermedades Inflamatorias del Intestino/patología , Proteína 1 Similar al Receptor de Interleucina-1/genética , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Interleucina-33/genética , Ratones , Ratones Noqueados , MicroARNs/genéticaRESUMEN
(1) Background: Colorectal cancer (CRC) is among the best examples of the relationship between inflammation and increased cancer risk. (2) Methods: To examine the effects of spontaneous low-grade chronic inflammation on the pathogenesis of CRC, we developed a new murine model of colitis-associated cancer (CAC) by crossing Mucin 2 mutated mice (Winnie) with ApcMin/+ mice. (3) Results: The resulting Winnie-ApcMin/+ model combines an inflammatory background with a genetic predisposition to small intestinal polyposis. Winnie-ApcMin/+ mice show an early occurrence of inflammatory signs and dysplastic lesions in the distal colon with a specific molecular signature. (4) Conclusion: The Winnie-ApcMin/+ model is a perfect model to demonstrate that chronic inflammation represents a crucial risk factor for the onset and progression of tumoral lesions in individuals genetically predisposed to CRC.
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Neoplasias Asociadas a Colitis/etiología , Susceptibilidad a Enfermedades , Genes APC , Animales , Apoptosis/genética , Biopsia , Proliferación Celular , Citoesqueleto , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Predisposición Genética a la Enfermedad , Inmunohistoquímica , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Ratones , Clasificación del TumorRESUMEN
γδ T lymphocytes, dominant T cell subsets in the intestine, mediate both regulatory and pathogenic roles, yet the mechanisms underlying such opposing effects remain unclear. In this study, we identified a unique γδ T cell subset that coexpresses high levels of gut-homing integrins, CD103 and α4ß7. They were exclusively found in the mesenteric lymph node after T cell-mediated colitis induction, and their appearance preceded the inflammation. Adoptive transfer of the CD103+α4ß7high subsets enhanced Th1/Th17 T cell generation and accumulation in the intestine, and the disease severity. The level of generation correlated with the disease severity. Moreover, these cells were also found to be elevated in a spontaneous mouse model of ileitis. Based on the procolitogenic function, we referred to this subset as "inflammatory" γδ T cells. Targeting inflammatory γδ T cells may open a novel strategy to treat inflammatory diseases where γδ T cells play a pathogenic role including inflammatory bowel disease.
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Antígenos CD/inmunología , Enfermedades Inflamatorias del Intestino/inmunología , Cadenas alfa de Integrinas/inmunología , Integrinas/inmunología , Subgrupos de Linfocitos T/inmunología , Traslado Adoptivo , Animales , Modelos Animales de Enfermedad , Citometría de Flujo , Perfilación de la Expresión Génica , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores de Antígenos de Linfocitos T gamma-delta/inmunología , Receptores Mensajeros de Linfocitos/inmunología , TranscriptomaRESUMEN
OBJECTIVE: Alternatively activated macrophages (M2) are associated with the progression of spasmolytic polypeptide-expressing metaplasia (SPEM) in the stomach. However, the precise mechanism(s) and critical mediators that induce SPEM are unknown. DESIGN: To determine candidate genes important in these processes, macrophages from the stomach corpus of mice with SPEM (DMP-777-treated) or advanced SPEM (L635-treated) were isolated and RNA sequenced. Effects on metaplasia development after acute parietal cell loss induced by L635 were evaluated in interleukin (IL)-33, IL-33 receptor (ST2) and IL-13 knockout (KO) mice. RESULTS: Profiling of metaplasia-associated macrophages in the stomach identified an M2a-polarised macrophage population. Expression of IL-33 was significantly upregulated in macrophages associated with advanced SPEM. L635 induced metaplasia in the stomachs of wild-type mice, but not in the stomachs of IL-33 and ST2 KO mice. While IL-5 and IL-9 were not required for metaplasia induction, IL-13 KO mice did not develop metaplasia in response to L635. Administration of IL-13 to ST2 KO mice re-established the induction of metaplasia following acute parietal cell loss. CONCLUSIONS: Metaplasia induction and macrophage polarisation after parietal cell loss is coordinated through a cytokine signalling network of IL-33 and IL-13, linking a combined response to injury by both intrinsic mucosal mechanisms and infiltrating M2 macrophages.
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Interleucina-13/metabolismo , Interleucina-33/metabolismo , Macrófagos/metabolismo , Metaplasia/metabolismo , Estómago/citología , Animales , Citometría de Flujo , Mucosa Gástrica/metabolismo , Inmunohistoquímica , Péptidos y Proteínas de Señalización Intercelular , Proteína 1 Similar al Receptor de Interleucina-1 , Interleucina-13/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Células Parietales Gástricas/citología , Péptidos/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores de Interleucina/genética , Transducción de SeñalRESUMEN
TNF-like cytokine 1A (TL1A) is expressed on APCs and provides costimulatory signals to activated lymphocytes that bear its functional receptor, death receptor 3 (DR3). TL1A/DR3 signaling is involved in the pathogenesis of human and experimental inflammatory bowel disease. In the current study, we investigated the role of this cytokine/receptor pair in acute intestinal injury/repair pathways. We demonstrate that intact DR3 signaling protected mice from acute dextran sodium sulfate colitis because DR3(-/-) mice showed more severe mucosal inflammation and increased mortality. DR3(-/-) mice were compromised in their ability to maintain adequate numbers of CD4(+)CD25(+)Foxp3(+) regulatory T cells in response to acute mucosal damage. This defect in immune regulation led to a nonspecific upregulation of effector proinflammatory pathways, which was most prominent for the Th17 immunophenotype. TL1A(-/-) mice were similarly more susceptible to dextran sodium sulfate colitis, although without mortality and with delayed kinetics compared with DR3(-/-) mice, and also displayed significantly reduced numbers of regulatory T cells. Infection of DR3(-/-) mice with Salmonella typhimurium was associated with defective microbial clearance and elevated bacterial load. Taken together, our findings indicate a novel protective role for the TL1A/DR3 axis in the regulation of mucosal homeostasis during acute intestinal injury/repair, which contrasts with its known pathogenic function during chronic intestinal inflammation.
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Colitis/inmunología , Intestinos/patología , Miembro 25 de Receptores de Factores de Necrosis Tumoral/metabolismo , Infecciones por Salmonella/inmunología , Salmonella typhimurium/inmunología , Linfocitos T Reguladores/inmunología , Células Th17/inmunología , Miembro 15 de la Superfamilia de Ligandos de Factores de Necrosis Tumoral/metabolismo , Animales , Células Cultivadas , Sulfato de Dextran , Factores de Transcripción Forkhead/metabolismo , Humanos , Intestinos/microbiología , Ratones , Ratones Noqueados , Ratones SCID , Miembro 25 de Receptores de Factores de Necrosis Tumoral/genética , Transducción de Señal/genética , Miembro 15 de la Superfamilia de Ligandos de Factores de Necrosis Tumoral/genéticaRESUMEN
Tumor epithelial cells develop within a microenvironment consisting of extracellular matrix, growth factors, and cytokines produced by nonepithelial stromal cells. In response to paracrine signals from tumor epithelia, stromal cells modify the microenvironment to promote tumor growth and metastasis. Here, we identify interleukin 33 (IL-33) as a regulator of tumor stromal cell activation and mediator of intestinal polyposis. In human colorectal cancer, IL-33 expression was induced in the tumor epithelium of adenomas and carcinomas, and expression of the IL-33 receptor, IL1RL1 (also referred to as IL1-R4 or ST2), localized predominantly to the stroma of adenoma and both the stroma and epithelium of carcinoma. Genetic and antibody abrogation of responsiveness to IL-33 in the Apc(Min/+) mouse model of intestinal tumorigenesis inhibited proliferation, induced apoptosis, and suppressed angiogenesis in adenomatous polyps, which reduced both tumor number and size. Similar to human adenomas, IL-33 expression localized to tumor epithelial cells and expression of IL1RL1 associated with two stromal cell types, subepithelial myofibroblasts and mast cells, in Apc(Min/+) polyps. In vitro, IL-33 stimulation of human subepithelial myofibroblasts induced the expression of extracellular matrix components and growth factors associated with intestinal tumor progression. IL-33 deficiency reduced mast cell accumulation in Apc(Min/+) polyps and suppressed the expression of mast cell-derived proteases and cytokines known to promote polyposis. Based on these findings, we propose that IL-33 derived from the tumor epithelium promotes polyposis through the coordinated activation of stromal cells and the formation of a protumorigenic microenvironment.
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Neoplasias del Colon/metabolismo , Neoplasias Colorrectales/metabolismo , Regulación Neoplásica de la Expresión Génica , Interleucinas/metabolismo , Poliposis Intestinal/metabolismo , Animales , Apoptosis , Proliferación Celular , Pólipos del Colon/metabolismo , Células Epiteliales/metabolismo , Humanos , Interleucina-33 , Mastocitos/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Miofibroblastos/metabolismo , Neovascularización Patológica , Análisis de Secuencia por Matrices de Oligonucleótidos , Transducción de Señal , Células Th2/metabolismo , Transcriptoma , Cicatrización de HeridasRESUMEN
Although a clear association has been established between IL-33 and inflammatory bowel disease, mechanistic studies to date, primarily using acute murine models of colitis, have yielded contradicting results, demonstrating both pathogenic and protective roles. We used a well-characterized, spontaneous model of inflammatory bowel disease [ie, SAMP1/YitFc (SAMP) mice] to investigate the role of IL-33 during chronic intestinal inflammation. Our results showed marked eosinophil infiltration into the gut mucosa with increased levels of eotaxins and type 2 helper T-cell (Th2) cytokines as disease progressed and became more severe, which could be reversed upon either eosinophil depletion or blockade of IL-33 signaling. Exogenous IL-33 administration recapitulated these effects in ilea of uninflamed (parental) control AKR/J mice. Human data supported these findings, showing colocalization and up-regulation of IL-33 and eosinophils in the colonic mucosa of inflammatory bowel disease patients versus noninflamed controls. Finally, colonization of commensal flora by fecal material transplantation into germ-free SAMP and the presence of the gut microbiome induced IL-33, subsequent eosinophil infiltration, and mounting of Th2 immune responses, leading to exacerbation of chronic intestinal inflammation characteristic of SAMP mice. These data demonstrate a pathogenic role for IL-33-mediated eosinophilia and activation of Th2 immunity in chronic intestinal inflammation that is dependent on the gut microbiome. Targeting IL-33 may represent a novel therapeutic approach to treat patients with inflammatory bowel disease.
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Eosinófilos/citología , Ileítis/patología , Interleucina-33/metabolismo , Células Th2/inmunología , Animales , Citocinas/metabolismo , Modelos Animales de Enfermedad , Ileítis/inmunología , Inflamación/inmunología , Inflamación/metabolismo , Mucosa Intestinal/metabolismo , Ratones , Regulación hacia ArribaRESUMEN
BACKGROUND & AIMS: The lymphatic chemokine CCL21 is required for dendritic cell (DC) migration from tissues to lymph nodes, which helps establish tolerance to foreign yet harmless antigens. We demonstrate that CCL21 is almost completely absent from SAMP1/YitFc (SAMP) mice, which spontaneously develop chronic ileitis that resembles Crohn's disease, and that DC migration is severely impaired in these mice compared with AKR mice (controls). Toll-like receptor agonists like the Toll-like receptor 7 agonist R848 induce DC maturation and mobilization. METHODS: We collected intestinal and other tissues and mesenteric lymph nodes (MLN) from SAMP mice. Expression of CCL21 was measured by quantitative reverse transcription polymerase chain reaction and immunofluorescence analyses; spontaneous and induced migration of DCs were assessed by flow cytometry. We analyzed production of retinoic acid by DCs and their ability to induce development of regulatory T cells. Mice were fed R848 to determine its effects on migration of DCs and development of ileitis in SAMP mice. RESULTS: SAMP mice expressed almost no CCL21 in any tissue tested. Their CD11b(+)CD103(+) DCs were defective in migration from the ileal lamina propria to the MLN. DCs from SAMP mice also had a greatly reduced ability to produce retinoic acid and induce development of regulatory T cells compared with control mice. Young SAMP mice had reduced CCL21 expression and decreased DC migration before developing ileitis. Administration of R848 to adult SAMP mice increased migration of DC to the MLN and development of regulatory T cells there, and reduced the severity of ileitis. CONCLUSIONS: Loss of CCL21 signaling and DC migration is required for development of ileitis in SAMP mice. Reagents such as R848, which activate DC migration to the MLN, may be developed as treatments for patients with Crohn's disease.
Asunto(s)
Movimiento Celular/inmunología , Quimiocina CCL21/inmunología , Enfermedad de Crohn/inmunología , Células Dendríticas/inmunología , Ileítis/inmunología , Ganglios Linfáticos/inmunología , Animales , Movimiento Celular/efectos de los fármacos , Quimiocina CCL21/genética , Células Dendríticas/efectos de los fármacos , Modelos Animales de Enfermedad , Imidazoles/farmacología , Glicoproteínas de Membrana/agonistas , Ratones , Ratones Endogámicos , ARN Mensajero/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Linfocitos T Reguladores/inmunología , Receptor Toll-Like 7/agonistasRESUMEN
Nucleotide-binding oligomerization domain-containing 2 (NOD2) is an intracellular receptor that plays an essential role in innate immunity as a sensor of a component of the bacterial cell wall, muramyl dipeptide (MDP). Crohn's disease (CD)-associated NOD2 variants lead to defective innate immune responses, including decreased NF-κB activation and cytokine production. We report herein that SAMP1/YitFc (SAMP) mice, which develop spontaneous CD-like ileitis in the absence of NOD2 genetic mutations, fail to respond to MDP administration by displaying decreased innate cytokine production and dysregulated NOD2 signaling compared with parental AKR control mice. We show that, unlike in other mouse strains, in vivo administration of MDP does not prevent dextran sodium sulfate-induced colitis in SAMP mice and that the abnormal NOD2 response is specific to the hematopoietic cellular component. Moreover, we demonstrate that MDP fails to enhance intracellular bacterial killing in SAMP mice. These findings shed important light on the initiating molecular events underlying CD-like ileitis.