RESUMEN
Disease-associated astrocyte subsets contribute to the pathology of neurologic diseases, including multiple sclerosis and experimental autoimmune encephalomyelitis1-8 (EAE), an experimental model for multiple sclerosis. However, little is known about the stability of these astrocyte subsets and their ability to integrate past stimulation events. Here we report the identification of an epigenetically controlled memory astrocyte subset that exhibits exacerbated pro-inflammatory responses upon rechallenge. Specifically, using a combination of single-cell RNA sequencing, assay for transposase-accessible chromatin with sequencing, chromatin immunoprecipitation with sequencing, focused interrogation of cells by nucleic acid detection and sequencing, and cell-specific in vivo CRISPR-Cas9-based genetic perturbation studies we established that astrocyte memory is controlled by the metabolic enzyme ATP-citrate lyase (ACLY), which produces acetyl coenzyme A (acetyl-CoA) that is used by histone acetyltransferase p300 to control chromatin accessibility. The number of ACLY+p300+ memory astrocytes is increased in acute and chronic EAE models, and their genetic inactivation ameliorated EAE. We also detected the pro-inflammatory memory phenotype in human astrocytes in vitro; single-cell RNA sequencing and immunohistochemistry studies detected increased numbers of ACLY+p300+ astrocytes in chronic multiple sclerosis lesions. In summary, these studies define an epigenetically controlled memory astrocyte subset that promotes CNS pathology in EAE and, potentially, multiple sclerosis. These findings may guide novel therapeutic approaches for multiple sclerosis and other neurologic diseases.
Asunto(s)
Astrocitos , Encefalomielitis Autoinmune Experimental , Memoria Epigenética , Esclerosis Múltiple , Animales , Femenino , Humanos , Masculino , Ratones , Acetilcoenzima A/metabolismo , Astrocitos/enzimología , Astrocitos/metabolismo , Astrocitos/patología , ATP Citrato (pro-S)-Liasa/metabolismo , Cromatina/genética , Cromatina/metabolismo , Ensamble y Desensamble de Cromatina , Secuenciación de Inmunoprecipitación de Cromatina , Sistemas CRISPR-Cas , Encefalomielitis Autoinmune Experimental/enzimología , Encefalomielitis Autoinmune Experimental/genética , Encefalomielitis Autoinmune Experimental/metabolismo , Encefalomielitis Autoinmune Experimental/patología , Inflamación/enzimología , Inflamación/genética , Inflamación/metabolismo , Inflamación/patología , Esclerosis Múltiple/enzimología , Esclerosis Múltiple/genética , Esclerosis Múltiple/metabolismo , Esclerosis Múltiple/patología , Análisis de Expresión Génica de una Sola Célula , Transposasas/metabolismoRESUMEN
Astrocytes play important roles in the central nervous system (CNS) physiology and pathology. Indeed, astrocyte subsets defined by specific transcriptional activation states contribute to the pathology of neurologic diseases, including multiple sclerosis (MS) and its pre-clinical model experimental autoimmune encephalomyelitis (EAE) 1-8 . However, little is known about the stability of these disease-associated astrocyte subsets, their regulation, and whether they integrate past stimulation events to respond to subsequent challenges. Here, we describe the identification of an epigenetically controlled memory astrocyte subset which exhibits exacerbated pro-inflammatory responses upon re-challenge. Specifically, using a combination of single-cell RNA sequencing (scRNA-seq), assay for transposase-accessible chromatin with sequencing (ATAC-seq), chromatin immunoprecipitation with sequencing (ChIP-seq), focused interrogation of cells by nucleic acid detection and sequencing (FIND-seq), and cell-specific in vivo CRISPR/Cas9-based genetic perturbation studies we established that astrocyte memory is controlled by the metabolic enzyme ATP citrate lyase (ACLY), which produces acetyl coenzyme A (acetyl-CoA) used by the histone acetyltransferase p300 to control chromatin accessibility. ACLY + p300 + memory astrocytes are increased in acute and chronic EAE models; the genetic targeting of ACLY + p300 + astrocytes using CRISPR/Cas9 ameliorated EAE. We also detected responses consistent with a pro-inflammatory memory phenotype in human astrocytes in vitro ; scRNA-seq and immunohistochemistry studies detected increased ACLY + p300 + astrocytes in chronic MS lesions. In summary, these studies define an epigenetically controlled memory astrocyte subset that promotes CNS pathology in EAE and, potentially, MS. These findings may guide novel therapeutic approaches for MS and other neurologic diseases.
RESUMEN
The development of therapeutic approaches for the induction of robust, long-lasting and antigen-specific immune tolerance remains an important unmet clinical need for the management of autoimmunity, allergy, organ transplantation and gene therapy. Recent breakthroughs in our understanding of immune tolerance mechanisms have opened new research avenues and therapeutic opportunities in this area. Here, we review mechanisms of immune tolerance and novel methods for its therapeutic induction.
RESUMEN
Dendritic cells (DCs) have a role in the development and activation of self-reactive pathogenic T cells1,2. Genetic variants that are associated with the function of DCs have been linked to autoimmune disorders3,4, and DCs are therefore attractive therapeutic targets for such diseases. However, developing DC-targeted therapies for autoimmunity requires identification of the mechanisms that regulate DC function. Here, using single-cell and bulk transcriptional and metabolic analyses in combination with cell-specific gene perturbation studies, we identify a regulatory loop of negative feedback that operates in DCs to limit immunopathology. Specifically, we find that lactate, produced by activated DCs and other immune cells, boosts the expression of NDUFA4L2 through a mechanism mediated by hypoxia-inducible factor 1α (HIF-1α). NDUFA4L2 limits the production of mitochondrial reactive oxygen species that activate XBP1-driven transcriptional modules in DCs that are involved in the control of pathogenic autoimmune T cells. We also engineer a probiotic that produces lactate and suppresses T cell autoimmunity through the activation of HIF-1α-NDUFA4L2 signalling in DCs. In summary, we identify an immunometabolic pathway that regulates DC function, and develop a synthetic probiotic for its therapeutic activation.
Asunto(s)
Enfermedades Autoinmunes , Sistema Nervioso Central , Células Dendríticas , Subunidad alfa del Factor 1 Inducible por Hipoxia , Ácido Láctico , Humanos , Enfermedades Autoinmunes/inmunología , Enfermedades Autoinmunes/metabolismo , Enfermedades Autoinmunes/prevención & control , Autoinmunidad , Sistema Nervioso Central/citología , Sistema Nervioso Central/inmunología , Sistema Nervioso Central/patología , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/química , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Ácido Láctico/metabolismo , Probióticos/uso terapéutico , Especies Reactivas de Oxígeno/metabolismo , Linfocitos T/inmunología , Retroalimentación Fisiológica , Lactasa/genética , Lactasa/metabolismo , Análisis de la Célula IndividualRESUMEN
Dendritic cells (DCs) control the generation of self-reactive pathogenic T cells. Thus, DCs are considered attractive therapeutic targets for autoimmune diseases. Using single-cell and bulk transcriptional and metabolic analyses in combination with cell-specific gene perturbation studies we identified a negative feedback regulatory pathway that operates in DCs to limit immunopathology. Specifically, we found that lactate, produced by activated DCs and other immune cells, boosts NDUFA4L2 expression through a mechanism mediated by HIF-1α. NDUFA4L2 limits the production of mitochondrial reactive oxygen species that activate XBP1-driven transcriptional modules in DCs involved in the control of pathogenic autoimmune T cells. Moreover, we engineered a probiotic that produces lactate and suppresses T-cell autoimmunity in the central nervous system via the activation of HIF-1α/NDUFA4L2 signaling in DCs. In summary, we identified an immunometabolic pathway that regulates DC function, and developed a synthetic probiotic for its therapeutic activation.
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Genome-wide association studies have identified risk loci linked to inflammatory bowel disease (IBD)1-a complex chronic inflammatory disorder of the gastrointestinal tract. The increasing prevalence of IBD in industrialized countries and the augmented disease risk observed in migrants who move into areas of higher disease prevalence suggest that environmental factors are also important determinants of IBD susceptibility and severity2. However, the identification of environmental factors relevant to IBD and the mechanisms by which they influence disease has been hampered by the lack of platforms for their systematic investigation. Here we describe an integrated systems approach, combining publicly available databases, zebrafish chemical screens, machine learning and mouse preclinical models to identify environmental factors that control intestinal inflammation. This approach established that the herbicide propyzamide increases inflammation in the small and large intestine. Moreover, we show that an AHR-NF-κB-C/EBPß signalling axis operates in T cells and dendritic cells to promote intestinal inflammation, and is targeted by propyzamide. In conclusion, we developed a pipeline for the identification of environmental factors and mechanisms of pathogenesis in IBD and, potentially, other inflammatory diseases.
Asunto(s)
Ambiente , Herbicidas , Inflamación , Enfermedades Inflamatorias del Intestino , Intestinos , Animales , Ratones , Inflamación/inducido químicamente , Inflamación/etiología , Inflamación/inmunología , Inflamación/patología , Enfermedades Inflamatorias del Intestino/inducido químicamente , Enfermedades Inflamatorias del Intestino/etiología , Enfermedades Inflamatorias del Intestino/inmunología , Enfermedades Inflamatorias del Intestino/patología , Pez Cebra , Aprendizaje Automático , Bases de Datos Factuales , Modelos Animales de Enfermedad , Intestinos/efectos de los fármacos , Intestinos/inmunología , Intestinos/metabolismo , Intestinos/patología , FN-kappa B , Proteína beta Potenciadora de Unión a CCAAT , Receptores de Hidrocarburo de Aril , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Linfocitos T/metabolismo , Células Dendríticas/efectos de los fármacos , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Herbicidas/efectos adversosRESUMEN
Immune checkpoint inhibitors represent some of the most important cancer treatments developed in the last 20 y. However, existing immunotherapy approaches benefit only a minority of patients. Here, we provide evidence that the aryl hydrocarbon receptor (AhR) is a central player in the regulation of multiple immune checkpoints in oral squamous cell carcinoma (OSCC). Orthotopic transplant of mouse OSCC cells from which the AhR has been deleted (MOC1AhR-KO) results, within 1 wk, in the growth of small tumors that are then completely rejected within 2 wk, concomitant with an increase in activated T cells in tumor-draining lymph nodes (tdLNs) and T cell signaling within the tumor. By 2 wk, AhR+ control cells (MOC1Cas9), but not MOC1AhR-KO cells up-regulate exhaustion pathways in the tumor-infiltrating T cells and expression of checkpoint molecules on CD4+ T cells (PD-1, CTLA4, Lag3, and CD39) and macrophages, dendritic cells, and Ly6G+ myeloid cells (PD-L1 and CD39) in tdLNs. Notably, MOC1AhR-KO cell transplant renders mice 100% immune to later challenge with wild-type tumors. Analysis of altered signaling pathways within MOC1AhR-KO cells shows that the AhR controls baseline and IFNγ-induced Ido and PD-L1 expression, the latter of which occurs through direct transcriptional control. These observations 1) confirm the importance of malignant cell AhR in suppression of tumor immunity, 2) demonstrate the involvement of the AhR in IFNγ control of PD-L1 and IDO expression in the cancer context, and 3) suggest that the AhR is a viable target for modulation of multiple immune checkpoints.
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Carcinoma de Células Escamosas/inmunología , Inmunidad , Neoplasias de la Boca/inmunología , Receptores de Hidrocarburo de Aril/genética , Receptores de Hidrocarburo de Aril/metabolismo , Carcinoma de Células Escamosas de Cabeza y Cuello/inmunología , Animales , Antígenos CD , Antígenos Ly , Antígeno B7-H1 , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Linfocitos T CD4-Positivos , Antígeno CTLA-4 , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/terapia , Línea Celular Tumoral , Dioxinas , Proteínas de Punto de Control Inmunitario , Inmunoterapia/métodos , Activación de Linfocitos , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Ratones Noqueados , Ratones SCID , Neoplasias de la Boca/patología , Transducción de Señal , Carcinoma de Células Escamosas de Cabeza y Cuello/terapia , Linfocitos T/inmunología , Proteína del Gen 3 de Activación de LinfocitosRESUMEN
OBJECTIVE: MS is an autoimmune demyelinating disease of the CNS, which causes neurologic deficits in young adults and leads to progressive disability. The aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor, can drive anti-inflammatory functions in peripheral immune cells and also in CNS-resident cells. Laquinimod is a drug developed for the treatment of MS known to activate AHR, but the cellular targets of laquinimod are still not completely known. In this work, we analyzed the contribution of AHR activation in astrocytes to its beneficial effects in the experimental autoimmune encephalomyelitis (EAE) preclinical model of MS. METHODS: We used conditional knockout mice, in combination with genome-wide analysis of gene expression by RNA-seq and in vitro culture systems to investigate the effects of laquinimod on astrocytes. RESULTS: We found that AHR activation in astrocytes by laquinimod ameliorates EAE, a preclinical model of MS. Genome-wide RNA-seq transcriptional analyses detected anti-inflammatory effects of laquinimod in glial cells during EAE. Moreover, we established that the Delaq metabolite of laquinimod dampens proinflammatory mediator production while activating tissue-protective mechanisms in glia. CONCLUSIONS: Taken together, these findings suggest that AHR activation by clinically relevant AHR agonists may represent a novel therapeutic approach for the treatment of MS.
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Astrocitos/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Encefalomielitis Autoinmune Experimental/metabolismo , Encefalomielitis Autoinmune Experimental/prevención & control , Quinolonas/uso terapéutico , Receptores de Hidrocarburo de Aril/metabolismo , Animales , Astrocitos/efectos de los fármacos , Astrocitos/inmunología , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/inmunología , Encefalomielitis Autoinmune Experimental/inmunología , Femenino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Quinolonas/farmacología , Receptores de Hidrocarburo de Aril/inmunologíaRESUMEN
Mesenchymal stem cells (MSCs) are promising candidates for the development of cell-based drug delivery systems for autoimmune inflammatory diseases, such as multiple sclerosis (MS). Here, we investigated the effect of Ro-31-8425, an ATP-competitive kinase inhibitor, on the therapeutic properties of MSCs. Upon a simple pretreatment procedure, MSCs spontaneously took up and then gradually released significant amounts of Ro-31-8425. Ro-31-8425 (free or released by MSCs) suppressed the proliferation of CD4+ T cells in vitro following polyclonal and antigen-specific stimulation. Systemic administration of Ro-31-8425-loaded MSCs ameliorated the clinical course of experimental autoimmune encephalomyelitis (EAE), a murine model of MS, displaying a stronger suppressive effect on EAE than control MSCs or free Ro-31-8425. Ro-31-8425-MSC administration resulted in sustained levels of Ro-31-8425 in the serum of EAE mice, modulating immune cell trafficking and the autoimmune response during EAE. Collectively, these results identify MSC-based drug delivery as a potential therapeutic strategy for the treatment of autoimmune diseases. KEY MESSAGES: MSCs can spontaneously take up the ATP-competitive kinase inhibitor Ro-31-8425. Ro-31-8425-loaded MSCs gradually release Ro-31-8425 and exhibit sustained suppression of T cells. Ro-31-8425-loaded MSCs have more sustained serum levels of Ro-31-8425 than free Ro-31-8425. Ro-31-8425-loaded MSCs are more effective than MSCs and free Ro-31-8425 for EAE therapy.
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Sistemas de Liberación de Medicamentos/métodos , Encefalomielitis Autoinmune Experimental/tratamiento farmacológico , Inhibidores Enzimáticos/administración & dosificación , Indoles/administración & dosificación , Maleimidas/administración & dosificación , Células Madre Mesenquimatosas/efectos de los fármacos , Esclerosis Múltiple/tratamiento farmacológico , Trasplante Heterólogo/métodos , Animales , Proliferación Celular/efectos de los fármacos , Liberación de Fármacos , Encefalomielitis Autoinmune Experimental/sangre , Encefalomielitis Autoinmune Experimental/inmunología , Inhibidores Enzimáticos/sangre , Femenino , Humanos , Inmunidad/efectos de los fármacos , Indoles/sangre , Maleimidas/sangre , Células Madre Mesenquimatosas/metabolismo , Ratones , Ratones Endogámicos C57BL , Esclerosis Múltiple/sangre , Esclerosis Múltiple/inmunología , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología , Distribución Tisular , Resultado del TratamientoRESUMEN
Therapeutic approaches for the induction of immune tolerance remain an unmet clinical need for the treatment of autoimmune diseases, including multiple sclerosis (MS). Based on its role in the control of the immune response, the ligand-activated transcription factor aryl hydrocarbon receptor (AhR) is a candidate target for novel immunotherapies. Here, we report the development of AhR-activating nanoliposomes (NLPs) to induce antigen-specific tolerance. NLPs loaded with the AhR agonist ITE and a T cell epitope from myelin oligodendrocyte glycoprotein (MOG)35-55 induced tolerogenic dendritic cells and suppressed the development of experimental autoimmune encephalomyelitis (EAE), a preclinical model of MS, in preventive and therapeutic setups. EAE suppression was associated with the expansion of MOG35-55-specific FoxP3+ regulatory T cells (Treg cells) and type 1 regulatory T cells (Tr1 cells), concomitant with a reduction in central nervous system-infiltrating effector T cells (Teff cells). Notably, NLPs induced bystander suppression in the EAE model established in C57BL/6 × SJL F1 mice. Moreover, NLPs ameliorated chronic progressive EAE in nonobese diabetic mice, a model which resembles some aspects of secondary progressive MS. In summary, these studies describe a platform for the therapeutic induction of antigen-specific tolerance in autoimmune diseases.
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Encefalomielitis Autoinmune Experimental/tratamiento farmacológico , Tolerancia Inmunológica/efectos de los fármacos , Inmunosupresores/administración & dosificación , Esclerosis Múltiple/tratamiento farmacológico , Animales , Efecto Espectador/efectos de los fármacos , Efecto Espectador/inmunología , Combinación de Medicamentos , Encefalomielitis Autoinmune Experimental/inmunología , Epítopos de Linfocito T/inmunología , Femenino , Humanos , Inmunosupresores/inmunología , Indoles/administración & dosificación , Indoles/inmunología , Liposomas , Ratones , Esclerosis Múltiple/inmunología , Glicoproteína Mielina-Oligodendrócito/administración & dosificación , Glicoproteína Mielina-Oligodendrócito/inmunología , Nanopartículas/química , Fragmentos de Péptidos/administración & dosificación , Fragmentos de Péptidos/inmunología , Receptores de Hidrocarburo de Aril/agonistas , Receptores de Hidrocarburo de Aril/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/inmunología , Linfocitos T Reguladores/inmunología , Tiazoles/administración & dosificación , Tiazoles/inmunologíaRESUMEN
For decades, the aryl hydrocarbon receptor (AHR) was studied for its role in environmental chemical toxicity i.e., as a quirk of nature and a mediator of unintended consequences of human pollution. During that period, it was not certain that the AHR had a "normal" physiological function. However, the ongoing accumulation of data from an ever-expanding variety of studies on cancer, cancer immunity, autoimmunity, organ development, and other areas bears witness to a staggering array of AHR-controlled normal and pathological activities. The objective of this review is to discuss how the AHR has gone from a likely contributor to genotoxic environmental carcinogen-induced cancer to a master regulator of malignant cell progression and cancer aggression. Particular focus is placed on the association between AHR activity and poor cancer outcomes, feedback loops that control chronic AHR activity in cancer, and the role of chronically active AHR in driving cancer cell invasion, migration, cancer stem cell characteristics, and survival.
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Regulación Neoplásica de la Expresión Génica , Neoplasias/patología , Receptores de Hidrocarburo de Aril/metabolismo , Animales , Humanos , Neoplasias/metabolismo , Receptores de Hidrocarburo de Aril/genéticaRESUMEN
Genome-wide studies have identified genetic variants linked to neurologic diseases. Environmental factors also play important roles, but no methods are available for their comprehensive investigation. We developed an approach that combines genomic data, screens in a novel zebrafish model, computational modeling, perturbation studies, and multiple sclerosis (MS) patient samples to evaluate the effects of environmental exposure on CNS inflammation. We found that the herbicide linuron amplifies astrocyte pro-inflammatory activities by activating signaling via sigma receptor 1, inositol-requiring enzyme-1α (IRE1α), and X-box binding protein 1 (XBP1). Indeed, astrocyte-specific shRNA- and CRISPR/Cas9-driven gene inactivation combined with RNA-seq, ATAC-seq, ChIP-seq, and study of patient samples suggest that IRE1α-XBP1 signaling promotes CNS inflammation in experimental autoimmune encephalomyelitis (EAE) and, potentially, MS. In summary, these studies define environmental mechanisms that control astrocyte pathogenic activities and establish a multidisciplinary approach for the systematic investigation of the effects of environmental exposure in neurologic disorders.
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Astrocitos/metabolismo , Sistema Nervioso Central/metabolismo , Animales , Sistema Nervioso Central/inmunología , Biología Computacional/métodos , Encefalomielitis Autoinmune Experimental/inmunología , Endorribonucleasas/metabolismo , Ambiente , Exposición a Riesgos Ambientales/efectos adversos , Genoma , Genómica , Humanos , Inflamación/metabolismo , Linurona/efectos adversos , Ratones , Ratones Endogámicos C57BL , Esclerosis Múltiple/inmunología , Proteínas Serina-Treonina Quinasas/metabolismo , Receptores sigma/efectos de los fármacos , Receptores sigma/metabolismo , Transducción de Señal , Proteína 1 de Unión a la X-Box/metabolismo , Pez CebraRESUMEN
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor with important functions in the immune response and cancer. AHR agonists are provided by the environment, the commensal flora and the metabolism. Considering AHR physiological functions, AHR agonists may have important effects on health and disease. Thus, the quantification of AHR agonists in biological samples is of scientific and clinical relevance. We compared different reporter systems for the detection of AHR agonists in serum samples of Multiple Sclerosis (MS) patients, and assessed the influence of transfection methods and cell lines in a reporter-based in vitro assay. While the use of stable or transient reporters did not influence the measurement of AHR agonistic activity, the species of the cell lines used in these reporter assays had important effects on the reporter readings. These observations suggest that cell-specific factors influence AHR activation and signaling. Thus, based on the reported species selectivity of AHR ligands and the cell species-of-origin effects that we describe in this manuscript, the use of human cell lines is encouraged for the analysis of AHR agonistic activity in human samples. These findings may be relevant for the analysis of AHR agonists in human samples in the context of inflammatory and neoplastic disorders.
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Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/agonistas , Bioensayo/métodos , Genes Reporteros , Esclerosis Múltiple/sangre , Receptores de Hidrocarburo de Aril/agonistas , Adulto , Anciano , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/inmunología , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Contaminantes Ambientales/sangre , Femenino , Células HEK293 , Células Hep G2 , Humanos , Masculino , Ratones , Persona de Mediana Edad , Esclerosis Múltiple/inmunología , Receptores de Hidrocarburo de Aril/inmunología , Receptores de Hidrocarburo de Aril/metabolismo , TransfecciónRESUMEN
Unconjugated bilirubin (UCB), a product of heme oxidation, has known immunosuppressant properties but the molecular mechanisms, other than antioxidant effects, remain largely unexplored. We note that UCB modulates T helper type 17 (Th17) immune responses, in a manner dependent upon heightened expression of CD39 ectonucleotidase. UCB has protective effects in experimental colitis, where it enhances recovery after injury and preferentially boosts IL-10 production by colonic intraepithelial CD4+ cells. In vitro, UCB confers immunoregulatory properties on human control Th17 cells, as reflected by increased levels of FOXP3 and CD39 with heightened cellular suppressor ability. Upregulation of CD39 by Th17 cells is dependent upon ligation of the aryl hydrocarbon receptor (AHR) by UCB. Genetic deletion of CD39, as in Entpd1-/- mice, or dysfunction of AHR, as in Ahrd mice, abrogates these UCB salutary effects in experimental colitis. However, in inflammatory bowel disease (IBD) samples, UCB fails to confer substantive immunosuppressive properties upon Th17 cells, because of decreased AHR levels under the conditions tested in vitro. Immunosuppressive effects of UCB are mediated by AHR resulting in CD39 upregulation by Th17. Boosting downstream effects of AHR via UCB or enhancing CD39-mediated ectoenzymatic activity might provide therapeutic options to address development of Th17 dysfunction in IBD.
RESUMEN
Multiple sclerosis (MS) is an autoimmune inflammatory demyelinating disease of the CNS that causes disability in young adults as a result of the irreversible accumulation of neurological deficits. Although there are potent disease-modifying agents for its initial relapsing-remitting phase, these therapies show limited efficacy in secondary progressive MS (SPMS). Thus, there is an unmet clinical need for the identification of disease mechanisms and potential therapeutic approaches for SPMS. Here, we show that the sphingosine 1-phosphate receptor (S1PR) modulator fingolimod (FTY720) ameliorated chronic progressive experimental autoimmune encephalomyelitis in nonobese diabetic mice, an experimental model that resembles several aspects of SPMS, including neurodegeneration and disease progression driven by the innate immune response in the CNS. Indeed, S1PR modulation by FTY720 in murine and human astrocytes suppressed neurodegeneration-promoting mechanisms mediated by astrocytes, microglia, and CNS-infiltrating proinflammatory monocytes. Genome-wide studies showed that FTY720 suppresses transcriptional programs associated with the promotion of disease progression by astrocytes. The study of the molecular mechanisms controlling these transcriptional modules may open new avenues for the development of therapeutic strategies for progressive MS.
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Astrocitos/efectos de los fármacos , Inmunosupresores/farmacología , Esclerosis Múltiple Crónica Progresiva/tratamiento farmacológico , Receptores de Lisoesfingolípidos/metabolismo , Animales , Astrocitos/metabolismo , Línea Celular Tumoral , Progresión de la Enfermedad , Encefalomielitis Autoinmune Experimental/tratamiento farmacológico , Encefalomielitis Autoinmune Experimental/patología , Femenino , Clorhidrato de Fingolimod/farmacología , Clorhidrato de Fingolimod/uso terapéutico , Humanos , Inmunosupresores/uso terapéutico , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos NOD , Microglía/metabolismo , Monocitos/inmunología , Monocitos/metabolismo , Esclerosis Múltiple Crónica Progresiva/patología , Cultivo Primario de Células , Esfingosina/metabolismo , Receptores de Esfingosina-1-Fosfato , Transcriptoma/efectos de los fármacosRESUMEN
Existing therapies for inflammatory bowel disease that are based on broad suppression of inflammation result in variable clinical benefit and unwanted side effects. A potential therapeutic approach for promoting immune tolerance is the in vivo induction of regulatory T cells (Tregs). Here we report that activation of the aryl hydrocarbon receptor using the non-toxic agonist 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) induces human Tregs in vitro that suppress effector T cells through a mechanism mediated by CD39 and Granzyme B. We then developed a humanized murine system whereby human CD4+ T cells drive colitis upon exposure to 2,4,6-trinitrobenzenesulfonic acid and assessed ITE as a potential therapeutic. ITE administration ameliorated colitis in humanized mice with increased CD39, Granzyme B, and IL10-secreting human Tregs. These results develop an experimental model to investigate human CD4+ T responses in vivo and identify the non-toxic AHR agonist ITE as a potential therapy for promoting immune tolerance in the intestine.
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Colitis/inmunología , Colitis/metabolismo , Receptores de Hidrocarburo de Aril/metabolismo , Linfocitos T Reguladores/inmunología , Animales , Modelos Animales de Enfermedad , Factores de Transcripción Forkhead/metabolismo , Humanos , Ratones , Tiazoles , Factor de Crecimiento Transformador beta1/farmacología , Ácido TrinitrobencenosulfónicoRESUMEN
Type 1 diabetes (T1D) is a T cell-dependent autoimmune disease that is characterized by the destruction of insulin-producing ß cells in the pancreas. The administration to patients of ex vivo-differentiated FoxP3(+) regulatory T (Treg) cells or tolerogenic dendritic cells (DCs) that promote Treg cell differentiation is considered a potential therapy for T1D; however, cell-based therapies cannot be easily translated into clinical practice. We engineered nanoparticles (NPs) to deliver both a tolerogenic molecule, the aryl hydrocarbon receptor (AhR) ligand 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE), and the ß cell antigen proinsulin (NPITE+Ins) to induce a tolerogenic phenotype in DCs and promote Treg cell generation in vivo. NPITE+Ins administration to 8-week-old nonobese diabetic mice suppressed autoimmune diabetes. NPITE+Ins induced a tolerogenic phenotype in DCs, which was characterized by a decreased ability to activate inflammatory effector T cells and was concomitant with the increased differentiation of FoxP3(+) Treg cells. The induction of a tolerogenic phenotype in DCs by NPs was mediated by the AhR-dependent induction of Socs2, which resulted in inhibition of nuclear factor κB activation and proinflammatory cytokine production (properties of tolerogenic DCs). Together, these data suggest that NPs constitute a potential tool to reestablish tolerance in T1D and potentially other autoimmune disorders.
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Diabetes Mellitus Tipo 1/inmunología , Células Secretoras de Insulina/inmunología , Proteínas Supresoras de la Señalización de Citocinas/inmunología , Linfocitos T Reguladores/inmunología , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/agonistas , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/inmunología , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/patología , Humanos , Indoles/química , Indoles/farmacología , Células Secretoras de Insulina/patología , Ratones Endogámicos NOD , Nanopartículas/química , Nanopartículas/uso terapéutico , Receptores de Hidrocarburo de Aril/agonistas , Receptores de Hidrocarburo de Aril/genética , Receptores de Hidrocarburo de Aril/inmunología , Proteínas Supresoras de la Señalización de Citocinas/genética , Linfocitos T Reguladores/patología , Tiazoles/química , Tiazoles/farmacologíaRESUMEN
Astrocytes have important roles in the central nervous system (CNS) during health and disease. Through genome-wide analyses we detected a transcriptional response to type I interferons (IFN-Is) in astrocytes during experimental CNS autoimmunity and also in CNS lesions from patients with multiple sclerosis (MS). IFN-I signaling in astrocytes reduces inflammation and experimental autoimmune encephalomyelitis (EAE) disease scores via the ligand-activated transcription factor aryl hydrocarbon receptor (AHR) and the suppressor of cytokine signaling 2 (SOCS2). The anti-inflammatory effects of nasally administered interferon (IFN)-ß are partly mediated by AHR. Dietary tryptophan is metabolized by the gut microbiota into AHR agonists that have an effect on astrocytes to limit CNS inflammation. EAE scores were increased following ampicillin treatment during the recovery phase, and CNS inflammation was reduced in antibiotic-treated mice by supplementation with the tryptophan metabolites indole, indoxyl-3-sulfate, indole-3-propionic acid and indole-3-aldehyde, or the bacterial enzyme tryptophanase. In individuals with MS, the circulating levels of AHR agonists were decreased. These findings suggest that IFN-Is produced in the CNS function in combination with metabolites derived from dietary tryptophan by the gut flora to activate AHR signaling in astrocytes and suppress CNS inflammation.
Asunto(s)
Astrocitos/inmunología , Encefalomielitis Autoinmune Experimental/inmunología , Microbioma Gastrointestinal , Interferón Tipo I/inmunología , Esclerosis Múltiple/inmunología , Receptores de Hidrocarburo de Aril/inmunología , Linfocitos T/inmunología , Triptófano/metabolismo , Animales , Estudios de Casos y Controles , Proliferación Celular , Sistema Nervioso Central/inmunología , Sistema Nervioso Central/metabolismo , Quimiocina CCL2/metabolismo , Inmunoprecipitación de Cromatina , Cromatografía Líquida de Alta Presión , Encefalomielitis Autoinmune Experimental/metabolismo , Técnica del Anticuerpo Fluorescente , Perfilación de la Expresión Génica , Técnicas de Silenciamiento del Gen , Proteína Ácida Fibrilar de la Glía/metabolismo , Humanos , Immunoblotting , Indicán/orina , Indoles/metabolismo , Inflamación , Interferón beta/farmacología , Limosilactobacillus reuteri , Ratones , Ratones Noqueados , Esclerosis Múltiple/metabolismo , Proteínas de Resistencia a Mixovirus/metabolismo , Óxido Nítrico Sintasa de Tipo II/metabolismo , Imagen Óptica , Reacción en Cadena de la Polimerasa , Receptor de Interferón alfa y beta/genética , Receptores de Hidrocarburo de Aril/metabolismo , Factor de Transcripción STAT1/metabolismo , Serotonina , Proteínas Supresoras de la Señalización de Citocinas , Triptofanasa/metabolismoRESUMEN
The T cell receptor (TCR) controls the cellular adaptive immune response to antigens, but our understanding of TCR repertoire diversity and response to challenge is still incomplete. For example, TCR clones shared by different individuals with minimal alteration to germline gene sequences (public clones) are detectable in all vertebrates, but their significance is unknown. Although small in size, the zebrafish TCR repertoire is controlled by processes similar to those operating in mammals. Thus, we studied the zebrafish TCR repertoire and its response to stimulation with self and foreign antigens. We found that cross-reactive public TCRs dominate the T cell response, endowing a limited TCR repertoire with the ability to cope with diverse antigenic challenges. These features of vertebrate public TCRs might provide a mechanism for the rapid generation of protective T cell immunity, allowing a short temporal window for the development of more specific private T cell responses.