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1.
Cell ; 187(8): 2010-2028.e30, 2024 Apr 11.
Article En | MEDLINE | ID: mdl-38569542

Gut inflammation involves contributions from immune and non-immune cells, whose interactions are shaped by the spatial organization of the healthy gut and its remodeling during inflammation. The crosstalk between fibroblasts and immune cells is an important axis in this process, but our understanding has been challenged by incomplete cell-type definition and biogeography. To address this challenge, we used multiplexed error-robust fluorescence in situ hybridization (MERFISH) to profile the expression of 940 genes in 1.35 million cells imaged across the onset and recovery from a mouse colitis model. We identified diverse cell populations, charted their spatial organization, and revealed their polarization or recruitment in inflammation. We found a staged progression of inflammation-associated tissue neighborhoods defined, in part, by multiple inflammation-associated fibroblasts, with unique expression profiles, spatial localization, cell-cell interactions, and healthy fibroblast origins. Similar signatures in ulcerative colitis suggest conserved human processes. Broadly, we provide a framework for understanding inflammation-induced remodeling in the gut and other tissues.


Colitis, Ulcerative , Colitis , Animals , Humans , Mice , Colitis/metabolism , Colitis/pathology , Colitis, Ulcerative/metabolism , Colitis, Ulcerative/pathology , Fibroblasts/metabolism , Fibroblasts/pathology , In Situ Hybridization, Fluorescence/methods , Inflammation/metabolism , Inflammation/pathology , Cell Communication , Gastrointestinal Tract/metabolism , Gastrointestinal Tract/pathology
2.
Nature ; 627(8005): 865-872, 2024 Mar.
Article En | MEDLINE | ID: mdl-38509377

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.


Astrocytes , Encephalomyelitis, Autoimmune, Experimental , Epigenetic Memory , Multiple Sclerosis , Animals , Female , Humans , Male , Mice , Acetyl Coenzyme A/metabolism , Astrocytes/enzymology , Astrocytes/metabolism , Astrocytes/pathology , ATP Citrate (pro-S)-Lyase/metabolism , Chromatin/genetics , Chromatin/metabolism , Chromatin Assembly and Disassembly , Chromatin Immunoprecipitation Sequencing , CRISPR-Cas Systems , Encephalomyelitis, Autoimmune, Experimental/enzymology , Encephalomyelitis, Autoimmune, Experimental/genetics , Encephalomyelitis, Autoimmune, Experimental/metabolism , Encephalomyelitis, Autoimmune, Experimental/pathology , Inflammation/enzymology , Inflammation/genetics , Inflammation/metabolism , Inflammation/pathology , Multiple Sclerosis/enzymology , Multiple Sclerosis/genetics , Multiple Sclerosis/metabolism , Multiple Sclerosis/pathology , Single-Cell Gene Expression Analysis , Transposases/metabolism
3.
bioRxiv ; 2024 Jan 05.
Article En | MEDLINE | ID: mdl-38260616

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.

4.
Nature ; 620(7975): 881-889, 2023 Aug.
Article En | MEDLINE | ID: mdl-37558878

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.


Autoimmune Diseases , Central Nervous System , Dendritic Cells , Hypoxia-Inducible Factor 1, alpha Subunit , Lactic Acid , Humans , Autoimmune Diseases/immunology , Autoimmune Diseases/metabolism , Autoimmune Diseases/prevention & control , Autoimmunity , Central Nervous System/cytology , Central Nervous System/immunology , Central Nervous System/pathology , Dendritic Cells/immunology , Dendritic Cells/metabolism , Hypoxia-Inducible Factor 1, alpha Subunit/chemistry , Hypoxia-Inducible Factor 1, alpha Subunit/genetics , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Lactic Acid/metabolism , Probiotics/therapeutic use , Reactive Oxygen Species/metabolism , T-Lymphocytes/immunology , Feedback, Physiological , Lactase/genetics , Lactase/metabolism , Single-Cell Analysis
5.
bioRxiv ; 2023 May 09.
Article En | MEDLINE | ID: mdl-37214800

Gut inflammation involves contributions from immune and non-immune cells, whose interactions are shaped by the spatial organization of the healthy gut and its remodeling during inflammation. The crosstalk between fibroblasts and immune cells is an important axis in this process, but our understanding has been challenged by incomplete cell-type definition and biogeography. To address this challenge, we used MERFISH to profile the expression of 940 genes in 1.35 million cells imaged across the onset and recovery from a mouse colitis model. We identified diverse cell populations; charted their spatial organization; and revealed their polarization or recruitment in inflammation. We found a staged progression of inflammation-associated tissue neighborhoods defined, in part, by multiple inflammation-associated fibroblasts, with unique expression profiles, spatial localization, cell-cell interactions, and healthy fibroblast origins. Similar signatures in ulcerative colitis suggest conserved human processes. Broadly, we provide a framework for understanding inflammation-induced remodeling in the gut and other tissues.

6.
Nutrients ; 15(6)2023 Mar 15.
Article En | MEDLINE | ID: mdl-36986134

Obesity is a chronic, relapsing, and multifactorial disease characterized by excessive accumulation of adipose tissue (AT), and is associated with inflammation mainly in white adipose tissue (WAT) and an increase in pro-inflammatory M1 macrophages and other immune cells. This milieu favors the secretion of cytokines and adipokines, contributing to AT dysfunction (ATD) and metabolic dysregulation. Numerous articles link specific changes in the gut microbiota (GM) to the development of obesity and its associated disorders, highlighting the role of diet, particularly fatty acid composition, in modulating the taxonomic profile. The aim of this study was to analyze the effect of a medium-fat-content diet (11%) supplemented with omega-3 fatty acids (D2) on the development of obesity, and on the composition of the GM compared with a control diet with a low fat content (4%) (D1) over a 6-month period. The effect of omega-3 supplementation on metabolic parameters and the modulation of the immunological microenvironment in visceral adipose tissue (VAT) was also evaluated. Six-weeks-old mice were adapted for two weeks and then divided into two groups of eight mice each: a control group D1 and the experimental group D2. Their body weight was recorded at 0, 4, 12, and 24 weeks post-differential feeding and stool samples were simultaneously collected to determine the GM composition. Four mice per group were sacrificed on week 24 and their VAT was taken to determine the immune cells phenotypes (M1 or M2 macrophages) and inflammatory biomarkers. Blood samples were used to determine the glucose, total LDL and HDL cholesterol LDL, HDL and total cholesterol, triglycerides, liver enzymes, leptin, and adiponectin. Body weight measurement showed significant differences at 4 (D1 = 32.0 ± 2.0 g vs. D2 = 36.2 ± 4.5 g, p-value = 0.0339), 12 (D1 = 35.7 ± 4.1 g vs. D2 = 45.3 ± 4.9 g, p-value = 0.0009), and 24 weeks (D1 = 37.5 ± 4.7 g vs. D2 = 47.9 ± 4.7, p-value = 0.0009). The effects of diet on the GM composition changed over time: in the first 12 weeks, α and ß diversity differed considerably according to diet and weight increase. In contrast, at 24 weeks, the composition, although still different between groups D1 and D2, showed changes compared with previous samples, suggesting the beneficial effects of omega-3 fatty acids in D2. With regard to metabolic analysis, the results did not reveal relevant changes in biomarkers in accordance with AT studies showing an anti-inflammatory environment and conserved structure and function, which is in contrast to reported findings for pathogenic obesity. In conclusion, the results suggest that the constant and sustained administration of omega-3 fatty acids induced specific changes in GM composition, mainly with increases in Lactobacillus and Ligilactobacillus species, which, in turn, modulated the immune metabolic response of AT in this mouse model of obesity.


Fatty Acids, Omega-3 , Gastrointestinal Microbiome , Animals , Mice , Intra-Abdominal Fat/metabolism , Obesity/metabolism , Adipose Tissue/metabolism , Body Weight , Fatty Acids, Omega-3/pharmacology , Fatty Acids, Omega-3/metabolism , Dietary Supplements , Biomarkers/metabolism , Diet, High-Fat/adverse effects , Mice, Inbred C57BL
7.
bioRxiv ; 2023 Mar 21.
Article En | MEDLINE | ID: mdl-36993446

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.

8.
Science ; 379(6636): 1023-1030, 2023 03 10.
Article En | MEDLINE | ID: mdl-36893254

Cell-cell interactions in the central nervous system play important roles in neurologic diseases. However, little is known about the specific molecular pathways involved, and methods for their systematic identification are limited. Here, we developed a forward genetic screening platform that combines CRISPR-Cas9 perturbations, cell coculture in picoliter droplets, and microfluidic-based fluorescence-activated droplet sorting to identify mechanisms of cell-cell communication. We used SPEAC-seq (systematic perturbation of encapsulated associated cells followed by sequencing), in combination with in vivo genetic perturbations, to identify microglia-produced amphiregulin as a suppressor of disease-promoting astrocyte responses in multiple sclerosis preclinical models and clinical samples. Thus, SPEAC-seq enables the high-throughput systematic identification of cell-cell communication mechanisms.


Amphiregulin , Astrocytes , Autocrine Communication , Genetic Testing , Microfluidic Analytical Techniques , Microglia , Astrocytes/physiology , Genetic Testing/methods , High-Throughput Screening Assays , Microfluidic Analytical Techniques/methods , Microglia/physiology , Amphiregulin/genetics , Autocrine Communication/genetics , Gene Expression , Humans
9.
Nature ; 614(7947): 326-333, 2023 02.
Article En | MEDLINE | ID: mdl-36599367

Multiple sclerosis is a chronic inflammatory disease of the central nervous system1. Astrocytes are heterogeneous glial cells that are resident in the central nervous system and participate in the pathogenesis of multiple sclerosis and its model experimental autoimmune encephalomyelitis2,3. However, few unique surface markers are available for the isolation of astrocyte subsets, preventing their analysis and the identification of candidate therapeutic targets; these limitations are further amplified by the rarity of pathogenic astrocytes. Here, to address these challenges, we developed focused interrogation of cells by nucleic acid detection and sequencing (FIND-seq), a high-throughput microfluidic cytometry method that combines encapsulation of cells in droplets, PCR-based detection of target nucleic acids and droplet sorting to enable in-depth transcriptomic analyses of cells of interest at single-cell resolution. We applied FIND-seq to study the regulation of astrocytes characterized by the splicing-driven activation of the transcription factor XBP1, which promotes disease pathology in multiple sclerosis and experimental autoimmune encephalomyelitis4. Using FIND-seq in combination with conditional-knockout mice, in vivo CRISPR-Cas9-driven genetic perturbation studies and bulk and single-cell RNA sequencing analyses of samples from mouse experimental autoimmune encephalomyelitis and humans with multiple sclerosis, we identified a new role for the nuclear receptor NR3C2 and its corepressor NCOR2 in limiting XBP1-driven pathogenic astrocyte responses. In summary, we used FIND-seq to identify a therapeutically targetable mechanism that limits XBP1-driven pathogenic astrocyte responses. FIND-seq enables the investigation of previously inaccessible cells, including rare cell subsets defined by unique gene expression signatures or other nucleic acid markers.


Astrocytes , Encephalomyelitis, Autoimmune, Experimental , Microfluidics , Multiple Sclerosis , Nucleic Acids , Single-Cell Gene Expression Analysis , Animals , Humans , Mice , Astrocytes/metabolism , Astrocytes/pathology , Gene Expression Regulation , Mice, Knockout , Multiple Sclerosis/pathology , Microfluidics/methods , Single-Cell Gene Expression Analysis/methods , Nucleic Acids/analysis , Gene Editing
10.
Nature ; 611(7937): 801-809, 2022 11.
Article En | MEDLINE | ID: mdl-36266581

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.


Environment , Herbicides , Inflammation , Inflammatory Bowel Diseases , Intestines , Animals , Mice , Inflammation/chemically induced , Inflammation/etiology , Inflammation/immunology , Inflammation/pathology , Inflammatory Bowel Diseases/chemically induced , Inflammatory Bowel Diseases/etiology , Inflammatory Bowel Diseases/immunology , Inflammatory Bowel Diseases/pathology , Zebrafish , Machine Learning , Databases, Factual , Disease Models, Animal , Intestines/drug effects , Intestines/immunology , Intestines/metabolism , Intestines/pathology , NF-kappa B , CCAAT-Enhancer-Binding Protein-beta , Receptors, Aryl Hydrocarbon , T-Lymphocytes/drug effects , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Dendritic Cells/drug effects , Dendritic Cells/immunology , Dendritic Cells/metabolism , Herbicides/adverse effects
11.
J Exp Med ; 218(9)2021 09 06.
Article En | MEDLINE | ID: mdl-34292315

Astrocytes are abundant glial cells in the central nervous system (CNS) that control multiple aspects of health and disease. Through their interactions with components of the blood-brain barrier (BBB), astrocytes not only regulate BBB function, they also sense molecules produced by peripheral immune cells, including cytokines. Here, we review the interactions between immune cells and astrocytes and their roles in health and neurological diseases, with a special focus on multiple sclerosis (MS). We highlight known pathways that participate in astrocyte crosstalk with microglia, NK cells, T cells, and other cell types; their contribution to the pathogenesis of neurological diseases; and their potential value as therapeutic targets.


Astrocytes/physiology , Killer Cells, Natural/physiology , Microglia/cytology , Multiple Sclerosis/immunology , Astrocytes/cytology , Blood-Brain Barrier , Cell Communication , Humans , Killer Cells, Natural/immunology , Microglia/metabolism , Multiple Sclerosis/pathology , T-Lymphocytes/immunology , T-Lymphocytes/metabolism
12.
Nat Med ; 27(7): 1212-1222, 2021 07.
Article En | MEDLINE | ID: mdl-34183837

Inflammatory bowel disease (IBD) is a complex chronic inflammatory disorder of the gastrointestinal tract. Extracellular adenosine triphosphate (eATP) produced by the commensal microbiota and host cells activates purinergic signaling, promoting intestinal inflammation and pathology. Based on the role of eATP in intestinal inflammation, we developed yeast-based engineered probiotics that express a human P2Y2 purinergic receptor with up to a 1,000-fold increase in eATP sensitivity. We linked the activation of this engineered P2Y2 receptor to the secretion of the ATP-degrading enzyme apyrase, thus creating engineered yeast probiotics capable of sensing a pro-inflammatory molecule and generating a proportional self-regulated response aimed at its neutralization. These self-tunable yeast probiotics suppressed intestinal inflammation in mouse models of IBD, reducing intestinal fibrosis and dysbiosis with an efficacy similar to or higher than that of standard-of-care therapies usually associated with notable adverse events. By combining directed evolution and synthetic gene circuits, we developed a unique self-modulatory platform for the treatment of IBD and potentially other inflammation-driven pathologies.


Adenosine Triphosphate/metabolism , Apyrase/metabolism , Inflammatory Bowel Diseases/therapy , Probiotics/therapeutic use , Receptors, Purinergic P2Y2/metabolism , Saccharomyces cerevisiae/metabolism , Animals , Apyrase/genetics , CRISPR-Cas Systems/genetics , Disease Models, Animal , Dysbiosis/prevention & control , Female , Fibrosis/prevention & control , Gastrointestinal Microbiome/physiology , Gastrointestinal Tract/microbiology , Gastrointestinal Tract/pathology , Humans , Inflammatory Bowel Diseases/pathology , Male , Mice , Mice, Inbred C57BL , Receptors, Purinergic P2Y2/genetics , Saccharomyces cerevisiae/genetics
13.
Eur J Pharm Sci ; 164: 105912, 2021 Sep 01.
Article En | MEDLINE | ID: mdl-34133985

Benznidazole (BZ) is a first-line drug for the treatment of Chagas disease; however, it presents several disadvantages that could hamper its therapeutic success. Multiparticulate drug delivery systems (MDDS) are promising carriers to improve the performance of drugs. We developed BZ-loaded MDDS intended for improving Chagas disease therapy. To assess their efficacy and safety, Trypanosoma (T) cruzi infected BALB/c mice were orally treated with free BZ or BZ-MDDS at different regimens (doses of 50 and 100 mg/kg/day, administered daily or at 2- or 5-days intervals) and compared with infected non-treated (INT) mice. At 100 mg/kg/day, independent of the administration regimen, both treatments were able to override the parasitemia, and at 50 mg/kg/day significantly reduced it compared to INT mice. BZ-MDDS at a dose of 100 mg/kg/day administered every 5 days (BZ-MDDS 100-13d) induced the lowest cardiac parasite load, indicating an improved efficacy with lower total dose of BZ when loaded to the MDDS. Reactive oxygen species produced by leukocytes were higher in INT and mice treated with BZ at 50 mg/kg/day compared to 100 mg/kg/day, likely because of persistent infection. BZ-MDDS treatments markedly reduced heart and liver injury markers compared to INT mice and those receiving the standard treatment. Therefore, BZ-MDDS exhibited enhanced activity against T. cruzi infection even at lower doses and reduced administration frequency compared to free BZ while increasing the treatment safety. They likely avoid undesired side effects of BZ by keeping a sustained concentration, avoiding plasmatic drug peaks. BZ-MDDS evidenced significant improvements in experimental Chagas disease treatment and can be considered as a potential improved therapeutic alternative against this illness.


Chagas Disease , Nitroimidazoles , Trypanocidal Agents , Trypanosoma cruzi , Animals , Chagas Disease/drug therapy , Mice , Mice, Inbred BALB C , Parasitemia/drug therapy
14.
Science ; 372(6540)2021 04 23.
Article En | MEDLINE | ID: mdl-33888612

Cell-cell interactions control the physiology and pathology of the central nervous system (CNS). To study astrocyte cell interactions in vivo, we developed rabies barcode interaction detection followed by sequencing (RABID-seq), which combines barcoded viral tracing and single-cell RNA sequencing (scRNA-seq). Using RABID-seq, we identified axon guidance molecules as candidate mediators of microglia-astrocyte interactions that promote CNS pathology in experimental autoimmune encephalomyelitis (EAE) and, potentially, multiple sclerosis (MS). In vivo cell-specific genetic perturbation EAE studies, in vitro systems, and the analysis of MS scRNA-seq datasets and CNS tissue established that Sema4D and Ephrin-B3 expressed in microglia control astrocyte responses via PlexinB2 and EphB3, respectively. Furthermore, a CNS-penetrant EphB3 inhibitor suppressed astrocyte and microglia proinflammatory responses and ameliorated EAE. In summary, RABID-seq identified microglia-astrocyte interactions and candidate therapeutic targets.


Astrocytes/physiology , Cell Communication , Central Nervous System/pathology , Encephalomyelitis, Autoimmune, Experimental/physiopathology , Microglia/physiology , Multiple Sclerosis/physiopathology , Single-Cell Analysis , Animals , Antigens, CD/metabolism , Brain/pathology , Brain/physiopathology , Central Nervous System/physiopathology , Encephalomyelitis, Autoimmune, Experimental/pathology , Ephrin-B3/metabolism , Herpesvirus 1, Suid/genetics , Humans , Male , Mice , Mice, Inbred C57BL , Mitochondria/metabolism , Multiple Sclerosis/pathology , NF-kappa B/metabolism , Nerve Tissue Proteins/metabolism , RNA-Seq , Reactive Oxygen Species/metabolism , Receptor, EphB3/antagonists & inhibitors , Receptor, EphB3/metabolism , Receptors, Cell Surface/metabolism , Semaphorins/metabolism , Signal Transduction , T-Lymphocytes/physiology , TOR Serine-Threonine Kinases/metabolism
15.
Nature ; 590(7846): 473-479, 2021 02.
Article En | MEDLINE | ID: mdl-33408417

Astrocytes are glial cells that are abundant in the central nervous system (CNS) and that have important homeostatic and disease-promoting functions1. However, little is known about the homeostatic anti-inflammatory activities of astrocytes and their regulation. Here, using high-throughput flow cytometry screening, single-cell RNA sequencing and CRISPR-Cas9-based cell-specific in vivo genetic perturbations in mice, we identify a subset of astrocytes that expresses the lysosomal protein LAMP12 and the death receptor ligand TRAIL3. LAMP1+TRAIL+ astrocytes limit inflammation in the CNS by inducing T cell apoptosis through TRAIL-DR5 signalling. In homeostatic conditions, the expression of TRAIL in astrocytes is driven by interferon-γ (IFNγ) produced by meningeal natural killer (NK) cells, in which IFNγ expression is modulated by the gut microbiome. TRAIL expression in astrocytes is repressed by molecules produced by T cells and microglia in the context of inflammation. Altogether, we show that LAMP1+TRAIL+ astrocytes limit CNS inflammation by inducing T cell apoptosis, and that this astrocyte subset is maintained by meningeal IFNγ+ NK cells that are licensed by the microbiome.


Astrocytes/immunology , Gastrointestinal Microbiome/immunology , Inflammation/prevention & control , Interferon-gamma/immunology , Killer Cells, Natural/immunology , Lysosomal Membrane Proteins/metabolism , TNF-Related Apoptosis-Inducing Ligand/metabolism , Animals , Apoptosis , Astrocytes/metabolism , Biomarkers , Central Nervous System/immunology , Encephalomyelitis, Autoimmune, Experimental/immunology , Encephalomyelitis, Autoimmune, Experimental/prevention & control , Female , Homeostasis , Humans , Inflammation/immunology , Meninges/cytology , Meninges/immunology , Mice , Mice, Inbred C57BL , T-Lymphocytes/cytology , T-Lymphocytes/immunology
16.
J Leukoc Biol ; 109(1): 233-244, 2021 01.
Article En | MEDLINE | ID: mdl-32450615

Chronic Chagas cardiomyopathy is the main infectious myocarditis worldwide. Almost 30% of Trypanosoma cruzi infected individuals develop slow and progressive myocarditis that leads to ventricular dilation and heart failure. Heart transplantation is an established, valuable therapeutic option for end-stage Chagas disease patients. Although the pathophysiology of Chagas disease has been addressed for decades by numerous groups, the cardiac immunologic mechanisms involved in the progression of clinical manifestation are still unknown. Growing evidence demonstrates that hypoxia-inducible factor (HIF)-1α plays indispensable roles in driving immune response by triggering the expression of CD73 purinergic ecto-enzyme. Purinergic system controls the duration and magnitude of purine signals directed to modulate immune cells through the conversion of extracellular ATP (microbicide/proinflammatory) to the immunoregulatory metabolite adenosine. In the present work, we described that infiltrating leukocytes within cardiac explants from patients with end-stage Chagas cardiomyopathy up-regulated HIF-1α and CD73 expression. Moreover, the number of HIF-1α+ and CD73+ leukocytes positively correlated with the myocarditis severity and the local parasite load. Furthermore, we demonstrated a direct relationship between tissue parasite persistence and the influx of immune cells to the infected hearts, which ultimately determine the severity of the myocarditis. These findings provide evidence that CD73-dependent regulatory pathways are locally triggered in the myocardium of patients with end-stage Chagas disease.


5'-Nucleotidase/biosynthesis , Chagas Cardiomyopathy/immunology , Hypoxia-Inducible Factor 1, alpha Subunit/biosynthesis , Leukocytes/immunology , Myocarditis/immunology , Adult , Chagas Cardiomyopathy/complications , Chagas Cardiomyopathy/pathology , Female , GPI-Linked Proteins/biosynthesis , Humans , Leukocytes/metabolism , Male , Middle Aged , Myocarditis/etiology , Myocarditis/pathology , Myocardium/immunology , Myocardium/pathology
18.
Article En | MEDLINE | ID: mdl-32714876

Galectins are animal lectins with high affinity for ß-galactosides that drive the immune response through several mechanisms. In particular, the role of galectin-8 (Gal-8) in inflammation remains controversial. To analyze its role in a chronic inflammatory environment, we studied a murine model of Trypanosoma cruzi infection. The parasite induces alterations that lead to the development of chronic cardiomyopathy and/or megaviscera in 30% of infected patients. The strong cardiac inflammation along with fibrosis leads to cardiomyopathy, the most relevant consequence of Chagas disease. By analyzing infected wild-type (iWT) and Gal-8-deficient (iGal-8KO) C57BL/6J mice at the chronic phase (4-5 months post-infection), we observed that the lack of Gal-8 favored a generalized increase in heart, skeletal muscle, and liver inflammation associated with extensive fibrosis, unrelated to tissue parasite loads. Remarkably, increased frequencies of neutrophils and macrophages were observed within cardiac iGal-8KO tissue by flow cytometry. It has been proposed that Gal-8, as well as other galectins, induces the surface expression of the inner molecule phosphatidylserine on activated neutrophils, which serves as an "eat-me" signal for macrophages, favoring viable neutrophil removal and tissue injury protection, a process known as preaparesis. We found that the increased neutrophil rates could be associated with the absence of Gal-8-dependent preaparesis, leading to a diminished neutrophil-clearing capability in macrophages. Thus, our results support that Gal-8 exerts an anti-inflammatory role in chronic T. cruzi infection.


Chagas Disease , Galectins/immunology , Trypanosoma cruzi , Animals , Anti-Inflammatory Agents , Disease Models, Animal , Mice , Mice, Inbred C57BL , Mice, Knockout
19.
Nat Neurosci ; 23(8): 939-951, 2020 08.
Article En | MEDLINE | ID: mdl-32690969

Zika virus (ZIKV) is a flavivirus linked to multiple birth defects including microcephaly, known as congenital ZIKV syndrome. The identification of host factors involved in ZIKV replication may guide efficacious therapeutic interventions. In genome-wide transcriptional studies, we found that ZIKV infection triggers aryl hydrocarbon receptor (AHR) activation. Specifically, ZIKV infection induces kynurenine (Kyn) production, which activates AHR, limiting the production of type I interferons (IFN-I) involved in antiviral immunity. Moreover, ZIKV-triggered AHR activation suppresses intrinsic immunity driven by the promyelocytic leukemia (PML) protein, which limits ZIKV replication. AHR inhibition suppressed the replication of multiple ZIKV strains in vitro and also suppressed replication of the related flavivirus dengue. Finally, AHR inhibition with a nanoparticle-delivered AHR antagonist or an inhibitor developed for human use limited ZIKV replication and ameliorated newborn microcephaly in a murine model. In summary, we identified AHR as a host factor for ZIKV replication and PML protein as a driver of anti-ZIKV intrinsic immunity.


Receptors, Aryl Hydrocarbon/metabolism , Virus Replication , Zika Virus/metabolism , Animals , Chlorocebus aethiops , Hep G2 Cells , Humans , Vero Cells , Zika Virus Infection/metabolism
20.
Nature ; 578(7796): 593-599, 2020 02.
Article En | MEDLINE | ID: mdl-32051591

Multiple sclerosis is a chronic inflammatory disease of the CNS1. Astrocytes contribute to the pathogenesis of multiple sclerosis2, but little is known about the heterogeneity of astrocytes and its regulation. Here we report the analysis of astrocytes in multiple sclerosis and its preclinical model experimental autoimmune encephalomyelitis (EAE) by single-cell RNA sequencing in combination with cell-specific Ribotag RNA profiling, assay for transposase-accessible chromatin with sequencing (ATAC-seq), chromatin immunoprecipitation with sequencing (ChIP-seq), genome-wide analysis of DNA methylation and in vivo CRISPR-Cas9-based genetic perturbations. We identified astrocytes in EAE and multiple sclerosis that were characterized by decreased expression of NRF2 and increased expression of MAFG, which cooperates with MAT2α to promote DNA methylation and represses antioxidant and anti-inflammatory transcriptional programs. Granulocyte-macrophage colony-stimulating factor (GM-CSF) signalling in astrocytes drives the expression of MAFG and MAT2α and pro-inflammatory transcriptional modules, contributing to CNS pathology in EAE and, potentially, multiple sclerosis. Our results identify candidate therapeutic targets in multiple sclerosis.


Astrocytes/pathology , Central Nervous System/pathology , Inflammation/pathology , MafG Transcription Factor/genetics , Repressor Proteins/genetics , Animals , Antioxidants/metabolism , Astrocytes/metabolism , Central Nervous System/metabolism , DNA Methylation , Encephalomyelitis, Autoimmune, Experimental/genetics , Encephalomyelitis, Autoimmune, Experimental/pathology , Female , Granulocyte-Macrophage Colony-Stimulating Factor/metabolism , Humans , Inflammation/genetics , Male , Methionine Adenosyltransferase/genetics , Mice , Multiple Sclerosis/genetics , Multiple Sclerosis/pathology , NF-E2-Related Factor 2/genetics , Sequence Analysis, RNA , Signal Transduction , Transcription, Genetic
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