RESUMO
Although enteric helminth infections modulate immunity to mucosal pathogens, their effects on systemic microbes remain less established. Here, we observe increased mortality in mice coinfected with the enteric helminth Heligmosomoides polygyrus bakeri (Hpb) and West Nile virus (WNV). This enhanced susceptibility is associated with altered gut morphology and transit, translocation of commensal bacteria, impaired WNV-specific T cell responses, and increased virus infection in the gastrointestinal tract and central nervous system. These outcomes were due to type 2 immune skewing, because coinfection in Stat6-/- mice rescues mortality, treatment of helminth-free WNV-infected mice with interleukin (IL)-4 mirrors coinfection, and IL-4 receptor signaling in intestinal epithelial cells mediates the susceptibility phenotypes. Moreover, tuft cell-deficient mice show improved outcomes with coinfection, whereas treatment of helminth-free mice with tuft cell-derived cytokine IL-25 or ligand succinate worsens WNV disease. Thus, helminth activation of tuft cell-IL-4-receptor circuits in the gut exacerbates infection and disease of a neurotropic flavivirus.
Assuntos
Coinfecção , Nematospiroides dubius/fisiologia , Transdução de Sinais , Infecções por Strongylida/patologia , Vírus do Nilo Ocidental/fisiologia , Animais , Linfócitos T CD8-Positivos/imunologia , Modelos Animais de Doenças , Suscetibilidade a Doenças , Mucosa Intestinal/parasitologia , Mucosa Intestinal/virologia , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/parasitologia , Neurônios/virologia , Receptores de Interleucina-4/metabolismo , Fator de Transcrição STAT6/genética , Índice de Gravidade de Doença , Infecções por Strongylida/parasitologiaRESUMO
Chikungunya virus (CHIKV), an emerging alphavirus, has infected millions of people. However, the factors modulating disease outcome remain poorly understood. Here, we show in germ-free mice or in oral antibiotic-treated conventionally housed mice with depleted intestinal microbiomes that greater CHIKV infection and spread occurs within 1 day of virus inoculation. Alteration of the microbiome alters TLR7-MyD88 signaling in plasmacytoid dendritic cells (pDCs) and blunts systemic production of type I interferon (IFN). Consequently, circulating monocytes express fewer IFN-stimulated genes and become permissive for CHIKV infection. Reconstitution with a single bacterial species, Clostridium scindens, or its derived metabolite, the secondary bile acid deoxycholic acid, can restore pDC- and MyD88-dependent type I IFN responses to restrict systemic CHIKV infection and transmission back to vector mosquitoes. Thus, symbiotic intestinal bacteria modulate antiviral immunity and levels of circulating alphaviruses within hours of infection through a bile acid-pDC-IFN signaling axis, which affects viremia, dissemination, and potentially transmission.
Assuntos
Ácidos e Sais Biliares/metabolismo , Febre de Chikungunya/patologia , Microbioma Gastrointestinal , Interferon Tipo I/metabolismo , Animais , Antibacterianos/farmacologia , Febre de Chikungunya/imunologia , Febre de Chikungunya/veterinária , Vírus Chikungunya/genética , Vírus Chikungunya/isolamento & purificação , Clostridiales/fisiologia , Células Dendríticas/citologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Transplante de Microbiota Fecal , Microbioma Gastrointestinal/efeitos dos fármacos , Masculino , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Monócitos/citologia , Monócitos/imunologia , Monócitos/metabolismo , Fator 88 de Diferenciação Mieloide/deficiência , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , RNA Viral/sangue , Fator de Transcrição STAT1/deficiência , Transdução de Sinais , Receptor 7 Toll-Like/metabolismoRESUMO
The colonic epithelium can undergo multiple rounds of damage and repair, often in response to excessive inflammation. The responsive stem cell that mediates this process is unclear, in part because of a lack of in vitro models that recapitulate key epithelial changes that occur in vivo during damage and repair. Here, we identify a Hopx+ colitis-associated regenerative stem cell (CARSC) population that functionally contributes to mucosal repair in mouse models of colitis. Hopx+ CARSCs, enriched for fetal-like markers, transiently arose from hypertrophic crypts known to facilitate regeneration. Importantly, we established a long-term, self-organizing two-dimensional (2D) epithelial monolayer system to model the regenerative properties and responses of Hopx+ CARSCs. This system can reenact the "homeostasis-injury-regeneration" cycles of epithelial alterations that occur in vivo. Using this system, we found that hypoxia and endoplasmic reticulum stress, insults commonly present in inflammatory bowel diseases, mediated the cyclic switch of cellular status in this process.
Assuntos
Técnicas de Cultura de Células/métodos , Colo/patologia , Células-Tronco/patologia , Células 3T3 , Animais , Colite/patologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/patologia , Proteínas de Homeodomínio/metabolismo , Camundongos , Modelos Biológicos , Oxigênio/farmacologia , Regeneração/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacosRESUMO
Although chronic gastrointestinal dysmotility syndromes are a common worldwide health problem, underlying causes for these disorders are poorly understood. We show that flavivirus infection of enteric neurons leads to acute neuronal injury and cell death, inflammation, bowel dilation, and slowing of intestinal transit in mice. Flavivirus-primed CD8+ T cells promote these phenotypes, as their absence diminished enteric neuron injury and intestinal transit delays, and their adoptive transfer reestablished dysmotility after flavivirus infection. Remarkably, mice surviving acute flavivirus infection developed chronic gastrointestinal dysmotility that was exacerbated by immunization with an unrelated alphavirus vaccine or exposure to a non-infectious inflammatory stimulus. This model of chronic post-infectious gastrointestinal dysmotility in mice suggests that viral infections with tropism for enteric neurons and the ensuing immune response might contribute to the development of bowel motility disorders in humans. These results suggest an opportunity for unique approaches to diagnosis and therapy of gastrointestinal dysmotility syndromes.
Assuntos
Infecções por Flavivirus/patologia , Flavivirus/patogenicidade , Motilidade Gastrointestinal , Intestinos/patologia , Animais , Linfócitos T CD8-Positivos/imunologia , Flavivirus/genética , Infecções por Flavivirus/imunologia , Infecções por Flavivirus/virologia , Intestinos/virologia , Leucócitos/citologia , Leucócitos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/patologia , Neurônios/ultraestrutura , RNA Viral/isolamento & purificação , RNA Viral/metabolismo , SíndromeRESUMO
Most tissue-resident macrophage populations develop during embryogenesis, self-renew in the steady state and expand during type 2 immunity. Whether shared mechanisms regulate the proliferation of macrophages in homeostasis and disease is unclear. Here we found that the transcription factor Bhlhe40 was required in a cell-intrinsic manner for the self-renewal and maintenance of large peritoneal macrophages (LPMs), but not that of other tissue-resident macrophages. Bhlhe40 was necessary for the proliferation, but not the polarization, of LPMs in response to the cytokine IL-4. During infection with the helminth Heligmosomoides polygyrus bakeri, Bhlhe40 was required for cell cycling of LPMs. Bhlhe40 repressed the expression of genes encoding the transcription factors c-Maf and Mafb and directly promoted expression of transcripts encoding cell cycle-related proteins to enable the proliferation of LPMs. In LPMs, Bhlhe40 bound to genomic sites co-bound by the macrophage lineage-determining factor PU.1 and to unique sites, including Maf and loci encoding cell-cycle-related proteins. Our findings demonstrate a tissue-specific control mechanism that regulates the proliferation of resident macrophages in homeostasis and type 2 immunity.
Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Proteínas de Homeodomínio/genética , Homeostase/genética , Homeostase/imunologia , Imunidade/genética , Macrófagos/imunologia , Macrófagos/metabolismo , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Biomarcadores , Ciclo Celular/genética , Ciclo Celular/imunologia , Proliferação de Células , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Técnicas de Inativação de Genes , Infecções por Helicobacter/genética , Infecções por Helicobacter/imunologia , Helicobacter pylori/imunologia , Proteínas de Homeodomínio/metabolismo , Imunofenotipagem , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/metabolismo , Camundongos , Camundongos Transgênicos , Monócitos/imunologia , Monócitos/metabolismo , Especificidade de Órgãos/genética , Especificidade de Órgãos/imunologia , TranscriptomaRESUMO
In the mammalian intestine, crypts of Leiberkühn house intestinal epithelial stem/progenitor cells at their base. The mammalian intestine also harbors a diverse array of microbial metabolite compounds that potentially modulate stem/progenitor cell activity. Unbiased screening identified butyrate, a prominent bacterial metabolite, as a potent inhibitor of intestinal stem/progenitor proliferation at physiologic concentrations. During homeostasis, differentiated colonocytes metabolized butyrate likely preventing it from reaching proliferating epithelial stem/progenitor cells within the crypt. Exposure of stem/progenitor cells in vivo to butyrate through either mucosal injury or application to a naturally crypt-less host organism led to inhibition of proliferation and delayed wound repair. The mechanism of butyrate action depended on the transcription factor Foxo3. Our findings indicate that mammalian crypt architecture protects stem/progenitor cell proliferation in part through a metabolic barrier formed by differentiated colonocytes that consume butyrate and stimulate future studies on the interplay of host anatomy and microbiome metabolism.
Assuntos
Bactérias/metabolismo , Butiratos/metabolismo , Colo/citologia , Colo/microbiologia , Microbioma Gastrointestinal , Células-Tronco/metabolismo , Acil-CoA Desidrogenase/deficiência , Acil-CoA Desidrogenase/genética , Animais , Proliferação de Células , Intestino Delgado/citologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Oxirredução , Moléculas com Motivos Associados a Patógenos/metabolismo , Células-Tronco/citologia , Peixe-ZebraRESUMO
Despite the accepted health benefits of consuming dietary fiber, little is known about the mechanisms by which fiber deprivation impacts the gut microbiota and alters disease risk. Using a gnotobiotic mouse model, in which animals were colonized with a synthetic human gut microbiota composed of fully sequenced commensal bacteria, we elucidated the functional interactions between dietary fiber, the gut microbiota, and the colonic mucus barrier, which serves as a primary defense against enteric pathogens. We show that during chronic or intermittent dietary fiber deficiency, the gut microbiota resorts to host-secreted mucus glycoproteins as a nutrient source, leading to erosion of the colonic mucus barrier. Dietary fiber deprivation, together with a fiber-deprived, mucus-eroding microbiota, promotes greater epithelial access and lethal colitis by the mucosal pathogen, Citrobacter rodentium. Our work reveals intricate pathways linking diet, the gut microbiome, and intestinal barrier dysfunction, which could be exploited to improve health using dietary therapeutics.
Assuntos
Fibras na Dieta/administração & dosagem , Microbioma Gastrointestinal , Mucosa Intestinal/microbiologia , Animais , Citrobacter rodentium/fisiologia , Colite/microbiologia , Colo/microbiologia , Suscetibilidade a Doenças , Infecções por Enterobacteriaceae/microbiologia , Escherichia coli , Feminino , Vida Livre de Germes , Humanos , Masculino , Camundongos , Mucina-2/genéticaRESUMO
Decreases in the diversity of enteric bacterial populations are observed in patients with Crohn's disease (CD) and ulcerative colitis (UC). Less is known about the virome in these diseases. We show that the enteric virome is abnormal in CD and UC patients. In-depth analysis of preparations enriched for free virions in the intestine revealed that CD and UC were associated with a significant expansion of Caudovirales bacteriophages. The viromes of CD and UC patients were disease and cohort specific. Importantly, it did not appear that expansion and diversification of the enteric virome was secondary to changes in bacterial populations. These data support a model in which changes in the virome may contribute to intestinal inflammation and bacterial dysbiosis. We conclude that the virome is a candidate for contributing to, or being a biomarker for, human inflammatory bowel disease and speculate that the enteric virome may play a role in other diseases.
Assuntos
Caudovirales/isolamento & purificação , Colite Ulcerativa/virologia , Doença de Crohn/virologia , Disbiose/virologia , Microviridae/isolamento & purificação , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Estudos de Casos e Controles , Caudovirales/genética , Estudos de Coortes , Colite Ulcerativa/microbiologia , Colite Ulcerativa/patologia , Colite Ulcerativa/terapia , Doença de Crohn/microbiologia , Doença de Crohn/patologia , Doença de Crohn/terapia , Disbiose/microbiologia , Disbiose/patologia , Disbiose/terapia , Fezes/microbiologia , Fezes/virologia , Humanos , Metagenoma , Microviridae/genéticaRESUMO
The stem cells that maintain and repair the postnatal skeleton remain undefined. One model suggests that perisinusoidal mesenchymal stem cells (MSCs) give rise to osteoblasts, chondrocytes, marrow stromal cells, and adipocytes, although the existence of these cells has not been proven through fate-mapping experiments. We demonstrate here that expression of the bone morphogenetic protein (BMP) antagonist gremlin 1 defines a population of osteochondroreticular (OCR) stem cells in the bone marrow. OCR stem cells self-renew and generate osteoblasts, chondrocytes, and reticular marrow stromal cells, but not adipocytes. OCR stem cells are concentrated within the metaphysis of long bones not in the perisinusoidal space and are needed for bone development, bone remodeling, and fracture repair. Grem1 expression also identifies intestinal reticular stem cells (iRSCs) that are cells of origin for the periepithelial intestinal mesenchymal sheath. Grem1 expression identifies distinct connective tissue stem cells in both the bone (OCR stem cells) and the intestine (iRSCs).
Assuntos
Osso e Ossos/citologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Intestino Delgado/citologia , Células-Tronco Mesenquimais/citologia , Animais , Cartilagem/metabolismo , Intestino Delgado/metabolismo , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Subsets of innate lymphoid cells (ILCs) reside in the mucosa and regulate immune responses to external pathogens. While ILCs can be phenotypically classified into ILC1, ILC2 and ILC3 subsets, the transcriptional control of commitment to each ILC lineage is incompletely understood. Here we report that the transcription factor Runx3 was essential for the normal development of ILC1 and ILC3 cells but not of ILC2 cells. Runx3 controlled the survival of ILC1 cells but not of ILC3 cells. Runx3 was required for expression of the transcription factor RORγt and its downstream target, the transcription factor AHR, in ILC3 cells. The absence of Runx3 in ILCs exacerbated infection with Citrobacter rodentium. Therefore, our data establish Runx3 as a key transcription factor in the lineage-specific differentiation of ILC1 and ILC3 cells.
Assuntos
Subunidade alfa 3 de Fator de Ligação ao Core/metabolismo , Imunidade Inata , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/metabolismo , Animais , Antígenos Ly/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Diferenciação Celular/imunologia , Linhagem da Célula/imunologia , Citrobacter rodentium/imunologia , Citrobacter rodentium/patogenicidade , Subunidade alfa 3 de Fator de Ligação ao Core/deficiência , Subunidade alfa 3 de Fator de Ligação ao Core/genética , Subunidade beta de Fator de Ligação ao Core/deficiência , Subunidade beta de Fator de Ligação ao Core/genética , Subunidade beta de Fator de Ligação ao Core/metabolismo , Infecções por Enterobacteriaceae/etiologia , Infecções por Enterobacteriaceae/imunologia , Subunidade alfa de Receptor de Interleucina-7/metabolismo , Mucosa Intestinal/citologia , Mucosa Intestinal/imunologia , Subpopulações de Linfócitos/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptor 1 Desencadeador da Citotoxicidade Natural/metabolismo , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/deficiência , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Receptores de Hidrocarboneto Arílico/genética , Receptores de Hidrocarboneto Arílico/metabolismoRESUMO
Pathogenic simian immunodeficiency virus (SIV) infection is associated with enteropathy, which likely contributes to AIDS progression. To identify candidate etiologies for AIDS enteropathy, we used next-generation sequencing to define the enteric virome during SIV infection in nonhuman primates. Pathogenic, but not nonpathogenic, SIV infection was associated with significant expansion of the enteric virome. We identified at least 32 previously undescribed enteric viruses during pathogenic SIV infection and confirmed their presence by using viral culture and PCR testing. We detected unsuspected mucosal adenovirus infection associated with enteritis as well as parvovirus viremia in animals with advanced AIDS, indicating the pathogenic potential of SIV-associated expansion of the enteric virome. No association between pathogenic SIV infection and the family-level taxonomy of enteric bacteria was detected. Thus, enteric viral infections may contribute to AIDS enteropathy and disease progression. These findings underline the importance of metagenomic analysis of the virome for understanding AIDS pathogenesis.
Assuntos
Caliciviridae/isolamento & purificação , Intestinos/virologia , Parvoviridae/isolamento & purificação , Picornaviridae/isolamento & purificação , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/fisiologia , Animais , Caliciviridae/classificação , Caliciviridae/genética , Chlorocebus aethiops , Fezes/microbiologia , Fezes/virologia , Intestinos/microbiologia , Dados de Sequência Molecular , Parvoviridae/classificação , Parvoviridae/genética , Filogenia , Picornaviridae/classificação , Picornaviridae/genética , Reação em Cadeia da Polimerase , Síndrome de Imunodeficiência Adquirida dos Símios/microbiologia , Vírus da Imunodeficiência Símia/patogenicidadeRESUMO
Defense against attaching-and-effacing bacteria requires the sequential generation of interleukin 23 (IL-23) and IL-22 to induce protective mucosal responses. Although CD4(+) and NKp46(+) innate lymphoid cells (ILCs) are the critical source of IL-22 during infection, the precise source of IL-23 is unclear. We used genetic techniques to deplete mice of specific subsets of classical dendritic cells (cDCs) and analyzed immunity to the attaching-and-effacing pathogen Citrobacter rodentium. We found that the signaling receptor Notch2 controlled the terminal stage of cDC differentiation. Notch2-dependent intestinal CD11b(+) cDCs were an obligate source of IL-23 required for survival after infection with C. rodentium, but CD103(+) cDCs dependent on the transcription factor Batf3 were not. Our results demonstrate a nonredundant function for CD11b(+) cDCs in the response to pathogens in vivo.
Assuntos
Citrobacter rodentium/imunologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Receptor Notch2/metabolismo , Animais , Antígenos CD/metabolismo , Antígeno CD11b/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Células Dendríticas/citologia , Infecções por Enterobacteriaceae/imunologia , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/mortalidade , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Interleucina-23/metabolismo , Mucosa Intestinal/microbiologia , Lectinas Tipo C/metabolismo , Receptor beta de Linfotoxina/genética , Receptor beta de Linfotoxina/metabolismo , Camundongos , Camundongos Transgênicos , Antígenos de Histocompatibilidade Menor , Receptor Notch2/deficiência , Receptores de Superfície Celular/metabolismo , Transdução de Sinais , Baço/imunologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Cicatrização/genética , Cicatrização/imunologiaRESUMO
It is unclear why disease occurs in only a small proportion of persons carrying common risk alleles of disease susceptibility genes. Here we demonstrate that an interaction between a specific virus infection and a mutation in the Crohn's disease susceptibility gene Atg16L1 induces intestinal pathologies in mice. This virus-plus-susceptibility gene interaction generated abnormalities in granule packaging and unique patterns of gene expression in Paneth cells. Further, the response to injury induced by the toxic substance dextran sodium sulfate was fundamentally altered to include pathologies resembling aspects of Crohn's disease. These pathologies triggered by virus-plus-susceptibility gene interaction were dependent on TNFalpha and IFNgamma and were prevented by treatment with broad spectrum antibiotics. Thus, we provide a specific example of how a virus-plus-susceptibility gene interaction can, in combination with additional environmental factors and commensal bacteria, determine the phenotype of hosts carrying common risk alleles for inflammatory disease.
Assuntos
Proteínas de Transporte/genética , Doença de Crohn/genética , Doença de Crohn/virologia , Predisposição Genética para Doença , Íleo/patologia , Norovirus , Animais , Proteínas Relacionadas à Autofagia , Doença de Crohn/patologia , Perfilação da Expressão Gênica , Humanos , Interferon gama/metabolismo , Camundongos , Celulas de Paneth/metabolismo , Celulas de Paneth/virologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Inflammatory bowel diseases, which include Crohn's disease and ulcerative colitis, affect several million individuals worldwide. Crohn's disease and ulcerative colitis are complex diseases that are heterogeneous at the clinical, immunological, molecular, genetic, and microbial levels. Individual contributing factors have been the focus of extensive research. As part of the Integrative Human Microbiome Project (HMP2 or iHMP), we followed 132 subjects for one year each to generate integrated longitudinal molecular profiles of host and microbial activity during disease (up to 24 time points each; in total 2,965 stool, biopsy, and blood specimens). Here we present the results, which provide a comprehensive view of functional dysbiosis in the gut microbiome during inflammatory bowel disease activity. We demonstrate a characteristic increase in facultative anaerobes at the expense of obligate anaerobes, as well as molecular disruptions in microbial transcription (for example, among clostridia), metabolite pools (acylcarnitines, bile acids, and short-chain fatty acids), and levels of antibodies in host serum. Periods of disease activity were also marked by increases in temporal variability, with characteristic taxonomic, functional, and biochemical shifts. Finally, integrative analysis identified microbial, biochemical, and host factors central to this dysregulation. The study's infrastructure resources, results, and data, which are available through the Inflammatory Bowel Disease Multi'omics Database ( http://ibdmdb.org ), provide the most comprehensive description to date of host and microbial activities in inflammatory bowel diseases.
Assuntos
Microbioma Gastrointestinal/genética , Doenças Inflamatórias Intestinais/microbiologia , Animais , Fungos/patogenicidade , Microbioma Gastrointestinal/imunologia , Saúde , Humanos , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/terapia , Doenças Inflamatórias Intestinais/virologia , Filogenia , Especificidade da Espécie , Transcriptoma , Vírus/patogenicidadeRESUMO
Microbially derived metabolites in the intestine regulate host immunity and impact disease pathophysiology in various organs. Sun et al. (2015) suggest a direct effect of microbial metabolites on pancreatic endocrine cells in regulating type 1 diabetes pathophysiology.
Assuntos
Catelicidinas/metabolismo , Diabetes Mellitus Tipo 1/imunologia , Células Secretoras de Insulina/imunologia , Intestinos/imunologia , Microbiota/fisiologia , Pâncreas/imunologia , Animais , Feminino , MasculinoRESUMO
The local microenvironment shapes macrophage differentiation in each tissue. We hypothesized that in the peritoneum, local factors in addition to retinoic acid can support GATA6-driven differentiation and function of peritoneal large cavity macrophages (LCMs). We found that soluble proteins produced by mesothelial cells lining the peritoneal cavity maintained GATA6 expression in cultured LCMs. Analysis of global gene expression of isolated mesothelial cells highlighted mesothelin (Msln) and its binding partner mucin 16 (Muc16) as candidate secreted ligands that potentially regulate GATA6 expression in peritoneal LCMs. Mice deficient for either of these molecules showed diminished GATA6 expression in peritoneal and pleural LCMs that was most prominent in aged mice. The more robust phenotype in older mice suggested that monocyte-derived macrophages were the target of Msln and Muc16. Cell transfer and bone marrow chimera experiments supported this hypothesis. We found that lethally irradiated Msln-/- and Muc16-/- mice reconstituted with wild-type bone marrow had lower levels of GATA6 expression in peritoneal and pleural LCMs. Similarly, during the resolution of zymosan-induced inflammation, repopulated peritoneal LCMs lacking expression of Msln or Muc16 expressed diminished GATA6. These data support a role for mesothelial cell-produced Msln and Muc16 in local macrophage differentiation within large cavity spaces such as the peritoneum. The effect appears to be most prominent on monocyte-derived macrophages that enter into this location as the host ages and also in response to infection.
Assuntos
Macrófagos Peritoneais , Macrófagos , Camundongos , Animais , Cavidade Peritoneal , Peritônio , EpitélioRESUMO
Oral infection with Toxoplasma gondii results in dysbiosis and enteritis, both of which revert to normal during chronic infection. However, whether infection leaves a lasting impact on mucosal responses remains uncertain. Here we examined the effect of the chemical irritant dextran sodium sulfate (DSS) on intestinal damage and wound healing in chronically infected mice. Our findings indicate that prior infection with T. gondii exacerbates damage to the colon caused by DSS and impairs wound healing by suppressing stem cell regeneration of the epithelium. Enhanced tissue damage was attributable to inflammatory monocytes that emerge preactivated from bone marrow, migrate to the intestine, and release inflammatory mediators, including nitric oxide. Tissue damage was reversed by neutralization of inflammatory monocytes or nitric oxide, revealing a causal mechanism for tissue damage. Our findings suggest that chronic infection with T. gondii enhances monocyte activation to increase inflammation associated with a secondary environmental insult.
Assuntos
Colite/complicações , Toxoplasmose/complicações , Animais , Doença Crônica , Suscetibilidade a Doenças , Microbioma Gastrointestinal , Mucosa Intestinal/patologia , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/patologia , Regeneração , Células-Tronco/patologiaRESUMO
OBJECTIVE: Loss-of-function mutations in genes generating reactive oxygen species (ROS), such as NOX1, are associated with IBD. Mechanisms whereby loss of ROS drive IBD are incompletely defined. DESIGN: ROS measurements and single-cell transcriptomics were performed on colonoids stratified by NOX1 genotype and TNFα stimulation. Clustering of epithelial cells from human UC (inflamed and uninflamed) scRNASeq was performed. Validation of M cell induction was performed by immunohistochemistry using UEA1 (ulex europaeus agglutin-1 lectin) and in vivo with DSS injury. RESULTS: TNFα induces ROS production more in NOX1-WT versus NOX1-deficient murine colonoids under a range of Wnt-mediated and Notch-mediated conditions. scRNASeq from inflamed and uninflamed human colitis versus TNFα stimulated, in vitro colonoids defines substantially shared, induced transcription factors; NOX1-deficient colonoids express substantially lower levels of STAT3 (signal transducer and activator of transcription 3), CEBPD (CCAAT enhancer-binding protein delta), DNMT1 (DNA methyltransferase) and HIF1A (hypoxia-inducible factor) baseline. Subclustering unexpectedly showed marked TNFα-mediated induction of M cells (sentinel cells overlying lymphoid aggregates) in NOX1-deficient colonoids. M cell induction by UEA1 staining is rescued with H2O2 and paraquat, defining extra- and intracellular ROS roles in maintenance of LGR5+ stem cells. DSS injury demonstrated GP2 (glycoprotein-2), basal lymphoplasmacytosis and UEA1 induction in NOX1-deficiency. Principal components analyses of M cell genes and decreased DNMT1 RNA velocity correlate with UC inflammation. CONCLUSIONS: NOX1 deficiency plus TNFα stimulation contribute to colitis through dysregulation of the stem cell niche and altered cell differentiation, enhancing basal lymphoplasmacytosis. Our findings prioritise ROS modulation for future therapies.
Assuntos
Colite , Doenças Inflamatórias Intestinais , Camundongos , Humanos , Animais , Espécies Reativas de Oxigênio/metabolismo , Fator de Necrose Tumoral alfa/efeitos adversos , Células M , NADPH Oxidase 1/genética , NADPH Oxidase 1/metabolismo , Peróxido de Hidrogênio/efeitos adversos , Colite/induzido quimicamenteRESUMO
The global coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to unprecedented social and economic consequences. The risk of morbidity and mortality due to COVID-19 increases dramatically in the presence of coexisting medical conditions, while the underlying mechanisms remain unclear. Furthermore, there are no approved therapies for COVID-19. This study aims to identify SARS-CoV-2 pathogenesis, disease manifestations, and COVID-19 therapies using network medicine methodologies along with clinical and multi-omics observations. We incorporate SARS-CoV-2 virus-host protein-protein interactions, transcriptomics, and proteomics into the human interactome. Network proximity measurement revealed underlying pathogenesis for broad COVID-19-associated disease manifestations. Analyses of single-cell RNA sequencing data show that co-expression of ACE2 and TMPRSS2 is elevated in absorptive enterocytes from the inflamed ileal tissues of Crohn disease patients compared to uninflamed tissues, revealing shared pathobiology between COVID-19 and inflammatory bowel disease. Integrative analyses of metabolomics and transcriptomics (bulk and single-cell) data from asthma patients indicate that COVID-19 shares an intermediate inflammatory molecular profile with asthma (including IRAK3 and ADRB2). To prioritize potential treatments, we combined network-based prediction and a propensity score (PS) matching observational study of 26,779 individuals from a COVID-19 registry. We identified that melatonin usage (odds ratio [OR] = 0.72, 95% CI 0.56-0.91) is significantly associated with a 28% reduced likelihood of a positive laboratory test result for SARS-CoV-2 confirmed by reverse transcription-polymerase chain reaction assay. Using a PS matching user active comparator design, we determined that melatonin usage was associated with a reduced likelihood of SARS-CoV-2 positive test result compared to use of angiotensin II receptor blockers (OR = 0.70, 95% CI 0.54-0.92) or angiotensin-converting enzyme inhibitors (OR = 0.69, 95% CI 0.52-0.90). Importantly, melatonin usage (OR = 0.48, 95% CI 0.31-0.75) is associated with a 52% reduced likelihood of a positive laboratory test result for SARS-CoV-2 in African Americans after adjusting for age, sex, race, smoking history, and various disease comorbidities using PS matching. In summary, this study presents an integrative network medicine platform for predicting disease manifestations associated with COVID-19 and identifying melatonin for potential prevention and treatment of COVID-19.