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1.
Nat Commun ; 12(1): 1836, 2021 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-33758175

RESUMO

To prevent damage to the host or its commensal microbiota, epithelial tissues must match the intensity of the immune response to the severity of a biological threat. Toll-like receptors allow epithelial cells to identify microbe associated molecular patterns. However, the mechanisms that mitigate biological noise in single cells to ensure quantitatively appropriate responses remain unclear. Here we address this question using single cell and single molecule approaches in mammary epithelial cells and primary organoids. We find that epithelial tissues respond to bacterial microbe associated molecular patterns by activating a subset of cells in an all-or-nothing (i.e. digital) manner. The maximum fraction of responsive cells is regulated by a bimodal epigenetic switch that licenses the TLR2 promoter for transcription across multiple generations. This mechanism confers a flexible memory of inflammatory events as well as unique spatio-temporal control of epithelial tissue-level immune responses. We propose that epigenetic licensing in individual cells allows for long-term, quantitative fine-tuning of population-level responses.


Assuntos
Bactérias/imunologia , Células Epiteliais/imunologia , Imunidade Inata , Lipopeptídeos/imunologia , NF-kappa B/metabolismo , Receptor 2 Toll-Like/metabolismo , Animais , Bactérias/metabolismo , Linhagem Celular , Citocinas/metabolismo , Citocinas/farmacologia , Metilação de DNA/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Flagelina/farmacologia , Regulação da Expressão Gênica/genética , Regulação da Expressão Gênica/imunologia , Humanos , Processamento de Imagem Assistida por Computador , Imunidade Inata/efeitos dos fármacos , Imunidade Inata/genética , Hibridização in Situ Fluorescente , Glândulas Mamárias Animais , Camundongos , Organoides/efeitos dos fármacos , Organoides/imunologia , Organoides/metabolismo , Regiões Promotoras Genéticas , RNA-Seq , Transdução de Sinais/imunologia , Análise de Célula Única , Receptor 2 Toll-Like/agonistas , Receptor 2 Toll-Like/genética , Receptores Toll-Like/agonistas , Receptores Toll-Like/metabolismo
2.
Nat Immunol ; 22(2): 216-228, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33462454

RESUMO

CD4+ effector lymphocytes (Teff) are traditionally classified by the cytokines they produce. To determine the states that Teff cells actually adopt in frontline tissues in vivo, we applied single-cell transcriptome and chromatin analyses to colonic Teff cells in germ-free or conventional mice or in mice after challenge with a range of phenotypically biasing microbes. Unexpected subsets were marked by the expression of the interferon (IFN) signature or myeloid-specific transcripts, but transcriptome or chromatin structure could not resolve discrete clusters fitting classic helper T cell (TH) subsets. At baseline or at different times of infection, transcripts encoding cytokines or proteins commonly used as TH markers were distributed in a polarized continuum, which was functionally validated. Clones derived from single progenitors gave rise to both IFN-γ- and interleukin (IL)-17-producing cells. Most of the transcriptional variance was tied to the infecting agent, independent of the cytokines produced, and chromatin variance primarily reflected activities of activator protein (AP)-1 and IFN-regulatory factor (IRF) transcription factor (TF) families, not the canonical subset master regulators T-bet, GATA3 or RORγ.


Assuntos
Bactérias/patogenicidade , Infecções Bacterianas/microbiologia , Linfócitos T CD4-Positivos/microbiologia , Linfócitos T CD4-Positivos/parasitologia , Colo/microbiologia , Colo/parasitologia , Microbioma Gastrointestinal , Heligmosomatoidea/patogenicidade , Enteropatias Parasitárias/parasitologia , Animais , Bactérias/imunologia , Infecções Bacterianas/genética , Infecções Bacterianas/imunologia , Infecções Bacterianas/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Cromatina/genética , Cromatina/metabolismo , Citrobacter rodentium/imunologia , Citrobacter rodentium/patogenicidade , Colo/imunologia , Colo/metabolismo , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Heligmosomatoidea/imunologia , Interações Hospedeiro-Patógeno , Fatores Reguladores de Interferon/genética , Fatores Reguladores de Interferon/metabolismo , Enteropatias Parasitárias/genética , Enteropatias Parasitárias/imunologia , Enteropatias Parasitárias/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Nematospiroides dubius/imunologia , Nematospiroides dubius/patogenicidade , Nippostrongylus/imunologia , Nippostrongylus/patogenicidade , Fenótipo , Salmonella enterica/imunologia , Salmonella enterica/patogenicidade , Análise de Célula Única , Fator de Transcrição AP-1/genética , Fator de Transcrição AP-1/metabolismo , Transcriptoma
3.
Gut ; 70(4): 698-706, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33431578

RESUMO

OBJECTIVE: Although COVID-19 is primarily a respiratory illness, there is mounting evidence suggesting that the GI tract is involved in this disease. We investigated whether the gut microbiome is linked to disease severity in patients with COVID-19, and whether perturbations in microbiome composition, if any, resolve with clearance of the SARS-CoV-2 virus. METHODS: In this two-hospital cohort study, we obtained blood, stool and patient records from 100 patients with laboratory-confirmed SARS-CoV-2 infection. Serial stool samples were collected from 27 of the 100 patients up to 30 days after clearance of SARS-CoV-2. Gut microbiome compositions were characterised by shotgun sequencing total DNA extracted from stools. Concentrations of inflammatory cytokines and blood markers were measured from plasma. RESULTS: Gut microbiome composition was significantly altered in patients with COVID-19 compared with non-COVID-19 individuals irrespective of whether patients had received medication (p<0.01). Several gut commensals with known immunomodulatory potential such as Faecalibacterium prausnitzii, Eubacterium rectale and bifidobacteria were underrepresented in patients and remained low in samples collected up to 30 days after disease resolution. Moreover, this perturbed composition exhibited stratification with disease severity concordant with elevated concentrations of inflammatory cytokines and blood markers such as C reactive protein, lactate dehydrogenase, aspartate aminotransferase and gamma-glutamyl transferase. CONCLUSION: Associations between gut microbiota composition, levels of cytokines and inflammatory markers in patients with COVID-19 suggest that the gut microbiome is involved in the magnitude of COVID-19 severity possibly via modulating host immune responses. Furthermore, the gut microbiota dysbiosis after disease resolution could contribute to persistent symptoms, highlighting a need to understand how gut microorganisms are involved in inflammation and COVID-19.


Assuntos
Bactérias , Disbiose , Microbioma Gastrointestinal/imunologia , Trato Gastrointestinal , Imunidade , Adulto , Bactérias/genética , Bactérias/imunologia , Bactérias/isolamento & purificação , Proteína C-Reativa/análise , /diagnóstico , /imunologia , Citocinas/análise , DNA Bacteriano/isolamento & purificação , Disbiose/epidemiologia , Disbiose/etiologia , Disbiose/imunologia , Disbiose/virologia , Feminino , Trato Gastrointestinal/imunologia , Trato Gastrointestinal/microbiologia , Trato Gastrointestinal/virologia , Hong Kong , Humanos , Masculino , /isolamento & purificação , Índice de Gravidade de Doença , Transferases/análise
4.
Microbiome ; 9(1): 33, 2021 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-33516266

RESUMO

BACKGROUND: Identifying which taxa are targeted by immunoglobulins can uncover important host-microbe interactions. Immunoglobulin binding of commensal taxa can be assayed by sorting bound bacteria from samples and using amplicon sequencing to determine their taxonomy, a technique most widely applied to study Immunoglobulin A (IgA-Seq). Previous experiments have scored taxon binding in IgA-Seq datasets by comparing abundances in the IgA bound and unbound sorted fractions. However, as these are relative abundances, such scores are influenced by the levels of the other taxa present and represent an abstract combination of these effects. Diversity in the practical approaches of prior studies also warrants benchmarking of the individual stages involved. Here, we provide a detailed description of the design strategy for an optimised IgA-Seq protocol. Combined with a novel scoring method for IgA-Seq datasets that accounts for the aforementioned effects, this platform enables accurate identification and quantification of commensal gut microbiota targeted by host immunoglobulins. RESULTS: Using germ-free and Rag1-/- mice as negative controls, and a strain-specific IgA antibody as a positive control, we determine optimal reagents and fluorescence-activated cell sorting (FACS) parameters for IgA-Seq. Using simulated IgA-Seq data, we show that existing IgA-Seq scoring methods are influenced by pre-sort relative abundances. This has consequences for the interpretation of case-control studies where there are inherent differences in microbiota composition between groups. We show that these effects can be addressed using a novel scoring approach based on posterior probabilities. Finally, we demonstrate the utility of both the IgA-Seq protocol and probability-based scores by examining both novel and published data from in vivo disease models. CONCLUSIONS: We provide a detailed IgA-Seq protocol to accurately isolate IgA-bound taxa from intestinal samples. Using simulated and experimental data, we demonstrate novel probability-based scores that adjust for the compositional nature of relative abundance data to accurately quantify taxon-level IgA binding. All scoring approaches are made available in the IgAScores R package. These methods should improve the generation and interpretation of IgA-Seq datasets and could be applied to study other immunoglobulins and sample types. Video abstract.


Assuntos
Microbioma Gastrointestinal/imunologia , Imunoglobulina A/imunologia , Simbiose , Animais , Bactérias/genética , Bactérias/imunologia , Bactérias/isolamento & purificação , Conjuntos de Dados como Assunto , Feminino , Microbioma Gastrointestinal/genética , Intestinos/imunologia , Intestinos/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL
5.
Biomed Pharmacother ; 133: 111047, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33378954

RESUMO

Traditional Chinese medicines (TCMs) are medicines that are widely used in oriental countries under the guidance of ancient Chinese medicinal philosophies. With thousands of years of experiences in fighting against diseases, TCMs are gaining increasing importance in the world. Although the efficacy of TCMs is well recognized in clinic, the toxicity of TCMs has become a serious issue around the world in recent years. In general, the toxicity of TCMs is caused by the toxic medicinal compounds and contaminants in TCMs such as pesticides, herbicides, and heavy metals. Recent studies have demonstrated that gut microbiota can interact with TCMs and thus influence the toxicity of TCMs. However, there is no focused review on gut microbiota and the toxicity of TCMs. Here, we summarized the influences of the gut microbiota on the toxicity of medicinal compounds in TCMs and the corresponding mechanisms were offered. Then, we discussed the relationships between gut microbiota and the TCM contaminants. In addition, we discussed the methods of manipulating gut microbiota to reduce the toxicity of TCMs. At the end of this review, the perspectives on gut microbiota and the toxicity of TCMs were also discussed.


Assuntos
Bactérias/metabolismo , Contaminação de Medicamentos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/etiologia , Medicamentos de Ervas Chinesas/efeitos adversos , Microbioma Gastrointestinal , Intestinos/microbiologia , Medicina Tradicional Chinesa/efeitos adversos , Bactérias/imunologia , Biotransformação , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/microbiologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controle , Medicamentos de Ervas Chinesas/metabolismo , Microbioma Gastrointestinal/efeitos dos fármacos , Interações Hospedeiro-Patógeno , Humanos , Intestinos/efeitos dos fármacos , Intestinos/imunologia , Fatores de Risco
6.
Methods Mol Biol ; 2183: 9-18, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32959237

RESUMO

The immunoglobulin capture assay (ICA) enables the enrichment for pathogen-specific plasmablasts from individuals with a confirmed adaptive immune response to vaccination or disseminated infection. Only single recombinant antigens have been used previously as probes in this ICA and it was unclear whether the method was applicable to complex probes such as whole bacterial cells. Here, we describe the enrichment of plasmablasts specific for polysaccharide and protein antigens of both Streptococcus pneumoniae and Neisseria meningitidis using whole formalin-fixed bacterial cells as probes. The modified ICA protocol described here allowed for a pathogen-specific hmAb cloning efficiency of >80%.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/isolamento & purificação , Especificidade de Anticorpos/imunologia , Bactérias/imunologia , Imunoensaio/métodos , Sondas Moleculares , Anticorpos Antibacterianos/imunologia , Afinidade de Anticorpos , Formação de Anticorpos/imunologia , Antígenos de Bactérias/imunologia , Interações Hospedeiro-Patógeno , Humanos , Imunoglobulina G/imunologia , Plasmócitos/imunologia , Plasmócitos/metabolismo , Streptococcus pneumoniae/imunologia
7.
Methods Mol Biol ; 2183: 43-62, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32959240

RESUMO

There is still a lack of vaccines for many bacterial infections for which the best treatment option would be a prophylactic one. On the other hand, effectiveness has been questioned for some existing vaccines, prompting new developments. Therapeutic vaccines are also becoming a treatment option in specific cases where antibiotics tend to fail. In this scenario, refinement and extension of the classical reverse vaccinology approach is allowing scientists to find new and more effective antigens. In this chapter, we describe an in silico methodology that integrates pangenomic, immunoinformatic, structural, and evolutionary approaches for the screening of potential antigens in a given bacterial species. The strategy focuses on targeting relatively conserved epitopes in core proteins to design broadly cross-protective vaccines and avoid allele-specific immunity. The proposed methodological steps and computational tools can be easily implemented in a reverse vaccinology approach not only to identify new leads with strong immune response but also to develop diagnostic assays.


Assuntos
Antígenos de Bactérias/imunologia , Bactérias/imunologia , Proteínas de Bactérias/imunologia , Biologia Computacional , Proteoma , Proteômica , Antígenos de Bactérias/genética , Antígenos de Bactérias/metabolismo , Bactérias/genética , Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Vacinas Bacterianas/imunologia , Biologia Computacional/métodos , Bases de Dados Factuais , Genoma Bacteriano , Estudo de Associação Genômica Ampla , Genômica/métodos , Humanos , Anotação de Sequência Molecular , Proteômica/métodos , Vacinologia , Navegador , Fluxo de Trabalho
8.
Science ; 370(6514)2020 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-33060333

RESUMO

Lipid droplets (LDs) are the major lipid storage organelles of eukaryotic cells and a source of nutrients for intracellular pathogens. We demonstrate that mammalian LDs are endowed with a protein-mediated antimicrobial capacity, which is up-regulated by danger signals. In response to lipopolysaccharide (LPS), multiple host defense proteins, including interferon-inducible guanosine triphosphatases and the antimicrobial cathelicidin, assemble into complex clusters on LDs. LPS additionally promotes the physical and functional uncoupling of LDs from mitochondria, reducing fatty acid metabolism while increasing LD-bacterial contacts. Thus, LDs actively participate in mammalian innate immunity at two levels: They are both cell-autonomous organelles that organize and use immune proteins to kill intracellular pathogens as well as central players in the local and systemic metabolic adaptation to infection.


Assuntos
Bactérias/imunologia , Interações Hospedeiro-Patógeno/imunologia , Imunidade Inata , Gotículas Lipídicas/imunologia , Animais , Peptídeos Catiônicos Antimicrobianos/metabolismo , Ácidos Graxos/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Células HEK293 , Humanos , Lipopolissacarídeos/imunologia , Macrófagos/imunologia , Macrófagos/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/imunologia
9.
Front Immunol ; 11: 2192, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33072084

RESUMO

During the last years probiotics gained the attention of clinicians for their use in the prevention and treatment of multiple diseases. Probiotics main mechanisms of action include enhanced mucosal barrier function, direct antagonism with pathogens, inhibition of bacterial adherence and invasion capacity in the intestinal epithelium, boosting of the immune system and regulation of the central nervous system. It is accepted that there is a mutual communication between the gut microbiota and the liver, the so-called "microbiota-gut-liver axis" as well as a reciprocal communication between the intestinal microbiota and the central nervous system through the "microbiota-gut-brain axis." Moreover, recently the "gut-lung axis" in bacterial and viral infections is considerably discussed for bacterial and viral infections, as the intestinal microbiota amplifies the alveolar macrophage activity having a protective role in the host defense against pneumonia. The importance of the normal human intestinal microbiota is recognized in the preservation of health. Disease states such as, infections, autoimmune conditions, allergy and other may occur when the intestinal balance is disturbed. Probiotics seem to be a promising approach to prevent and even reduce the symptoms of such clinical states as an adjuvant therapy by preserving the balance of the normal intestinal microbiota and improving the immune system. The present review states globally all different disorders in which probiotics can be given. To date, Stronger data in favor of their clinical use are provided in the prevention of gastrointestinal disorders, antibiotic-associated diarrhea, allergy and respiratory infections. We hereby discuss the role of probiotics in the reduction of the respiratory infection symptoms and we focus on the possibility to use them as an adjuvant to the therapeutic approach of the pandemic COVID-19. Nevertheless, it is accepted by the scientific community that more clinical studies should be undertaken in large samples of diseased populations so that the assessment of their therapeutic potential provide us with strong evidence for their efficacy and safety in clinical use.


Assuntos
Bactérias/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus , Microbioma Gastrointestinal/imunologia , Pandemias , Pneumonia Viral , Probióticos/uso terapêutico , Aderência Bacteriana/imunologia , Encéfalo/imunologia , Encéfalo/microbiologia , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/microbiologia , Infecções por Coronavirus/terapia , Humanos , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia , Pneumonia Viral/epidemiologia , Pneumonia Viral/imunologia , Pneumonia Viral/microbiologia , Pneumonia Viral/terapia
11.
Adv Exp Med Biol ; 1267: 117-133, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32894480

RESUMO

Antibiotic resistance is a global epidemic, becoming increasingly pressing due to its rapid spread. There is thus a critical need to develop new therapeutic approaches. In addition to searching for new antibiotics, looking into existing mechanisms of natural host defense may enable researchers to improve existing defense mechanisms, and to develop effective, synthetic drugs guided by natural principles. Histones, primarily known for their role in condensing mammalian DNA, are antimicrobial and share biochemical similarities with antimicrobial peptides (AMPs); however, the mechanism by which histones kill bacteria is largely unknown. Both AMPs and histones are similar in size, cationic, contain a high proportion of hydrophobic amino acids, and possess the ability to form alpha helices. AMPs, which mostly kill bacteria through permeabilization or disruption of the biological membrane, have recently garnered significant attention for playing a key role in host defenses. This chapter outlines the structure and function of histone proteins as they compare to AMPs and provides an overview of their role in innate immune responses, especially regarding the action of specific histones against microorganisms and their potential mechanism of action against microbial pathogens.


Assuntos
Antibacterianos/química , Antibacterianos/imunologia , Bactérias/imunologia , Histonas/química , Histonas/imunologia , Animais , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Bactérias/efeitos dos fármacos , Histonas/farmacologia , Imunidade Inata
12.
Am J Physiol Lung Cell Mol Physiol ; 319(4): L603-L619, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32783615

RESUMO

Respiratory cilia are the driving force of the mucociliary escalator, working in conjunction with secreted airway mucus to clear inhaled debris and pathogens from the conducting airways. Respiratory cilia are also one of the first contact points between host and inhaled pathogens. Impaired ciliary function is a common pathological feature in patients with chronic airway diseases, increasing susceptibility to respiratory infections. Common respiratory pathogens, including viruses, bacteria, and fungi, have been shown to target cilia and/or ciliated airway epithelial cells, resulting in a disruption of mucociliary clearance that may facilitate host infection. Despite being an integral component of airway innate immunity, the role of respiratory cilia and their clinical significance during airway infections are still poorly understood. This review examines the expression, structure, and function of respiratory cilia during pathogenic infection of the airways. This review also discusses specific known points of interaction of bacteria, fungi, and viruses with respiratory cilia function. The emerging biological functions of motile cilia relating to intracellular signaling and their potential immunoregulatory roles during infection will also be discussed.


Assuntos
Bactérias/imunologia , Cílios/metabolismo , Fungos/imunologia , Depuração Mucociliar/fisiologia , Vírus/imunologia , Células Epiteliais/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Humanos , Imunidade Inata/imunologia , Muco/metabolismo , Sistema Respiratório/imunologia
13.
Mol Cell ; 79(3): 416-424.e5, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32645367

RESUMO

CRISPR-Cas12c/d proteins share limited homology with Cas12a and Cas9 bacterial CRISPR RNA (crRNA)-guided nucleases used widely for genome editing and DNA detection. However, Cas12c (C2c3)- and Cas12d (CasY)-catalyzed DNA cleavage and genome editing activities have not been directly observed. We show here that a short-complementarity untranslated RNA (scoutRNA), together with crRNA, is required for Cas12d-catalyzed DNA cutting. The scoutRNA differs in secondary structure from previously described tracrRNAs used by CRISPR-Cas9 and some Cas12 enzymes, and in Cas12d-containing systems, scoutRNA includes a conserved five-nucleotide sequence that is essential for activity. In addition to supporting crRNA-directed DNA recognition, biochemical and cell-based experiments establish scoutRNA as an essential cofactor for Cas12c-catalyzed pre-crRNA maturation. These results define scoutRNA as a third type of transcript encoded by a subset of CRISPR-Cas genomic loci and explain how Cas12c/d systems avoid requirements for host factors including ribonuclease III for bacterial RNA-mediated adaptive immunity.


Assuntos
Bactérias/genética , Proteínas de Bactérias/genética , Sistemas CRISPR-Cas , Endodesoxirribonucleases/genética , Genoma Bacteriano/imunologia , RNA Bacteriano/genética , Pequeno RNA não Traduzido/genética , Bactérias/classificação , Bactérias/imunologia , Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Sequência de Bases , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , Endodesoxirribonucleases/metabolismo , Escherichia coli/genética , Escherichia coli/imunologia , Escherichia coli/metabolismo , Conformação de Ácido Nucleico , Filogenia , RNA Bacteriano/química , RNA Bacteriano/metabolismo , RNA Guia/genética , RNA Guia/metabolismo , Pequeno RNA não Traduzido/química , Pequeno RNA não Traduzido/metabolismo , Alinhamento de Sequência , Homologia de Sequência do Ácido Nucleico
14.
Science ; 369(6501): 320-325, 2020 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-32675374

RESUMO

Restricted V(D)J recombination during fetal development was postulated to limit antibody repertoire breadth and prevent autoimmunity. However, newborn serum contains abundant autoantibodies, suggesting that B cell tolerance during gestation is not yet fully established. To investigate this apparent paradox, we evaluated the reactivities of more than 450 antibodies cloned from single B cells from human fetal liver, bone marrow, and spleen. We found that incomplete B cell tolerance in early human fetal life favored the accumulation of polyreactive B cells that bound both apoptotic cells and commensal bacteria from healthy adults. Thus, the restricted fetal preimmune repertoire contains potentially beneficial self-reactive innate-like B cell specificities that may facilitate the removal of apoptotic cells during development and shape gut microbiota assembly after birth.


Assuntos
Anticorpos/imunologia , Linfócitos B/imunologia , Feto/imunologia , Autoanticorpos/imunologia , Autoantígenos/imunologia , Autoimunidade , Bactérias/imunologia , Feminino , Humanos , Imunidade Inata , Especificidade de Órgãos , Gravidez , Recombinação V(D)J
15.
Proc Natl Acad Sci U S A ; 117(31): 18649-18660, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32690687

RESUMO

Starting at birth, the immune system of newborns and children encounters and is influenced by environmental challenges. It is still not completely understood how γδ T cells emerge and adapt during early life. Studying the composition of T cell receptors (TCRs) using next-generation sequencing (NGS) in neonates, infants, and children can provide valuable insights into the adaptation of T cell subsets. To investigate how neonatal γδ T cell repertoires are shaped by microbial exposure after birth, we monitored the γ-chain (TRG) and δ-chain (TRD) repertoires of peripheral blood T cells in newborns, infants, and young children from Europe and sub-Saharan Africa. We identified a set of TRG and TRD sequences that were shared by all children from Europe and Africa. These were primarily public clones, characterized by simple rearrangements of Vγ9 and Vδ2 chains with low junctional diversity and usage of non-TRDJ1 gene segments, reminiscent of early ontogenetic subsets of γδ T cells. Further profiling revealed that these innate, public Vγ9Vδ2+ T cells underwent an immediate TCR-driven polyclonal proliferation within the first 4 wk of life. In contrast, γδ T cells using Vδ1+ and Vδ3+ TRD rearrangements did not significantly expand after birth. However, different environmental cues may lead to the observed increase of Vδ1+ and Vδ3+ TRD sequences in the majority of African children. In summary, we show how dynamic γδ TCR repertoires develop directly after birth and present important differences among γδ T cell subsets.


Assuntos
Receptores de Antígenos de Linfócitos T gama-delta , Subpopulações de Linfócitos T/imunologia , África ao Sul do Saara , Bactérias/imunologia , Criança , Pré-Escolar , Europa (Continente) , Rearranjo Gênico do Linfócito T/genética , Rearranjo Gênico do Linfócito T/imunologia , Humanos , Lactente , Recém-Nascido , Estudos Longitudinais , Receptores de Antígenos de Linfócitos T gama-delta/genética , Receptores de Antígenos de Linfócitos T gama-delta/imunologia
16.
Sci Rep ; 10(1): 9466, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32528054

RESUMO

Microbial involvement in the pathogenesis have been suggested in both antineutrophil cytoplasmic antibody-associated vasculitis (AAV) and sarcoidosis, both of which have lung involvement. However, exhaustive research to assess the bacteria in the lung in AAV and in sarcoidosis have not been performed. We sought to elucidate the distinct dysbiotic lung microbiota between AAV and sarcoidosis. We used 16S rRNA gene high-throughput sequencing to obtain the bacterial community composition of bronchoalveolar lavage fluid (BALF) in patients with AAV (n = 16) compared to patients with sarcoidosis (n = 21). The patients had not undergone therapy with immunosuppressive medication when their BALF was acquired. No difference was observed in α-diversity between patients with AAV and patients with sarcoidosis when using all the detected taxa. We defined the taxa of the oral cavity by using the data of oral microbiota of healthy individuals from the Human Microbiome Project (HMP). The analysis using only oral taxa made the difference in α-diversity between AAV and sarcoidosis clearer compared with those using all the detected taxa. Besides, the analysis using detected taxa except for oral taxa also made the difference in α-diversity between AAV and sarcoidosis clearer compared with those using all the detected taxa. A linear negative relationship between the α-diversity and Birmingham vasculitis activity score (BVAS) was detected in the AAV group. The observed p-value for the effect of the disease groups on the ß-diversity was small while the effect of other factors including sex and smoking status did not have small p-values. By excluding oral taxa from all the detected taxa, we found a cluster mainly consisted of sarcoidosis patients which was characterized with microbial community monopolized by Erythrobacteraceae family. Our results suggested the importance of considering the influence of oral microbiota in evaluating lung microbiota.


Assuntos
Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/microbiologia , Anticorpos Anticitoplasma de Neutrófilos/imunologia , Bactérias/imunologia , Pulmão/imunologia , Pulmão/microbiologia , Microbiota/imunologia , Sarcoidose/microbiologia , Idoso , Idoso de 80 Anos ou mais , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/imunologia , Bactérias/genética , Líquido da Lavagem Broncoalveolar/imunologia , Líquido da Lavagem Broncoalveolar/microbiologia , Feminino , Humanos , Masculino , Microbiota/genética , Pessoa de Meia-Idade , RNA Ribossômico 16S/genética , Sarcoidose/imunologia
17.
Nat Immunol ; 21(7): 746-755, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32514064

RESUMO

Plasma membranes of animal cells are enriched for cholesterol. Cholesterol-dependent cytolysins (CDCs) are pore-forming toxins secreted by bacteria that target membrane cholesterol for their effector function. Phagocytes are essential for clearance of CDC-producing bacteria; however, the mechanisms by which these cells evade the deleterious effects of CDCs are largely unknown. Here, we report that interferon (IFN) signals convey resistance to CDC-induced pores on macrophages and neutrophils. We traced IFN-mediated resistance to CDCs to the rapid modulation of a specific pool of cholesterol in the plasma membrane of macrophages without changes to total cholesterol levels. Resistance to CDC-induced pore formation requires the production of the oxysterol 25-hydroxycholesterol (25HC), inhibition of cholesterol synthesis and redistribution of cholesterol to an esterified cholesterol pool. Accordingly, blocking the ability of IFN to reprogram cholesterol metabolism abrogates cellular protection and renders mice more susceptible to CDC-induced tissue damage. These studies illuminate targeted regulation of membrane cholesterol content as a host defense strategy.


Assuntos
Infecções Bacterianas/imunologia , Toxinas Bacterianas/imunologia , Hidroxicolesteróis/metabolismo , Interferons/isolamento & purificação , Fagócitos/imunologia , Estreptolisinas/imunologia , Animais , Bactérias/imunologia , Bactérias/metabolismo , Proteínas de Bactérias/administração & dosagem , Proteínas de Bactérias/imunologia , Proteínas de Bactérias/metabolismo , Toxinas Bacterianas/metabolismo , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular/imunologia , Células Cultivadas , Modelos Animais de Doenças , Suscetibilidade a Doenças/imunologia , Feminino , Interações entre Hospedeiro e Microrganismos/imunologia , Humanos , Microscopia Intravital , Masculino , Camundongos , Camundongos Transgênicos , Fagócitos/citologia , Fagócitos/metabolismo , Cultura Primária de Células , Esteroide Hidroxilases/genética , Esteroide Hidroxilases/metabolismo , Estreptolisinas/administração & dosagem , Estreptolisinas/metabolismo
18.
Sci Rep ; 10(1): 7805, 2020 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-32385373

RESUMO

Transplantation of germ-free (GF) mice with microbiota from mice or humans stimulates the intestinal immune system in disparate ways. We transplanted a human microbiota into GF C57BL/6 mice and a murine C57BL/6 microbiota into GF C57BL/6 mice and Swiss-Webster (SW) mice. Mice were bred to produce an offspring generation. 56% of the Operational Taxonomic Units (OTUs) present in the human donor microbiota established in the recipient mice, whereas 81% of the C57BL/6 OTUs established in the recipient C57BL/6 and SW mice. Anti-inflammatory bacteria such as Faecalibacterium and Bifidobacterium from humans were not transferred to mice. Expression of immune-related intestinal genes was lower in human microbiota-mice and not different between parent and offspring generation. Expression of intestinal barrier-related genes was slightly higher in human microbiota-mice. Cytokines and chemokines measured in plasma were differentially present in human and mouse microbiota-mice. Minor differences in microbiota and gene expression were found between transplanted mice of different genetics. It is concluded that important immune-regulating bacteria are lost when transplanting microbiota from humans to C57BL/6 mice, and that the established human microbiota is a weak stimulator of the murine immune system. The results are important for study design considerations in microbiota transplantation studies involving immunological parameters.


Assuntos
Bactérias/imunologia , Microbioma Gastrointestinal/imunologia , Sistema Imunitário/microbiologia , Transplantes/microbiologia , Animais , Bifidobacterium , Colo/microbiologia , Microbioma Gastrointestinal/genética , Vida Livre de Germes/genética , Humanos , Camundongos , Camundongos Endogâmicos C57BL
19.
Am J Physiol Gastrointest Liver Physiol ; 318(5): G907-G911, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32249590

RESUMO

The mammalian intestine is host to a vast number of microbial organisms. The immune system must balance tolerance with innate and adaptive defense mechanisms to maintain homeostasis with the microbial community. Interestingly, microbial metabolites have been shown to play a role in shaping the host immune response, thus assisting with adaptations that have significant implications for human health and disease. New investigations have uncovered roles for metabolites in modulating almost every aspect of the immune system. In this minireview, we survey these recent findings, which taken together reveal nuanced interactions that we are just beginning to understand.


Assuntos
Bactérias/metabolismo , Microbioma Gastrointestinal , Imunidade Inata , Imunidade nas Mucosas , Mucosa Intestinal/microbiologia , Animais , Anticorpos/metabolismo , Linfócitos B/imunologia , Linfócitos B/metabolismo , Bactérias/imunologia , Interações Hospedeiro-Patógeno , Humanos , Mediadores da Inflamação/metabolismo , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Linfócitos/imunologia , Linfócitos/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Neuroimunomodulação , Transdução de Sinais , Linfócitos T/imunologia , Linfócitos T/metabolismo
20.
Adv Exp Med Biol ; 1254: 105-116, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32323273

RESUMO

Immunoglobulin A (IgA) is the major immunoglobulin isotype produced by the gut immune system, and many studies revealed key roles of IgA in establishing host-bacteria mutualism. This chapter will review current understandings for the function of gut IgA in regulating commensal microbiota. IgA specifically recognizes bacterial species that strongly stimulate host's immune responses, and suppresses their overgrowth or reduces the expressions of bacterial pro-inflammatory genes. On the other hand, IgA coatings on symbiotic bacteria enhance bacteria-mucus and bacteria-bacteria interactions, which induce production of metabolites enforcing mucosal barrier functions. Such diversified effects suggest that multiple factors may be involved in the mechanisms of IgA-bacteria interactions, including IgA specificity to microbial epitopes, mode of cellular responses of IgA synthesis (T-dependent and T-independent) and post-translational modifications of IgA proteins, such as glycosylation.


Assuntos
Microbioma Gastrointestinal/imunologia , Homeostase , Imunoglobulina A/imunologia , Bactérias/imunologia , Simbiose
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