The gut microbiota influences the reactivity of the immune system, and Parabacteroides distasonis has emerged as an anti-inflammatory commensal. Here, we investigated whether its lysate could prevent severe forms of neuroinflammation in experimental autoimmune encephalomyelitis (EAE) in mice and how this preventive strategy affects the gut microbiota and immune response. Lysate of anaerobically cultured P. distasonis (Pd lysate) was orally administered to C57BL/6 mice in four weekly doses. One week later, EAE was induced and disease severity was assessed three weeks after induction. Fecal microbiota changes in both vehicle- and Pd lysate-treated animals was analyzed by 16S V3-V4 amplicon sequencing and qPCR, antimicrobial peptide expression in the intestinal mucosa was measured by qPCR, and immune cell composition in the mesenteric and inguinal lymph nodes was measured by multicolor flow cytometry. Pd lysate significantly delayed the development of EAE and reduced its severity when administered prior to disease induction. EAE induction was the main factor in altering the gut microbiota, decreasing the abundance of lactobacilli and segmented filamentous bacteria. Pd lysate significantly increased the intestinal abundance of the genera Anaerostipes, Parabacteroides and Prevotella, and altered the expression of antimicrobial peptides in the intestinal mucosa. It significantly increased the frequency of regulatory T cells, induced an anti-inflammatory milieu in mesenteric lymph nodes, and reduced the activation of T cells at the priming site. Pd lysate prevents severe forms of EAE by triggering a T regulatory response and modulating T cell priming to autoantigens. Pd lysate could thus be a future modulator of neuroinflammation that increases the resistance to multiple sclerosis.

• Klíčová slova
• Parabacteroides distasonis, experimental autoimmune encephalomyelitis, inflammation, microbiota, multiple sclerosis, regulatory T cells,
• MeSH
• Bacteroidetes imunologie   MeSH
• encefalomyelitida autoimunitní experimentální * imunologie   prevence a kontrola   MeSH
• myši inbrední C57BL * MeSH
• myši MeSH
• střevní mikroflóra * imunologie   MeSH
• střevní sliznice imunologie   mikrobiologie   metabolismus   MeSH
• T-lymfocyty imunologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Non-infectious uveitis is considered an autoimmune disease responsible for a significant burden of blindness in developed countries and recent studies have linked its pathogenesis to dysregulation of the gut microbiota. We tested the immunomodulatory properties of two probiotics, Escherichia coli Nissle 1917 (EcN) and E. coli O83:K24:H31 (EcO), in a model of experimental autoimmune uveitis (EAU). To determine the importance of bacterial viability and treatment timing, mice were orally treated with live or autoclaved bacteria in both preventive and therapeutic schedules. Disease severity was assessed by ophthalmoscopy and histology, immune phenotypes in mesenteric and cervical lymph nodes were analyzed by flow cytometry and the gut immune environment was analyzed by RT-PCR and/or gut tissue culture. EcN, but not EcO, protected against EAU but only as a live organism and only when administered before or at the time of disease induction. Successful prevention of EAU was accompanied by a decrease in IRBP-specific T cell response in the lymph nodes draining the site of immunization as early as 7 days after the immunization and eye-draining cervical lymph nodes when the eye inflammation became apparent. Furthermore, EcN promoted an anti-inflammatory response in Peyer's patches, increased gut antimicrobial peptide expression and decreased production of inducible nitric oxide synthase in macrophages. In summary, we show here that EcN controls inflammation in EAU and suggest that probiotics may have a role in regulating the gut-eye axis.

• Klíčová slova
• Escherichia coli Nissle 1917, experimental autoimmune uveitis, macrophages, mucosal immune system, probiotics,
• MeSH
• autoimunitní nemoci terapie   MeSH
• Escherichia coli * MeSH
• modely nemocí na zvířatech MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• probiotika * aplikace a dávkování   farmakologie   MeSH
• střevní sliznice patologie   MeSH
• uveitida terapie   MeSH
• zánět terapie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Alterations in the gut microbiota composition and diversity seem to play a role in the development of chronic diseases, including inflammatory bowel disease (IBD), leading to gut barrier disruption and induction of proinflammatory immune responses. This opens the door for the use of novel health-promoting bacteria. We selected five Parabacteroides distasonis strains isolated from human adult and neonates gut microbiota. We evaluated in vitro their immunomodulation capacities and their ability to reinforce the gut barrier and characterized in vivo their protective effects in an acute murine model of colitis. The in vitro beneficial activities were highly strain dependent: two strains exhibited a potent anti-inflammatory potential and restored the gut barrier while a third strain reinstated the epithelial barrier. While their survival to in vitro gastric conditions was variable, the levels of P. distasonis DNA were higher in the stools of bacteria-treated animals. The strains that were positively scored in vitro displayed a strong ability to rescue mice from colitis. We further showed that two strains primed dendritic cells to induce regulatory T lymphocytes from naïve CD4+ T cells. This study provides better insights on the functionality of commensal bacteria and crucial clues to design live biotherapeutics able to target inflammatory chronic diseases such as IBD.

• Klíčová slova
• IBD, colitis, functional screening, holobiont, immune response, live biotherapeutic products (LBP), microbiota, probiotics,
• MeSH
• Bacteroidetes genetika   imunologie   izolace a purifikace   MeSH
• Caco-2 buňky MeSH
• DNA bakterií genetika   metabolismus   MeSH
• dospělí MeSH
• feces mikrobiologie   MeSH
• idiopatické střevní záněty imunologie   mikrobiologie   MeSH
• kolitida chemicky indukované   imunologie   mikrobiologie   MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• kyselina trinitrobenzensulfonová škodlivé účinky   MeSH
• lidé MeSH
• modely nemocí na zvířatech MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• novorozenec MeSH
• regulační T-lymfocyty imunologie   MeSH
• střevní mikroflóra imunologie   MeSH
• střevní sliznice imunologie   MeSH
• zvířata MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• myši MeSH
• novorozenec MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DNA bakterií MeSH
• kyselina trinitrobenzensulfonová MeSH

Diet is a major factor determining gut microbiota composition and perturbances in this complex ecosystem are associated with the inflammatory bowel disease (IBD). Here, we used gnotobiotic approach to analyze, how interaction between diet rich in proteins and gut microbiota influences the sensitivity to intestinal inflammation in murine model of ulcerative colitis. We found that diet rich in animal protein (aHPD) exacerbates acute dextran sulfate sodium (DSS)-induced colitis while diet rich in plant protein (pHPD) does not. The deleterious effect of aHPD was also apparent in chronic DSS colitis and was associated with distinct changes in gut bacteria and fungi. Therefore, we induced acute DSS-colitis in germ-free mice and transferred gut microbiota from aCD or aHPD fed mice to find that this effect requires presence of microbes and aHPD at the same time. The aHPD did not change the number of regulatory T cells or Th17 cells and still worsened the colitis in immuno-deficient RAG2 knock-out mice suggesting that this effect was not dependent on adaptive immunity. The pro-inflammatory effect of aHPD was, however, abrogated when splenic macrophages were depleted with clodronate liposomes. This treatment prevented aHPD induced increase in colonic Ly-6Chigh pro-inflammatory monocytes, but the ratio of resident Ly-6C-/low macrophages was not changed. These data show that the interactions between dietary protein of animal origin and gut microbiota increase sensitivity to intestinal inflammation by promoting pro-inflammatory response of monocytes.

• Klíčová slova
• colitis, dietary protein, germ-free, macrophage, microbiota,
• MeSH
• adaptivní imunita imunologie   MeSH
• buňky Th17 imunologie   metabolismus   MeSH
• dieta škodlivé účinky   MeSH
• dietní proteiny aplikace a dávkování   škodlivé účinky   MeSH
• DNA vazebné proteiny metabolismus   MeSH
• kolitida imunologie   metabolismus   patologie   MeSH
• kolon imunologie   metabolismus   patologie   MeSH
• makrofágy imunologie   metabolismus   patologie   MeSH
• modely nemocí na zvířatech MeSH
• monocyty imunologie   metabolismus   patologie   MeSH
• myši inbrední BALB C MeSH
• myši knockoutované MeSH
• myši MeSH
• regulační T-lymfocyty imunologie   metabolismus   MeSH
• střeva imunologie   patologie   MeSH
• střevní mikroflóra imunologie   fyziologie   MeSH
• zánět imunologie   metabolismus   patologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dietní proteiny MeSH
• DNA vazebné proteiny MeSH

BACKGROUND: Disturbances in the intestinal microbial community (i.e. dysbiosis) or presence of the microbes with deleterious effects on colonic mucosa has been linked to the pathogenesis of inflammatory bowel diseases. However the role of microbiota in induction and progression of ulcerative colitis (UC) has not yet been fully elucidated. METHODS: Three lines of human microbiota-associated (HMA) mice were established by gavage of colon biopsy from three patients with active UC. The shift in microbial community during its transferring from humans to mice was analyzed by next-generation sequencing using Illumina MiSeq sequencer. Spontaneous or dextran sulfate sodium (DSS)-induced colitis and microbiota composition profiling in germ-free mice and HMA mice over 3-4 generations were assessed to decipher the features of the distinctive and crucial events occurring during microbial colonization and animal reproduction. RESULTS: None of the HMA mice developed colitis spontaneously. When treated with DSS, mice in F4 generation of one line of colonized mice (aHMA) developed colitis. Compared to the DSS-resistant earlier generations of aHMA mice, the F4 generation have increased abundance of Clostridium difficile and decrease abundance of C. symbiosum in their cecum contents measured by denaturing gradient gel electrophoresis and DNA sequencing. CONCLUSION: In our study, mucosa-associated microbes of UC patients were not able to induce spontaneous colitis in gnotobiotic BALB/c mice but they were able to increase the susceptibility to DSS-induced colitis, once the potentially deleterious microbes found a suitable niche.

• Klíčová slova
• Dysbiosis, Germ-free mice, Microbiota, Ulcerative colitis,
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Microbial sensing by Toll-like receptors (TLR) and its negative regulation have an important role in the pathogenesis of inflammation-related cancer. In this study, we investigated the role of negative regulation of Toll-like receptors signaling and gut microbiota in the development of colitis-associated cancer in mouse model. METHODS: Colitis-associated cancer was induced by azoxymethane and dextran sodium sulfate in wild-type and in interleukin-1 receptor-associated kinase M (IRAK-M)-deficient mice with or without antibiotic (ATB) treatment. Local cytokine production was analyzed by multiplex cytokine assay or enzyme-linked immunosorbent assay, and regulatory T cells were analyzed by flow cytometry. Changes in microbiota composition during tumorigenesis were analyzed by pyrosequencing, and β-glucuronidase activity was measured in intestinal content by fluorescence assay. RESULTS: ATB treatment of wild-type mice reduced the incidence and severity of tumors. Compared with nontreated mice, ATB-treated mice had significantly lower numbers of regulatory T cells in colon, altered gut microbiota composition, and decreased β-glucuronidase activity. However, the β-glucuronidase activity was not as low as in germ-free mice. IRAK-M-deficient mice not only developed invasive tumors, but ATB-induced decrease in β-glucuronidase activity did not rescue them from severe carcinogenesis phenotype. Furthermore, IRAK-M-deficient mice had significantly increased levels of proinflammatory cytokines in the tumor tissue. CONCLUSIONS: We conclude that gut microbiota promotes tumorigenesis by increasing the exposure of gut epithelium to carcinogens and that IRAK-M-negative regulation is essential for colon cancer resistance even in conditions of altered microbiota. Therefore, gut microbiota and its metabolic activity could be potential targets for colitis-associated cancer therapy.

• MeSH
• azoxymethan toxicita   MeSH
• cytokiny genetika   metabolismus   MeSH
• gastrointestinální trakt mikrobiologie   MeSH
• karcinogeny toxicita   MeSH
• kinázy asociované s receptory interleukinu-1 fyziologie   MeSH
• kolitida chemicky indukované   komplikace   MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• messenger RNA genetika   MeSH
• metagenom * MeSH
• myši inbrední C57BL MeSH
• myši knockoutované MeSH
• myši MeSH
• nádory tračníku etiologie   metabolismus   patologie   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• průtoková cytometrie MeSH
• receptory interleukinu-1 metabolismus   MeSH
• regulační T-lymfocyty imunologie   metabolismus   patologie   MeSH
• signální transdukce MeSH
• síran dextranu toxicita   MeSH
• toll-like receptory genetika   metabolismus   MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• azoxymethan MeSH
• cytokiny MeSH
• Irak3 protein, mouse MeSH Prohlížeč
• karcinogeny MeSH
• kinázy asociované s receptory interleukinu-1 MeSH
• messenger RNA MeSH
• receptory interleukinu-1 MeSH
• síran dextranu MeSH
• toll-like receptory MeSH

BACKGROUND: Probiotic bacteria can be used for the prevention and treatment of human inflammatory diseases including inflammatory bowel diseases (IBD). However, the nature of active components and exact mechanisms of this beneficial effects have not been fully elucidated. Our aim was to investigate if lysate of probiotic bacterium L. casei DN-114 001 (Lc) could decrease the severity of intestinal inflammation in a murine model of IBD. METHODOLOGY/PRINCIPAL FINDINGS: The preventive effect of oral administration of Lc significantly reduces the severity of acute dextran sulfate sodium (DSS) colitis in BALB/c but not in SCID mice. In order to analyze how this beneficial effect interferes with well-known phases of intestinal inflammation pathogenesis in vivo and in vitro, we evaluated intestinal permeability using the FITC-labeled dextran method and analysed tight junction proteins expression by immunofluorescence and PCR. We also measured CD4(+)FoxP3(+) regulatory T cells proportion by FACS analysis, microbiota composition by pyrosequencing, and local cytokine production by ELISA. Lc leads to a significant protection against increased intestinal permeability and barrier dysfunction shown by preserved ZO-1 expression. We found that the Lc treatment increases the numbers of CD4(+)FoxP3(+) regulatory T cells in mesenteric lymph nodes (MLN), decreases production of pro-inflammatory cytokines TNF-α and IFN-γ, and anti-inflammatory IL-10 in Peyer's patches and large intestine, and changes the gut microbiota composition. Moreover, Lc treatment prevents lipopolysaccharide-induced TNF-α expression in RAW 264.7 cell line by down-regulating the NF-κB signaling pathway. CONCLUSION/SIGNIFICANCE: Our study provided evidence that even non-living probiotic bacteria can prevent the development of severe forms of intestinal inflammation by strengthening the integrity of intestinal barrier and modulation of gut microenvironment.

• MeSH
• aktivace makrofágů účinky léků   MeSH
• akutní nemoc MeSH
• aplikace orální MeSH
• down regulace účinky léků   MeSH
• fosfoproteiny metabolismus   MeSH
• imunita účinky léků   MeSH
• kolitida mikrobiologie   patologie   patofyziologie   prevence a kontrola   MeSH
• Lactobacillus casei metabolismus   MeSH
• lidé MeSH
• lipopolysacharidy farmakologie   MeSH
• membránové proteiny metabolismus   MeSH
• metagenom účinky léků   MeSH
• myši inbrední BALB C MeSH
• myši SCID MeSH
• myši MeSH
• NF-kappa B metabolismus   MeSH
• permeabilita účinky léků   MeSH
• počet lymfocytů MeSH
• probiotika aplikace a dávkování   farmakologie   MeSH
• protein zonula occludens 1 MeSH
• regulační T-lymfocyty cytologie   účinky léků   MeSH
• střevní sliznice účinky léků   imunologie   mikrobiologie   MeSH
• TNF-alfa biosyntéza   MeSH
• trávicí systém účinky léků   mikrobiologie   patofyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• fosfoproteiny MeSH
• lipopolysacharidy MeSH
• membránové proteiny MeSH
• NF-kappa B MeSH
• protein zonula occludens 1 MeSH
• TJP1 protein, human MeSH Prohlížeč
• Tjp1 protein, mouse MeSH Prohlížeč
• TNF-alfa MeSH

BACKGROUND: Oral thiopurines are effective and widely used in treatment of inflammatory bowel disease (IBD) in humans, although their use is limited due the development of adverse events. Here, we examine the efficacy and toxicity of oral treatment with 6-tioguanine (6-TG) and azathioprine (AZA) in a murine model of IBD. METHODS: We induced acute or chronic colitis in BALB/c mice by one or four cycles of 3% dextran sulphate sodium (DSS), respectively. Mice were treated by daily gavages of various dosages of 6-tioguanine, azathioprine, or by phosphate buffered saline (PBS) starting the first day of DSS or after two cycles of DSS, respectively. We monitored the efficacy and toxicity by measuring the weight change and serum alanine aminotransferase (ALT) activity and by disease severity and histology, at the end of the experiment. Moreover, we measured cytokine production after colon fragment cultivation by enzyme-linked immunoabsorbent assay and numbers of apoptotic cells in the spleen by flow cytometry. RESULTS: 6-TG is effective in the treatment of acute DSS-induced colitis in a dose-dependent manner and 40 μg of 6-TG is significantly more effective in the treatment of acute colitis than both AZA and PBS. This effect is accompanied by decrease of IL-6 and IFN-γ production in colon. We did not observe histological abnormalities in liver samples from control (PBS) or 6-TG treated mice. However, liver samples from most mice treated with AZA showed mild, yet distinct signs of hepatotoxicity. In chronic colitis, all thiopurine derivatives improved colitis, 20 μg of 6-TG per dose was superior. High doses of 6-TG led to significant weight loss at the end of the therapy, but none of the thiopurine derivatives increased levels of serum ALT. Both thiopurine derivatives reduced the proportion of apoptotic T helper cells, but a high production of both IL-6 and TGF-β was observed only in colon of AZA-treated mice. CONCLUSIONS: Use of 6-TG in the treatment of experimental colitis in mice appears superior to AZA administration and placebo. In contrast to 6-TG, the use of AZA resulted in histological liver abnormalities.

• MeSH
• akutní nemoc MeSH
• alanintransaminasa krev   MeSH
• analýza rozptylu MeSH
• apoptóza MeSH
• azathioprin terapeutické užití   toxicita   MeSH
• chronická nemoc MeSH
• hmotnostní úbytek účinky léků   MeSH
• interferon gama metabolismus   MeSH
• interleukin-6 metabolismus   MeSH
• játra účinky léků   patologie   MeSH
• kolitida krev   chemicky indukované   farmakoterapie   patologie   MeSH
• kolon metabolismus   patologie   MeSH
• modely u zvířat MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• síran dextranu MeSH
• T-lymfocyty pomocné-indukující MeSH
• thioguanin terapeutické užití   toxicita   MeSH
• transformující růstový faktor beta metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alanintransaminasa MeSH
• azathioprin MeSH
• interferon gama MeSH
• interleukin-6 MeSH
• síran dextranu MeSH
• thioguanin MeSH
• transformující růstový faktor beta MeSH

Metagenomic approaches are currently being used to decipher the genome of the microbiota (microbiome), and, in parallel, functional studies are being performed to analyze the effects of the microbiota on the host. Gnotobiological methods are an indispensable tool for studying the consequences of bacterial colonization. Animals used as models of human diseases can be maintained in sterile conditions (isolators used for germ-free rearing) and specifically colonized with defined microbes (including non-cultivable commensal bacteria). The effects of the germ-free state or the effects of colonization on disease initiation and maintenance can be observed in these models. Using this approach we demonstrated direct involvement of components of the microbiota in chronic intestinal inflammation and development of colonic neoplasia (i.e., using models of human inflammatory bowel disease and colorectal carcinoma). In contrast, a protective effect of microbiota colonization was demonstrated for the development of autoimmune diabetes in non-obese diabetic (NOD) mice. Interestingly, the development of atherosclerosis in germ-free apolipoprotein E (ApoE)-deficient mice fed by a standard low-cholesterol diet is accelerated compared with conventionally reared animals. Mucosal induction of tolerance to allergen Bet v1 was not influenced by the presence or absence of microbiota. Identification of components of the microbiota and elucidation of the molecular mechanisms of their action in inducing pathological changes or exerting beneficial, disease-protective activities could aid in our ability to influence the composition of the microbiota and to find bacterial strains and components (e.g., probiotics and prebiotics) whose administration may aid in disease prevention and treatment.

• MeSH
• autoimunitní nemoci etiologie   mikrobiologie   MeSH
• gastrointestinální trakt mikrobiologie   MeSH
• gnotobiologické modely * MeSH
• imunita MeSH
• lidé MeSH
• metagenom imunologie   MeSH
• modely nemocí na zvířatech MeSH
• nádory etiologie   mikrobiologie   MeSH
• sliznice imunologie   MeSH
• zánět etiologie   mikrobiologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH