"NV17-31248A"
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Závěrečná zpráva o řešení grantu Agentury pro zdravotnický výzkum MZ ČR
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Mechanismus vzniku autoimunitního procesu je stále předmětem intenzívního výzkumu. Jedna z hypotéz určuje za spouštěcí prvek u geneticky predisponovaných jedinců infekční proces. Hlavním cílem navrhovaného projektu je získat nové poznatky o mechanismu vzniku a možnostech ovlivnění zrak-ohrožující autoimunitní uveitidy. Zvláštní důraz bude kladen na objasnění vlivu mikroorganismů (včetně komensálních) a podíl vrozené imunity v procesu uveitidy a na jejich cílenou regulaci. K dosažení těchto cílů bude využita analýza nitroočních tekutin, séra a mikrobiomu pacientů s autoimunitní uveitidou a model experimentální autoimunitní uveitidy (EAU) u myši, včetně unikátního modelu gnotobiotického. Výsledky získané z pokusů na experimentálním modelu budou porovnány s klinickým výzkumem u pacientů s autoimunitní uveitidou. Získané poznatky přispějí k navržení nového léčebného protokolu uveitid v humánní medicíně, a tím k dosažení vyšší kvality prevence slepoty následkem uveitidy.; Significant effort has been made to understand mechanisms leading to the initiation of autoimmune diseases. One hypothesis determines infection as the triggering cause in genetically predisposed individuals. The main aim of this project is to gain new knowledge of the mechanisms and possibilities of regulation of sight-threatening autoimmune uveitis. Special emphasis will be put on clarifying the influence of microorganisms (including commensal bacteria) and participation of innate immunity in the process of uveitis, and their directed regulation. To achieve these goals, the analysis of intraocular fluids, serum and microbiome of patients with autoimmune uveitis, and model of the experimental autoimmune uveitis (EAU) in mice, including the unique gnotobiotic model, will be used. The experimental results will be compared to those from clinical research of patients with autoimmune uveitis. The acquired data will contribute to the definition of new therapeutic strategies in human uveitis and thus help to attain a higher quality of prevention of blindness in affected patients.
- MeSH
- autoimunitní nemoci mikrobiologie MeSH
- Escherichia coli MeSH
- gnotobiologické modely MeSH
- lidé MeSH
- mikrobiota MeSH
- modely nemocí na zvířatech MeSH
- myši MeSH
- přirozená imunita MeSH
- probiotika terapeutické užití MeSH
- uveitida mikrobiologie MeSH
- zánět prevence a kontrola MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- Konspekt
- Ortopedie. Chirurgie. Oftalmologie
- NLK Obory
- oftalmologie
- alergologie a imunologie
- mikrobiologie, lékařská mikrobiologie
- NLK Publikační typ
- závěrečné zprávy o řešení grantu AZV MZ ČR
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.
- 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
The world-wide incidence of many immune-mediated and metabolic diseases, including those of the intestines and liver, is steadily increasing. Gut microbiota plays a central role in the pathogenesis of these diseases as it mediates environmental changes to the intestinal immune system. Various environmental factors including diet, food additives and medication also trigger the compositional and functional alterations of microbiota, that is, dysbiosis, and this dysbiosis is closely associated with many chronic inflammatory diseases. However, the causal relationship remains unclear for the majority of these diseases. In this review, we discuss essential epidemiological data, known pathogenetic factors including those of genetic and environmental nature, while mainly focusing on the role of gut microbiota in the development of selected intestinal and liver diseases. Using specific examples, we also briefly describe some of the most widely-used animal models including gnotobiotic models and their contribution to the research of pathogenetic mechanisms of the host-microbiota relationship.
- MeSH
- dysbióza mikrobiologie patofyziologie MeSH
- gnotobiologické modely fyziologie MeSH
- modely nemocí na zvířatech MeSH
- myši MeSH
- nemoci jater mikrobiologie patofyziologie MeSH
- nemoci střev mikrobiologie patofyziologie MeSH
- střevní mikroflóra fyziologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Autoimmune uveitis is a serious sightthreatening disease that in many cases fails to respond to conventional immunosuppressive or biological therapy. Experimental models used in research allow more detailed study of pathogenesis of the autoimmune process and testing new therapeutic strategies. Recent results show that infection can trigger autoimmune diseases, and some commensal microorganisms are essential in causing disease activity. The aim of this work was to assess the effect of broadspectrum antibiotics - combination of metronidazole and ciprofloxacin or metronidazole alone - on the intensity of intraocular inflammation in experimental autoimmune uveitis (EAU). EAU was induced in mouse strain C57BL/6J by interphotoreceptor retinoid- binding protein in complete Freund's adjuvant and pertussis toxin. The grade of uveitis was assessed clinically and histologically in haematoxylin and eosin- stained tissues. Lymphocytes and macrophages were detected in cryosections using the immunoperoxidase method with antibodies. The therapy was commenced one week before EAU induction and continued throughout the experiment. In addition, metronidazole treatment was also started two weeks before EAU induction. Antibiotics significantly reduced the intensity of uveitis compared to the control group (P < 0.05). The effects of combination of ciprofloxacin and metronidazole and of metronidazole alone were similar when the therapy started one week before EAU induction (P < 0.05). Metronidazole commenced two weeks before EAU induction and throughout the experiment suppressed the intensity of EAU with even higher statistical significance (P < 0.0001). It can be assumed that the high protective effect of metronidazole on EAU intensity may be due not only to its antimicrobial effect, but also to its immunomodulatory activity.
- MeSH
- ciprofloxacin farmakologie terapeutické užití MeSH
- metronidazol farmakologie terapeutické užití MeSH
- myši inbrední C57BL MeSH
- stupeň závažnosti nemoci MeSH
- uveitida komplikace farmakoterapie patologie MeSH
- zánět komplikace farmakoterapie patologie MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The worldwide incidence of many immune-mediated and metabolic diseases, initially affecting only the wealthy Western countries, is increasing rapidly. Many of these diseases are associated with the compositional and functional alterations of gut microbiota, i.e., dysbiosis. The most consistent markers of the dysbiosis are a decrease in microbiota diversity and an expansion of Proteobacteria. The role of food preservatives as potential triggers of gut microbiota dysbiosis has been long overlooked. Using a human microbiota-associated mouse model, we demonstrate that a mixture of common antimicrobial food additives induces dysbiosis characterised by an overgrowth of Proteobacteria phylum and a decrease in the Clostridiales order. Remarkably, human gut microbiota in a Nod2-deficient genetic background is even more susceptible to the induction of Proteobacteria dysbiosis by additives than the microbiota in a wild-type background. To conclude, our data demonstrate that antimicrobial food additives trigger gut microbiota dysbiosis in both wild-type and Nod2-deficient backgrounds and at the exposure levels reached in European populations. Whether this additive-modified gut microbiota plays a significant role in the pathogenesis of immune-mediated and metabolic diseases remains to be elucidated.
- Publikační typ
- časopisecké články MeSH
Každý jedinec žije v úzkém společenství s mikroorganizmy, které osidlují všechny epitelové povrchy sliznic a kůže. Stále rostoucí množství nových poznatků o významu komenzálních mikrobů pro zdraví vyvolává velký zájem o mikrobiotu napříč lékařskými obory. Mikrobiota, zejména střevní, hraje klíčovou roli ve vývoji a fungování řady fyziologických mechanizmů, zejména imunitních. Mikrobiota vytváří s hostitelem symbiotický vztah: podmiňuje imunologickou rovnováhu, umožňuje efektivní imunitní reakce a brání kolonizaci patogenními mikroorganizmy. Alterace vzájemného vztahu mikrobioty a hostitele (dysbióza) vede k vývoji zánětlivých, autoimunitních i nádorových chorob. Pro medicínu budoucnosti se nyní otevírají nové možnosti: ovlivnit složení a funkci mikrobioty i její interakce nejen změnou životního stylu a způsobu stravování, ale i přímo, probiotiky nebo přenosem fekální mikrobioty.
Each individual is colonized by broad spectrum of microbes. Recent surge of interest in microbiota across all fields of medicine was motivated by an increasing body of knowledge on how commensals influence human health. This is most notable in the gut, where most microbes reside, but microbes colonizing other niches, such as oral cavity or skin, may influence health as well. Microbiota fundamentally influences the immune system development and its perturbation, i.e. dysbiosis, is associated with many inflammatory, autoimmune and neoplastic diseases. Microbiota forms a symbiotic relationship with the host - maintaining balanced and efficient immune response and protects from colonization by pathogens. Modern medicine may benefit greatly by adopting these ideas for therapeutic or prophylactic purposes. These may include manipulation with microbiota by diet, changes in lifestyle or directly by probiotics or fecal microbiota transfer.
- MeSH
- lidé MeSH
- mikrobiota * imunologie MeSH
- probiotika terapeutické užití MeSH
- slizniční imunita * MeSH
- střevní mikroflóra imunologie MeSH
- zánět imunologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
The aim of this work was to test the hypothesis that antimicrobial food additives may alter the composition of human gut microbiota by selectively suppressing the growth of susceptible gut microbes. To explore the influence of antimicrobial food additives on the composition of the human gut microbiota, we examined the susceptibility of both aerobic and anaerobic gut bacteria to sodium benzoate, sodium nitrite, and potassium sorbate, and their combinations, using a broth microdilution method. The tested bacteria exhibited a wide range of susceptibilities to food additives. For example, the most susceptible strain, Bacteroides coprocola, was almost 580 times more susceptible to sodium nitrite than the most resistant strain, Enterococcus faecalis. However, most importantly, we found that gut microbes with known anti-inflammatory properties, such as Clostridium tyrobutyricum or Lactobacillus paracasei, were significantly more susceptible to additives than microbes with known proinflammatory or colitogenic properties, such as Bacteroides thetaiotaomicron or Enterococcus faecalis. Our data show that some human gut microbes are highly susceptible to antimicrobial food additives. We speculate that permanent exposure of human gut microbiota to even low levels of additives may modify the composition and function of gut microbiota and thus influence the host's immune system. Whether the effect of additive-modified gut microbiota on the human immune system could explain, at least in part, the increasing incidence of allergies and autoimmune diseases remains to be shown.
