Interleukin (IL)-17 protects epithelial barriers by inducing the secretion of antimicrobial peptides. However, the effect of IL-17 on Paneth cells (PCs), the major producers of antimicrobial peptides in the small intestine, is unclear. Here, we show that the targeted ablation of the IL-17 receptor (IL-17R) in PCs disrupts their antimicrobial functions and decreases the frequency of ileal PCs. These changes become more pronounced after colonization with IL-17 inducing segmented filamentous bacteria. Mice with PCs that lack IL-17R show an increased inflammatory transcriptional profile in the ileum along with the severity of experimentally induced ileitis. These changes are associated with a decrease in the diversity of gut microbiota that induces a severe ileum pathology upon transfer to genetically susceptible mice, which can be prevented by the systemic administration of IL-17a/f in microbiota recipients. In an exploratory analysis of a small cohort of pediatric patients with Crohn's disease, we have found that a portion of these patients exhibits a low number of lysozyme-expressing ileal PCs and a high ileitis severity score, resembling the phenotype of mice with IL-17R-deficient PCs. Our study identifies IL-17R-dependent signaling in PCs as an important mechanism that maintains ileal homeostasis through the prevention of dysbiosis.

• MeSH
• antimikrobiální peptidy MeSH
• dítě MeSH
• dysbióza mikrobiologie   MeSH
• ileitida * mikrobiologie   MeSH
• ileum mikrobiologie   MeSH
• interleukin-17 MeSH
• lidé MeSH
• mikrobiota * MeSH
• myši MeSH
• Panethovy buňky patologie   MeSH
• receptory interleukinu-17 * genetika   MeSH
• zánět patologie   MeSH
• zvířata MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

Salmonella Typhimurium is a Gram-negative bacterium that causes enterocolitis in humans and pigs. Lipopolysaccharide (LPS) is a component of the outer leaflet of Gram-negative bacteria that provokes endotoxin shock. LPS can be synthesized completely or incompletely and creates S (smooth) or R (rough) chemotypes. Toll-like receptors (TLR) 2, 4, and 9 initiate an inflammatory reaction to combat bacterial infections. We associated/challenged one-week-old gnotobiotic piglets with wild-type S. Typhimurium with S chemotype or its isogenic ∆rfa mutants with R chemotype LPS. The wild-type S. Typhimurium induced TLR2 and TLR4 mRNA expression but not TLR9 mRNA expression in the ileum and colon of one-week-old gnotobiotic piglets 24 h after challenge. The TLR2 and TLR4 stimulatory effects of the S. Typhimurium ∆rfa mutants were related to the completeness of their LPS chain. The transcription of IL-12/23 p40, IFN-γ, and IL-6 in the intestine and the intestinal and plasmatic levels of IL-12/23 p40 and IL-6 but not IFN-γ were related to the activation of TLR2 and TLR4 signaling pathways. The avirulent S. Typhimurium ∆rfa mutants are potentially useful for modulation of the TLR2 and TLR4 signaling pathways to protect the immunocompromised gnotobiotic piglets against subsequent infection with the virulent S. Typhimurium.

• MeSH
• gnotobiologické modely fyziologie   MeSH
• ileum metabolismus   mikrobiologie   MeSH
• kolon metabolismus   mikrobiologie   MeSH
• miniaturní prasata MeSH
• mutace fyziologie   MeSH
• prasata MeSH
• Salmonella typhimurium genetika   izolace a purifikace   MeSH
• salmonelóza genetika   metabolismus   patologie   MeSH
• toll-like receptor 4 metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The gut microbiota play an important role in shaping brain functions and behavior, including the activity of the hypothalamus-pituitary-adrenocortical (HPA) axis. However, little is known about the effect of the microbiota on the distinct structures (hypothalamus, pituitary, and adrenals) of the HPA axis. In the present study, we analyzed the influence of the microbiota on acute restraint stress (ARS) response in the pituitary, adrenal gland, and intestine, an organ of extra-adrenal glucocorticoid synthesis. Using specific pathogen-free (SPF) and germ-free (GF) male BALB/c mice, we showed that the plasma corticosterone response to ARS was higher in GF than in SPF mice. In the pituitary, stress downregulated the expression of the gene encoding CRH receptor type 1 (Crhr1), upregulated the expression of the Fkbp5 gene regulating glucocorticoid receptor sensitivity and did not affect the expression of the proopiomelanocortin (Pomc) and glucocorticoid receptor (Gr) genes. In contrast, the microbiota downregulated the expression of pituitary Pomc and Crhr1 but had no effect on Fkbp5 and Gr. In the adrenals, the steroidogenic pathway was strongly stimulated by ARS at the level of the steroidogenic transcriptional regulator Sf-1, cholesterol transporter Star and Cyp11a1, the first enzyme of steroidogenic pathway. In contrast, the effect of the microbiota was significantly detected at the level of genes encoding steroidogenic enzymes but not at the level of Sf-1 and Star. Unlike adrenal Sf-1, the expression of the gene Lrh-1, which encodes the crucial transcriptional regulator of intestinal steroidogenesis, was modulated by the microbiota and ARS and this effect differed between the ileum and colon. The findings demonstrate that gut microbiota have an impact on the response of the pituitary, adrenals and intestine to ARS and that the interaction between stress and the microbiota during activation of glucocorticoid steroidogenesis differs between organs. The results suggest that downregulated expression of pituitary Pomc and Crhr1 in SPF animals might be an important factor in the exaggerated HPA response of GF mice to stress.

• MeSH
• enzym štěpící postranní řetězce cholesterolu genetika   MeSH
• fosfoproteiny genetika   MeSH
• fyzické omezení * MeSH
• hypofýza metabolismus   MeSH
• ileum metabolismus   mikrobiologie   MeSH
• kolon metabolismus   mikrobiologie   MeSH
• kortikosteron krev   MeSH
• myši inbrední BALB C MeSH
• nadledviny metabolismus   MeSH
• pro-opiomelanokortin genetika   MeSH
• psychický stres krev   mikrobiologie   MeSH
• receptory hormonu uvolňujícího kortikotropin genetika   MeSH
• regulace genové exprese MeSH
• steroidogenní faktor 1 genetika   MeSH
• střevní mikroflóra * MeSH
• systém hypofýza - nadledviny * MeSH
• systém hypotalamus-hypofýza * MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

In this study, we addressed differences in the development of gut microbiota in 4 successive batches of commercially hatched broiler parent chickens. When planning this study, we expected to find a batch with compromised performance which would allow identification of microbiota of suboptimal composition. Microbiota composition was determined only by sequencing the V3/V4 region of 16S rRNA genes in samples collected from chickens 5 to 18 wk of age. In a total, 100 and 160 samples originating from the ileum or cecum were processed, respectively. In one of the flocks with suboptimal performance we identified an increased abundance of Helicobacter brantae forming over 80% of ileal microbiota in individual chickens. Moreover, we also tested samples of 53-wk-old hens from the same genetic line in which egg production decreased. In this case, cecal microbiota was enriched for Fusobacterium mortiferum forming over 30% of total cecal microbiota. Although none of the identified unusual microbiota members have been well recognized as pathogenic, they may represent new opportunistic pathogens of chickens worth of further investigation. Analysis of gut microbiota composition by next generation sequencing thus proved as a useful and unbiased alternative to bacterial culture, especially in the cases of unspecific symptoms like decrease in flock performance.

• MeSH
• Bacteria klasifikace   izolace a purifikace   MeSH
• bakteriální RNA analýza   MeSH
• cékum mikrobiologie   MeSH
• Fusobacterium izolace a purifikace   MeSH
• Helicobacter izolace a purifikace   MeSH
• ileum mikrobiologie   MeSH
• kur domácí mikrobiologie   MeSH
• RNA ribozomální 16S analýza   MeSH
• sekvenční analýza RNA veterinární   MeSH
• střevní mikroflóra * MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The Campylobacter jejuni-host interaction may be affected by the host's gut microbiota through competitive exclusion, metabolites, or modification of the immune response. To understand this interaction, C. jejuni colonization and local immune responses were compared in chickens with different gut microbiota compositions. Birds were treated with an antibiotic cocktail (AT) (experiments 1 and 2) or raised under germfree (GF) conditions (experiment 3). At 18 days posthatch (dph), they were orally inoculated either with 104 CFU of C. jejuni or with diluent. Cecal as well as systemic C. jejuni colonization, T- and B-cell numbers in the gut, and gut-associated tissue were compared between the different groups. Significantly higher numbers of CFU of C. jejuni were detected in the cecal contents of AT and GF birds, with higher colonization rates in spleen, liver, and ileum, than in birds with a conventional gut microbiota (P < 0.05). Significant upregulation of T and B lymphocyte numbers was detected in cecum, cecal tonsils, and bursa of Fabricius of AT or GF birds after C. jejuni inoculation compared to the respective controls (P < 0.05). This difference was less clear in birds with a conventional gut microbiota. Histopathological gut lesions were observed only in C. jejuni-inoculated AT and GF birds but not in microbiota-colonized C. jejuni-inoculated hatchmates. These results demonstrate that the gut microbiota may contribute to the control of C. jejuni colonization and prevent lesion development. Further studies are needed to identify key players of the gut microbiota and the mechanisms behind their protective role.

• MeSH
• antibakteriální látky farmakologie   MeSH
• B-lymfocyty imunologie   mikrobiologie   MeSH
• bursa Fabricii účinky léků   imunologie   mikrobiologie   MeSH
• Campylobacter jejuni účinky léků   imunologie   patogenita   MeSH
• cékum účinky léků   imunologie   mikrobiologie   MeSH
• gnotobiologické modely imunologie   MeSH
• ileum účinky léků   imunologie   mikrobiologie   MeSH
• interakce hostitele a patogenu imunologie   MeSH
• játra účinky léků   imunologie   mikrobiologie   MeSH
• kampylobakterové infekce imunologie   mikrobiologie   veterinární   MeSH
• kur domácí MeSH
• mikrobiální interakce imunologie   MeSH
• nemoci drůbeže imunologie   mikrobiologie   MeSH
• počet mikrobiálních kolonií MeSH
• slezina účinky léků   imunologie   mikrobiologie   MeSH
• střevní mikroflóra imunologie   MeSH
• T-lymfocyty imunologie   mikrobiologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Clostridium perfringens-induced necrotic enteritis is generally controlled by antibiotics. However, because of increasing antibiotic resistance, other antibacterial agents are required, preferably ones that do not affect the beneficial intestinal microbiota of the host. This study evaluated the in vitro selective growth-inhibitory effect of 8-hydroxyquinoline (8HQ) on C. perfringens vs. bifidobacteria in a medium containing chicken ileal digesta. Prior to the experiments, the minimum inhibitory concentrations of 8HQ and penicillin G were determined by broth microdilution assay. The minimum inhibitory concentration values of 8HQ for C. perfringens were 16-32 times lower than the values for bifidobacteria. Treatment of autoclaved and non-autoclaved chicken ileal digesta with 8HQ showed a selective anticlostridial effect. After incubation of C. perfringens with autoclaved ileal digesta for 3 h, all 8HQ concentrations tested (32-2048 μg/mL) significantly reduced C. perfringens bacterial count. In contrast, the same treatment had no or only a slight effect on bifidobacteria counts. Unlike 8HQ, penicillin G did not exhibit any selectivity. Similar results were obtained after incubation for 24 h. In non-autoclaved ileal digesta, all 8HQ concentrations tested significantly reduced C. perfringens bacterial counts after incubation for 30 min and 3 h, while no effect was observed on bifidobacteria. These results suggest that 8HQ may serve as a prospective veterinary compound for use against necrotic enteritis in poultry.

• MeSH
• antibakteriální látky farmakologie   MeSH
• Bifidobacterium účinky léků   MeSH
• Clostridium perfringens účinky léků   MeSH
• ileum mikrobiologie   MeSH
• klostridiové infekce prevence a kontrola   veterinární   virologie   MeSH
• kur domácí mikrobiologie   MeSH
• nemoci drůbeže prevence a kontrola   virologie   MeSH
• oxychinolin farmakologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Porcine ileum is populated with a high proportion of B cells but previous studies have shown that they are not developed there. While B cells prevail in the ileum even in germ-free animals, microbial colonization is a major factor that causes even a greater prevalence of B cells in the ileum and further differential representation of lymphoid cells throughout small intestine. Analysis of lymphoid subpopulations showed that the effector cells appear only after colonization. These include class-switched IgM(+)IgA(+) B cells, primed CD2(-)CD21(+) B cells, antibody-producing/memory CD2(+)CD21(-) B cells, and effector/memory CD4(+)CD8(+) αβ Th cells. While colonization resulted in a uniform distribution of effector cells throughout the gut, it caused a decrease in the frequency of cytotoxic αβ and CD2(+)CD8(+) γδ T cells. These results suggest that the ileum is a site where naive B cells expand presumably to increase antibody repertoire but the entire small intestine is immunofunctionally comparable.

• MeSH
• aktivace lymfocytů MeSH
• B-lymfocyty imunologie   mikrobiologie   MeSH
• Bacteria růst a vývoj   imunologie   MeSH
• CD antigeny metabolismus   MeSH
• cytotoxické T-lymfocyty imunologie   mikrobiologie   MeSH
• gnotobiologické modely imunologie   MeSH
• ileum imunologie   mikrobiologie   MeSH
• imunofenotypizace MeSH
• imunologická paměť MeSH
• mikrobiota imunologie   MeSH
• podskupiny B-lymfocytů imunologie   mikrobiologie   MeSH
• přesmyk imunoglobulinových tříd MeSH
• receptory antigenů T-buněk alfa-beta metabolismus   MeSH
• receptory antigenů T-buněk gama-delta metabolismus   MeSH
• Sus scrofa imunologie   MeSH
• T-lymfocyty pomocné-indukující imunologie   mikrobiologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The significance of maternal immunity against non-typhoid Salmonella spp. acquired by piglets via colostrum and milk was evaluated in a Salmonella enterica serovar Typhimurium challenge experiment. Piglets from sows vaccinated with an experimental inactivated vaccine exhibited high levels of serum immunoglobulins G and A against S. Typhimurium 4 days after birth, just prior to experimental oral challenge. The S. Typhimurium load in the ileal and caecal wall of piglets 3 days after experimental inoculation was lower by a 2-log magnitude compared to unvaccinated controls. Such a vaccine, delivering colostral/lactogenic immunity to piglets thus has the potential to reduce the prevalence non-typhoid Salmonella spp. infection.

• MeSH
• bakteriální nálož veterinární   MeSH
• bakteriální vakcíny imunologie   MeSH
• cékum mikrobiologie   MeSH
• ileum mikrobiologie   MeSH
• imunita získaná od matky * MeSH
• imunoglobulin A krev   MeSH
• imunoglobulin G krev   MeSH
• inaktivované vakcíny imunologie   MeSH
• kolostrum imunologie   MeSH
• mléko imunologie   MeSH
• nemoci prasat imunologie   mikrobiologie   MeSH
• novorozená zvířata MeSH
• prasata MeSH
• Salmonella typhimurium imunologie   MeSH
• salmonelová infekce u zvířat imunologie   mikrobiologie   MeSH
• slizniční imunita MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The colonization, translocation and protective effect of two intestinal bacteria - PR4 (pig commensal strain of Bifidobacterium choerinum) or EcN (probiotic Escherichia coli strain Nissle 1917) - against subsequent infection with a virulent LT2 strain of Salmonella enterica serovar Typhimurium were studied in gnotobiotic pigs after oral association. The clinical state of experimental animals correlated with bacterial translocation and levels of inflammatory cytokines [a chemokine, interleukin (IL)-8, a proinflammatory cytokine, tumour necrosis factor (TNF)-α and an anti-inflammatory cytokine, IL-10] in plasma and intestinal lavages. Gnotobiotic pigs orally mono-associated with either PR4 or EcN thrived, and bacteria were not found in their blood. No significant inflammatory cytokine response was observed. Mono-association with Salmonella caused devastating septicaemia characterized by high levels of IL-10 and TNF-α in plasma and TNF-α in the intestine. Di-associated gnotobiotic pigs were given PR4 or EcN for 24 h. Subsequently, they were infected orally with Salmonella and euthanized 24 h later. Pigs associated with bifidobacteria before Salmonella infection suffered from severe systemic infection and mounted similar cytokine responses as pigs infected with Salmonella alone. In contrast, EcN interfered with translocation of Salmonella into mesenteric lymph nodes and systemic circulation. Pigs pre-associated with EcN thrived and their clinical condition correlated with the absence of IL-10 in their plasma and a decrease of TNF-α in plasma and ileum.

• MeSH
• antibióza MeSH
• Bifidobacterium imunologie   MeSH
• cytokiny analýza   krev   MeSH
• Escherichia coli imunologie   MeSH
• gnotobiologické modely MeSH
• ileum imunologie   mikrobiologie   MeSH
• kolon imunologie   mikrobiologie   MeSH
• prasata MeSH
• probiotika terapeutické užití   MeSH
• Salmonella typhimurium imunologie   MeSH
• salmonelová infekce u zvířat imunologie   terapie   MeSH
• střeva imunologie   mikrobiologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

OBJECTIVES: Alarmin high mobility group box 1 (HMGB1) is essential for correct DNA folding and transcription. It can be released from damaged cells or secreted by stimulated cells. HMGB1 has been detected in serum or plasma as a late marker of sepsis, but its suitability as a marker of sepsis has been disputed. METHODS: One-week-old germ-free piglets were orally infected/colonized with enteric bacterial pathogens (Salmonella Typhimurium or Escherichia coli O55) or with probiotic bacteria (E. coli Nissle 1917) for 24 h. The transcriptions of HMGB1, interleukin (IL)-8, tumor necrosis factor (TNF)-α, and IL-10 (quantitative reverse transcription and polymerase chain reaction), their protein levels (ELISA), and clinical state of the piglets (somnolence, anorexia, diarrhea, tachycardia, tachypnea, and tremor) were estimated. RESULTS: The piglets infected with enteric pathogens suffered from infections. HMGB1 was transcribed in the terminal ileum constitutively, regardless of any bacterial presence. In contrast, the transcription of cytokines was upregulated by virulent bacteria. HMGB1, IL-8, and TNF-α levels in the ileum were increased by both enteric pathogens, while IL-10 levels increased in E. coli O55-infected piglets only. HMGB1 significantly increased in the plasma of piglets infected with virulent E. coli only, but cytokine levels were in most cases increased by both virulent bacteria. HMGB1 and cytokine levels in ileum lavages and plasma of piglets colonized with probiotic E. coli remained comparable to those of the non-stimulated germ-free piglets. CONCLUSION: The local and systemic expression of HMGB1, its relationship to the inflammatory cytokines, and clinical findings showed HMGB1 as a suitable marker of severity of sepsis in the gnotobiotic piglet infection model.

• MeSH
• bakteriální infekce krev   imunologie   mikrobiologie   MeSH
• biologické markery krev   MeSH
• ELISA MeSH
• Escherichia coli růst a vývoj   MeSH
• gnotobiologické modely MeSH
• ileum metabolismus   mikrobiologie   MeSH
• interleukin-10 krev   MeSH
• interleukin-8 krev   MeSH
• modely nemocí na zvířatech MeSH
• novorozená zvířata krev   imunologie   mikrobiologie   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• prasata MeSH
• protein HMGB1 krev   MeSH
• průjem MeSH
• Salmonella typhimurium růst a vývoj   MeSH
• sepse krev   imunologie   mikrobiologie   MeSH
• stupeň závažnosti nemoci MeSH
• tachykardie MeSH
• TNF-alfa krev   MeSH
• tremor MeSH
• zánět krev   imunologie   mikrobiologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH