Project description:Host Defense Peptides (HDPs) such as cathelicidins are multifunctional effectors of the innate immune system with both antimicrobial and pleiotropic immunomodulatory functions. Chicken cathelicidin-2 (CATH-2) has multiple immunomodulatory effects in vitro and the D-amino acid analog of this peptide has been shown to partially protect young chicks from a bacterial infection. However, the mechanisms responsible for CATH-2 mediated in vivo protection have not been investigated so far. In this study, D-CATH-2 was administered in ovo and the immune status and microbiota of the chicks were investigated at 7 days posthatch to elucidate the in vivo mechanisms of the peptide. In three consecutive studies, no effects on numbers and functions of immune cells were found and only small changes were seen in gene expression of PBMCs. Between studies, intestinal microbiota composition was highly variable, suggesting that it was strongly influenced by environmental factors. In both studies, in ovo D-CATH-2 treatment caused significant reduction of Ruminococcaceae and Butyricicoccus in the cecum and Escherichia/Shigella in both ileum and cecum. In conclusion, this study shows that, in the absence of an infectious stimulus, in ovo administration of a CATH-2 analog alters the microbiota composition, but does not affect the chicks immune system posthatch. Overall design: Expression profiling of PBMCs from chicks treated in ovo with cathelicidin-2 or placebo
Project description:Advanced age is associated with chronic low-grade inflammation, which is usually referred to as inflammaging. Elderly are also known to have an altered gut microbiota composition. However, whether inflammaging is a cause or consequence of an altered gut microbiota composition is not clear. In this study gut microbiota from young or old conventional mice was transferred to young germ-free mice. Four weeks after gut microbiota transfer immune cell populations in spleen, Peyer’s patches, and mesenteric lymph nodes from conventionalized germ-free mice were analyzed by flow cytometry. In addition, whole-genome gene expression in the ileum was analyzed by microarray. Gut microbiota composition of donor and recipient mice was analyzed with 16S rDNA sequencing. Here we show by transferring aged microbiota to young germ-free mice that certain bacterial species within the aged microbiota promote inflammaging. This effect was associated with lower levels of Akkermansia and higher levels of TM7 bacteria and Proteobacteria in the aged microbiota after transfer. The aged microbiota promoted inflammation in the small intestine in the germ-free mice and enhanced leakage of inflammatory bacterial components into the circulation was observed. Moreover, the aged microbiota promoted increased T cell activation in the systemic compartment. In conclusion, these data indicate that the gut microbiota from old mice contributes to inflammaging after transfer to young germ-free mice. Overall design: Gut microbiota from young or old conventional mice was transferred to young germ-free mice. Four weeks after gut microbiota transfer whole-genome gene expression in the distal ileum was analyzed by microarray.
Project description:We found that mainstream cigarette smoking (4 cigarettes/day, 5 days/week for 2 weeks using Kentucky Research Cigarettes 3R4F) resulted in >20% decrease in the percentage of normal Paneth cell population in Atg16l1 T300A mice but showed minimal effect in wildtype littermate control mice, indicating that Atg16l1 T300A polymorphism confers sensitivity to cigarette smoking-induced Paneth cell damage. We performed cohousing experiments to test if Paneth cell phenotype is horizontally transmissible as is microbiota. Atg16l1 T300A and littermate controls that were exposed to cigarette smoking were used as microbiota donors, and these donor mice were exposed to smoking for 2 weeks prior to cohousing. Separate groups of Atg16l1 T300A and littermate controls that were not exposed to cigarette smoking were used as microbiota recipients. The microbiota recipients were co-housed with microbiota donors of the same genotype for 4 weeks, during this period the donors continued to be exposed to cigarette smoking. Cigarette smoking was performed using smoking chamber with the dosage and schedule as described above. At the end of the experiment, the fecal microbiota composition was analyzed by 16S rRNA sequencing.
Project description:During the last few decades, the long-lasting consequences of nutritional programming during the early phase of life have become increasingly evident, but the effects of maternal nutrition on the developing intestine are currently still relatively underexplored. In this study, we investigated in mice the effects of a maternal Western-style (WS) high fat/cholesterol diet, given during the perinatal period, on gene expression and microbiota composition of two-week-old offspring. Microarray analysis revealed that a perinatal WS diet caused significant changes in gene expression in the small intestine and colon of the suckling offspring. A strong sexually dimorphic effect was observed in the affected genes. However, pathway analysis of the differentially expressed genes displayed that in both sexes metabolic and immune functions were strongly affected. Integration of the microbiota and gene expression data applying a multivariate correlation analyses revealed that Bacteroidaceae, Porphyromonadaceae and Lachnospiraceae were the bacterial families that most strongly correlated with gene expression in the colon and not with the bacterial families displaying the most pronounced change due to perinatal exposure to a WS diet. Amongst the genes demonstrating a strong correlation with one or more bacterial families were genes of key importance for intestinal development or functioning (i.e., Pitx2 and Ace2). In conclusion, our data demonstrate a strong programming effect of a maternal WS diet on the development of the intestine in the offspring. Small intestine and colon were isolated from two-week-old pups of dams fed a low- or Western-style high fat/cholesterol diet and subjected to gene expression profiling.
Project description:The intestinal microbiota has been identified as an environmental factor that markedly impacts energy storage and body fat accumulation, yet the underlying mechanisms remain unclear. Here we show that the microbiota regulates body composition through the circadian transcription factor NFIL3. Nfil3 transcription oscillates diurnally in intestinal epithelial cells and the amplitude of the circadian oscillation is controlled by the microbiota through type 3 innate lymphoid cells (ILC3), STAT3, and the epithelial cell circadian clock. NFIL3 controls expression of a circadian lipid metabolic program and regulates lipid absorption and export in intestinal epithelial cells. These findings provide mechanistic insight into how the intestinal microbiota regulates body composition and establish NFIL3 as an essential molecular link among the microbiota, the circadian clock, and host metabolism. Overall design: 1. RNAseq analysis of epithelial cell transcripts in Nfil3fl/fl and Nfil3ΔIEC mice at 6 time points across a circadian cycle. Laser captured epithelial cells from 3 mice were pooled together for RNAseq at each time point. 2. 16s sequencing analysis of fecal bacterial composition in Nfil3fl/fl and Nfil3ΔIEC mice before and after switching from chow diet to high-fat diet.
Project description:Persistent mucosal inflammation and microbial infection are characteristic of Chronic Rhinosinusitis (CRS). Though mucosal microbiota dysbiosis is a characteristic feature of other chronic inflammatory diseases, the relationship between sinus microbiota composition and CRS is unknown. Here we demonstrate, using comparative microbiome profiling of a cohort of CRS patients and healthy subjects, that the sinus microbiota of CRS patients exhibit significantly reduced bacterial diversity. Characteristic of this community collapse is the depletion of multiple, phylogenetically distinct, Lactic Acid Bacteria and the concomitant increase in relative abundance of a single species, Corynebacterium tuberculostearicum. Recapitulating the conditions observed in our human cohort in a murine model confirmed the pathogenic potential of C. tuberculostearicum and the critical necessity for a replete mucosal microbiota to protect against this species. Moreover, we provide evidence that Lactobacillus sakei, identified from our comparative microbiome analyses as a potentially protective species, affords defense against C. tuberculostearicum sinus infection, even in the context of a depleted sinus bacterial community. These studies demonstrate that sinus mucosal health is highly dependent on the composition of the resident microbiota, and identifies a new sino-pathogen and a strong bacterial candidate for therapeutic intervention. A total of 14 samples were profiled for microbiome composition: 7 from non-sinusitis patients, and 7 from patients with clinically diagnosed chronic sinusitis.
Project description:The aim of this study is to characterise and compare the composition of the microbiota from sputum samples of cystic fibrosis sufferers from different centres. These data are part of a pre-publication release. For information on the proper use of pre-publication data shared by the Wellcome Trust Sanger Institute (including details of any publication moratoria), please see http://www.sanger.ac.uk/datasharing/
Project description:Maternal obesity alters placental tissue function and morphology with a corresponding increase in local inflammation. We and others showed that placenta size, inflammation and fetal growth are regulated by maternal diet and obesity status. Maternal obesity alters placental DNA methylation which in turn could likely impact gene transcription of of proteins critical for normal fetal development. RNA-binding motif single-stranded interacting protein 1 (RBMS1) is expressed by the placenta and likely modulates DNA replication and transcription regulation. Serum RBMS1 protein concentration is increased with maternal obesity and RBMS1 gene expression in liver tissue is induced by a high-fat diet and inflammation. However, it is not yet known whether placental RBMS1 mRNA expression and DNA methylation are altered by maternal obesity. Overall design: Methylation profiles of frozen placental tissue samples from overweight/obese (BMI>25) and non-overweight (BMI<25) were anaylzed
Project description:Chronic acid suppression by proton pump inhibitor (PPI) has been hypothesized to alter the gut microbiota via a change in intestinal pH. To evaluate the changes in gut microbiota composition by long-term PPI treatment. Twenty-four week old F344 rats were fed with (n = 5) or without (n = 6) lansoprazole (PPI) for 50 weeks. Then, profiles of luminal microbiota in the terminal ileum were analyzed. Pyrosequencing for 16S rRNA gene was performed by genome sequencer FLX (454 Life Sciences/Roche) and analyzed by metagenomic bioinformatics.
Project description:A mucus layer covers and protects the intestinal epithelial cells from direct contact with microbes. This mucus layer not only prevents inflammation but also plays an essential role in microbiota colonization, indicating the complex interplay between mucus composition-microbiota and intestinal health. However, it is unknown whether the mucus layer is influenced by age or sex and whether this contributes to reported differences in intestinal diseases in males and females or with ageing. Therefore, in this study we investigated the effect of age on mucus thickness, intestinal microbiota composition and immune composition in relation to sex. The ageing induced shrinkage of the colonic mucus layer was associated with bacterial penetration and direct contact of bacteria with the epithelium in both sexes. Additionally, several genes involved in the biosynthesis of mucus were downregulated in old mice, especially in males, and this was accompanied by a decrease in abundances of various Lactobacillus species and unclassified Clostridiales type IV and XIV and increase in abundance of the potential pathobiont Bacteroides vulgatus. The changes in mucus and microbiota in old mice were associated with enhanced activation of the immune system as illustrated by a higher percentage of effector T cells in old mice. Our data contribute to a better understanding of the interplay between mucus-microbiota-and immune responses and ultimately may lead to more tailored design of strategies to modulate mucus production in targeted groups. Overall design: Young (3 months) and old (19 months) male and female C57B1 mice were sacrificed by cervical dislocation. Approximately 1 cm of proximal colon was removed for microarray analysis.