Project description:The aim of this study was to characterize the transcriptional signature of MDR1+ human memory T cells isolated from clinically inflamed gut tissue, and compare it to local MDR1- memory T cells Human mononuclear cells were isolated from the peripheral blood of a healthy adult donor (Ficol density centrifugation) or from resected lesioned gut tissue of a patient with active Crohn's disease. For cell isolation from gut tissue, tissue was rinsed with PBS, treated with 0.15% DTT to remove mucous, then with 1 mM EDTA to remove epithelial cells and intra-epithelial lymphocytes. Remaining tissue was digested using Liberase-TL (Roche) plus 10 U/mL DNase I. Mononuclear cells were then filtered through 70 mM nylon filters and isolated via a 30%/ 70% Percol gradient. Mononuclear cells from blood or gut tissue were FACS-sorted into CD3+ CD4+ CD45RO+ MDR1+ or MDR1- memory T cells, using Rhodamine 123 (Rh123) efflux as a surrogate for MDR1 expression/ activity. Sorted cells were harvested directly ex vivo (without further in vitro culture or manipulation) prior to RNA extraction. MDR1- memory CD4+ T cells vs. MDR1+ memory CD4+ T cells from healthy donor peripheral blood or from active Crohn's disease lesioned tissue; MDR1- or MDR1+ memory CD4+ T cells from blood vs. inflamed gut tissue
Project description:Gut microbiome research is rapidly moving towards the functional characterization of the microbiota by means of shotgun meta-omics. Here, we selected a cohort of healthy subjects from an indigenous and monitored Sardinian population to analyze their gut microbiota using both shotgun metagenomics and shotgun metaproteomics. We found a considerable divergence between genetic potential and functional activity of the human healthy gut microbiota, in spite of a quite comparable taxonomic structure revealed by the two approaches. Investigation of inter-individual variability of taxonomic features revealed Bacteroides and Akkermansia as remarkably conserved and variable in abundance within the population, respectively. Firmicutes-driven butyrogenesis (mainly due to Faecalibacterium spp.) was shown to be the functional activity with the higher expression rate and the lower inter-individual variability in the study cohort, highlighting the key importance of the biosynthesis of this microbial by-product for the gut homeostasis. The taxon-specific contribution to functional activities and metabolic tasks was also examined, giving insights into the peculiar role of several gut microbiota members in carbohydrate metabolism (including polysaccharide degradation, glycan transport, glycolysis and short-chain fatty acid production). In conclusion, our results provide useful indications regarding the main functions actively exerted by the gut microbiota members of a healthy human cohort, and support metaproteomics as a valuable approach to investigate the functional role of the gut microbiota in health and disease.
Project description:Dietary intake of fruits and vegetables (FV) has been inversely associated with lower risk of ulcerative colitis. A pig model was used to evaluate the impact of feeding FV on the host response to dextran sulfate sodium (DSS)-induced colitis. Methods: Six-week-old pigs were fed a grower diet alone or supplemented with lyophilized FV equivalent to the half (half-FV) or full (full-FV) daily levels recommended for humans by the Dietary Guidelines for Americans (DGA). Pigs were fed a 1) grower diet alone (negative control), 2) grower diet and orally treated with 4% DSS for 10 days to induce colitis (positive control), 3) half-FV diet treated with 4% DSS or 4) full-FV diet treated with 4% DSS. Pigs were monitored for the development of clinical signs of colitis. Proximal colon (PC) contents and mucosa (PCM) were collected for gut metagenome, tissue transcriptome and histopathological analysis. Results: Pigs fed the full-FV diet did not exhibit diarrhea, showed less fecal occult blood (FOB), PCM crypt hyperplasia but with no differential expressed genes (DEG) or changes in PC microbiome diversity (p < 0.05). Pigs within the half-FV group exhibited increased group FOB and DEG associated with tissue remodeling, crypt and goblet cell hyperplasia in the PCM and no changes in PC microbiome diversity and two pigs exhibiting diarrhea (p < 0.05). Pigs within the DSS positive control group exhibited a reduced DEG involved with intestinal immune response and PC microbiome diversity with altered metagenome, increased group PCM erosion and FOB with persistent diarrhea in one pig (p < 0.05) Conclusions: Overall, our results showed that pigs fed a three-week full-FV supplemented diet, were resistant to DSS-induced colitis with a differential dose-dependent protective effect on host intestinal tissue and gut metagenome when exposed to an inflammatory challenge.