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:To study characteristics of the orapharyngeal epithelia which may influence susceptibility or resistance to HIV, we performed microarray analysis of the tonsil and gingival epithelium.Tonsil epithelium has been implicated in HIV pathogenesis, but its role in oral transmission remains controversial. We performed microarray analysis of Laser Capture Microdissected tonsil and gingival epithelium. Our data revealed that genes related to immune functions such as antibody production and antigen processing were increasingly expressed in tonsil compared to the epithelium of another oro-pharyngeal site, gingival epithelium. Importantly, tonsil epithelium highly expressed genes associated with HIV entrapment and/or transmission, including the HIV co-receptor CXCR4 and the potential HIV binding molecules, FcRγIII, complement receptor 2, and various complement components. This increased expression of molecules involved in viral recognition, binding and entry may favor virus-epithelium interaction in an environment with reduced innate anti-viral mechanisms. Specifically, secretory leukocyte protease inhibitor, an innate molecule with anti-HIV activity, was minimal in the tonsil epithelium, in contrast to oral mucosa. Collectively, our data suggest that increased expression of molecules associated with HIV binding and entry coupled with decreased innate anti-viral factors may render the tonsil a potential site for oral transmission. Experiment Overall Design: To study characteristics of the orapharyngeal epithelia which may influence susceptibility or resistance to HIV, we performed microarray analysis of the tonsil and gingival epithelium. Experiment Overall Design: Human palatine tonsils were obtained from routine therapeutic tonsillectomies (sleep apnea and non-tonsillitis) performed on otherwise healthy adults at the George Washington University Hospital with informed consent (IRB #099920). Gingival tissues were collected from healthy sites with probing depths < 3mm, with no clinical evidence of inflammation during routine therapeutic periodontal surgery at the University of Maryland, Department of Periodontics, with informed consent (IRB#1201211). Tissues were immediately snap frozen for the microarray studies. CM performed immediately at 10x magnification, using a Leica AS LMD system (Leica Microsystems). Areas unequivocally identified as epithelium were outlined , laser-dissected and captured and RNA from the tissues isolated. Preparation of biotin-labeled cRNA, hybridization, and scanning were performed according to manufacturerâs two cycle protocol (Affymetrix, Santa Clara, CA). Fluorescence intensity was measured using the Affymetrix GeneChip scanner and GeneChip Operating Software (GCOS, Affymetrix). Experiment Overall Design: Samples GSM173679, GSM173680,GSM173681, GSM173682, GSM173683, GSM173684, GSM173685, GSM173686, GSM173688, GSM173690 were processed togehter as "batch 1", while samples GSM173687 and GSM173689 were processed as "batch 2" together with sample GSM173691 which is a repeat of GSM173690, which was processed for comparison between the two batches. Experiment Overall Design:
Project description:The purpose of this study is to describe the effects of allogeneic stem cell transplant on oral microbiota and to examine differences in those patients who acquired respiratory complications. Forty-five patients were consented for the study and followed for 100 days post-transplant. Eleven patients represented by 115 speciment had specimens collected before and after transplant were subjected to further analysis. The Human Oral Microbe Identification Microarray was used for this analysis. In these 11 patients, five developed respiraotry complications after transplant and six did not develop this complication. Cluster analysis was used to identify patterns in the data.