Project description:To elucidate whether Enterotoxigenic Bacteroides fragilis (ETBF) plays a role in colorectal cancer tumorigenesis, a RNA-seq analysis was performed to compare the gene expression profiles of ETBF treated DLD-1 colorectal cancer cell lines.
Project description:Gut-educated IgA-secreting plasma cells that disseminate beyond the mucosa and into systemic tissues can help prevent disease in several contexts. Here we show, the commensal bacteria Bacteroides fragilis (Bf), is an efficient inducer of systemic IgA responses. The generation of bone marrow IgA plasma cells and high levels of serum IgA specific to Bf requires robust intestinal colonization. Bf-specific IgA responses were severely diminished in mice lacking Peyer’s patches, but not mice lacking a cecal patch. Colonization resulted in few changes in the host transcriptional profile in the gut, suggesting a commensal relationship. High levels of Bf-specific serum IgA, but not IgG, provided protection from peritoneal abscess formation in a bowel perforation model of Bf dissemination. These findings demonstrate a critical role for bacterial colonization and Peyer’s patches in the induction of robust systemic IgA responses that confer protection from bacterial dissemination originating from the gut.
Project description:Investigation of whole genome gene expression level changes in a Bacteroides fragilis NCTC 9343 delta-gmd-fcl delta-fkp mutant strain and a Bacteroides fragilis NCTC 9343 delta-lfg mutant strain, each as compared to the wild-type strain. The mutations engineered into these strains interfere with B. fragilis protein glycosylation.
Project description:Investigation of whole genome gene expression level changes in a Bacteroides fragilis NCTC 9343 delta-ungD1 delta-ungD2 double mutant compared to the wild-type strain. Keywords: expression analysis A six chip study using total RNA recovered from three separate wild-type cultures of Bacteroides fragilis NCTC 9343 and three separate cultures of a double mutant strain, Bacteroides fragilis NCTC 9343 delta-ungD1 delta-ungD2, in which ungD1 (BF1706) and ungD2 (BF2848) are deleted. Each chip measures the expression level of 4,302 genes from Bacteroides fragilis NCTC 9343 and the associated plasmid pBF9343 with fourteen 24-mer probe pairs (PM/MM) per gene, with three-fold technical redundancy.
Project description:Genome expression study of Bacteroides fragilis ATCC25285 strain containing the EcfO gene constitutively expressed from plasmid pFD340
Project description:Investigation of whole genome gene expression level changes in a Bacteroides fragilis NCTC 9343 delta-ungD1 delta-ungD2 delta-PSH triple mutant, compared to the wild-type strain. The mutations engineered into this strain render it acapsular. The mutants analyzed in this study are further described in Coyne, M. J., M. Chatzidaki-Livanis, L. C. Paoletti, and L. E. Comstock. 2008. Role of glycan synthesis in colonization of the mammalian gut by the bacterial symbiont Bacteroides fragilis. PNAS 105(35):13098-13103 (PID 18723678). A six chip study using total RNA recovered from three separate wild-type cultures of Bacteroides fragilis NCTC 9343 and three separate cultures of a triple mutant strain, Bacteroides fragilis NCTC 9343 delta-ungD1 delta-ungD2 delta-PSH, in which ungD1 (BF1706), ungD2 (BF2848), and six genes (BF3454 through BF3459) of the PSH capsular polysaccharide locus are truncated or deleted entirely. Each chip measures the expression level of 4,302 genes from Bacteroides fragilis NCTC 9343 and the associated plasmid pBF9343 with fourteen 24-mer probe pairs (PM/MM) per gene, with three-fold technical redundancy.
Project description:Bacteroides fragilis (Bf)'s T6SS locus has been characterized and shown to have functional activity in competition experiments. It has been demonstrated that symbiont nontoxigenic Bf strains have a more effective “weapon” effect on pathogenic Bf, which is realized through the activity of effector-immune (E-I) protein pairs. Intensive study of the T6SS structure has led to an understanding of certain issues related to its functional activity, but the exact regulatory mechanisms of E-I protein pair activity remain unclear. Proteomic annotation of T6SS components and detailed descriptions of all immune-effector pairs are currently available. In this research, we performed detailed proteogenomic analysis and subsequent proteomic annotation of the T6SS components of the toxigenic Bf BOB25. Fractionated cells, cultivated media and vesicles were prepared for proteome analysis by HPLC-MS/MS. Proteogenomic annotation and comparative genomic study of the T6SS loci of the toxigenic Bf BOB25 were carried out by comparison with the reference genomes of the following Bf strains: JIM10, NCTC 9343 and 638R. According to the data obtained, T6SS components were represented in all types of the analysed samples. The following components of the T6SS were identified in culture media and cells: ClpV (TssH), TssK, TssC, TssB, Hcp (TssD), and TetR. The predicted effector protein AKA51715.1 (VU15_08315) was also detected in media. The greatest amount of T6SS proteins, including the Hcp protein, was detected in the vesicle samples, which was also observed by TEM. Potential effectors, including AKA51715.1 (VU15_08315), AKA51716.1 (VU15_08320), AKA51728.1 (VU15_08385) and the immune protein AKA51727.1 (VU15_08380), were detected in vesicles. The presence of the immune and effector proteins in the Bf secretome indicates the high activity of the T6SS without bacterial competition. It is possible that the T6SS is also used by bacteria to regulate population size by altering the activity of different repertoires of E-I pairs.
Project description:Genome expression study of Bacteroides fragilis strain 638R comparing a EcfO null mutant with an empty vector to a anti-EcfO null mutant containing the EcfO gene on a plasmid under the control of an IPTG inducible promoter.