Project description:Although gut microbiomes are generally symbiotic or commensal, some of microbiomes become pathogenic under certain circumstances, which is one of key processes of pathogenesis. However, the factors involved in these complex gut-microbe interactions are largely unknown. Here we show that bacterial nucleoside catabolism using gut luminal uridine is required to boost inter-bacterial communications and gut pathogenesis in Drosophila. We found that uridine-derived uracil is required for DUOX-dependent ROS generation on the host side, whereas uridine-derived ribose induces quorum sensing and virulence gene expression on the bacterial side. Importantly, genetic ablation of bacterial nucleoside catabolism is sufficient to block the commensal-to-pathogen transition in vivo. Furthermore, we found that major commensal bacteria lack functional nucleoside catabolism, which is required to achieve gut-microbe symbiosis. The discovery of a novel role of bacterial nucleoside catabolism will greatly help to better understand the molecular mechanism of the commensal-to-pathogen transition in different contexts of host-microbe interactions.
Project description:Analysis of MyD88 as a putative mediator in host-microbe-interactions MyD88-Hairpin was micro-injected in Hydra AEP embryos. The resulting Hatchling D3 showed a patchy distribution of the transgene observed by GFP. By asexual reproduction via budding and constant selection for the marker gene GFP the transgene could be driven into different cell ines. Therefore two different cultures were established. Polyps that showed no GFP-Signal anymore (control) and Polyps with both, endodermal and ectodermal transgenic cell-lines (knockdown).
Project description:Azoarcus sp. BH72 is able to communicate via cell density-dependent gene regulation. Here, the impact of cell-free conditioned culture supernatants, obtained from stationary phase Azoarcus wild type cultures, on gene expression was investigated determining changes in transcript profiles when early exponential aerobic cultures were incubated with cell-free culture supernatants for one and four hours. Bacterial communication via quorum sensing (QS) is involved in the regulation of several cellular mechanisms such as metabolic processes, microbe-host interactions or biofilm formation. The nitrogen-fixing model endophyte of grasses Azoarcus sp. strain BH72 shows density-dependent gene regulation in the absence of common hydrophobic autoinducers for pilA encoding the structural protein of type IV pili that are essential for plant colonization. Here, we used a transcriptomic approach to identify target genes differentially regulated under QS conditions in conditioned supernatants in comparison to standard growth conditions. Analysis used RNA from the early exponential growth phase as control samples for comparison to the quorum-sensing condition samples taken at one hour and four hours after incubation with cell-free culture supernatants.
Project description:Yersinia pestis, the etiological agent of plague, is able to sense cell density by quorum sensing. The function of quorum sensing in Y. pestis is not clear. Here, the process of AHL quorum sensing was investigated by comparing transcript profiles when two AHL quorum-sensing signals are added in. The strain Δpgm (pigmentation-negative) mutant was called wild type. The two AHLs signals are N-(3-Oxooctanoyl)-L-homoserine lactone and N-Hexanoyl-DL-homoserine lactone.The control consisted of cells grown and treated under the same conditions without added signals.
Project description:Yersinia pestis, the etiological agent of plague, is able to sense cell density by quorum sensing. The function of quorum sensing in Y. pestis is not clear. Here, the process of quorum sensing was investigated by comparing transcript profiles when three quorum-sensing signals are added in. The strain ∆pgm (pigmentation-negative) mutant R88 was used as wild type. The three signals are AI-2, AHLs (N-(3-Oxooctanoyl)-L-homoserine lactone and N-Hexanoyl-DL-homoserine lactone).The control consisted of cells grown and treated under the same conditions without added signals.
Project description:Yersinia pestis, the etiological agent of plague, is able to sense cell density by quorum sensing. The function of quorum sensing in Y. pestis is not clear. Here, the process of AHL quorum sensing was investigated by comparing transcript profiles when two AHL quorum-sensing signals are added in. The strain ∆pgm (pigmentation-negative) mutant R88 was called wild type. The two AHLs signals are N-(3-Oxooctanoyl)-L-homoserine lactone and N-Hexanoyl-DL-homoserine lactone.The control consisted of cells grown and treated under the same conditions without added signals.
Project description:Yersinia pestis, the etiological agent of plague, is able to sense cell density by quorum sensing. The function of quorum sensing in Y. pestis is not clear. Here, the process of quorum sensing was investigated by comparing transcript profiles when three quorum-sensing signals are added in. The strain M-bM-^HM-^Fpgm (pigmentation-negative) mutant R88 was used as wild type. The three signals are AI-2, AHLs (N-(3-Oxooctanoyl)-L-homoserine lactone and N-Hexanoyl-DL-homoserine lactone).The control consisted of cells grown and treated under the same conditions without added signals. Six independent RNA samples from Y. pestis CO92 M-bM-^HM-^Fpgm cultures were paired with six independent RNA samples from 3 signals added cultures for hybridization to six two-color microarrays. A dye-swap design was used to remove the Cy5 and Cy3 dye bias.
Project description:The etiologic agent of bubonic plague, Yersinia pestis, senses cell density-dependent chemical signals to synchronize transcription between cells of the population in a process named quorum sensing. Though the closely related enteric pathogen Y. pseudotuberculosis uses quorum sensing system to regulate motility, the role of YpeIR quorum sensing in Y. pestis has been unclear. YpeIR is one of the AHL quorum sensing system in Y. pestis. In this study we performed transcriptional profiling experiments to identify Y. pestis YpeIR quorum sensing regulated functions at 37°C.
Project description:Yersinia pestis, the etiological agent of plague, is able to sense cell density by quorum sensing. The function of quorum sensing in Y. pestis is not clear. Here, the process of AHL quorum sensing was investigated by comparing transcript profiles when two AHL quorum-sensing signals are added in. The strain âpgm (pigmentation-negative) mutant R88 was called wild type. The two AHLs signals are N-(3-Oxooctanoyl)-L-homoserine lactone and N-Hexanoyl-DL-homoserine lactone.The control consisted of cells grown and treated under the same conditions without added signals. Six independent RNA samples from R88 cultures were paired with six independent RNA samples from two AHLs added cultures for hybridization to six two-color microarrays. A dye-swap design was used to remove the Cy5 and Cy3 dye bias.
Project description:Yersinia pestis, the etiological agent of plague, is able to sense cell density by quorum sensing. The function of quorum sensing in Y. pestis is not clear. Here, the process of AHL quorum sensing was investigated by comparing transcript profiles when two AHL quorum-sensing signals are added in. The strain Îpgm (pigmentation-negative) mutant was called wild type. The two AHLs signals are N-(3-Oxooctanoyl)-L-homoserine lactone and N-Hexanoyl-DL-homoserine lactone.The control consisted of cells grown and treated under the same conditions without added signals. Six independent RNA samples from Y. pestis CO92 Îpgm cultures were paired with six independent RNA samples from two AHLs added cultures for hybridization to six two-color microarrays. A dye-swap design was used to remove the Cy5 and Cy3 dye bias.