Project description:Braun/murein lipoprotein (Lpp) is one of the major outer membrane components of gram-negative bacteria belonging to the enterobacteriaceae family that that is involved in inflammatory responses and septic shock. We previously characterized a delta-lpp isogenic mutant of Yersinia pestis CO92 and found that this mutant was defective in surviving in macrophages and was attenuated in a mouse inhalation model of plague when compared to the highly virulent wild-type (WT) bacterium. To better understand how deletion of the lpp gene might affect Yersinia virulence, we performed global transcriptional profiling of the genes in the WT Y. pestis CO92 and its delta-lpp mutant by using microarrays. The organisms were cultured at both 26 and 37 degrees Celsius to simulate the flea vector and mammalian host environments, respectively. Our data revealed vastly different effects of lpp mutation on the transcriptomes of Y. pestis grown at 37 versus 26°C. While the absence of Lpp resulted mainly in the down-regulation of metabolic genes at 26°C, the Y. pestis CO92 lpp mutant cultured at 37°C exhibited profound alterations in stress response and virulence genes, compared to the WT bacterium. We further investigated one of the stress-related genes (htrA) down-regulated in the lpp mutant relative to WT Y. pestis, as HtrA was previously shown to be important for intracellular survival of Y. enterocolitica in macrophages. Indeed, complementation of the delta-lpp mutant with the htrA gene in trans restored intracellular survival of the Y. pestis lpp mutant. Our results support a role for Lpp in Y. pestis CO92 adapatation to the host environment, possibly via transcriptional activation of htrA.
Project description:Quorum sensing is a cell to cell communication process that involves chemical signaling. Yersinia pestis, the agent of plague, has two functional AHL quorum sensing systems Ysp and Ype. For several reasons, it was not clear what effect AHL pathways have on virulence gene expression and survival in the two different hosts, flea and human. To investigate to what effect AHL quorum sensing has on gene expression, we conducted microarray studies comparing Yersinia pestis CO92 (∆pgm) to a double AHL mutant strain (∆pgm ΔypeIR) at 30°C.
Project description:Quorum sensing is a cell to cell communication process that involves chemical signaling. Yersinia pestis, the agent of plague, has two functional AHL quorum sensing systems Ysp and Ype. For several reasons, it was not clear what effect AHL pathways have on virulence gene expression and survival in the two different hosts, flea and human. To investigate to what effect AHL quorum sensing has on gene expression, we conducted microarray studies comparing Yersinia pestis CO92 (∆pgm) to a double AHL mutant strain (∆pgm ΔypeIR ΔyspIR) at 37°C.
Project description:Quorum sensing is a cell to cell communication process that involves chemical signaling. Yersinia pestis, the agent of plague, has two functional AHL quorum sensing systems Ysp and Ype. For several reasons, it was not clear what effect AHL pathways have on virulence gene expression and survival in the two different hosts, flea and human. To investigate to what effect Ysp AHL quorum sensing has on gene expression, we conducted microarray studies comparing Yersinia pestis CO92 (∆pgm) to a single AHL mutant strain (∆pgm ΔyspI) at 30°C.
Project description:Quorum sensing is a cell to cell communication process that involves chemical signaling. Yersinia pestis, the agent of plague, has two functional AHL quorum sensing systems Ysp and Ype. For several reasons, it was not clear what effect AHL pathways have on virulence gene expression and survival in the two different hosts, flea and human. To investigate to what effect Ysp AHL quorum sensing has on gene expression, we conducted microarray studies comparing Yersinia pestis CO92 (∆pgm) to a single AHL mutant strain (∆pgm ΔyspI) at 37°C.
Project description:Quorum sensing is a cell to cell communication process that involves chemical signaling. Yersinia pestis, the agent of plague, has two functional AHL quorum sensing systems Ysp and Ype. For several reasons, it was not clear what effect AHL pathways have on virulence gene expression and survival in the two different hosts, flea and human. To investigate to what effect AHL quorum sensing has on gene expression, we conducted microarray studies comparing Yersinia pestis CO92 (âpgm) to a double AHL mutant strain (âpgm ÎypeIR ÎyspIR) at 37°C. Six independent RNA samples from Y. pestis CO92 R114 AHL deficient cultures were paired with six independent RNA samples from control Y. pestis CO92 R88 cultures for hybridization to six two-color microarrays. For three arrays, the control RNA sample was labeled with Alexa 555 dye and the experimental RNA sample was labeled with Alexa 647 dye; the dyes were reversed for the other three arrays to account for any dye bias.
Project description:Quorum sensing is a cell to cell communication process that involves chemical signaling. Yersinia pestis, the agent of plague, has two functional AHL quorum sensing systems Ysp and Ype. For several reasons, it was not clear what effect AHL pathways have on virulence gene expression and survival in the two different hosts, flea and human. To investigate to what effect AHL quorum sensing has on gene expression, we conducted microarray studies comparing Yersinia pestis CO92 (â??pgm) to a double AHL mutant strain (â??pgm Î?ypeIR) at 30°C. Six independent RNA samples from Y. pestis CO92 Î?pgm Î?ypeIR cultures were paired with six independent RNA samples from control Y. pestis CO92 R88 cultures for hybridization to six two-color microarrays. For three arrays, the control RNA sample was labeled with Alexa 555 dye and the experimental RNA sample was labeled with Alexa 647 dye; the dyes were reversed for the other three arrays to account for any dye bias.
Project description:Quorum sensing is a cell to cell communication process that involves chemical signaling. Yersinia pestis, the agent of plague, has two functional AHL quorum sensing systems Ysp and Ype. For several reasons, it was not clear what effect AHL pathways have on virulence gene expression and survival in the two different hosts, flea and human. To investigate to what effect Ysp AHL quorum sensing has on gene expression, we conducted microarray studies comparing Yersinia pestis CO92 (âpgm) to a single AHL mutant strain (âpgm ÎyspI) at 37°C. Six independent RNA samples from Y. pestis CO92 Îpgm ÎyspI cultures were paired with six independent RNA samples from control Y. pestis CO92 R88 cultures for hybridization to six two-color microarrays. For three arrays, the control RNA sample was labeled with Alexa 555 dye and the experimental RNA sample was labeled with Alexa 647 dye; the dyes were reversed for the other three arrays to account for any dye bias.
Project description:Quorum sensing is a cell to cell communication process that involves chemical signaling. Yersinia pestis, the agent of plague, has two functional AHL quorum sensing systems Ysp and Ype. For several reasons, it was not clear what effect AHL pathways have on virulence gene expression and survival in the two different hosts, flea and human. To investigate to what effect Ysp AHL quorum sensing has on gene expression, we conducted microarray studies comparing Yersinia pestis CO92 (âpgm) to a single AHL mutant strain (âpgm ÎyspI) at 30°C. Six independent RNA samples from Y. pestis CO92 Îpgm ÎyspI cultures were paired with six independent RNA samples from control Y. pestis CO92 R88 cultures for hybridization to six two-color microarrays. For three arrays, the control RNA sample was labeled with Alexa 555 dye and the experimental RNA sample was labeled with Alexa 647 dye; the dyes were reversed for the other three arrays to account for any dye bias.