ABSTRACT: Comparative genome characterization of Leptospira interrogans from mild and severe leptospirosis patients using Next-generation sequencing data
Project description:The overall goal of these experiments was to determine how human endothelial cells respond to pathogenic Leptospira interrogans. Leptospira interrogans causes leptospirosis, the most widespread zoonotic infection in the world. A hallmark of leptospirosis is widespread endothelial damage, which in severe cases leads to hemorrhage. In these experiments, we infected two endothelial cell lines with pathogenic Leptospira interrogans serovar Canicola strain Ca12-005, and as controls, with the non-pathogenic Leptospira biflexa serovar Patoc strain Pfra. As additional controls, uninfected cells were also included in the analyses.
Project description:The overall goal of these experiments was to determine how human endothelial cells respond to pathogenic Leptospira interrogans. Leptospira interrogans causes leptospirosis, the most widespread zoonotic infection in the world. A hallmark of leptospirosis is widespread endothelial damage, which in severe cases leads to hemorrhage. In these experiments, we infected two endothelial cell lines with pathogenic Leptospira interrogans serovar Canicola strain Ca12-005, and as controls, with the non-pathogenic Leptospira biflexa serovar Patoc strain Pfra. As additional controls, uninfected cells were also included in the analyses.
Project description:The overall goal of these experiments was to determine how human endothelial cells respond to pathogenic Leptospira interrogans. Leptospira interrogans causes leptospirosis, the most widespread zoonotic infection in the world. A hallmark of leptospirosis is widespread endothelial damage, which in severe cases leads to hemorrhage. In these experiments, we infected two endothelial cell lines with pathogenic Leptospira interrogans serovar Canicola strain Ca12-005, and as controls, with the non-pathogenic Leptospira biflexa serovar Patoc strain Pfra. As additional controls, uninfected cells were also included in the analyses. The cell line used fhere was a microvascular endothelial line, HMEC (Ades et al, 1992. HMEC-1: establishment of an immortalized human microvascular endothelial cell line. J Invest Dermatol. 99:683-690); due to loss of the original analysis files, only raw data files are provided. Infection times were performed at a multiplicity of infection (# bacteria/endothelial cell) of 10 for either 1 hour or 3 hours, after which RNA was harvested and reverse transcribed. Labeled cDNAs were used to probe HEEBO arrays purchased from Microarrays Inc. (Nashville, TN). In each of three biological replicate experiments, for each time point, three comparisons were made. First, the L. interrogans-infected cells were compared to the L. biflexa-infected cells. Second, the L. Interrogans-infected cells were compared to the uninfected cells. Third, the L. biflexa-infected cells were compared to the uninfected cells. A second endothelial cell line,
Project description:The overall goal of these experiments was to determine how human endothelial cells respond to pathogenic Leptospira interrogans. Leptospira interrogans causes leptospirosis, the most widespread zoonotic infection in the world. A hallmark of leptospirosis is widespread endothelial damage, which in severe cases leads to hemorrhage. In these experiments, we infected two endothelial cell lines with pathogenic Leptospira interrogans serovar Canicola strain Ca12-005, and as controls, with the non-pathogenic Leptospira biflexa serovar Patoc strain Pfra. As additional controls, uninfected cells were also included in the analyses. The cell line used was Ea.hy926, a macrovascular line (Edgell, C. J.,et al. 1990. In vitro Cell. & Dev. Biol. 26:1167-1172, and Edgell, C. J., et al. 1983. Proc. Natl. Acad. Sci. 80:3734-3737). Infection times were performed at a multiplicity of infection (# bacteria/endothelial cell) of 10 for either 1 hour or 3 hours, after which RNA was harvested and reverse transcribed. Labeled cDNAs were used to probe HEEBO arrays purchased from Microarrays Inc. (Nashville, TN). In each of three biological replicate experiments, for each time point, three comparisons were made. First, the L. interrogans-infected cells were compared to the L. biflexa-infected cells. Second, the L. Interrogans-infected cells were compared to the uninfected cells. Third, the L. biflexa-infected cells were compared to the uninfected cells. A second endothelial cell line, HMEC (Ades et al, 1992. HMEC-1: establishment of an immortalized human microvascular endothelial cell line. J Invest Dermatol. 99:683-690), which is of microvascular origin, was also used; raw data files are provided separately.
Project description:Leptospirosis, an emerging zoonotic disease with worldwide distribution, is caused by spirochetes belonging to the genus Leptospira. More than 500,000 cases of severe leptospirosis are reported annually, with .10% of these being fatal. Leptospires can survive for weeks in suitably moist conditions before encountering a new host. Reservoir hosts, typically rodents, exhibit little to no signs of disease but shed large numbers of organisms in their urine. Transmission occurs when mucosal surfaces or abraded skin come into contact with infected urine or urine-contaminated water or soil. In humans, leptospires can cause a variety of clinical manifestations, ranging from asymptomatic or mild fever to severe icteric (Weil’s) disease and pulmonary haemorrhage. Currently, little is known about how Leptospira persist within a reservoir host. Prior in vitro studies have suggested that leptospires alter their transcriptomic and proteomic profiles in response to environmental signals encountered during mammalian infection. However, no study has examined gene expression by leptospires within a mammalian host-adapted state. To obtain a more faithful representation of how leptospires respond to host-derived signals, we used RNA-Seq to compare the transcriptome of L. interrogans cultivated within dialysis membrane chambers (DMCs) implanted into the peritoneal cavities of rats with that of organisms grown in vitro. In addition to determining the relative expression levels of ‘‘core’’ housekeeping genes under both growth conditions, we identified 166 genes that are differentially-expressed by L. interrogans in vivo. Our analyses highlight physiological aspects of host adaptation by leptospires relating to heme uptake and utilization. We also identified 11 novel non-coding transcripts that are candidate small regulatory RNAs. The DMC model provides a facile system for studying the transcriptional and antigenic changes associated with mammalian host-adaption, selection of targets for mutagenesis, and the identification of previously unrecognized virulence determinants. Transcriptome analysis of L. interrogans Copenhageni FIOCRUZ L1-130 using RNA from 2 different conditions using RNA-seq. Also, the reproducibility and robustness of data is ensured by three biological replicates from each condition.
Project description:Leptospira, the causative agent of leptospirosis is known to have several proteases with potential to degrade extracellular matrix. However, a multipronged approach to identify, classify, characterize and elucidate their role has not been attempted. In this study, we carried out in-depth proteomic analysis of Triton X-114 fractions of Leptospira interrogans using high-resolution LC-MS/MS.
Project description:Pathogenic Leptospira spp. are the causative agents of the zoonotic disease leptospirosis. During infection, Leptospira are confronted with deadly reactive oxygen species (ROS). Withstanding ROS produced by the host innate immunity is an important strategy evolved by pathogenic Leptospira for persisting in and colonizing hosts. The peroxide stress regulator, PerRA, represses genes involved in ROS defenses in L. interrogans. We have identified an ORF encoding a putative second PerR in pathogenic Leptospira that we named PerRB. We have determined the transcriptomic profil of a single perRB and a double perRAperRB mutants. The concomitant inactivation of perRA and perRB has a pleiotropic effect on the transcriptomic profil of L. interrogans. The lack of both PerRA and PerRB regulators led to the differential expression of several virulence-associated genes and a loss of virulence. Our findings provide new insights into a new regulatory network that controls virulence and host colonization.
Project description:Leptospirosis, an emerging zoonotic disease with worldwide distribution, is caused by spirochetes belonging to the genus Leptospira. More than 500,000 cases of severe leptospirosis are reported annually, with .10% of these being fatal. Leptospires can survive for weeks in suitably moist conditions before encountering a new host. Reservoir hosts, typically rodents, exhibit little to no signs of disease but shed large numbers of organisms in their urine. Transmission occurs when mucosal surfaces or abraded skin come into contact with infected urine or urine-contaminated water or soil. In humans, leptospires can cause a variety of clinical manifestations, ranging from asymptomatic or mild fever to severe icteric (Weil’s) disease and pulmonary haemorrhage. Currently, little is known about how Leptospira persist within a reservoir host. Prior in vitro studies have suggested that leptospires alter their transcriptomic and proteomic profiles in response to environmental signals encountered during mammalian infection. However, no study has examined gene expression by leptospires within a mammalian host-adapted state. To obtain a more faithful representation of how leptospires respond to host-derived signals, we used RNA-Seq to compare the transcriptome of L. interrogans cultivated within dialysis membrane chambers (DMCs) implanted into the peritoneal cavities of rats with that of organisms grown in vitro. In addition to determining the relative expression levels of ‘‘core’’ housekeeping genes under both growth conditions, we identified 166 genes that are differentially-expressed by L. interrogans in vivo. Our analyses highlight physiological aspects of host adaptation by leptospires relating to heme uptake and utilization. We also identified 11 novel non-coding transcripts that are candidate small regulatory RNAs. The DMC model provides a facile system for studying the transcriptional and antigenic changes associated with mammalian host-adaption, selection of targets for mutagenesis, and the identification of previously unrecognized virulence determinants.
Project description:Leptospira, the causative agent of leptospirosis is known to have several proteases with potential to degrade extracellular matrix. However, a multipronged approach to identify, classify, characterize and elucidate their role has not been attempted. In this study, we carried out in-depth proteomic analysis of Triton X-114 fractions of Leptospira interrogans using high-resolution LC-MS/MS. Our analysis resulted in the identification of 104 of 130 proteases predicted by MEROPS. Approximately 3.5% of the Leptospira genome complements for proteases, which include catalytic types of metallo-, serine-, cysteine-, aspartic-, threonine- and asparagine- peptidases. Comparison of proteases from different serovars revealed that M04, M09B, M14A, M75, M28A, A01 and U73 protease families are exclusively present in pathogenic form. The M23 and S33 protease families are represented with more than 14 members in Leptospira. In silico prediction and characterization of the proteases revealed that several proteases are membrane anchored and secretory, classical as well as non-classical system. This study demonstrates the diversity and complexity of proteases, while maintaining conservation across the serovars in Leptospira and their differential expression under pathogenic conditions.
Project description:Pathogenic Leptospira spp. are the causative agents of the zoonotic disease leptospirosis. During infection, Leptospira are confronted with deadly reactive oxygen species (ROS). Withstanding ROS produced by the host innate immunity is an important strategy evolved by pathogenic Leptospira for persisting in and colonizing hosts. The peroxide stress regulator, PerR, represses genes involved in ROS defenses in L. interrogans. We have performed RNA sequencing in WT and perR mutant strains to characterize the L. interrogans adaptive response to hydrogen peroxide. We showed that Leptospira solicit three main peroxidase machineries (catalase, cytochrome C peroxidase and peroxiredoxin) and heme to adapt to peroxide stress as well as canonical chaperones of the heat shock response, and DNA repair. Determining the PerR regulon allowed to identify the PerR-dependent mechanisms of the peroxide adaptive response and has revealed a regulatory network involving other transcriptional regulators, two-component systems and sigma factors as well as non-coding RNAs that putatively orchestrate, in concert with PerR, this adaptive response. Our findings provide comprehensive insight into the mechanisms required by pathogenic Leptospira to overcome infection-related oxidants. This will participate in framing future hypothesis-driven studies to identify and decipher novel virulence mechanisms.