Chlamydia trachomatis
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ABSTRACT:
PROVIDER: PRJNA175480 | ENA |
REPOSITORIES: ENA
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Project description:Chlamydia trachomatis causes chronic inflammatory diseases of the eye and genital tract of global medical importance. The chlamydial plasmid plays an important role in the pathophysiology of these diseases as plasmid-deficient organisms are highly attenuated. The plasmid encodes both noncoding RNAs and eight conserved ORFs of undefined function. To understand plasmid gene function we generated plasmid shuttle vectors with deletions in each of the eight ORFs. The individual deletion mutants were used to transform chlamydiae and the transformants were characterized in terms of plasmid biology and transcriptional profiling. We show that pgp1-2, -6 and -8 are essential for plasmid maintenance while the other ORFs can be deleted and the plasmid stably maintained. We further show that a pgp4 knockout mutant exhibits an in vitro phenotype similar to its isogenic plasmid-less strain in terms of abnormal inclusion morphology and lack of glycogen accumulation. Microarray and qRT-PCR analysis revealed that pgp4 is involved in transcriptional regulation of multiple chromosomal genes; including the glycogen synthase gene glgA. Based on our results, we propose that Pgp1 is a plasmid replicative helicase, Pgp2 is a plasmid replication protein, Pgp4 is a transcriptional regulator of virulence associated chromosomal genes, and Pgp6-8 are plasmid partitioning proteins. These findings have important implications for understanding the plasmidM-bM-^@M-^Ys role in chlamydial pathogenesis and the development of novel antigenically multivalent live-attenuated chlamydial vaccines. Chlamydia trachomatis wild type vs. two deletion mutants, and mock
2013-02-28 | E-GEOD-40979 | biostudies-arrayexpress
Project description:Chlamydia trachomatis causes chronic inflammatory diseases of the eye and genital tract of global medical importance. The chlamydial plasmid plays an important role in the pathophysiology of these diseases as plasmid-deficient organisms are highly attenuated. The plasmid encodes both noncoding RNAs and eight conserved ORFs of undefined function. To understand plasmid gene function we generated plasmid shuttle vectors with deletions in each of the eight ORFs. The individual deletion mutants were used to transform chlamydiae and the transformants were characterized in terms of plasmid biology and transcriptional profiling. We show that pgp1-2, -6 and -8 are essential for plasmid maintenance while the other ORFs can be deleted and the plasmid stably maintained. We further show that a pgp4 knockout mutant exhibits an in vitro phenotype similar to its isogenic plasmid-less strain in terms of abnormal inclusion morphology and lack of glycogen accumulation. Microarray and qRT-PCR analysis revealed that pgp4 is involved in transcriptional regulation of multiple chromosomal genes; including the glycogen synthase gene glgA. Based on our results, we propose that Pgp1 is a plasmid replicative helicase, Pgp2 is a plasmid replication protein, Pgp4 is a transcriptional regulator of virulence associated chromosomal genes, and Pgp6-8 are plasmid partitioning proteins. These findings have important implications for understanding the plasmid’s role in chlamydial pathogenesis and the development of novel antigenically multivalent live-attenuated chlamydial vaccines.
2013-02-28 | GSE40979 | GEO
Project description:To determine the role that GrgA plays in chlamydial physiology, we constructed a Chlamydia trachomatis mutant that we term L/cgad-peig, in which the chromosomal grgA (ctl0766 or ct504) has been disrupted by Targetron mutagenesis, and the plasmid carries an inducible grgA under the control of anhydrotetracycline (ATC). RNA-Seq analysis was performed for L2/cgad-peig grown with and without ATC.
2023-11-29 | GSE234589 | GEO
Project description:C. trachomatis possess a cryptic 7.5 kb plasmid of unknown function. Here we describe a comprehensive molecular and biological characterization of the naturally occurring plasmidless human Chlamydia trachomatis strain L2 (25667R). We found that despite minimal chromosomal polymorphisms the LGV L2 (25667R) strain was indistinguishable from the L2 (434) plasmid positive strain in its in vitro infectivity characteristics such as growth kinetics, plaquing efficiency, and plaque size. The primary in vitro phenotypic differences between L2 (434) and L2 (25667R) were the accumulation of glycogen granules in the inclusion matrix and the lack of the typical intra-inclusion Brownian-like movement characteristic of C. trachomatis strains. Conversely, we observed a marked difference between the two strains in their ability to colonize and infect the female mouse genital tract. The ID50 of the L2 (25667R) plasmidless strain was 500 fold greater (1.XX x 10X IFU) than the L2 (434) plasmid bearing strain (1. XX x 10X IFU). Transcriptome analysis of the two strains clearly demonstrated a decrease in transcript levels of a subset of chromosomal genes for the L2 (25667R) strain. Among those genes was glgA which encodes for glycogen synthase; a finding consistent with the failure of the L2 (25667R) strain to accumulate glycogen granules. Collectively, these findings support an important role for the plasmid in in vivo infectivity and suggest that this virulence characteristic might be controlled by the plasmids ability to regulate the expression of specific chromosomal genes. These results also support an important role for the plasmid in the pathogenesis of human infection and disease. Keywords: strain comparison C. trachomatis strain L2-25667R compared to strain L2-434
2010-05-06 | E-GEOD-10199 | biostudies-arrayexpress
Project description:C. trachomatis possess a cryptic 7.5 kb plasmid of unknown function. Here we describe a comprehensive molecular and biological characterization of the naturally occurring plasmidless human Chlamydia trachomatis strain L2 (25667R). We found that despite minimal chromosomal polymorphisms the LGV L2 (25667R) strain was indistinguishable from the L2 (434) plasmid positive strain in its in vitro infectivity characteristics such as growth kinetics, plaquing efficiency, and plaque size. The primary in vitro phenotypic differences between L2 (434) and L2 (25667R) were the accumulation of glycogen granules in the inclusion matrix and the lack of the typical intra-inclusion Brownian-like movement characteristic of C. trachomatis strains. Conversely, we observed a marked difference between the two strains in their ability to colonize and infect the female mouse genital tract. The ID50 of the L2 (25667R) plasmidless strain was 500 fold greater (1.XX x 10X IFU) than the L2 (434) plasmid bearing strain (1. XX x 10X IFU). Transcriptome analysis of the two strains clearly demonstrated a decrease in transcript levels of a subset of chromosomal genes for the L2 (25667R) strain. Among those genes was glgA which encodes for glycogen synthase; a finding consistent with the failure of the L2 (25667R) strain to accumulate glycogen granules. Collectively, these findings support an important role for the plasmid in in vivo infectivity and suggest that this virulence characteristic might be controlled by the plasmids ability to regulate the expression of specific chromosomal genes. These results also support an important role for the plasmid in the pathogenesis of human infection and disease. Keywords: strain comparison
2009-01-15 | GSE10199 | GEO
Project description:The obligate intracellular developmental cycle of Chlamydia trachomatis presents significant challenges in defining its proteome. In this study we have applied quantitative proteomics to both the intracellular reticulate body (RB) and the extracellular elementary body (EB) from C. trachomatis. We used C. trachomatis L2 which is a model chlamydial isolate for such a study since it has a high infectivity: particle ratio and there is an excellent quality genome sequence. EBs and RBs (>99% pure) were quantified by chromosomal and plasmid copy number using PCR to determine the concentrations of chlamydial proteins per bacterial cell. RBs harvested at 15h post infection (PI) were purified by three successive rounds of gradient centrifugation. This is the earliest possible time to obtain purified RBs, free from host cell components in quantity, within the constraints of the technology, EBs were purified at 48h PI. We then used two-dimensional reverse phase UPLC to fractionate RB or EB peptides before mass spectroscopic analysis, providing absolute amount estimates of chlamydial proteins.
2016-06-28 | PXD003025 | Pride
Project description:Heat shock-induced transcriptomic response in Chlamydia trachomatis
2021-12-08 | GSE173366 | GEO
Project description:In this project we examined the in-vitro effect of female sex hormones (estradiol and progesterone at average physiological concentrations) during a infection mediated by Chlamydia trachomatis serovar D, on the gene expression of human endometrial cell line ECC-1 The effects of the female sex hormones progesterone and oestradiol while infected by Chlamydia trachomatis were examined at two timepoints.
2011-08-02 | E-GEOD-31149 | biostudies-arrayexpress
Project description:Chlamydia trachomatis serovariants are responsible for either Trachoma, the leading cause of infectious blindness or sexually transmitted disease, wherein the endocervix is the most frequently infected site in women. Disease caused by Chlamydia typically involves chronic inflammation and scarring. Recent work with a live-attenuated A2497 plasmid deficient vaccine strain (A2497-) demonstrated protection in nonhuman primates against trachoma and a lack of measurable ocular pathology in A2497- infected monkeys. We therefore performed host cell transcriptome analysis of Hela cells infected with A2497 plasmid-containing (A2497) and A2497- Chlamydia over time. Our results indicate that relative to wild type A2497, the A2497- variant illicits a transcriptome response indicative of lowered inflammation response a delayed apoptosis response, a reduction in immune cell recruitement cytokine expression and a reduction in genes involved in cell proliferation and or fibrosis-like activities. The data provided here suggests a model that may explain how plasmid deficient chlamydia may provide an immuno-protective response without the pathology normally seen with plasmid-containing bacteria. Ct infection with and without plasmid time series
2014-11-25 | E-GEOD-56168 | biostudies-arrayexpress
Project description:Chlamydia trachomatis serovariants are responsible for either Trachoma, the leading cause of infectious blindness or sexually transmitted disease, wherein the endocervix is the most frequently infected site in women. Disease caused by Chlamydia typically involves chronic inflammation and scarring. Recent work with a live-attenuated A2497 plasmid deficient vaccine strain (A2497-) demonstrated protection in nonhuman primates against trachoma and a lack of measurable ocular pathology in A2497- infected monkeys. We therefore performed host cell transcriptome analysis of Hela cells infected with A2497 plasmid-containing (A2497) and A2497- Chlamydia over time. Our results indicate that relative to wild type A2497, the A2497- variant illicits a transcriptome response indicative of lowered inflammation response a delayed apoptosis response, a reduction in immune cell recruitement cytokine expression and a reduction in genes involved in cell proliferation and or fibrosis-like activities. The data provided here suggests a model that may explain how plasmid deficient chlamydia may provide an immuno-protective response without the pathology normally seen with plasmid-containing bacteria.
2014-11-25 | GSE56168 | GEO