Chlamydia trachomatis
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PROVIDER: PRJNA171054 | ENA |
REPOSITORIES: ENA
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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:The obligate intracellular bacterium Chlamydia has a unique developmental cycle that alternates between two contrasting cell types. With a hardy envelope and highly condensed genome, the small elementary body (EB) maintains limited metabolic activities yet can survive in an extracellular environment and is infectious. After entering host cells, EBs differentiate into larger and proliferating reticulate bodies (RBs). Progeny EBs are derived from RBs in late developmental stages and eventually exit host cells. How the expression of the chlamydial genome consisting of nearly 1000 genes governs the chlamydial developmental cycle is unclear. A previous microarray study identified only 29 immediately early genes, defined as genes activated by the first hour postinoculation, in C. trachomatis. By performing RNA sequencing analysis for C. trachomatis cultures with high multiplicities of infection (i.e., MOI of 50 and 200), we observed that 730 C. trachomatis genes underwent 2- to 900-fold activation within one hour postinoculation. By conducting quantitative reverse transcription real-time PCR (qRT-PCR) analysis for 48 of the 730 genes using an MOI of 1, we confirmed the expression increases in 46 genes. Our results demonstrate that the immediate early transcriptome is tens of times more extensive than previously realized. Gene ontology analysis indicates that the activation spans across all functional categories. We conclude that a supermajority of the C. trachomatis genes are activated almost immediately after EBs are inside host cells to initiate the differentiation toward RBs and to establish an intracellular niche conducive for chlamydial development and growth. RNA-Seq analysis was performed for Chlamydia trachomatis L2
2024-01-30 | GSE248988 | GEO
Project description:By comprehensive quantitative proteome analysis we characterize the three growth forms elementary body (EB), reticulate body (RB) and aberrant reticulate body (ARB) of Chlamydia trachomatis genital strain D/UW-3/CX
2017-01-04 | PXD003883 | Pride
Project description:The obligate intracellular human pathogen Chlamydia pneumoniae was subjected to dRNA-Seq to gain insights into the transcriptome. The two distinct life cycle forms elementary bodies (EB) and reticulate bodies (RB) were isolated from human Hep2 cell line by differential gradient centrifugation.
2011-08-18 | GSE24999 | GEO
Project description:The obligate intracellular human pathogen Chlamydia pneumoniae was subjected to dRNA-Seq to gain insights into the transcriptome. The two distinct life cycle forms elementary bodies (EB) and reticulate bodies (RB) were isolated from human Hep2 cell line by differential gradient centrifugation. Total RNA was isolated and partially treated with Terminator Exonuclease to digest RNA without 5'-PPP and thereby enrich for native 5' ends.
2011-08-18 | E-GEOD-24999 | biostudies-arrayexpress
Project description:Chlamydia trachomatis is the most common sexually transmitted infection and the bacterial agent of trachoma globally. C. trachomatis undergoes a biphasic developmental cycle involving an infectious elementary body and a replicative reticulate body. Little is currently known about the expression of host cell mRNAs, lncRNAs, and miRNAs at different stages of C. trachomatis development. Here, we performed RNA-seq and miR-seq on HeLa cells infected with C. trachomatis serovar E at 20 hpi and 44 hpi with or without IFN-γ treatment. Our study identified and validated differentially expressed host cell mRNAs, lncRNAs, and miRNAs during infection. Infection at 20 hpi showed the most differential upregulation of both coding and non-coding genes while infection at 44 hpi in the presence of IFN-γ resulted in a dramatic downregulation of a large proportion of genes. Using RT-qPCR, we validated the top 5 stage-specific upregulated mRNAs and miRNAs. One of the commonly expressed miRNAs at all three stages, miR-193b-5p, showed significant expression in clinical serum samples of C. trachomatis-infected patients as compared to sera from healthy controls and HIV-1-infected patients. Furthermore, at 20 hpi we observed significant upregulation of antigen processing and presentation, and T helper cell differentiation pathways whereas T cell receptor, mTOR, and Rap1 pathways were modulated at 44 hpi. Treatment with IFN-γ at 44 hpi showed the regulation of cytokine-cytokine receptor interaction, FoxO signaling, and Ras signaling pathways. Our study documents a role for the stage-specific transcriptional manipulation of the host cell genome and important signaling pathways that are necessary for the survival of pathogen and could serve as potential biomarkers in the diagnosis and management of the disease.
2021-01-13 | GSE158814 | GEO
Project description:Chlamydia trachomatis is a significant human pathogen yet their obligate intracellular nature severe restrictions upon research. Chlamydiae undergo a complex developmental cycle characterized by an infectious cell type known as the elementary body (EB) and an intracellular active replicative form called the reticulate body (RB). EBs have historically been described as metabolically dormant. A cell-free (axenic) culture system was developed which showed high levels of metabolic and biosynthetic activity from both EBs and RBs. EBs preferentially utilized glucose-6-phosphate as an energy source whereas RBs required ATP. Both developmental forms showed improved activity when incubated under microaerobic conditions. Incorporation of isotopically-labeled amino acids into proteins from both developmental forms indicated unique expression profiles which were confirmed by genome-wide transcriptional analysis. The described axenic culture system will greatly enhance biochemical and physiological analyses of chlamydiae. Chlamydia axenic metabolic activity
2012-11-20 | E-GEOD-39530 | biostudies-arrayexpress
Project description:Both prokaryotic and eukaryotic organisms take deterministic decisions to reprogram cell fates. A macroscopic manifestation of such an event is the remodelling of the cellsâ morphology and it typically is governed at the molecular scale by massive reorganization of the cellular transcriptome. With the regulation at the level of transcription initiation representing the most common form for such developmental reprogramming, cells typically rely on one or several master regulators to coordinate the the activity of hundreds of genes simultaneously by directly binding to their promoters. Despite the apparent simplicity of prokaryotes and their reduced genome size compared to that of their eukaryotic counterparts, free-living bacteria typically encode hundreds of transcription factors (TFs) in their genomes that could act as master TFs. By contrast, obligate intracellular bacteria such as Chlamydiae have a drastically reduced genome due to their intimate association with the host and thus a smaller number of TF genes. The genomes of members of the Chlamydiaceae family, which include the well-known bacterial pathogens Chlamydia trachomatis and Chlamydia pneumoniae, are only 1-1.2 Mbp. By contrast, members of the environmental Chlamydiae Waddlia chondrophila and Parachlamydia acanthamoebae have a 2-fold and 3-fold larger genome, respectively, likely allowing for an expansion of the host range while still retaining their host dependence and parasitic life style. Moreover, they all exhibit a characteristic chlamydial developmental cycle via two functionally specialized morphotypes, the infectious non-dividing elementary bodies (EBs) and the non-infectious dividing reticulate bodies (RBs). This developmental cycle is usually divided in three stages: the early stage during which EBs enter host cells and differentiate into RBs; the mid-stage where RBs proliferate inside a vacuole called inclusion and the late stage where RBs differentiate back into EBs and are released after exocytosis or cell lysis. Chlamydial genes are thus classified into three different temporal classes (early, mid and late expressed genes), likely reflecting the need of these transcripts in each of the three developmental stages. W. chondrophila, an emerging pathogen implicated in abortion in bovine and miscarriage in humans, encodes less than 20 TFs, 10 of which are conserved among the Chlamydiae. In light of this low TF multiplicity in the chlamydial pan-genome along with the common developmental cycle and parasitic life style, we aimed to define the regulatory pan-genome of each these conserved TFs to identify the elusive chlamydial master regulator and to characterize underling specificity for its target promoters using chromatin-immunoprecipitation followed by deep-sequencing (ChIP-Seq) of chlamydial cells growing inside the host. The immunochemistry of ChIP-Seq has the advantage of minimizing the contaminating nucleic acids compared to chlamydial transcriptome studies, it has the added benefit of providing the first unambiguous glimpse into the regulatory landscape of a bacterium inside host, offering a solid framework in understanding the stochastic and/or deterministic switches that bacteria rely on during infections. Examination of the regulatory network of an intracellular pathogen
2016-02-19 | E-GEOD-68059 | biostudies-arrayexpress
Project description:Chlamydia trachomatis is a significant human pathogen yet their obligate intracellular nature severe restrictions upon research. Chlamydiae undergo a complex developmental cycle characterized by an infectious cell type known as the elementary body (EB) and an intracellular active replicative form called the reticulate body (RB). EBs have historically been described as metabolically dormant. A cell-free (axenic) culture system was developed which showed high levels of metabolic and biosynthetic activity from both EBs and RBs. EBs preferentially utilized glucose-6-phosphate as an energy source whereas RBs required ATP. Both developmental forms showed improved activity when incubated under microaerobic conditions. Incorporation of isotopically-labeled amino acids into proteins from both developmental forms indicated unique expression profiles which were confirmed by genome-wide transcriptional analysis. The described axenic culture system will greatly enhance biochemical and physiological analyses of chlamydiae.
2012-11-20 | GSE39530 | GEO
Project description:In this project we examined in-vitro effect of female sex hormones, estradiol and progesterone at average physiological concentration level on Chlamydia trachomatis gene expression level. Regulation of chlamydial gene expression by the female sex hormones oestradiol and progesterone was examined. A total of 16 chlamydial arrays were analysed with the 4 culture conditions (no hormone, E, P, E+P) x four replicates. Bacterial samples were grown in non-hormone treated culture were used as control
2010-09-16 | E-GEOD-24119 | biostudies-arrayexpress