Tissue Tropism in Chlamydia pneumoniae Infection
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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:Chlamydia pneumoniae, an obligate intracellular bacterium, causes pneumonia in humans and mice. Toll-like receptors and the key adaptor molecule MyD88 play a critical role in inducing immunity against this microorganism and are crucial to survive the infection. To explore the influence of MyD88 on induction of immune responses in vivo on a genome wide level, WT or MyD88-/- mice were infected with C. pneumoniae upon anesthesia and the pulmonary transcriptome was analyzed three days later by microarrays. We find that the infection induced the transcription of 360 genes and repressed 18 genes in WT mice. Of these, 221 genes were not or weakly induced in lungs of MyD88-/- mice. This cluster contains primarily genes encoding for chemokines, cytokines and other immune effector molecules. Genes induced by interferons were abundant in a cluster of 102 genes which were only partially MyD88-dependent. Interestingly, a set of 37 genes were induced more strongly in MyD88-/- mice and most of them are involved in the regulation of cellular replication. In summary, ex vivo analysis of the pulmonary transcriptome upon infection with C. pneumoniae demonstrated a major impact of MyD88 on inflammatory responses but not on interferon-type responses, and identified MyD88-independent genes involved in cellular replication Keywords: lung, Chlamydia pneumoniae, mice, myd88, TLR, infection, knock out
2007-03-27 | GSE6688 | GEO
Project description:This experiment is an additional experiment to GSE6688. Mouse macrophages (ANA-1 cells) were infected in vitro with C. pneumoniae with a M.O.I. of 10. Twenty two genes were significantly upregulated. Examples of the most upregulated genes in mouse macrophages after C. pneumoniae infection are serum amyloid A3 (saa3), a protein that is mainly produced by activated macrophages during tissue injury or inflammation, MIP-2 (cxcl2) and irg1. Expression levels of all genes induced by C. pneumoniae in macrophages in vitro correlated with the results obtained from infected lungs from wild type mice (GSE6688), suggesting that this cell type participates in host defense in vivo against C. pneumoniae. Keywords: Chlamydia pneumoniae, ANA-1 macrophages, in vitro, infection
2007-03-27 | GSE6690 | 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:To date there is no clear explanation as to how Chlamydia pneumoniae heat shock protein 60 (cHSP60) gets activated either through TLR-2/4, MAPKinase (p38/JNK/ERK), apoptotic/antiapoptotic, chemokines and inflammatory cytokines pathways leading to coronary artery disease (CAD). Hence to better understanding towards cHSP60 signaling in CAD patients, we performed experiments at RNA levels in cHSP60 positive and negative groups of CAD patients. For the determination of positivity for C. pneumoniae, Helicobacter pylori, Cytomegalovirus and Herpes Simplex Virus in atheromatous plaque multiplex Real Time PCR was performed. Monoplex Real Time PCR was also performed with 16S rRNA and HSP60 gene Chlamydia pneumoniae. Further study was performed only on cHSP60 positive (negative for H. pylori, CMV & HSV-1) and cHSP60 negative (also negative for H. pylori, CMV & HSV-1) CAD patients.
2010-01-06 | GSE19590 | GEO
Project description:BackgroundChlamydia pneumoniae (Cpn) are obligate intracellular bacteria that cause acute infections of the upper and lower respiratory tract and have been implicated in chronic inflammatory diseases. Although of significant clinical relevance, complete genome sequences of only four clinical Cpn strains have been obtained. All of them were isolated from the respiratory tract and shared more than 99% sequence identity. Here we investigate genetic differences on the whole-genome level that are related to Cpn tissue tropism and pathogenicity.ResultsWe have sequenced the genomes of 18 clinical isolates from different anatomical sites (e.g. lung, blood, coronary arteries) of diseased patients, and one animal isolate. In total 1,363 SNP loci and 184 InDels have been identified in the genomes of all clinical Cpn isolates. These are distributed throughout the whole chlamydial genome and enriched in highly variable regions. The genomes show clear evidence of recombination in at least one potential region but no phage insertions. The tyrP gene was always encoded as single copy in all vascular isolates. Phylogenetic reconstruction revealed distinct evolutionary lineages containing primarily non-respiratory Cpn isolates. In one of these, clinical isolates from coronary arteries and blood monocytes were closely grouped together. They could be distinguished from all other isolates by characteristic nsSNPs in genes involved in RB to EB transition, inclusion membrane formation, bacterial stress response and metabolism.ConclusionsThis study substantially expands the genomic data of Cpn and elucidates its evolutionary history. The translation of the observed Cpn genetic differences into biological functions and the prediction of novel pathogen-oriented diagnostic strategies have to be further explored.
| S-EPMC4489044 | biostudies-literature
Project description:This experiment is an additional experiment to GSE6688. Mouse macrophages (ANA-1 cells) were infected in vitro with C. pneumoniae with a M.O.I. of 10. Twenty two genes were significantly upregulated. Examples of the most upregulated genes in mouse macrophages after C. pneumoniae infection are serum amyloid A3 (saa3), a protein that is mainly produced by activated macrophages during tissue injury or inflammation, MIP-2 (cxcl2) and irg1. Expression levels of all genes induced by C. pneumoniae in macrophages in vitro correlated with the results obtained from infected lungs from wild type mice (GSE6688), suggesting that this cell type participates in host defense in vivo against C. pneumoniae. Experiment Overall Design: ANA-1 macrophages were infected with Chlamydia pneumoniae or left untreated. After 8h total RNA was extracted. Two biological replicates were performed resulting in 4 arrays in total
2008-06-15 | E-GEOD-6690 | biostudies-arrayexpress
Project description:Purpose: To further define the enhanced metabolic activity of Chlamydia pneumoniae under hypoxia, a transcriptome screen was performed. Next-genration sequencing (NGS) has revolutioned systems-based analysis of transcriptomic pathways. The goals of this study are to compare the transcriptomic profile of C. pneumoniae, grown within HEp-2 cells under normoxic and hypoxic conditions. Methods: Total RNA of C. pneumoniae infected HEp-2 cells cultured under normoxia (20% O2) or hypoxia (2% O2) was isolated by NucleoSpin RNA kit (Macherey Nagel). Human rRNA was depleted by RiboZero rRNA removal kit (Epicentre) in order to enrich bacterial RNA. The tagged cDNA libraries, in the size range of 250 –400 bp, were pooled and single-read sequencing (read length 50 bp) was performed on Illumina HiSeq 2000 by BGI-Hong Kong. Illumina reads were mapped to the Chlamydia genome (GeneBank, version AE001363.1) by TopHat (version TopHat v1.0.12. Gene expression was determined by the Htseq package and data was normalized using the RPKM conversion. Finally, the differential expression analysis was done using the Bioconductor package NOISeq version 2.6.0. The NOISeq-sim function included in the package allows for differential expression estimates in absence of replication by simulating replicates considering that reads counts follow a multinominal distribution. Results: Ranking of differentially expressed chlamydial genes by NOISeq-sim revealed 153 upregulated and 18 downregulated candidate genes. The expression profile of selected genes was validated using qRT-PCR. Most of the upregulated genes under hypoxia belong to the transcriptional and translational machinery or have unknown function. Moreover, transporters show increased expression under hypoxia such as the ATP/ADP translocase (Cpn0614) responsible for NAD uptake. Within the group of metabolic genes, numerous genes belonging to the energy metabolism and nucleotide metabolism were upregulated under hypoxia. Furthermore, thioredoxin reductase (trxB) belonging to the chlamydial redox system was upregulated. Conclusions: Our study represents the first detailed transcriptomic analysis of C. pneumoniae infected HEp-2 cells under hypoxic conditions, generated by RNA-seq technology. Our results show an increased expression of trxB, a part of the chlamydial redox system, which might reduce reactive oxygen species (ROS) under hypoxia. Interestingly, infection of hypoxic cells indeed resulted in a decreased ROS generation compared to hypoxic non-infected cells. We conclude that enhanced growth of C. pneumoniae is the result of hypoxia-induced mitochondrial dysfunction and the associated metabolic switch. Particularly, mitochondrial hyperpolarization is a central mechanism which promotes C. pneumoniae growth under hypoxic conditions. Further, our data imply that mitochondrial dysfunction could also play a major role for other intracellular pathogens, since mitochondrial dysfunction usually occurs under hypoxia and could thereby influence intracellular growth.
2017-11-24 | GSE94697 | GEO
Project description:Infection with Chlamydia pneumoniae, a human respiratory pathogen, has been associated with various chronic diseases such as asthma, coronary heart disease and importantly atherosclerosis. Possibly because the pathogen can exist in a persistent form. TNF-a has been reported to induce chlamydial persitence in epithelial cell lines, however the mechanism of TNF-a-induced persistence has not been reported. Moreover, C. pneumoniae persistently infect human dendritic cells (DCs) and activate DCs to produce cytokines including TNF-a. Induction of chlamydial persistence by other cytokines such as IFN-g is known to be due to indoleamine 2,3-dioxygenase (IDO) activity. The present study therefore, investigated whether C. pneumoniae infection can induce IDO activity in dendritic cells, and whether the restriction of chlamydial growth in the DCs by TNF-a is IDO-dependent. Our data indicate that infection of DCs with C. pneumoniae resulted in the induction of IDO expression. Reporting on our use of anti-TNF-a antibody adalimumab and varying concentrations of TNF-a, we further demonstrate that IDO induction following infection of DCs with C. pneumoniae is TNF-a-dependent. The anti-chlamydial activity induced by TNF-a and the expression of chlamydial 16S rRNA gene, euo, groEL1, ftsk and tal genes was correlated with the induction of IDO. Addition of excess amounts of tryptophan to the DC cultures resulted in abrogation of the TNF-a-mediated chlamydial growth restriction. These findings suggest that infection of DCs by C. pneumoniae induces production of functional IDO, which subsequently causes depletion of tryptophan. This may represent a potential mechanism for DCs to restrict bacterial growth in chlamydial infections. Keywords: Chlamydia pneumoniae, Dendritic cells, TNF-a, Indoleamine 2,3-dioxygenase
2009-08-21 | GSE12806 | GEO
Project description:Chlamydia pneumoniae B21 Genome sequencing
| PRJNA230008 | ENA