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.
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
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.
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.
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.
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
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