Transcriptional profile of Beijing/East-Asian Mycobacterium tuberculosis isolates
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ABSTRACT: Transcriptional profile comparison among Beijing and non-Beijing M. tuberculosis isolates. Three M. tuberculosis strains were compared. The laboratory reference strain, H37Rv, belongs to the Euro-American or lineage 4. Two clinical isolates of the East-Asian or lineage 2: 98_1663 is a pre-Beijing or Group 1 isolate, and HN878 is a Beijing or Group 5 isolate. Three replicates were performed for each comparison using two different biological samples.
Project description:Genomic comparisons among PDIM positive and negative isolates. Standard in vitro exponential phase cultures of M. tuberculosis H37Rv ATCC27294 were plated on 7H11 plates. Individual colonies were sub-cultured in 7H9 broth and metabolically labeled with [14C] propionic acid. The apolar lipid fraction was then extracted from those cultures and assayed for PDIM (phthiocerol dimycocerosate) content via TLC. Individual isolates producing and deficient in PDIM were selected for performing genomic comparisons. Four M. tuberculosis clones derived from the same parental strain were compared. Two of them were PDIM producers while the other two were PDIM deficient. Two replicates were performed for each comparison.
Project description:Transcriptional profile comparison among PDIM positive and negative isolates. Standard in vitro exponential phase cultures of M. tuberculosis H37Rv ATCC27294 were plated on 7H11 plates. Individual colonies were sub-cultured in 7H9 broth and metabolically labeled with [14C] propionic acid. The apolar lipid fraction was then extracted from those cultures and assayed for PDIM (phthiocerol dimycocerosate) content via TLC. Individual isolates producing and deficient in PDIM were selected for performing transcriptional profile comparisons. Four M. tuberculosis clones derived from the same parental strain were compared. Two of them were PDIM producers while the other two were PDIM deficient. Two or four replicates were performed for each comparison using two different biological samples.
Project description:What is the influence of mutations in PPE38 on the secretome composition of M. tuberculosis? Certain clinical isolates of M. tuberculosis belonging to the Beijing lineage have mutations in ppe38 and this leads to a loss of secretion of the PE_PGRS substrates and hypervirulence in a mouse model of M. tuberculosis. Culture filtrates (secretomes) of 3 strains have been collected of which strain SAWC_2088 has intact PPE38 and Strains SAWC_2135 and SAWC_2701 have mutated PPE38. The strains with mutated PPE38 were also complemented by reintroducing the corresponding genes on an integrative plasmid. Label-free single-shot proteomics was used to profile protein expression in M. tuberculosis secretomes.
Project description:Autophagy is a conserved lysosomal-dependent cellular degradation process shown to play a key role in immune defense against Mycobacterium tuberculosis inside host macrophages. Induction of autophagy enhances mycobacterial phagosome acquisition of lysosomal hydrolases, resulting in the destruction of intracellular M. tuberculosis reference strain H37Rv and strains belonging to the East African Indian genotype. However, our previous study showed that strains belonging to the hypervirulent M. tuberculosis Beijing genotype have a special ability to resist autophagic killing but the mechanism involved remains unclear. In this study, we carried out whole transcriptome analyses of host macrophages infected with the autophagy resistant Beijing strain compared to that of H37Rv. Our results identified several genes that are differentially regulated in the Beijing strain-infected host cells including those function in the lysosome positioning pathway. Host macrophages depleted of Kxd1 and Pleckhm2, two proteins in this pathway, can now enhance the lysosomal hydrolase acquisition into the Beijing phagosomes and restrict the bacterial survival upon autophagy induction. High-content image analysis showed an increase in lysosome numbers at the cell periphery in host cells infected with the autophagy resistant Beijing strain in a Pleckhm2-dependent manner. Taken together, these data indicated that the M. tuberculosis Beijing strain escapes autophagic elimination by upregulating the lysosome positioning pathway resulting in an increase in lysosome relocation toward the cell periphery and therefore sparing the mycobacteria from autophagic restriction. Our work thus identified new strategy employed by M. tuberculosis to evade autophagy which may provide potential new targets for drug discovery against tuberculosis
Project description:Transcriptional profiling of mycobacterium tuberculosis clinical isolates in China comparing extensively drug-resistant tuberculosis with drug sensitive one. The same condition experiment. The samples were from the different drug-resistant strains. Only one replicate.
Project description:The Epstein Barr virus (EBV) encoded latent membrane protein-1 (LMP1) is a functional homologue of the tumor necrosis factor receptor family and contributes substantially to the oncogenic potential of EBV through activation of Nuclear Factor-kappaB (NF-kappaB). MicroRNAs (miRNAs) are a class of small RNA molecules that are involved in the regulation of cellular processes such as growth, development, and apoptosis, and have recently been linked to cancer phenotypes. Through miRNA microarray analysis, we demonstrate that LMP1 dysregulates the expression of several cellular miRNAs, including the most highly regulated of these, miR-146a. Quantitative RT-PCR analysis confirmed induced expression of miR-146a by LMP1. Analysis of miR-146a expression in EBV latency type III and type I cell lines revealed substantial expression of miR-146a in type III (which express LMP1) but not in type I cell lines. Reporter studies demonstrated that LMP1 induces miR-146a predominantly through two NF-kappaB binding sites in the miR-146a promoter and identified a role for an OCT-1 site in conferring basal and induced expression. Array analysis of cellular mRNAs expressed in Akata cells transduced with an miR-146a expressing retrovirus identified genes that are directly or indirectly regulated by miR-146a, including a group of interferon responsive genes that are inhibited by miR-146a. Since miR-146a is known to be induced by agents that activate the interferon response pathway (including LMP1), these results suggest that miR-146a functions in a negative feedback loop to modulate the intensity and/or duration of the interferon response. Keywords: Analysis of gene expression changes altered by the microRNA, miR-146a EBV positive Burkitt's lymphoma cell line, Akata, was infected with the control retrovirus, pEhyg, or the miR-146a expressing retrovirus, pEhyg-miR-146a. Two infections were carried out for control retrovirus and two infections were carried out with the pEhyg-miR-146a retrovirus. Total RNA was prepared from each of the 4 infections. Control and miR-146a infection set 1 was subjected to dual color array analysis on chip 1. Control and miR-146a infection set 2 was subjected to dual color array analysis on second array of chip 1. Dye swaps of each of these were carried out on two arrays from a second chip (chip 2).
Project description:The goal of this work was to identify transcripts in maize endosperm that are regulated by water stress and the transcription factor Vp1 Keywords: stress response Plants were grown from F1 hybrid seed produced from inbreds W22 and ACR5855, where both inbred parents contributed mutant vp1-R alleles. Florets were fertilized with pollen from either homozygous vp1 pollen, thus creating vp1/vp1/vp1 mutant endosperms, or Vp1 pollen, thus creating Vp1/vp1/vp1 endosperms. Water stress treatment was imposed by withholding irrigation at 5 days after pollination; endosperms were sampled at 10 d after pollination. The study had 2 X 2 factorial design with two genotypes and two watering treatments; there were 6 biological replicates.
Project description:We developed a non-invasive ex vivo HT29 cell-based minimal model to fingerprint the mucosa-associated microbiota fraction in humans. HT29 cell-associated fractions were characterized by the universal phylogenetic array platform HTF-Microbi.Array, both in presence or in absence of a TNF-M-NM-1-mediated pro-inflammatory stimulus. A high taxonomical level fingerprint profiling of the mucosa-associated microbiota was performed on a group of 12 breast-fed infants and 6 adults (used as controls). Relative abundance of the bacterial species was assessed by using a so-called HTF-Microbi.Array, based on a ligation detection reaction (LDR) - Univerasal array (UA) assay, capable of correctly identify up to 31 intestinal bacterial groups, covering up to 95% of the human gut microbiota