The CRISPR/Cas system in Neisseria meningitidis affects bacterial adhesion to human nasopharyngeal epithelial cells
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ABSTRACT:
ORGANISM(S): Neisseria meningitidis 8013
PROVIDER: GSE110891 | GEO | 2018/05/01
REPOSITORIES: GEO
Similar Datasets
Project description:Neisseria meningitidis is an obligate commensal colonising the human nasopharynx and occasionally invades the bloodstream causing life-threatening meningitis and septicaemia. The gene NMB0419 on the genome of N. meningitidis MC58 encodes a putative Sel1-like repeat (SLR) containing protein, which has been implicated in mediating meningococcal invasion of epithelial cells. We prepared RNA samples from N. meningitidis MC58 (WT) and its isogenic mutant of NMB0419 grown to log phase in in-vitro culture. The RNA samples were subjected to RNA sequencing. The resulting transcriptomes were compared to determine the genes that differentially expressed in NMB0419 mutant.
2017-03-07 | GSE81572 | GEO
Project description:Neisseria meningitidis is a human commensal that occasionally causes life-threatening infections such as bacterial meningitis and septicemia. Despite experimental evidence that gene regulation as well as the expression of small non-coding RNAs (sRNAs) affect meningococcal virulence, the organization of its transcriptome, including in particular the biogenesis of sRNAs and their mode of action, is only poorly understood. Here, we addressed these issues using a combination of high-throughput technologies. We applied differential RNA-seq (dRNA-seq) to produce a single-nucleotide resolution map of the primary transcriptome of N. meningitidis strain 8103. Our dRNA-seq analysis predicted 1,625 transcriptional start sites (TSS) including 65 non-coding RNA transcripts, of which 20 were further validated by Northern analysis. This allowed for the discovery of a novel CRISPR-associated sRNA with a Cas9-independent biogenesis. Genome-wide mapping of σ 70-dependent and independent promoters revealed that classical Escherichia coli-like σ70 promoter are absent in most of the protein coding genes in meningococci. The majority of the 706 primary TSSs (pTSSs) were associated with coding sequences, including 382 pTSS obtained for single genes and 240 pTSSs obtained for genes located in operons. By Hfq RNA immunoprecipitation sequencing (RIP-seq) we identified a large Hfq-centered post-transcriptional regulatory network comprising 24 sRNAs and 407 potential mRNA targets, and rifampicin stability assays demonstrated that Hfq binding confers enhanced stability on sRNAs. We finally confirmed the interactions of two sRNAs and their cognate target mRNA in vivo. Both directly repress prpB encoding a methylisocitrate lyse which was previously shown to be involved in meningococcal colonization of the human nasopharynx.The combination of both high-throughput approaches thus creates a compendium that not only provides a valuable data resource, but also allows for a better understanding of meningococcal transcriptome organization and riboregulation with implications for colonization of the human nasopharynx.
2017-03-21 | GSE85252 | GEO
Project description:Neisseria meningitidis, the meningococcus, bears the potential of life-threatening invasive diseases, but it usually colonizes the nasopharynx without causing any symptoms. Within the nasopharynx, Neisseria meningitidis must face temperature changes depending on the ambient air temperature. Indeed, the nasopharyngeal temperature can be substantially lower than 37°C, the temperature commonly used in experimental settings. Here, we compared meningococcal biofilm formation, autoaggregation and cellular adherence between 32°C and 37°C and found a clear increase in all these phenotypes at 32°C, suggestive for a stronger in vivo colonization capability at this temperature. A comparative proteome analysis approach revealed differential protein expression levels between 32°C and 37°C, predominantly affecting the outer membrane. Among 375 analyzed proteins, 75 were localized in the outer membrane, 37 in the periplasm, 48 in the inner membrane and 215 in the cytosol. The outer membrane proteins NHBA, NMB1030 and ACP showed strongest upregulation at 32°C and were partially responsible for the observed temperature-dependent phenotypes. Screening of different global regulators of Neisseria meningitidis revealed that the extracytoplasmic sigma factor, E, might be involved in the temperature-dependent biofilm formation. In conclusion, subtle temperature changes trigger adaptation events promoting mucosal colonization by meningococci
2016-10-10 | PXD003690 | Pride
Project description:Neisseria meningitidis is a commensal of humans that can colonize the nasopharyngeal epithelium for weeks to months and occasionally invades to cause life-threatening septicemia and meningitis. Comparatively little is known about meningococcal gene expression during colonization beyond those first few hours. In this study, the transcriptome of adherent serogroup B N. meningitidis strain MC58 was determined at intervals during prolonged cocultivation with confluent monolayers of the human respiratory epithelial cell line 16HBE14. At different time points up to 21 days, 7 to 14% of the meningococcal genome was found to be differentially regulated. The transcriptome of adherent meningococci obtained after 4 h of coculture was markedly different from that obtained after prolonged cocultivation (24 h, 96 h, and 21 days). Genes persistently upregulated during prolonged cocultivation included three genes (hfq, misR/phoP, and lrp) encoding global regulatory proteins. Many genes encoding known adhesins involved in epithelial adherence were upregulated, including those of a novel locus (spanning NMB0342 to NMB0348 [NMB0342-NMB0348]) encoding epithelial cell-adhesive function. Sixteen genes (including porA, porB, rmpM, and fbpA) encoding proteins previously identified by their immunoreactivity to sera from individuals colonized long term with serogroup B meningococci were also upregulated during prolonged cocultivation, indicating that our system models growth conditions in vivo during the commensal state. Surface-expressed proteins downregulated in the nasopharynx (and thus less subject to selection pressure) but upregulated in the bloodstream (and thus vulnerable to antibody-mediated bactericidal activity) should be interesting candidate vaccine antigens, and in this study, three new proteins fulfilling these criteria have been identified: NMB0497, NMB0866, and NMB1882. [Data is also available from http://bugs.sgul.ac.uk/E-BUGS-141]
2013-11-02 | E-BUGS-141 | biostudies-arrayexpress
Project description:Although usually a harmless colonizer of the human nasopharynx, Neisseria meningitidis (meningococcus) can spread to the blood stream and cause invasive disease. For survival in blood, N. meningitidis evades the complement system by expression of a polysaccharide capsule and surface proteins sequestering the complement regulator fH. Meningococcal strains are highly diverse and are categorized by their serogroup and multilocus sequence typing. The sequence type 41/44 clonal complex makes up a major proportion of serogroup B meningococcal disease worldwide, but it is also common in asymptomatic carriers. Proteome analysis of a serum resistant isolate from invasive meningococcal disease and two less resistant isolates from healthy carriers identified NspA as the sole protein consistently expressed more abundantly in the invasive isolate. Knock-out of nspA reduced serum resistance, accompanied by stronger deposition of membrane attack complex (C5b9). High or low expression of NspA was associated with sequence variation within a homopolymeric tract located in the -10/-35 region of the nspA promotor: A tract with 5 adenosines dictated low NspA expression, whereas a 6-adenosine motif led to high NspA expression. High levels of NspA correlated with high factor H sequestration onto the bacteria. We could not link the homopolymeric tract length to phase variation, unlike described for other N. meningitidis surface proteins with similar sequence motifs. Epidemiological evidence from carriage and disease isolates indicates that NspA contributes to serum resistance, but is not a prerequisite for invasive disease. Thus, the lineage ST-41/44 meningococcal strains are heterogenous in their NspA expression.
2019-02-28 | PXD010505 | Pride
Project description:Meningococcal sepsis is an overwhelming form of the sepsis syndrome which may cause mortality within 12-24 hours in previously healthy children and adults, where the causative infectious agent is N. meningitidis, an obligate human pathogen. The genomic changes induced by N. meningitidis are modulated by the anti-inflammatory cytokine interleukin-10 (IL-10), which is present in large quantities in plasma from patients with meningococcal sepsis. This present study investigated kinase activities in human monocytes stimulated by N. meningitidis and IL-10. The first aim was to identify array peptides that could indicate which signaling pathways were activated or inhibited by the host response to the meningococci. The second aim was to detect whether IL-10 affected N. meningitidis-nduced phosphorylation of array peptides, in order to identify potential targets of the IL-10 anti-inflammatory response. We approached this using a strategy where elutriation-purified human monocytes are stimulated in vitro with N. meningitidis and IL-10, with concentrations corresponding to previously measured levels in patients with fulminant meningococcal septicemia. This work examined activation or inhibition of signaling pathways mediated by tyrosine kinases when purified human monocytes are in vitro incubated with N. meningitidis in the presence or absence of IL-10.
2017-12-15 | E-MTAB-4795 | biostudies-arrayexpress
Project description:Neisseria meningitidis is the leading cause of bacterial meningitis and septicemia worldwide. The novel ST-4821 clonal complex caused several serogroup C meningococcal outbreaks unexpectedly during 2003–2005 in China. We fabricated a whole-genome microarray of Chinese N. meningitidis serogroup C representative isolate 053442 and characterized 27 ST-4821 complex isolates which were isolated from different serogroups using comparative genomic hybridization (CGH) analysis. This paper provides important clues which are helpful to understand the genome composition and genetic background of different serogroups isolates, and possess significant meaning to the study of the newly emerged hyperinvasive lineage. Keywords: comparative genomic hybridization
2007-11-28 | GSE7780 | GEO
Project description:Background: Biological interpretation of gene expression data may differ depending on underlying assumptions and statistical tests used by the chosen bioinformatic tool. We used Gene Set Enrichment Analysis (GSEA) and Ingenuity Pathway Analysis (IPA) to analyze previously generated gene expression profiles induced in human monocytes by N. meningitidis and IL-10 (“the model system”), and by meningococcal sepsis plasma before and after immunodepletion of IL-10 (“the patient plasma system”). The objectives were to compare whether these two methods resulted in similar biological interpretation of the datasets; and identify whether GSEA provided additional insight about the human monocyte host response to meningococcal activation. Results: In both experimental models, GSEA and IPA associated genes induced in monocytes by N. meningitidis with pro-inflammatory innate immune activation, including TNF-signaling, Toll-like receptor signaling, JAK-STAT-signaling, type I and type II interferon. GSEA associated genes regulated by the presence of IL-10 with similar gene sets in both the model system and the patient plasma system. In the model system, GSEA and IPA identified 170 genes associated with oxidative phosphorylation/mitochondrial function to be down-regulated in monocytes stimulated with meningococci. In the patient plasma system, GSEA and IPA combined identified 122 genes associated with oxidative phosphorylation/mitochondrial dysfunction to be down-regulated by meningococcal sepsis plasma depleted for IL-10. Combining analyses from GSEA and IPA identified that some genes associated with oxidative phosphorylation/mitochondrial function that were inhibited by N. meningitidis were partially up-regulated by IL-10. Conclusions: Biological processes associated with the gene expression changes in the model system of meningococcal sepsis was comparable to the results found in the patient plasma system. By combining GSEA with IPA, we have discovered an inhibitory effect exerted by N. meningitidis on genes associated with oxidative phosphorylation, and that IL-10 possibly partially dampen this strong inhibitory effect, thereby identifying, to our knowledge, yet another area where IL-10 regulates the effect of LPS. We suggest that relying on a single bioinformatic tool together with arbitrarily chosen filtering criteria for data analysis may result in overlooking relevant biological processes and signaling pathways associated with genes differentially expressed between compared experimental conditions.
2016-06-08 | GSE82315 | GEO
Project description:Background: Biological interpretation of gene expression data may differ depending on underlying assumptions and statistical tests used by the chosen bioinformatic tool. We used Gene Set Enrichment Analysis (GSEA) and Ingenuity Pathway Analysis (IPA) to analyze previously generated gene expression profiles induced in human monocytes by N. meningitidis and IL-10 (“the model system”), and by meningococcal sepsis plasma before and after immunodepletion of IL-10 (“the patient plasma system”). The objectives were to compare whether these two methods resulted in similar biological interpretation of the datasets; and identify whether GSEA provided additional insight about the human monocyte host response to meningococcal activation. Results: In both experimental models, GSEA and IPA associated genes induced in monocytes by N. meningitidis with pro-inflammatory innate immune activation, including TNF-signaling, Toll-like receptor signaling, JAK-STAT-signaling, type I and type II interferon. GSEA associated genes regulated by the presence of IL-10 with similar gene sets in both the model system and the patient plasma system. In the model system, GSEA and IPA identified 170 genes associated with oxidative phosphorylation/mitochondrial function to be down-regulated in monocytes stimulated with meningococci. In the patient plasma system, GSEA and IPA combined identified 122 genes associated with oxidative phosphorylation/mitochondrial dysfunction to be down-regulated by meningococcal sepsis plasma depleted for IL-10. Combining analyses from GSEA and IPA identified that some genes associated with oxidative phosphorylation/mitochondrial function that were inhibited by N. meningitidis were partially up-regulated by IL-10. Conclusions: Biological processes associated with the gene expression changes in the model system of meningococcal sepsis was comparable to the results found in the patient plasma system. By combining GSEA with IPA, we have discovered an inhibitory effect exerted by N. meningitidis on genes associated with oxidative phosphorylation, and that IL-10 possibly partially dampen this strong inhibitory effect, thereby identifying, to our knowledge, yet another area where IL-10 regulates the effect of LPS. We suggest that relying on a single bioinformatic tool together with arbitrarily chosen filtering criteria for data analysis may result in overlooking relevant biological processes and signaling pathways associated with genes differentially expressed between compared experimental conditions.
2016-06-08 | GSE82166 | GEO
Project description:In bacteria and archaea, CRISPR loci confer adaptive, sequence-based immunity against viruses and plasmids. CRISPR interference is specified by CRISPR RNAs (crRNAs) that are transcribed and processed from CRISPR spacers and repeats. Pre-crRNA processing is essential for CRISPR interference in all systems studied thus far. Here we examine crRNA biogenesis and CRISPR interference in naturally competent Neisseria spp., including the human pathogen N. meningitidis. Our studies reveal a unique crRNA maturation pathway in which crRNA transcription is driven by promoters that are embedded within each repeat, yielding crRNA 5’ ends are not formed by processing. Although crRNA 3’ end formation occurs through RNase III cleavage of a pre-crRNA/tracrRNA duplex, as in other Type II CRISPR systems, this processing event is dispensable for interference. The meningococcal pathway is the most streamlined CRISPR/cas system characterized to date. Endogenous CRISPR spacers frequently target genomic sequences of other Neisseria strains and so limit natural transformation, which is the primary source of genetic variation that contributes to immune evasion, antibiotic resistance, and virulence in N. meningitidis.
2013-04-23 | GSE44582 | GEO