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PROVIDER: PRJNA1053259 | ENA |
REPOSITORIES: ENA
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Project description:Brucellosis is a zoonosis of the Mediterranean and Middle-East regions linked to important economic losses and reduced animal welfare. To date, no effective diagnostic and/or prophylactic measures are available for the control of brucellosis, due to the residual virulence of the bacterial strain administered for vaccinal purposes and the difficulties in distinguishing vaccinated from infected animals. To overcome these issues, studies are desired to elucidate the bacterial biology and the pathogenetic mechanisms of both the vaccinal strain and the pathogenic strains. Here, we employed a label-free shotgun proteomics to investigate the protein repertoire of the vaccinal strain B. melitensis Rev.1 and compare it with the proteome of the Brucella melitensis 16 M, one of the most common field strains isolated from ruminants. Comparative proteomics profiling underlines common and diverging traits between the two strains, providing suggestions on the potential biochemical routes responsible of the residual virulence of the vaccinal strain; whilst the diverging traits are suggestive biochemical signatures to be further investigated to provide an optimized diagnostics capable of discriminating the vaccinated from infected animals.
2021-05-20 | PXD022472 | Pride
Project description:We used B. melitensis M5-90 wild type to construct gene-deleted strains of B. melitensis ∆per, RAW264.7 cells infected with B. melitensis M5-90 and B. melitensis M5-90 ∆per for 4h, respectively. miRNA microarray and mRNA array experiments were performed, qRT-PCR validation for miRNAs and mRNAs. We performed a joint analysis of differentially expressed miRNAs and mRNAs, and proved that the target gene of miRNA-146b is Tbc1d14. It further confirmed that miR-146b targeting tbc1d14 regulates brucella-mediated autophagy of RAW264.7 cells. Finally, the molecular mechanism of tbc1d14 influencing brucella-mediated autophagy of RAW264.7 cells was preliminarily revealed by DGE sequencing.
2019-02-14 | GSE126498 | GEO
Project description:We used B. melitensis M5-90 wild type to construct gene-deleted strains of B. melitensis ∆per, RAW264.7 cells infected with B. melitensis M5-90 and B. melitensis M5-90 ∆per for 4h, respectively. miRNA microarray and mRNA array experiments were performed, qRT-PCR validation for miRNAs and mRNAs. We performed a joint analysis of differentially expressed miRNAs and mRNAs, and proved that the target gene of miRNA-146b is Tbc1d14. It further confirmed that miR-146b targeting tbc1d14 regulates brucella-mediated autophagy of RAW264.7 cells. Finally, the molecular mechanism of tbc1d14 influencing brucella-mediated autophagy of RAW264.7 cells was preliminarily revealed by DGE sequencing.
2019-02-11 | GSE126343 | GEO
Project description:Brucella spp. are gram-negative, facultative intracellular pathogens that cause brucellosis in humans and animals. Iron is an essential element required for all organisms. Iron response regulator (Irr) is a crucial transcriptional regulator and can affect the growth and iron uptake of Brucella. The growth rate of Brucella melitensis M5-90 irr mutant was significantly lower than that of B. melitensis M5-90 under normal or iron-sufficient conditions, however, the growth rate of the B. melitensis M5-90 irr mutant was significantly higher than that of B. melitensis M5-90 under iron-limited conditions. In addition, irr mutation significantly reduced iron uptake under iron-limited conditions. Currently, bhuA (a heme transporter), bhuQ (heme utilization oxygenase Q), and RirA (iron-responsive regulator) have been identified as iron metabolism genes and are regulated by the Irr protein. These results suggest that the Irr protein has multiple target genes in the Brucella genome that are involved in iron metabolism. Therefore, a combination of RNA-seq and Dap-seq was used to investigate the other iron metabolism genes that are also regulated by the Irr protein in Brucella. A total of seven genes were identified as target genes for Irr in this study and the expression levels of these seven genes were similar in both the RNA-seq and qRT-PCR results. Furthermore, the DNA bases C and G and amino acids asparagine, arginine, histidine, and serine were predicted as predominant docking sites for DNA and Irr using the HDOCK server. The electrophoretic mobility shift assay confirmed that six out of the seven genes, namely rirA (BME_RS13665), membrane protein (BME_RS01725), hypothetical protein (BME_RS09560), Iron transporter (BME_RS14525), cation-transporting P-type ATPase (BME_RS10660), and 2Fe-2S binding protein (BME_RS13655), interact with the Irr protein. In summary, our results identified six genes regulated by the Irr protein that may participate in iron metabolism. In addition, from the RNA-seq results, the mutation of irr resulted in the down/upregulation of many genes that are associated with the bacterial secretion system, lipopolysaccharides, and flagellar assembly, and these three components are the main virulence factors for Brucella. Collectively, these results provide valuable insights for the exploration of Brucella iron metabolism and its effects on virulence.
2023-06-21 | GSE215027 | GEO
Project description:Brucellosis is a serious infectious disease and continues to be an important cause of morbidity. It can be seen almost anywhere in the world and at any age. Acute phase heals or becomes chronic form. Infection of 10-30% of patients becomes chronic, despite early diagnosis and treatment. Although our knowledge about Brucella virulence factors and the host response increase rapidly, how they can hidden from the immune system and cause chronic disease are still unknown. We aimed to investigate the immunological factors which belong to CD4+ T cells and their roles in the transition of brucellosis from acute to chronic infection. Using miRNA microarray, more than 2000 miRNAs were screened in CD4 + T cells of patients with acute or chronic brucellosis and healthy controls that were sorted from peripheral blood with flow cytometry and validated by RT-qPCR. Findings were evaluated using GeneSpring GX (Agilent) 13.0 software and KEGG pathway analysis. In comparison to acute cases, expression levels of 28 miRNAs were significantly altered in chronic cases. All of miRNAs were up-regulated in chronic cases in comparison with the control group. Apart from a miRNA (miR-4649-3p), 27 miRNAs were not expressed in the acute cases (p <0.05, fold change> 2). These miRNAs have the potential to be markers for chronic cases. The differential expressed miRNAs and their predicted target genes that involved in previously MAPK signaling pathway, regulation of actin cytoskeleton, endocytosis, and protein processing in endoplasmic reticulum indicating their potential roles in chronic brucellosis and its progression. It is the first study of miRNA expression analyzes of human CD4+ T cells to clarify the mechanism of inveteracy in brucellosis.
2017-12-21 | GSE107554 | GEO
Project description:Many pathogenic bacteria use a regulatory process termed Quorum Sensing (QS) to produce and detect small diffusible molecules to synchronize gene expression within a population. In Gram-negative bacteria, the detection and response to these molecules depend on transcriptional regulators belonging to the LuxR family. Such a system have been discovered in the intracellular pathogen Brucella melitensis, a Gram-negative bacteria responsible for brucellosis, a word-wide zoonosis remaining a serious public health concern in endemic countries. Two LuxR-type regulators, VjbR and BabR, have been identified in the genome of this pathogen. The vjbR mutant is highly attenuated in all tested models suggesting a crucial role of QS in the virulence of Brucella. This attenuation is at least due to the involvement of VjbR in the activation of the virB operon coding for a type four secretion system essential for Brucella to reach its intracellular replication compartment. At present, no function has been attributed to BabR. To assess the role of both Brucella QS-regulators, we performed in tandem comparative transcriptomic and proteomic analyses of vjbR and babR mutants. These experiments revealed that 10% of Brucella genome is regulated through those regulators, revealing that QS is a global regulatory system in this intracellular pathogen. The overlapping between BabR and VjbR targets suggest an unexpected cross-talk between these two regulators. Moreover, our results demonstrate that VjbR and BabR regulate many gene and/or proteins involved in stress response, metabolism and virulence. These targets are potentially involved in the adaptation of Brucella to the oxidative, pH and nutritional stresses encountered within the host. These findings highlight the involvement of QS in the virulence of Brucella and led us to suggest that this regulatory system could be implied in the spatial and sequential adaptation of Brucella to the host environment. Keywords: Quorum Sensing, Comparative gene expression, Brucella melitensis
2010-04-12 | GSE8844 | GEO
Project description:Facultative intracellular Brucella infect and survive inside macrophages, and the outcome of macrophage-Brucella interaction is a basis for establishment of a chronic Brucella infection. The majority of Brucella are killed at the early infection stage. A subpopulation of virulent Brucella strains is instead trafficked to an intracellular replicative phagosome, and are resistant to further attack and begin to multiply dramatically. Virulent Brucella also inhibit macrophage apoptosis that in turn favors pathogen survival and replication. We used the Affymetrix mouse GeneChip 430 2.0 array to analyze mouse macrophage gene expression profiles during the time course of virulent B. melitensis strain 16M infection. Keywords: time course
2006-06-30 | GSE5202 | GEO
Project description:Brucella type strains (B. abortus 544 and B. melitensis 16 M), field-isolates (B. abortus T and B. melitensis C) were independently cultivated six times on Tryptic Soy Broth at 37 °C in the presence of 5% CO2 until mid-logarithmic phase. The cells were harvested by brief centrifugation and the bacteria was inactivated using recommended ethanol precipitation procedure. Following which the cells were lysed, proteins quantified and the differentially expressed proteins among B. abortus and B. melitensis were identified using liquid chromatography-mass spectrometry (LC/MS) based label free quantitative proteomics analysis.
2020-06-11 | PXD006348 | Pride
Project description:Brucella dynamically engage macrophages while trafficking to an intracellular replicative niche as macrophages, the first line of innate host defense, attempt to eliminate organisms. Brucella melitensis, B. neotomae, and B. ovis are highly homologous, yet exhibit a range of host pathogenicity and specificity. RAW 264.7 macrophages infected with B. melitensis, and B. ovis exhibit divergent patterns of bacterial persistence and clearance; conversely, B. melitensis and B. neotomae exhibit similar patterns of infection. Evaluating early macrophage interaction with Brucella spp. allows discovery of host entry and intracellular translocation mechanisms, rather than bacterial replication. Microarray analysis of macrophage transcript levels following a 4 hr Brucella spp. infection revealed 130 probe sets altered compared to uninfected macrophages; specifically, 72 probe sets were increased and 58 probe sets were decreased with any Brucella spp. Interestingly, much of the inflammatory response was not regulated by the number of Brucella gaining intracellular entry, as macrophage transcript levels were often equivalent among B. melitensis, B. ovis, and B. neotomae infections. An additional 33 probe sets were identified with altered macrophage transcript levels among Brucella spp. infections that may correlate with species specific host defenses and intracellular survival. Gene ontological categorization unveiled genes altered among species are involved in cell growth and maintenance, response to external stimuli, transcription regulation, transporter activity, endopeptidase inhibitor activity and G-protein mediated signaling. Host transcript profiles provide a foundation to understand variations in Brucella spp. infections, while structure of the macrophage response and intracellular niche of Brucella spp. will be revealed through piecewise consideration of host signaling pathways. Keywords: Macrophage, intracellular pathogen, Brucella melitensis, Brucella neotomae, Brucella ovis, inflammatory immune response, species specificity
2010-01-01 | GSE8385 | GEO
Project description:Brucella spp. is an intracellular pathogen in vivo. The intracellular B. melitensis transcriptome was determined by initially enriched and then amplified B. melitensis RNA from total RNA of B. melitensis-infected HeLa cells. Analysis of microarray results identified 161 and 115 genes differentially expressed at 4 and 12 h p.i., respectively. Most of the genes (78%) differentially expressed were down-regulated at the earliest time point, but up-regulated (75%) at 12 h p.i. The analysis of the results indicates that Brucella undergo an adaptation period during the first 4 h p.i. that is overcome by 12 h p.i., permitting Brucella to replicate intracellularly. Specific genes and biological processes identified in this study will further help elucidate how Brucella act during the early infectious process to their eventual benefit and to the detriment of the naM-CM-/ve host. Keywords: Time course study of intracellular B. melitensis gene expression Gene expression of the intracellular Brucella melitensis was determined at 4 and 12 h p.i. We generated the following samples: A) B. melitensis total RNA enriched and amplified from total RNA of B. melitensis-infected HeLa cells at 4 h p.i.; B) Total RNA isolated from B. melitensis-infected HeLa cells at 4 h p.i.; C) B. melitensis total RNA enriched and amplified from total RNA of B. melitensis-infected HeLa cells at 12 h p.i.; D) Total RNA isolated from B. melitensis-infected HeLa cells at 12 h p.i. B. melitensis total RNA was initially enriched and then amplified from total RNA of B. melitensis-infected HeLa cells at 4 and 12 h p.i. in quadruplicate, indirectly labeled and co-hybridized against B. melitensis gDNA to a custom 3.2K B. melitensis oligo-array (n = 8). As there was a possibility that some HeLa transcripts cross-hybridize with probes on B. melitensis microarrays, the original total RNA from B. melitensis-infected HeLa cells were also co-hybridized against B. melitensis gDNA to B. melitensis oligo-arrays (n = 8), and any oligospots with signals were considered non-specific and eliminated from all analysis to avoid false positive gene detection. The intracellular B. melitensis gene expression was compared to the gene expression of the inoculum (n = 2). Every Brucella melitensis open reading frame was printed in triplicate on each microarray, thereby providing three technical replicates for each biological replicates. Each replicate was normalized against labeled Brucella melitensis genomic DNA.
2012-12-27 | E-GEOD-14704 | biostudies-arrayexpress