Project description:Microarray analysis determined that 7.82% (244/3334) of Brucella abortus genes were up-regulated and 5.4% (180/3334) were down-regulated in RAW264.7 macrophages, compared to free-living bacteria in TSB In the study, Brucela abortus was isolated from infected macrophages at 24 post-infection, DNA microarray was used to analysis the differentially expressed genes between intracellular bacteria and free-living ones in TSB
Project description:Microarray analysis determined that 7.82% (244/3334) of Brucella abortus genes were up-regulated and 5.4% (180/3334) were down-regulated in RAW264.7 macrophages, compared to free-living bacteria in TSB
Project description:Gene expression analysis of wild-type and STING knock-out mouse bone marrow-derived macrophages (mBMDM) infected with Brucella abortus or transfected with Brucella abortus DNA. Genes whose expression are affected by Brucella abortus in a STING-dependent manner will be identified and signaling pathways regulated by STING will be elucidated.
Project description:In a time course study, we characterized global gene expression profile of B. abortus-infected macrophages from cattle naturally resistant (R) and susceptible (S) to brucellosis. B. abortus infection causes early down-regulation of transcript levels in Mø from R cattle at 4 h p.i. (22 up- and 126 down-regulated genes) which is reversed by 12 h post-infection (31 up- and 25 down-regulated genes), compared to uninfected control. On the other hand, B. abortus-infected S bovine macrophages exhibited a down-regulated expression profile at 4 (45 up- and 65 down-regulated genes) and 12 h p.i. (47 up- and 193 down-regulated genes). The analysis of the results indicates that B. abortus – infected Mø from cattle naturally R and S to brucellosis display different transcriptional profiles. Specific genes and biological processes identified in this study will further help elucidate how different macrophages from resistant and susceptible animals interact with Brucella during the early infectious process. Keywords: Expression profiling by microarray
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.
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.
Project description:We focused on whether transposon mutagenesis in Brucella abortus could induce difference in the trascriptional responses of RAW 264.7 cell infection model compared to the wild strain infected RAW 264.7 cells. The function of genes in Brucella abortus was analyzed through the identified differences in gene expression between RAW 264.7 cell infected with wild and mutant strains.
Project description:Identification of host responses at the gene transcription level provides a molecular profile of the events that occur following infection. Brucella abortus is a facultative intracellular pathogen of macrophages that induces chronic infection in humans and domestic animals. Using microarray technology, the response of macrophages 4 hours following B. abortus infection was analyzed to identify early intracellular infection events that occur in macrophages. Of the more than 6,000 genes, we identified over 140 genes that were reproducibly differentially transcribed. First, an increase in the transcription of a number of pro-inflammatory cytokines and chemokines, such as TNF-α, IL-1β, IL-1α, and members of the SCY family of proteins, was evident that may constitute a general host recruitment of antibacterial defenses. Alternatively, Brucella may subvert newly arriving macrophages for additional intracellular infection. Second, transcription of receptors and cytokines associated with antigen presentation, e.g., MHC class II and IL-12p40, were not evident at this 4 hour period of infection. Third, Brucella inhibited transcription of various host genes involved in apoptosis, cell cycling, and intracellular vesicular trafficking. Identification of macrophage genes whose transcription was inhibited suggests that Brucella utilizes specific mechanisms to target certain cell pathways. In conclusion, these data suggest that B. abortus can alter macrophage pathways to recruit additional macrophages for future infection while simultaneously inhibiting apoptosis and innate immune mechanisms within the macrophage permitting intracellular survival of the bacterium. These results provide insights into the pathogenic strategies used by Brucella to survive long-term within a hostile environment. Keywords: Macrophage, intracellular pathogen, Brucella abortus, inflammatory immune response
Project description:We focused on whether transposon mutagenesis in Brucella abortus could induce difference in the trascriptional responses of RAW 264.7 cell infection model compared to the wild strain infected RAW 264.7 cells. The function of genes in Brucella abortus was analyzed through the identified differences in gene expression between RAW 264.7 cell infected with wild and mutant strains. We analyzed altered transcription in RAW 264.7 cells at 0, 6, 12, and 24 h following the infection with 10 MOI of Brucella abortus wild and mutant strains.
Project description:We describe the isolation of sufficient Brucella abortus RNA from primary host cell environment using modified reported methods for RNA-seq analysis, and simultaneously characterize the transcriptional profiles of intracellular B. abortus and bone marrow-derived macrophages (BMM) from BALB/c mice at 24 h (replicative phase) post-infection.
