Project description:Mycobacterium marinum infection in zebrafish (Danio rerio) has been widely used to study human tuberculosis because the bacteria causing these two diseases are close relatives. We studied the zebrafish immune response to M. marinum infection through a whole-genome level transcriptome analysis. As expected based on the literature, our results showed the induction of genes coding proteins associated to immune signaling, cell migration and acute phase response indicating that the immune response to M. marinum infection in zebrafish is similar than the response to tuberculosis causing Mycobacterium tuberculosis in humans.
Project description:Zebrafish is a natural host of various Mycobacterium species and a surrogate model organism for tuberculosis research. Mycobacterium marinum (M. marinum) is evolutionarily most closely related to M. tuberculosis and shares the majority of virulence genes. Although zebrafish is not a natural host of the human pathogen, we have previously demonstrated successful robotic infection of zebrafish embryos with M. tuberculosis and performed drug treatment of the infected larvae. In the present study we examined for how long M. tuberculosis can be propagated in zebrafish larvae and tested a time series of infected larvae to study the transcriptional response via Illumina RNAseq. Granuloma-like structures carrying fluorescently labeled M. tuberculosis could be detected up to 9 days post infection. The continued presence of viable M. tuberculosis in the zebrafish larvae was further confirmed using the molecular bacterial load assay. The infected larvae showed a clear and specific transcriptional immune response with a high similarity to the response of zebrafish larvae infected with the surrogate species M. marinum. We conclude that M. tuberculosis can be propagated in zebrafish larvae for at least one week after infection and provide further evidence that M. marinum is a good surrogate model for M. tuberculosis.
Project description:Mycobacteria infect macrophages that aggregate with additional macrophages and lymphocytes to form granulomas. We have used a functional genomics approach to identify immune response genes expressed during granuloma formation in Mycobacterium marinum-infected transparent zebrafish larvae where individual infection steps can be viewed in real time. We assessed RNA expression profiles from zebrafish larvae that were either infected with Mycobacterium marinum or mock-infected. Zebrafish infections were performed at 1 day post-fertilization (dpf), and samples were derived from pools of 6dpf zebrafish larvae. Keywords: host response to infection
Project description:Mycobacteria infect macrophages that aggregate with additional macrophages and lymphocytes to form granulomas. We have used a functional genomics approach to identify immune response genes expressed during granuloma formation in Mycobacterium marinum-infected transparent zebrafish larvae where individual infection steps can be viewed in real time. We assessed RNA expression profiles from zebrafish larvae that were either infected with Mycobacterium marinum, mock-infected, or uninfected. Zebrafish infections were performed at 1 day post-fertilization (dpf), and samples were derived from pools of 6dpf zebrafish larvae. Keywords: host response to infection
Project description:We use the zebrafish embryo model to study the innate immune response against Mycobacterium marinum. Therefore, we injected M. marinum into the yolk at the 64 cell stage and took samples at 5 days post injection. This deep sequence study was designed to determine the gene expression profile by Mycobacterium marinum infection. RNA was isolated from embryos at 5 days post injection. Wildtypes zebrafish embryos were micro-injected into the yolk (64 cell stage) with 40 CFU of Mycobacterium marinum E11 mCherry bacteria suspended in PVP (Polyvinylpyrrolidone), or Non-injected as a control. After injections embryos were transferred into fresh egg water and incubated at 28M-BM-0C. At 5 days post injection 50 embryos per group were snap-frozen in liquid nitrogen, and total RNA was isolated using TRIZOL reagent.
Project description:Zebrafish Mycobacterium marinum infection has been widely used to model human tuberculosis because these two diseases share common features, e.g. latency, granuloma formation and reactivation. Here we infected adult zebrafish with a low dose of M. marinum, which usually leads to a chronic infection. At 14 days post infection we performed microarray analysis to characterize the immune response against this infection. Analysis was done using total RNA extracted from the abdominal organs of zebrafish. Our aim was to find novel genes underlying host defense mechanisms against M. marinum infection in zebrafish, and thus to produce novel information that is valuable when developing new treatments for human tuberculosis.
Project description:Mycobacterium avium is the most common nontuberculous mycobacterium (NTM) species causing infectious disease. Here, we characterized a M. avium infection model in zebrafish larvae, and compared it to M. marinum infection, a model of tuberculosis. Using RNAseq analysis, we found a distinct transcriptome response in cytokine-cytokine receptor interaction for M. avium and M. marinum infection. In addition, we found substantial differences in gene expression in metabolic pathways, phagosome formation, matrix remodeling, and apoptosis in response to these mycobacterial infections.
Project description:Both embryonic and adult zebrafish Mycobacterium marinum infection studies have contributed to our knowledge of the development and function of tuberculous granulomas, which are typical for mycobacterial pathogenesis. In this review we discuss how transcriptome profiling studies have helped to characterize this infection process and we include new RNA sequencing (RNA-Seq) data that reveals three main phases in the host response to M. marinum during the early stages of granuloma development in zebrafish embryos and larvae. The late-phase response shares common components with the strong and acute host transcriptome response that has previously been reported for S. typhimurium infection in zebrafish embryos. In contrast, the early/mid-phase response to M. marinum infection, characterized by suppressed pro-inflammatory signaling, is strikingly different from the acute response to S. typhimurium infection. Furthermore, M. marinum infection shows a collective and strongly fluctuating regulation of lipoproteins, while S. typhimurium infection has pronounced effects on amino acid metabolism and glycolysis.