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:This study reports on infection-inducible miRNAs in zebrafish. Using a custom-designed microarray platform for miRNA expression we found that miRNAs of the miR-21, miR-29, and miR-146 families were commonly induced by infection of zebrafish embryos with Salmonella typhimurium and by infection of adult fish with Mycobacterium marinum. A custom-designed Agilent zebrafish 8x15k miRNA platform was used to profile miRNA expression in zebrafish embryos infected with Salmonella typhimurium strain SL1027 and adult zebrafish infected with Mycobacterium marinum strain Mma20 . The 15k design contained a duplicate of 7604 probes of 60-oligonucleotide length. The probes consisted of 2x22 nucleotide sequences antisense to mature miRNAs separated by a spacer of 8 nucleotides (CGATCTTT) and with a second spacer with the same sequence at the end. From 7604 probes 546 were designed for left (5') and right (3') arms of the hairpins of zebrafish miRNAs known in miRBase, while the remainder 7058 probes corresponded to predicted hairpin structures in the zebrafish genome that might include additional miRNAs but were not considered in this study. Zebrafish embryos were infected at 28 hours post fertilization (hpf) by injecting 200-250 colony forming units of Salmonella typhimurium into the caudal vein and miRNA profiles of infected embryos were compared to control embryos injected with PBS (phosphate buffered saline) at 8 hours post-infection (hpi; 3 biological replicates and 2 technical replicates per each sample). Adult zebrafish were infected with 10000 colony forming units of Mycobacterium marinum and miRNA profiles were compared to PBS-injected control fish at 6 days post infection (dpi; 3 biological replicates). For dual color hybridization of the Agilent chips miRNA samples from infected zebrafish were labeled with Hy3 and samples from control fish were labeled with Hy5.
Project description:This study reports on infection-inducible miRNAs in zebrafish. Using a custom-designed microarray platform for miRNA expression we found that miRNAs of the miR-21, miR-29, and miR-146 families were commonly induced by infection of zebrafish embryos with Salmonella typhimurium and by infection of adult fish with Mycobacterium marinum.
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: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.
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