Project description:Mice were infected with wild type or ESX-1-deficient (deltaRD1) Mycobacterium marinum. 14 days post infection, infected and uninfected neutrophils from the infected tissue were sorted for single cell RNA sequencing analysis.
Project description:WhiB6 is a transcription factor that regulates expression of genes encoding ESX-1 substrates. We found that in the absence of the genes encoding conserved membrane components of the ESX-1 system, the expression of the whiB6 gene and genes encoding ESX-1 substrates were reduced.
Project description:The mechanisms of action of compound 8 in Mycobacterium marinum although it inhibits the secretion of the bacteria. In this experiment, we aim to investigated the effect of compound 8 on the global gene expression of Mycobacterium marinum
Project description:Raw and processed files in support of manuscript
The loss of the PDIM/PGL virulence lipids causes differential secretion of ESX-1 sub-strates in Mycobacterium marinum
The Virulence Lipid PDIM/PGL is essential for optimal protein secretion in Mycobacte-rium marinum
WT, PDIM and complement strains lysate and culture filtrate analysis of proteomes
Project description:We identify a putative link between miR-126 knockdown and neuroactive ligand and notch signalling pathways in uninfected and Mycobacterium marinum infected zebrafish embryos.
Project description:The ESX-1, type VII, secretion system represents the major virulence determinant of Mycobacterium tuberculosis. The ESX-1 cluster comprises approximately twenty genes and encodes a specialized secretion apparatus, which releases effectors into the extracellular milieu. The goal of this study is to understand the role of EspL. We show that EspL, a protein of 115 amino acids, is essential for mediating ESX-1-dependent virulence and for stabilization of EspE, EspF and EspH protein levels. Indeed, an espL knock-out mutant was unable to replicate intracellularly, secrete ESX-1 substrates or stimulate innate cytokine production. Moreover, loss of EspL also leads to downregulation in M. tuberculosis of WhiB6, a redox-sensitive transcriptional activator of ESX-1 genes.
Project description:Tuberculosis remains the most pervasive infectious disease and the recent emergence of multiple or even fully drug-resistant strains increases the risk and emphasizes the need for more efficient and better drug treatments. A key feature of mycobacteria pathogenesis, conserved between the human pathogen Mycobacterium tuberculosis and the model pathogen Mycobacterium marinum, is the metabolic switch to lipid catabolism during infection and altered expression of virulence genes in coordination with different stages of infection. This study aims at identifying genes that are involved in the establishment and maintenance of the infection. To achieve this, we have applied Transposon Sequencing (Tn-Seq) to M. marinum, an unbiased genome-wide strategy that combines saturation insertional mutagenesis and high throughput sequencing. This approach allowed us to precisely identify the localization and relative abundance of insertions in pools of transposon mutants. The essentiality of genes and the positive and negative fitness cost of mutations were quantitatively compared between in vitro growth and different stages of infection in two evolutionary distinct host phagocytes, the amoeba Dictyostelium discoideum and the murine BV2 microglial cells. We found that 57% of TA sites in the M. marinum genome were disrupted and that 568 genes (10.2%) were essential for M. marinum, which is comparable to previous Tn-Seq studies on M. tuberculosis and M. bovis. Major pathways involved in the survival of M. marinum during infection of D. discoideum were related to DNA damage repair, vitamin metabolism, the type VII secretion system (T7SS) ESX-1 and the Mce1 lipid transport system.
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: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: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.
