Transcription profiling of mouse lung from a strain overexpressing IL-10 under control of the macrophage-specific CD68 promoter (macIL-10tg mice) after Mycobacterium tuberculosis infection
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ABSTRACT: The cytokine IL-10 deactivates macrophages and has been shown to impair resistance to mycobacterial infection. We have infected transgenic mice overexpressing IL-10 under control of the macrophage-specific CD68 promoter (macIL-10tg mice) with Mycobacterium tuberculosis by aerosol and found increased bacterial loads in the lungs of macIL-10tg mice. To identify programs of genes regulated by IL-10 and associated with increased mycobacterial replication, genome-wide expression analysis was performed. Experiment Overall Design: Impact of IL-10 pulmonary gene expression in mouse M. tuberculosis infection
Project description:Using cell-based approaches and experimental mouse models for pulmonary TB we unveiled MDSCs as new myeloid populations directly interacting with Mycobacterium tuberculosis (Mtb). MDSCs readily phagocytosed Mtb, released proinflammatory (IL-6, IL-1M-NM-1) and immunomodulatory (IL-10) cytokines while retaining their suppressive capacity. MDSCs were identified at the site of infection in disease-resistant and -susceptible mice during pulmonary TB. Excessive MDSC accumulation in lungs correlated with elevated surface expression of IL-4RM-NM-1 and heightened TB lethality. Microarray experiments were performed as dual-color hybridizations on Agilent mouse whole genome catalog 44K arrays. To compensate for dye-specific effects, a dye-reversal color-swap was applied.
Project description:Pyrazinamide (PZA) is one of the first line antibiotics used for the treatment of tuberculosis (TB). we have used human monocyte and a mouse model of pulmonary TB to investigate whether treatment with PZA, in addition to its known anti-mycobacterial properties, modulate the host immune response during Mycobacterium tuberculosis (Mtb) infection. Mice were infected with Mtb and treatment with PZA was started at 28 days post-infection. At 42 days and 63 days post-infection, group of animals were euthanized and lung tissue was collected to isolate total RNA and used in microarray experiments. Mtb-infected, untreated animals served as controls.
Project description:The critical role of type I IFN (IFN I ) in viral disease is thoroughly documented while their function in bacterial infection remains ambiguous. General interest in biological functions of IFN I in Mycobacterium tuberculosis (Mtb) infection was raised by the identification of a distinct IFN I gene expression signature in tuberculosis (TB) patients. Here we demonstrate that TB-susceptible mice lacking the receptor for IFN I (IFNAR1) were protected from death upon aerogenic infection with Mtb. Increased survival was accompanied by reduced bacterial burden and ameliorated lung pathology as well as diminished production of proinflammatory IL-1?, among other cytokines. IFNAR1 signaling did not affect T cell responses, but markedly altered migration of inflammatory monocytes and neutrophils to the lung during pulmonary TB. This process was orchestrated by presence of IFNAR1 in both immune and tissue-resident radioresistant cells. IFNAR1-driven TB susceptibility was initiated by CXCL5/CXCL1-driven accumulation of neutrophils into alveoli and subsequently a distinct compartmentalization of Mtb in lung phagocytes. We conclude that IFN I alters early innate events at the site of Mtb invasion leading to unleashed inflammation. Hence, our data furnish a mechanistic explanation for the detrimental role of IFN I in pulmonary TB. dual-color color-swap
Project description:Iron plays a critical role in the pathogenesis of many organisms including Mtb. It is the preferred redox cofactor in many basic cellular processes but due to its insolubility and potential toxicity under physiological conditions is a limiting nutrient in the host environment. Previously, we demonstrated that Mtb requires the iron storage protein ferritin (BfrB), for adaptation to both low and sufficient concentrations of environmental iron. We also showed that absence of bfrB compromises the ability of Mtb to overcome iron deficiency and prevent excess iron toxicity. In this study, we tested whether vaccination with ?bfrB could elicit host protective immune response against virulent Mtb infection. The results show that immunization of mice with the ?bfrB stimulates protective immunity associated with reduced immunopathology and better containment of the infection compared to vaccination with BCG. Genome-wide transcriptome analysis showed a distinct expression pattern of significantly differentially expressed genes (SDEG) between the ?bfrB and BCG-vaccinated, Mtb-infected mice lungs. Our network/pathway analysis of SDEG revealed significant inhibition of inflammatory response genes and activation of fibrosis genes in the ?bfrB, compared to BCG vaccinated, Mtb-infected mice lungs. The results provide a frame work for the study of mechanisms of protection relevant for the design of new and improved preventive strategies for TB. Female C57BL/6 mice were vaccinated subcutaneously with ?bfrB or BCG . At 8 weeks post-vaccination, mice were aerosol infected with Mtb H37Rv. At 4 weeks post infection, mice were sacrificed and lungs were removed. Lung total RNA from vaccinated and Mtb-infected mice was extracted, purified and were processed separately for microarray analysis.
Project description:CD8+ T cells contribute to protective immunity to Mycobacterium tuberculosis (Mtb), but the principles that govern presentation of Mtb peptides on MHC class I (MHC-I) on the surface of infected macrophages for CD8+ T cell recognition are incompletely understood. Here, we use internal standard parallel reaction monitoring (IS-PRM, also known as SureQuant) to rigorously validate identifications of Mtb-derived MHC-I peptides obtained in data-dependent MS analyses. We further use SureQuant to quantify presentation of Mtb peptides derived from the secreted effector proteins EsxA and EsxJ across multiple experimental conditions. We show that presentation of both EsxA- and EsxJ-derived peptides requires the activity of the mycobacterial ESX-1 type VII secretion system, possibly indicating that ESX-1-mediated phagosome membrane damage allows Mtb proteins to access MHC-I antigen processing pathways. We show that this requirement is independent of type I interferon signaling that occurs downstream of phagosome damage. Treatment with inhibitors of conventional proteolytic pathways involved in MHC-I antigen processing inhibits presentation of self peptides as expected, but does not inhibit presentation of Mtb peptides, implying an alternative or redundant mechanism of processing.
Project description:Molecular profiling of effect of TNFα neutralization in contrast to anti-IL-17A or anti-IL-17F treatment for 28 days in lungs of M. tuberculosis infected C57BL/6 mice. Animals were treated once per week (starting day-1) with anti-mouse IL-17A or IL-17F antibodies (20 mg/kg i.p.), anti-mouse TNFα antibody (10 mg/kg), respective isotype control antibodies. Moreover, infected and non-infected TNFα-deficient mice were also analysed. Gene expression data revealed major changes of inflammatory and immune gene expression signatures 4 weeks post-infection (including host-pathogen interactions, macrophage recruitment, activation and polarization, host-anti-mycobacterial activities, immunomodulatory responses and extracellular matrix metallopeptidases) after TNFα blockade, while IL-17A or IL-17F neutralization elicited only mild changes of few genes without impaired host resistance four weeks after M. tuberculosis infection.
Project description:Deeper understanding of the crosstalk between host cells and Mycobacterium tuberculosis (Mtb) provides crucial guidelines for the rational design of novel intervention strategies against tuberculosis (TB). Mycobacteria possess a unique complex cell wall with arabinogalactan (AG) as critical component. AG has been identified as a virulence factor of Mtb which is recognized by host galectin-9. Here we demonstrate that galectin-9 directly inhibited mycobacterial growth through AG-binding property of carbohydrate-recognition domain 2. Furthermore, IgG antibodies with AG specificity were detected in serum of TB patients. Based on the interaction between galectin-9 and AG, we developed monoclonal antibody (mAb) screening assay and identified AG-specific mAbs which profoundly inhibit Mtb growth. Mechanistically, proteomic profiling and morphological characterizations revealed that AG-specific mAbs regulate AG biosynthesis, thereby inducing cell wall swelling. Thus, direct AG-binding by galectin-9 or antibodies contributes to protection against TB. Our findings pave the way for the rational design of novel immunotherapeutic strategies for TB control.
Project description:Global gene expressions of Mtb-infected mouse lungs were compared between with and without PDE4 inhibitor treatment. A lot of host genes are differentially expressed 21d and 28d post-Mtb infection. PDE4 inhibitor, however, downregulate 10% of genes among those and genes differentially regulated by PDE4 inhibitor are mainly involved immune response. Total RNA was isolated from Mtb-infected mouse lungs with or without CC-3052 (25 mg/kg/day) using Trizol reagent and gene profile was analyed using Affymetrix mouse ST 1.0
Project description:Unlike many pathogens that are overtly toxic to their hosts, the primary virulence determinant of Mycobacterium tuberculosis appears to be its ability to persist for years or decades within humans in a clinically latent state. Since early in the 20th century latency has been linked to hypoxic conditions within the host, but the response of M. tuberculosis to a hypoxic signal remains poorly characterized. The M. tuberculosis alpha-crystallin (acr) gene is powerfully and rapidly induced at reduced oxygen tensions, providing us with a means to identify regulators of the hypoxic response. Using a whole genome microarray, we identified >100 genes whose expression is rapidly altered by defined hypoxic conditions. Numerous genes involved in biosynthesis and aerobic metabolism are repressed, whereas a high proportion of the induced genes have no known function. Among the induced genes is an apparent operon that includes the putative two-component response regulator pair Rv3133cy Rv3132c. When we interrupted expression of this operon by targeted disruption of the upstream gene Rv3134c, the hypoxic regulation of acr was eliminated. These results suggest a possible role for Rv3132cy3133cy3134c in mycobacterial latency. Keywords: comparative genome hybridization design and stimulus or stress design Six samples were analyzed. The quality controls were biological replicate and technical replicate
Project description:Unlike many pathogens that are overtly toxic to their hosts, the primary virulence determinant of Mycobacterium tuberculosis appears to be its ability to persist for years or decades within humans in a clinically latent state. Since early in the 20th century latency has been linked to hypoxic conditions within the host, but the response of M. tuberculosis to a hypoxic signal remains poorly characterized. The M. tuberculosis alpha-crystallin (acr) gene is powerfully and rapidly induced at reduced oxygen tensions, providing us with a means to identify regulators of the hypoxic response. Using a whole genome microarray, we identified >100 genes whose expression is rapidly altered by defined hypoxic conditions. Numerous genes involved in biosynthesis and aerobic metabolism are repressed, whereas a high proportion of the induced genes have no known function. Among the induced genes is an apparent operon that includes the putative two-component response regulator pair Rv3133cy Rv3132c. When we interrupted expression of this operon by targeted disruption of the upstream gene Rv3134c, the hypoxic regulation of acr was eliminated. These results suggest a possible role for Rv3132cy3133cy3134c in mycobacterial latency.