Mus musculus
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA112061 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Granulomas function in humans during tuberculosis by focusing production of host antimicrobial factors against the causative bacterial agent Mycobacterium tuberculosis to contain infection. We show that mice unable to produce nitric oxide –itself an important antimicrobial molecule- demonstrate functional granulomas in the lung able to control infection after dermal infection. Disease in the lung was activated by administration of neutralising antibody against either TNF-α, which disrupted granuloma integrity, or INF-γ, which resulted in development of caseous necrosis within granulomas reminiscent of active human tuberculosis. In the latter case, the serpin protease inhibitor serpinb3a and its target protease, cathepsin G are highly expressed in cells local to necrotic regions in granulomas and serpinb3a induces necrosis of infected macrophages independently of cathepsin G binding. Therefore a single host protein is capable of inducing necrosis and bacterial growth during intracellular infection.
2010-12-22 | GSE14826 | GEO
Project description:Interferon (IFN)-γ-producing CD8+ T cells are involved in control of Mycobacterium tuberculosis (Mtb) infection, in part by promoting antimicrobial activities of macrophages. Whether Mtb counters these responses, particularly during the hypoxic conditions that arise within granulomas during infection, remains unknown. Using metabolomic, proteomic and genetic approaches, here we show that Mtb induces Rv0884c (SerC), a Mtb phosphoserine aminotransferase, to produce D-serine. This activity increased Mtb pathogenesis in mice but did not directly affect intramacrophage Mtb survival. Instead, D-serine inhibited IFN-γ production by CD8+ T cells, which indirectly reduced the ability of macrophages to restrict Mtb upon coculture. Mechanistically, D-serine interacted with WDR24, a subunit of GATOR2, and inhibited mTORC1 activation in T cells. This decreased T-bet transcription factor expression by CD8+ T cells and reduced IFN-γ production. Our findings suggest a mechanism of mycobacterial metabolic adaptation to hypoxia which leads to amino acid-dependent suppression of adaptive anti-TB immunity.
2024-08-10 | PXD050258 | Pride
Project description:An estimated two billion persons are latently infected with Mycobacterium tuberculosis. The host factors that initiate and maintain this latent state and the mechanisms by which M. tuberculosis survives within latent lesions are compelling but unanswered questions. One such host factor may be nitric oxide (NO), a product of activated macrophages that exhibits antimycobacterial properties. Evidence for the possible significance of NO comes from murine models of tuberculosis showing progressive infection in animals unable to produce the inducible isoform of NO synthase and in animals treated with a NO synthase inhibitor. Here, we show that O2 and low, nontoxic concentrations of NO competitively modulate the expression of a 48-gene regulon, which is expressed in vivo and prepares bacilli for survival during long periods of in vitro dormancy. NO was found to reversibly inhibit aerobic respiration and growth. A heme-containing enzyme, possibly the terminal oxidase in the respiratory pathway, likely senses and integrates NO and O2 levels and signals the regulon. These data lead to a model postulating that, within granulomas, inhibition of respiration by NO production and O2 limitation constrains M. tuberculosis replication rates in persons with latent tuberculosis.
2007-09-29 | E-SMDB-4062 | biostudies-arrayexpress
Project description:An estimated two billion persons are latently infected with Mycobacterium tuberculosis. The host factors that initiate and maintain this latent state and the mechanisms by which M. tuberculosis survives within latent lesions are compelling but unanswered questions. One such host factor may be nitric oxide (NO), a product of activated macrophages that exhibits antimycobacterial properties. Evidence for the possible significance of NO comes from murine models of tuberculosis showing progressive infection in animals unable to produce the inducible isoform of NO synthase and in animals treated with a NO synthase inhibitor. Here, we show that O2 and low, nontoxic concentrations of NO competitively modulate the expression of a 48-gene regulon, which is expressed in vivo and prepares bacilli for survival during long periods of in vitro dormancy. NO was found to reversibly inhibit aerobic respiration and growth. A heme-containing enzyme, possibly the terminal oxidase in the respiratory pathway, likely senses and integrates NO and O2 levels and signals the regulon. These data lead to a model postulating that, within granulomas, inhibition of respiration by NO production and O2 limitation constrains M. tuberculosis replication rates in persons with latent tuberculosis. The quality controls were biological replicate and technical replicate
2007-08-21 | E-GEOD-8839 | biostudies-arrayexpress
Project description:An estimated two billion persons are latently infected with Mycobacterium tuberculosis. The host factors that initiate and maintain this latent state and the mechanisms by which M. tuberculosis survives within latent lesions are compelling but unanswered questions. One such host factor may be nitric oxide (NO), a product of activated macrophages that exhibits antimycobacterial properties. Evidence for the possible significance of NO comes from murine models of tuberculosis showing progressive infection in animals unable to produce the inducible isoform of NO synthase and in animals treated with a NO synthase inhibitor. Here, we show that O2 and low, nontoxic concentrations of NO competitively modulate the expression of a 48-gene regulon, which is expressed in vivo and prepares bacilli for survival during long periods of in vitro dormancy. NO was found to reversibly inhibit aerobic respiration and growth. A heme-containing enzyme, possibly the terminal oxidase in the respiratory pathway, likely senses and integrates NO and O2 levels and signals the regulon. These data lead to a model postulating that, within granulomas, inhibition of respiration by NO production and O2 limitation constrains M. tuberculosis replication rates in persons with latent tuberculosis.
2007-08-22 | GSE8839 | GEO
Project description:Most individuals infected with Mycobacterium tuberculosis can control the infection by forming and maintaining TB granulomas at the local infection foci. However, when the chronic infection (also known as latency) becomes active, the caseous center of TB granuloma enlarges, and it liquefies and cavitates, ultimately releasing bacilli into airway. Deciphering how genes are regulated within TB granulomas will help to understand the granuloma biology. Therefore, we performed genome-wide microarray on caseous human pulmonary TB granulomas and compared with normal lung tissues.
2010-06-02 | GSE20050 | GEO
Project description:Necrotic cell death represents a major pathogenic mechanism of Mycobacterium tuberculosis (Mtb) infection. It is increasingly evident that Mtb induces several types of regulated necrosis but how these are interconnected and linked to the release of pro-inflammatory cytokines remains unknown. Exploiting a clinical cohort of tuberculosis patients, we show here that the number and size of necrotic lesions correlates with IL-1β plasma levels as a strong indicator of inflammasome activation. Our mechanistic studies reveal that Mtb triggers mitochondrial permeability transition (mPT) and subsequently extensive macrophage necrosis which requires activation of the NLRP3 inflammasome. NLRP3 driven mitochondrial damage is dependent on proteolytic activation of the pore forming effector protein gasdermin D (GSDMD) which links two distinct cell death machineries. Intriguingly, GSDMD, but not the membranolytic mycobacterial ESX-1 secretion system is dispensable for IL-1β secretion from Mtb-infected macrophages. Thus, our study dissects a novel mechanism of pathogen induced regulated necrosis by identifying mitochondria as central regulatory hubs capable of delineating cytokine secretion and lytic cell death.
2022-02-17 | PXD029017 | Pride
Project description:Most individuals infected with Mycobacterium tuberculosis can control the infection by forming and maintaining TB granulomas at the local infection foci. However, when the chronic infection (also known as latency) becomes active, the caseous center of TB granuloma enlarges, and it liquefies and cavitates, ultimately releasing bacilli into airway. Deciphering how genes are regulated within TB granulomas will help to understand the granuloma biology. Therefore, we performed genome-wide microarray on caseous human pulmonary TB granulomas and compared with normal lung tissues. Laser capture microdissection (LCM) was used to dissect out caseous granulomas from TB patients' lung tissues, excluding uninvolved areas. Total RNA were isolated from LCM-derived materials and used for microarray. As a control, parenchyma from normal lung tissues was prepared in the same manner as caseous granulomas. Sample GSM501252, Caseum 2-C, is missing a CEL file.
2010-06-08 | E-GEOD-20050 | biostudies-arrayexpress
Project description:Mycobacterium infection gives rise to granulomas predominantly composed of inflammatory M1-like macrophages, with bacteria-permissive M2 macrophages also detected in deep granulomas. Our histological analysis of Mycobacterium bovis bacillus Calmette-Guerin-elicited granulomas in guinea pigs revealed that S100A9-expressing neutrophils bordered a unique M2 niche within the inner circle of concentrically multilayered granulomas. We evaluated the effect of S100A9 on macrophage M2 polarization based on guinea pig studies. S100A9-deficient mouse neutrophils abrogated M2 polarization, which was critically dependent on COX-2 signaling in neutrophils. Mechanistic evidence suggested that nuclear S100A9 interacts with C/EBPβ, which cooperatively activates the Cox-2 promoter and amplifies prostaglandin E2 production, followed by M2 polarization in proximal macrophages. Since the M2 populations in guinea pig granulomas were abolished via treatment with celecoxib, a selective COX-2 inhibitor, we propose the S100A9/Cox-2 axis as a major pathway driving M2 niche formation in granulomas.
2023-03-01 | GSE162991 | GEO
Project description:Tuberculosis (TB) is a heterogeneous disease manifesting in a subset of individuals infected with aerosolized Mycobacterium tuberculosis (Mtb). Unlike human TB, murine infection results in uniformly high lung bacterial burdens and poorly organized granulomas. To develop a TB model that more closely resembles human disease, we infected mice with an ultra-low dose (ULD) of between 1-3 founding bacteria, reflecting a physiologic inoculum. ULD-infected mice exhibited highly heterogeneous bacterial burdens, well-circumscribed granulomas that shared features with human granulomas, and prolonged Mtb containment with unilateral pulmonary infection in some mice. We identified blood RNA signatures in mice infected with an ULD or a conventional Mtb dose (50-100 CFU) that correlated with lung bacterial burdens and predicted Mtb infection outcomes across species, including risk of progression to active TB in humans. Overall, these findings highlight the potential of the mouse TB model and show that ULD infection recapitulates key features of human TB.
2020-11-06 | GSE158807 | GEO