Project description: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:Bmdm cells were differentiated for 10 days and harvested and culture in six well plate followed by cytokine stimulation after 24 hrs cells were infected with mycobacterium tuberculosis to identify the host factors involved in infection. Total RNA was colloected from bmdm cells stimulated with cytokine and /or infected with mycobacterium tuberculosis in a time course experiments from 28hrs to 72 hrs.
Project description:Tuberculosis, a chronic granulomatous disease caused by Mycobacterium tuberculosis (Mtb), often becomes exacerbated upon co-infection with other pathogens, yet the underlying immunological mechanisms remain insufficiently understood. Here, mice were initially infected with the hypervirulent Mtb strain K, and later with lymphocytic choriomeningitis virus to investigate the mechanism of severe pulmonary pathology. Virus infection significantly reduced Mtb-specific IFN-g, increased bacterial loads, and aggravated lung inflammation in the lung of Mtb-infected mice, which did not occur in pre-existence of Th1 response by Bacillus Calmette-Guerin vaccination prior to the co-infection. Blockade of type I IFN receptor signaling reinvigorated Mtb-specific IFN-γ response and ameliorated pathogenesis by upregulating pulmonary CXCL9/10 production. Our results demonstrate that virus-induced type I IFN triggers severe immunopathology by deteriorating migration of Mtb-specific IFN-γ-producing T cells, suggesting the balance between type I and type II IFNs determines either control of Mtb or exacerbation of pathology in the lung upon viral infection
Project description:Macrophages are a protective replicative niche for Mycobacterium tuberculosis (Mtb) but can kill the infecting bacterium when appropriately activated. To identify mechanisms of clearance, we compared bacterial restriction by human macrophages after treatment with 26 compounds, including some currently in clinical trials for tuberculosis. All-trans-retinoic acid (ATRA), an active metabolite of vitamin A, drove the greatest increase in Mtb control. Bacterial clearance was transcriptionally and functionally associated with changes in macrophage cholesterol trafficking and lipid metabolism. To determine how these macrophage changes affected bacterial control, we performed the first Mtb CRISPR interference screen in an infection model, identifying Mtb genes specifically required to survive in ATRA-activated macrophages. These data showed that ATRA treatment starves Mtb of cholesterol and the downstream metabolite propionyl-CoA. Supplementation with sources of propionyl-CoA, including cholesterol, abrogated the restrictive effect of ATRA. This work demonstrates that targeting the coupled metabolism of Mtb and the macrophage improves control of infection, and that it is possible to genetically map the mode of bacterial death using CRISPR interference.
Project description:We report the application of RNA sequencing to assess the expression dynamics of miRNAs and their isoforms over time upon infection with a panel of six intracellular bacteria (Mycobacterium tuberculosis H37Rv, Mycobacterium tuberculosis Beijing strain GC1237, Mycobacterium bovis BCG, Salmonella typhimurium strain Keller, Staphloccocus epidermidis and Yersinia pseudotuberculosis) Study of miRNA expression dynamics of monocyte-derived dendritic cells upon bacterial infection using RNA sequencing
Project description:This SuperSeries is composed of the following subset Series: GSE6209: The global transcriptional profile of Mycobacterium tuberculosis during human macrophages infection GSE7962: Sigma factor E of Mycobacterium tuberculosis controls the expression of bacterial components that modulate macrophages Keywords: SuperSeries Refer to individual Series
Project description:Current antibiotic regimen to treat tuberculosis (TB) is ineffective in fully eliminating the bacterial load and in alleviating disease pathology. We examined the usefulness of a phosphodiesterase-4 inhibitor (CC-11050) as an adjunctive to anti-TB drug Isoniazid (INH) to improve the outcome of treatment in a rabbit model of active pulmonary TB. Control of Mycobacterium tuberculosis (Mtb) growth, disease pathology and the global transcriptional response in Mtb-infected lungs of rabbits with or without CC-11050 treatment were studied. The microarray experiments involves comparison of changes in gene expression between uninfected and Mtb-HN878 infected (Untreated) or CC-11050 treated rabbit lungs at 8 weeks post-treatment, starting at 4 weeks of infection (i.e, 12 weeks post infection).
Project description:Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), is an exquisitely adapted human pathogen capable of surviving for decades in the lungs of immune competent individuals in absence of disease. The World Health Organization estimates that 2 billion people have latent TB infection (LTBI), defined by positive immunologic response to Mtb antigens with no clinical signs of disease. A better understanding of host and pathogen determinants of LTBI and subsequent reactivation would benefit TB control efforts. Animal models of LTBI have been hampered mainly by an inability to achieve complete bacillary clearance. We have characterized a rabbit model of LTBI in which, similar to most humans, complete clearance of pulmonary Mtb infection and pathology occurs spontaneously. The evidence that Mtb-CDC1551-infected rabbits achieve LTBI, rather than sterilization, is based on the ability of the bacilli to be reactivated following immune suppression. The microarray experiments involves comparison of: 1) Changes in rabbit gene expression between Mtb-CDC1551 infected and uninfected animals at 2,4,8 and 12 weeks post infection. New Zealand White rabbits were infected with Mtb CDC1551 at 3.5log10 (on day 0). Lung tissue from Mtb-infected rabbits were isolated from uninfected (control) and at 2, 4, 8 and 16 weeks post infection and used for total RNA extraction. Total rabbit lung RNA was used for microarray analysis to determine infection induced changes in host gene expression.
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: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. Keywords: Effect of infection; effect of genotype; timecourse