Project description:Tuberculosis (TB) remains a deadly disease. The genetic diversity of Mycobacterium tuberculosis was neglected in the past, but is increasingly recognized as a determinant of immune responses and clinical outcomes of TB. However, how this bacterial diversity orchestrates immune responses to direct differences in TB severity remains unknown. We studied 681 patients with pulmonary TB and found that phylogenetically related M. tuberculosis isolates from cases with mild disease induced robust cytokine responses in macrophages. In contrast, isolates associated with severe TB cases failed to do so. Using representative isolates, we show that M. tuberculosis inducing a low cytokine response in macrophages also diminished activation of cytosolic surveillance systems, including cGAS and the inflammasome, suggesting a novel mechanism of immune escape. Isolates exhibiting this evasion strategy carried mutations in various components of the ESX-I secretion system. We conclude that host interactions with different M. tuberculosis strains results in variable TB severity.
Project description:Mycobacterium tuberculosis (M. tb), the cause of tuberculosis (TB), utilizes the blood circulation to spread systemically and establish infection, and the risk of developing active TB (pulmonary and extrapulmonary) is significantly increased in individuals infected with human immunodeficiency virus (HIV). In this work, we have used DNA microarray analysis to investigate the transcriptome of M. tb replicating in human whole blood from both HIV-negative and HIV-positive donors compared to M. tb grown in Middlebrook 7H9 broth media in order to identify M. tb adaptations to this host environment as well as M. tb mechanisms/factors contributing to increased active and disseminated TB during M. tb/HIV co-infection.
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.
Project description:We report a pilot investigation for poly-A RNAs differentially expressed during Mycobacterium tuberculosis infection. Participation in this investigation from March 2010 to July 2013 was voluntary, only subjects that were >18 years old and that informed written consent were considered eligible. The recruitment of tuberculosis (TB) patients was done at public hospitals in Rio de Janeiro, Brazil. The diagnostic criteria for active pulmonary tuberculosis was at least one AFB (acid-fast bacilli) -positive sputum sample for M. tuberculosis and/or positive sputum culture and/or compatible clinical evolution for pulmonary TB and less than 15 days of anti-TB treatment and was in accordance with those of the Brazilian Ministry of Health. Blood was collected from recent close contacts (rCt) and active tuberculosis (TB) index cases (n=6). Latent TB infection (LTBI) was accessed by both tuberculin skin test (TST, cut-off = 5mm) and in house interferon-gamma release assays (IGRA, cut-off = 100 pg/ml), therefore, 12 rCt were classified as uninfected controls and 16 with LTBI. Subsequently, the sequencing was performed following the standard protocols on Illumina HiSeq® 2500 Sequencing System (Illumina, San Diego, CA) running 100 bp paired-end reads (PE100) and generating approximately 30 million reads passing filter for each sample to produce the mRNA reads. Mining these RNAseq data, highly prominent modulation of DOCK9, EPHA4, and NPC2 mRNA expression was observed in the TB samples, indicating that they might have a role in TB pathogenesis. These differential modulations upon M. Tuberculosis infection were further validated by additional evidences in larger cohorts from different geographical areas.
Project description:Tuberculosis (TB) is still a major global health challenge, killing over 1.5 million people each year, and hence, there is a need to identify and develop novel treatments for Mycobacterium tuberculosis (M. tuberculosis). The prevalence of infections caused by nontuberculous mycobacteria (NTM) is also increasing and has overtaken TB cases in the United States and much of the developed world. Mycobacterium abscessus (M. abscessus) is one of the most frequently encountered NTM and is difficult to treat. We describe the use of drug-disease association using a semantic knowledge graph approach combined with machine learning models that has enabled the identification of several molecules for testing anti-mycobacterial activity. We established that niclosamide (M. tuberculosis IC90 2.95 μM; M. abscessus IC90 59.1 μM) and tribromsalan (M. tuberculosis IC90 76.92 μM; M. abscessus IC90 147.4 μM) inhibit M. tuberculosis and M. abscessus in vitro. To investigate the mode of action, we determined the transcriptional response of M. tuberculosis and M. abscessus to both compounds in axenic log phase, demonstrating a broad effect on gene expression that differed from known M. tuberculosis inhibitors. Both compounds elicited transcriptional responses indicative of respiratory pathway stress and the dysregulation of fatty acid metabolism. Further testing against drug-resistant isolates and other NTM is warranted to clarify the usefulness of these repurposed drugs for mycobacteria.
Project description:Synchronised cultures of Mycobacterium tuberculosis (M. tb H37Ra DnaAcos115) were used to determine the cell cycle dependent gene expression.
Project description:Tuberculosis (TB) is one of the top ten causes of death worldwide and the leading cause of death from a single infectious agent. Globally, an estimated of 10 million people developed TB in 2018 according to WHO report. An estimated one third of all TB cases are not diagnosed or notified, partly due to the major limitations of current diagnostic tools. To achieve the goals of the WHO’s End TB Strategy, which targets for 2030 a 90% reduction in the number of TB deaths and an 80% reduction in the TB incidence rate compared with levels in 2015, diagnostic tools are critically important. Among the three diagnostic priorities identified by the WHO and the TB community is the development of a point-of-care biomarker-based non-sputum-based test to diagnose pulmonary TB, and ideally also extrapulmonary TB. To be successfully implemented at point-of-cares, a new test should use an easily accessible sample, such as urine, blood or breath condensate. Here, we explored whether bacilli-derived molecules released in the extracellular milieu during infection could be detected in the exhaled breath condensate, allowing a specific diagnosis of TB. Interestingly, we detected by proteomic analysis a set of Mycobacterium tuberculosis proteins in all smear-positive and smear-negative adult patients, as well as of children with TB
Project description:Mycobacterium tuberculosis (M. tb), the cause of tuberculosis (TB), utilizes the blood circulation to spread systemically and establish infection, and the risk of developing active TB (pulmonary and extrapulmonary) is significantly increased in individuals infected with human immunodeficiency virus (HIV). In this work, we have used DNA microarray analysis to investigate the transcriptome of M. tb replicating in human whole blood from both HIV-negative and HIV-positive donors compared to M. tb grown in Middlebrook 7H9 broth media in order to identify M. tb adaptations to this host environment as well as M. tb mechanisms/factors contributing to increased active and disseminated TB during M. tb/HIV co-infection. We compared the global gene expression of M. tb H37Rv replicating in whole blood from 6 HIV- and 6 HIV+ individulas at 96 hr to M. tb grown to log phase in Middlebrook 7H9 media.