Responses of Monocytes derived macrophages from TB-infected and TB-free cattles to in vitro M.bovis challenge
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ABSTRACT: Macrophages from cattles with different infectious status of bovine tuberculosis have different responses to in vitro Mycobacterium bovis challenge. This is confirmed in our previous study exploring several immune-related genes using qPCR. Microarrays can help us better understand the differences by screening thousands of genes. Monocytes Derived Macrophages from 3 TB-infected cattles and 3 TB-free cattles were challenged with Mycobacterium bovis at a MOI of 10 at 6 hours, and the control group were the same unchallenged macrophages at 6 hours.
Project description:Transcriptional profiling of splenic lymphocytes derived from vaccinated mice, and ex-vivo exposed to M.tb.-infected macrophages in culture. Splenocytes from mice innoculated with Mycobacterium bovis BCG Pasteur (PAS), or M. bovis BCG Copenhagen (SSI), or heat killed BCG SSI (HK), or uninfected control, were ex vivo co-cultured with mouse bone marrow macrophages previously infected with M. tb.
Project description:Oxadiazolone (OX) derivatives have been investigated for their antimycobacterial activity against three pathogenic slow-growing mycobacteria: Mycobacterium marinum, Mycobacterium bovis BCG and the avirulent Mycobacterium tuberculosis (M. tb) mc26230. The encouraging MIC values obtained prompted us to test them against virulent M. tb H37Rv growth either in broth medium or inside macrophages. The OX compounds displayed a diversity of action and were found to act either on extracellular M. tb growth only with moderated MIC, or both intracellularly on infected macrophages as well as extracellularly on bacterial growth. One OX derivatives, HPOX, was selected and used in a competitive labelling/enrichment assay against the activity-based probe Desthiobiotin-FP in order to identify its putative target(s). This approach, combined with mass spectrometry, identified 18 potential candidates, all being serine or cysteine enzymes involved in M. tb lipid metabolism and/or in cell wall biosynthesis. Among them, Ag85A, CaeA, TesA, KasA and MetA have been reported as essential for in vitro growth of M. tb and/or its survival and persistence inside macrophages. Overall, our findings support the assumption that OX derivatives may represent a novel class of multi-target inhibitors leading to the arrest of M. tb growth through a cumulative inhibition of a large number of Ser- and Cys-containing enzymes involved in various important physiological processes.
Project description:Macrophages from cattles with different infectious status of bovine tuberculosis have different responses to in vitro Mycobacterium bovis challenge. This is confirmed in our previous study exploring several immune-related genes using qPCR. Microarrays can help us better understand the differences by screening thousands of genes.
Project description:New strategies are required to reduce the worldwide burden of tuberculosis. Intracellular survival and replication of Mycobacterium tuberculosis after macrophage phagocytosis is a fundamental step in the complex host-pathogen interactions that lead to granuloma formation and disease. Greater understanding of how the bacterium survives and thrives in these environments will inform novel drug and vaccine discovery programmes. Here, we use in-depth RNA sequencing of Mycobacterium bovis BCG from human THP-1 macrophages to describe the mycobacterial adaptations to the intracellular environment. We identify 329 significantly differentially regulated genes, highlighting cholesterol catabolism, methyl-citrate cycle and iron homeostasis as important for mycobacteria inside macrophages. Focused analysis of PE/PPE and cytochrome P450 gene families highlight additional pathways that are upregulated (35 and five respectively) 24h after infection. Comparison of the intracellular transcriptome to gene essentiality and immunogenicity studies identified 15 potential targets that are both required for intracellular survival and induced on infection, and eight genes upregulated that have been demonstrated to be immunogenic in TB patients. Further insight into these new and established targets will support drug and vaccine development efforts.
Project description:Mycobacteria of the Mycobacterium tuberculosis complex (MTBC) greatly impact on human and animal health worldwide. Mycobacterial life cycle is complex and the mechanisms resulting in pathogen infection and survival in host cells are not fully understood. Eurasian wild boar (Sus scrofa) are natural reservoir hosts for MTBC and a model for mycobacterial infection and tuberculosis (TB). In the wild boar TB model, mycobacterial infection affects the expression of innate and adaptive immune response genes in mandibular lymph nodes and oropharyngeal tonsils and biomarkers have been proposed as correlates with resistance to natural infection. However, the mechanisms used by mycobacteria to manipulate host immune response are not fully characterized. Our hypothesis is that the immune system proteins under-represented in infected animals when compared to uninfected controls are used by mycobacteria to guarantee pathogen infection and transmission. To address this hypothesis, a comparative proteomics approach was used to compare host response between uninfected (TB-) and M. bovis-infected young (TB+) and adult animals with different infection status [TB lesions localized in the head (TB+) or affecting multiple organs (TB++)]. The results identified host immune system proteins that play an important role in host response to mycobacteria. Calcium binding protein A9, Heme peroxidase, Lactotransferrin, Cathelicidin and Peptidoglycan-recognition protein were under-represented in TB+ animals when compared to uninfected TB- controls but protein levels increased as infection progressed in TB++ animals when compared to TB- and/or TB+ adult wild boar. MHCI was the only protein over-represented in TB+ adult wild boar when compared to uninfected TB- controls. The results reported here suggested that M. bovis manipulates host immune response by reducing the production of immune system proteins. However, as infection progresses, wild boar immune response recover to limit pathogen multiplication and promote survival that also facilitates pathogen transmission.
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.
Project description:The aim of this study was to compare the transcriptional response to TB in regions of different incidence / prevalence. Experimental Design: Whole blood collected in tempus tubes from patients with different spectra of TB disease. All patients were sampled prior to the initiation of any antimycobacterial therapy. Active Pulmonary TB: PTB - All patients confirmed by isolation of Mycobacterium Tuberculosis on culture of sputum. Latent TB: LTB - All patients were screened at a tuberculosis clinic. All were positive by Interferon-Gamma Release assay(IGRA); specifically Quantiferon Gold In-Tube Assay (Cellestis, Australia). Latent patients had no clinical, or microbiological evidence of active infection and were asymptomatic. Experimental Variables: Patient group: Active PTB; Latent TB. There are no healthy controls in this dataset as it was being used for validation only. Controls: Latent TB individuals are used as a control for PTB in this dataset since there are few to no unexposed adult controls in Cape Town.
Project description:Monocytes and granulocytes were isolated from blood of TB patients and household contacts. RNA was isolated and gene expression was measured using microarrays. House-hold contacts were matched to TB patients by gender and age. From each subject, two profiles (monocytes and granulocytes) were collected.
Project description:Monocytes and granulocytes were isolated from blood of TB patients and household contacts. RNA was isolated and microRNA expression was measured using microarrays. House-hold contacts were matched to TB patients by gender and age. From each subject, two profiles (monocytes and granulocytes) were collected.
Project description:Mycobacterium bovis (M. bovis) and Mycobacterium avium subspecies paratuberculosis (MAP) are important pathogens of cattle, causing bovine tuberculosis and Johne’s disease respectively. M. bovis and MAP infect residential macrophages in the lung and intestines respectively and subvert the macrophage biology to create a survival niche. To investigate this interaction we simultaneously studied the transcriptional response of bovine monocyte-derived macrophages to infection with two strains of M. bovis (AF2122/97 and G18) and two strains of MAP (C & L1).