Project description:Effect of Thiol reductive stress (DTT 1mM) on M.tb Rv was studied. DTT reduced at 1 mM concentration was added to log pahse culture of M.tb H37Rv. After Three hours RNA was isolated and hybridization was done on HRI-UMNDJ Mycobacterium tuberculosis 4.8K CAG_Mtb microarrays.
Project description:Gene expression microarray was performed using early log phase culture at 37 degree and 200 rpm followed by RNA extraction from M.tb H37Rv, HigB KO M.tb H37Rv and complemented Hig B KO M.tb H37Rv For gene expression profiling, total RNA was isolated from wild type H37Rv, higB KO mutant strain and complemented strains. The bacterial pellets for M.tb H37Rv wild type, M.tb H37Rv HigB KO mutant strain and complemented strain were resuspended in 1.0 ml TRIzol (Invitrogen Corporation, Carlsbad, CA); mRNA was extracted as per standard protocols and cleaned using RNAeasy columns (Qiagen GmbH, Hilden, Germany). Extracted mRNA (1 μg) was treated with DNase I using the Ambion DNA-free kit (Invitrogen Corporation, Carlsbad, CA) to remove genomic DNA contamination and quantified using Nanodrop 2000c spectrophotometer (Thermo Scientific, USA). The purity and integrity of RNA samples were assessed Agilent 2100 Bio analyzer (Agilent TechnologiesInc., USA). Further, 25ng of RNA was amplified and labeled using Low input Quick Amp WT Labeling kit (Agilent Technologies, USA). The labeled cRNA was purified using RNAeasy columns (Qiagen, USA) and total yields were quantified using Nanodrop 2000c spectrophotometer.
Project description:Expression profile of Mycobacterium tuberculosis H37Rv biofilm as induced by DTT (Reduced) 6mM DTT reduced at 6 mM concentration was added to log phase culture of Mtb H37Rv. After 29 hours RNA was isolated and hybridization was done on microarrays
Project description:In this study, RNA sequencing (Transcriptome sequencing) was employed to investigate the global transcriptome changes in the macrophages during the different strains of M.tb infection. THP-1 cells derived macrophages were exposed to the virulent M.tb strain H37Rv (Rv) or the avirulent M.tb strain H37Ra (Ra), and the M.tb BCG vaccine strain was used as a control. The cDNA libraries were prepared from M.tb infected macrophages and then sequenced.
Project description:Superbugs such as drug-resistant Mycobacterium tuberculosis (DR-M.tb) poses a serious global health threat. Upon infection, M.tb reaches the alveolar space and comes in close contact with soluble components of the human alveolar lining fluid (ALF) for an uncertain period of time prior to and following its encounter with alveolar compartment cells. Homeostatic ALF hydrolases, which main function is maintaining lung health, modify the M.tb cell envelope, driving M.tb-host cell interactions. Still, the contribution of human ALF to M.tb adaptation to the host during infection is poorly understood. Here, we exposed 4 M.tb strains (H37Rv, HN878, CDC1551, W-7642) with different levels of virulence, transmissibility, and drug resistance to human ALF for shorter (15 min) and longer (12 h) periods of time. RNA sequencing was performed to determine the strains’ transcriptional profiles in response to ALF exposure. Gene expression analysis showed a clear temporal and strain-specific adaptation to human ALF. When comparing ALF-exposed vs. unexposed bacteria for each M.tb strain, differential expression (DE) analysis revealed a total of 397 DE genes associated with lipid metabolism, cell envelope and processes, intermediary metabolism and respiration, and regulatory proteins, among others. Most DE was detected at 12 h post-ALF exposure, with DR-M.tb strain W-7642 having the highest number of DE genes. Interestingly, genes from the KstR2 regulon, which controls the degradation of cholesterol C and D rings, were significantly upregulated early in all strains post-ALF exposure. These results indicate that M.tb-ALF contact (15 min to 12 h prior to M.tb recognition by host cells in the alveolar space) drives global metabolic and physiologic changes in M.tb during the initial stages of the infection, with potential implications in infection outcome.
Project description:Transcriptome responsiveness was further tested by attempts to invoke the unfolded protein repsonse (UPR), a classic ER-based pathway stimulated by the presence of increased levels of unfolded polypeptides. The UPR is mediated via transcriptional responses in both yeast and metazoan cells, and can be reliably activated by addition of dithiothreitol (DTT). Using DTT at concentrations that invoke a UPR in mammalian cells, Arabidopsis, yeast and other systems, we found that, in T. brucei, DTT exposure led to rapid cell death. We analysed the transcriptome at 1 mM DTT, under conditions where cells remained viable, as assessed by motility. <br><br>part 1: 3 biological replicates of SMB cells grown under normal conditions, and 3 replicates of SMB cells treated with 1mM DTT for 1hr, as well as dye swaps were used. <br><br>part 2: 3 biological replicates of SMB cells <br>grown under normal conditions, and 3 replicates of SMB cells treated <br>with 1mM DTT for 4hr, as well as dye swaps were used.<br><br>The UPR can also be activated by addition of tunicamycin. Using tunicamycin at concentrations that invoke a UPR in mammalian cells, Arabidopsis, yeast and other systems, we found that, in T. brucei, tunicamycin exposure efficiently inhibits trypanosome N-glycosylation and that it resulted in growth arrest over a period of up to 24 hours. We analysed the transcriptome at 5 ?g/ml tunicamycin under conditions where cells remained viable, as assessed by motility.<br><br>part 3: 3 biological replicates of SMB cells grown under normal conditions, and 3 replicates of SMB cells treated with 5 ?g/ml tunicamycin for 4hr, as well as dye swaps were used.<br><br>part 4: 3 biological replicates of SMB cells grown under normal conditions, and 3 replicates of SMB cells treated with 5 ?g/ml tunicamycin for 24hr, as well as dye swaps were used.