Project description:Time-course expression analysis profiling whole blood samples collected from healthy South African adolescents while monitoring their potential acquisition of a Mycobacterium tuberculosis infection.
Project description:Mycobacterium tuberculosis has the ability to persist within the host in a clinically latent stage. One important condition believed to contribute to latency is reduced access to oxygen but the response of M. tuberculosis to hypoxia is partially characterized. Virtually all dormant models against tuberculosis the vaccine tested in animals used laboratory strains H37Rv or Erdman strains. But major outbreaks of TB occur with the strains that have widely different genotypes and phenotypes compare to H37Rv. In this study, we used a commercial oligonucleotide microarray to determine the overall transcriptional response of lab strain (H37Rv) and most prevalent strains of Mycobacterium tuberculosis from South India S7 and S10 to hypoxia. Analysis of microarray results revealed that a total of 1161 genes are differentially regulated in H37Rv, among them 659 genes are upregulated and 502 genes are down regulated when > 1.5 fold change was taken as cut off. Microarray data of clinical isolates showed total of 790 genes are differentially regulated in S7 clinical isolates among which 453 are upregulated and 337 are down regulated. Interestingly numerous genes are differentially regulated in S10 clinical isolates (total of 2805 genes) and 1463 are upregulated and 1342 genes are down regulated during reduced oxygen model (Wayne’s model). Real-time quantitative RT-PCR was performed for few genes to validate the microarray results. To our knowledge, this genome-wide transcriptomics approach has produced the first insights into the response of South Indian prevalent clinical strains of M. tuberculosis when exposed to reduced oxygen stress.
Project description:Background. Diabetes mellitus (DM) increases tuberculosis (TB) severity. We previously reported baseline blood microarray data in a South Indian pulmonary TB cohort with or without DM, finding no qualitative or quantitative differences in immune pathway gene expression. To extend those observations, we compared baseline and longitudinal blood gene expression in TB patients from South India and Brazil. Methods. Adults with pulmonary TB, with or without DM, were enrolled at two sites in India and one site in Brazil. Blood RNA sequencing (RNAseq) was performed at baseline and treatment months 2 and 6. Differentially expressed genes (DEGs) and pathway activation were compared by group and site. Comparison was also made with published RNAseq data from the TANDEM study South African and Romanian cohorts. Findings. No consistent pattern of DEGs discriminated TB from TBDM in India or Brazil. Pathway analysis also showed little commonality between sites, although a shared profile of complement activation and matrix degradation was identified in TBDM. Indian participants showed marked longitudinal changes in DEGs and pathways at 2 and 6 months of treatment, whereas these were stable in Brazilian participants. High variability in gene expression was observed between sites at baseline and during treatment. Interpretation. DM exacerbates matrix degradation in TB but is not associated with major immune gene expression or pathway differences compared to TB without DM. Comparison between cohorts in India, Brazil, Romania, and South Africa revealed an unexpectedly high degree of site-specific variation that may reflect population differences in TB pathobiology.
Project description:Transcriptional profiling of SirR and manganese regulated expression of genes in Mycobacterium tuberculosis strains comparing high manganese vs. low manganese in Rv (wild type Mycobacterium tuberculosis) and ST70 (mntR mutant strain of Mycobacterium tuberculosis)
Project description:Transcriptional profiling of SirR and manganese regulated expression of genes in Mycobacterium tuberculosis strains comparing high manganese vs. low manganese in Rv (wild type Mycobacterium tuberculosis) and ST70 (mntR mutant strain of Mycobacterium tuberculosis) Two strains each with two conditions experiment, Rv (Mycobacterium tuberculosis wild type strain) high manganese vs. low manganese and ST70 (mntR mutant strain of Mycobacterium tuberculosis) high manganese vs. low manganese. Number of biological replicates is 3 for each condition for each strain.
Project description:Comparison of gene expression profile of the whiB4 mutant strain of Mycobacterium tuberculosis with the wild type Mycobacterium tuberculosis H37RV Mtb WhiB4 mutant mRNA was compared with the mRNA of wtMtb H37RV under aerobic conditons
Project description:①Background:Tuberculosis is mainly a respiratory tract infection caused by mycobacterium tuberculosis and one of the leading causes of death worldwide. According to the Global Tuberculosis Report in 2021, About a quarter of the world's population is infected with Mycobacterium tuberculosis and China is the second highest burden of TB. Although TB diagnosis and prevention techniques have become more mature, the number of TB cases is still increasing, mainly due to: the prevalence of drug-resistant tuberculosis bacteria, tuberculosis and HIV co-infection, long incubation time of mycobacterium tuberculosis difficult to early diagnosis and so on. Therefore, it is of great significance to study the pathogenesis of mycobacterium tuberculosis infection.②Method: THP-1 cells were treated with 50ng/ml PMA for 24 hours, so that THP-1 cell can be induced into macrophages. After that THP-1 macrophages were infected with mycobacterium tuberculosis H37Rv(MOI=1), which were collected and applied to RNA-sequencing. The constructed sequencing library was sequenced using an Illumina Novaseq 6000 system.
Project description:Identification of blood biomarkers that prospectively predict progression of Mycobacterium tuberculosis infection to tuberculosis disease might lead to interventions that combat the tuberculosis epidemic. We aimed to assess whether global gene expression measured in whole blood of healthy people allowed identification of prospective signatures of risk of active tuberculosis disease. RESULTS:Between July 6, 2005, and April 23, 2007, we enrolled 6363 from the ACS study and 4466 from independent South African and Gambian cohorts. 46 progressors and 107 matched controls were identified in the ACS cohort. A 16 gene signature of risk was identified. The signature predicted tuberculosis progression with a sensitivity of 66·1% (95% CI 63·2â68·9) and a specificity of 80·6% (79·2â82·0) in the 12 months preceding tuberculosis diagnosis. The risk signature was validated in an untouched group of adolescents (p=0·018 for RNA sequencing and p=0·0095 for qRT-PCR) and in the independent South African and Gambian cohorts (p values <0·0001 by qRT-PCR) with a sensitivity of 53·7% (42·6â64·3) and a specificity of 82·8% (76·7â86) in 12 months preceding tuberculosis. Interpretation: The whole blood tuberculosis risk signature prospectively identified people at risk of developing active tuberculosis, opening the possibility for targeted intervention to prevent the disease. In this prospective cohort study, we followed up healthy, South African adolescents aged 12â18 years from the adolescent cohort study (ACS) who were infected with M tuberculosis for 2 years. We collected blood samples from study participants every 6 months and monitored the adolescents for progression to tuberculosis disease. A prospective signature of risk was derived from whole blood RNA sequencing data by comparing participants who developed active tuberculosis disease (progressors) with those who remained healthy (matched controls). After adaptation to multiplex qRT-PCR, the signature was used to predict tuberculosis disease in untouched adolescent samples and in samples from independent cohorts of South African and Gambian adult progressors and controls. Participants of the independent cohorts were household contacts of adults with active pulmonary tuberculosis disease.