Project description:Reaeration timecourse from a defined hypoxia model in Mycobacterium tuberculosis. The mechanism by which mycobacteria return to a replicating state upon re-exposure to favorable conditions is not well understood. In this study, we utilized reaeration from a defined hypoxia model to characterize the adaptive response of Mycobacterium tuberculosis (MTB) following a return to favorable growth conditions. Global transcriptional analysis identified the ~100 gene Reaeration Response, induced relative to both log-phase and hypoxic MTB. This response includes chaperones and proteases, as well as the transcription factor Rv2745c, a Clp protease gene regulator (ClgR) orthologue. During reaeration, genes repressed during hypoxia are also upregulated in a wave of transcription that includes genes crucial to transcription, translation and oxidative phosphorylation.
Project description:Reaeration timecourse from a defined hypoxia model in Mycobacterium tuberculosis. The mechanism by which mycobacteria return to a replicating state upon re-exposure to favorable conditions is not well understood. In this study, we utilized reaeration from a defined hypoxia model to characterize the adaptive response of Mycobacterium tuberculosis (MTB) following a return to favorable growth conditions. Global transcriptional analysis identified the ~100 gene Reaeration Response, induced relative to both log-phase and hypoxic MTB. This response includes chaperones and proteases, as well as the transcription factor Rv2745c, a Clp protease gene regulator (ClgR) orthologue. During reaeration, genes repressed during hypoxia are also upregulated in a wave of transcription that includes genes crucial to transcription, translation and oxidative phosphorylation. Each reaerating culture compared at multiple timepoints to a sample from the same culture at seven days of hypoxia. Three or more replicates at each timepoint.
Project description:Lysates of Mycobacterium tuberculosis (H37Rv auxotroph mc(2)6020) grown under various conditions (normoxia, hypoxia, reactivation from hypoxia) probed the serine hydrolase probe with ActivX-desthiobiotin FP.
Project description:Mtb appears to have developed specialized biomolecular infrastructure to survive and persist within granulomas, where it is subjected to a diverse set of stress conditions. One of these stress conditions is hypoxia. We hypothesized that host cell response is radically altered with hypoxia stressed Mtb and designed in-vitro experiments to study this phenomenon. Hypoxia-stressed as well as aerobically grown Mtb were used to infect rhesus macaque bone marrow derived macrophages (Rh-BMDMs) and the host global transcriptional response compared.
Project description:Mtb appears to have developed specialized biomolecular infrastructure to survive and persist within granulomas, where it is subjected to a diverse set of stress conditions. One of these stress conditions is hypoxia. We hypothesized that host cell response is radically altered with hypoxia stressed Mtb and designed in-vitro experiments to study this phenomenon. Hypoxia-stressed as well as aerobically grown Mtb were used to infect rhesus macaque bone marrow derived macrophages (Rh-BMDMs) and the host global transcriptional response compared. Using 4 x44 k Agilent arrays specific for rhesus macaque genome, we tested in biological duplicate the effect of aerogically grown Mtb on rhesus macaque BMDMs and compared this to the corresponding effect of the hypoxia-conditioned Mtb on rhesus macaque BMDMs
Project description:Tuberculosis caused by Mycobacterium tuberculosis (Mtb) infection remains a huge global public health problem. One striking characteristic of Mtb is its ability to adapt to hypoxia, and thus ensuing transition to dormant state for persistent infection, but how the hypoxia responses of Mtb is regulated remains largely unknown. Here, we performed a quantitative acetylome analysis to compare the acetylation profile of Mtb under aeration and hypoxia, and showed that 377 acetylation sites in 269 proteins of Mtb were significantly change under hypoxia. Especially, deacetylation of Dormancy Survival Regulator (DosR) at K182 promoted the hypoxia response of Mtb and enhanced transcription of DosR-targeted genes. Mechanistically, recombinant DosRK182R protein demonstrated enhanced DNA-binding activity in comparison with DosRK182Q protein. Moreover, Rv0998 was identified as an acetyltransferase that mediates the acetylation of DosR at K182. Deletion of Rv0998 also promoted the adaption of Mtb to hypoxia and transcription of DosR-targeted genes. Mice infected with Mtb strain containing acetylation-defective DosRK182R or lacking Rv0998 had much lower bacterial counts, and less severe histopathological impairments compared with those infected with the wild-type strain. Our findings suggest that hypoxia induces the deacetylation of DosR, which in turn increases its DNA binding ability to promote the transcription of target genes, allowing Mtbto transit to dormancy under hypoxia.
Project description:Transcription was arrested using 50 ug/ul of rifampin leaving RNA degradation as the sole vector responsible for mRNA abundance at 20C (cold) or in 0.2%O2 (hypoxia). mRNA half-lives were calculated from the decay of signal intensity from T0. Three replicates were sampled after 0, 1, 2, and 5 hours of mRNA decay in both cold and hypoxia for a total of 24 arrays.
Project description:These data represent the expression patterns of Mycobacterium tuberculosis in progressive hypoxia, nutrient depletion, and in-vivo hollow fiber models of dormancy. The assumptions are that the set of genes that respond to INH treatment during Log phase growth would not be differentially regulated during INH treatment in the dormancy models, and that the overall number of differentially regulated genes would be reduced do to the low metabolic state of the cells. Keywords: Dormancy Model Drug Response Comparison