Effect of hypoxia on Mycobacterium tuberculosis-host phagocyte interactions
Ontology highlight
ABSTRACT:
ORGANISM(S): Macaca mulatta
PROVIDER: GSE47163 | GEO | 2013/05/22
SECONDARY ACCESSION(S): PRJNA204939
REPOSITORIES: GEO
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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
2013-05-22 | E-GEOD-47163 | biostudies-arrayexpress
Project description:We hypothesized that individuals with immunological sensitization to Mycobacterium tuberculosis (Mtb), conventionally regarded as evidence of latent tuberculosis infection (LTBI), would demonstrate binary responses to preventive therapy. This would reflect the differential immunological consequences of the sterilization of viable infection in those with an active Mtb infection versus no Mtb killing in those who, despite T cell recognition of Mtb antigens, did not harbor viable Mtb bacilli. We investigated the blood transcriptional profiles of 18 individuals with a positive IGRA result and known recent exposure to an index person with isoniazid and rifampicin susceptible pulmonary tuberculosis, at baseline, 2 weeks after initiating combined rifampicin/isoniazid (RH) preventive therapy and at treatment completion. Healthy control volunteers with no history of TB exposure and negative IGRA results were also included. RNA from unstimulated and M. tuberculosis peptide stimulated whole blood (from QuantiFERON TB1 and TB2 tubes) was measured using Agilent microarrays. A set of 474 genes showed the greatest interpersonal and temporal expression variability in antigen-stimulated blood. By performing longitudinal unsupervised clustering analysis with the subset of most variable genes, the IGRA+ participants were separated into two distinct groups. The IGRA-negative controls clustered within one of these groups suggesting that, in contrast to the other subgroup of IGRA+ individuals, RH had no discernible effect in this subgroup. 117 genes were significantly differentially expressed over time between these two groups, with the majority of them associated with immunological pathways known to be important in mycobacterial control. We contend that the different host RNA response reflects lack of Mtb viability in the group that clustered with the IGRA- unexposed healthy controls, and Mtb viability in the one that clustered away. Gene expression patterns in the blood of IGRA+ individuals emerging during the course of RH treatment which reflect Mtb viability could have major implications in the identification of risk of progression/reactivation, treatment stratification and clinical trials for LTBI therapy.
2021-01-19 | GSE153340 | GEO
Project description:We hypothesized that individuals with immunological sensitization to Mycobacterium tuberculosis (Mtb), conventionally regarded as evidence of latent tuberculosis infection (LTBI), would demonstrate binary responses to preventive therapy. This would reflect the differential immunological consequences of the sterilization of viable infection in those with an active Mtb infection versus no Mtb killing in those who, despite T cell recognition of Mtb antigens, did not harbor viable Mtb bacilli. We investigated the blood transcriptional profiles of 18 individuals with a positive IGRA result and known recent exposure to an index person with isoniazid and rifampicin susceptible pulmonary tuberculosis, at baseline, 2 weeks after initiating combined rifampicin/isoniazid (RH) preventive therapy and at treatment completion. Healthy control volunteers with no history of TB exposure and negative IGRA results were also included. RNA from unstimulated and M. tuberculosis peptide stimulated whole blood (from QuantiFERON TB1 and TB2 tubes) was measured using Agilent microarrays. A set of 474 genes showed the greatest interpersonal and temporal expression variability in antigen-stimulated blood. By performing longitudinal unsupervised clustering analysis with the subset of most variable genes, the IGRA+ participants were separated into two distinct groups. The IGRA-negative controls clustered within one of these groups suggesting that, in contrast to the other subgroup of IGRA+ individuals, RH had no discernible effect in this subgroup. 117 genes were significantly differentially expressed over time between these two groups, with the majority of them associated with immunological pathways known to be important in mycobacterial control. We contend that the different host RNA response reflects lack of Mtb viability in the group that clustered with the IGRA- unexposed healthy controls, and Mtb viability in the one that clustered away. Gene expression patterns in the blood of IGRA+ individuals emerging during the course of RH treatment which reflect Mtb viability could have major implications in the identification of risk of progression/reactivation, treatment stratification and clinical trials for LTBI therapy.
2021-01-19 | GSE153326 | GEO
Project description:Reactive oxygen species such as hydrogen peroxide occur in all aerobically living organisms. Oxidative stress during fermentation can impair the fitness of the production host and the quality of the product. B. pumilus has been described as highly resistant to hydrogen peroxide. The response of exponentially growing B. pumilus cells to hydrogen peroxide was studied. Two-condition experiment, unstressed versus hydrogen peroxide stressed cells, 3 biological replicates
2014-05-17 | E-GEOD-57735 | biostudies-arrayexpress
Project description:The eukaryotic GID/CTLH complex is a highly conserved E3 ubiquitin ligase involved in a broad range of biological processes. However, a role of this complex in host antimicrobial defenses has not been described. We exploited Mycobacterium tuberculosis (Mtb) induced cytotoxicity in macrophages in a FACS based CRISPR genetic screen to identify host determinants of intracellular Mtb growth restriction. Our screen identified 5 (GID8, YPEL5, WDR26, UBE2H, MAEA) of the 10 predicted members of the GID/CTLH complex as determinants of intracellular growth of both Mtb and Salmonella serovar Typhimurium. We show that the antimicrobial properties of the GID/CTLH complex knockdown macrophages are mediated by enhanced GABAergic signaling, activated AMPK, increased autophagic flux and resistance to cell death. Meanwhile, Mtb isolated from GID/CTLH knockdown macrophages are nutritionally starved and oxidatively stressed. Our study identifies the GID/CTLH complex activity as broadly suppressive of host antimicrobial responses against intracellular bacterial infections.
2024-05-08 | GSE267063 | GEO
Project description:The capacity of Mycobacterium tuberculosis (Mtb) to sense, respond and adapt to variable and hostile environment within the host, has made it one of the most successful human pathogens. During different stages of infection, the bacillus is surrounding by a plethora of lipid rich molecules and current evidence points out the relevance of fatty acids during the Mtb infectious process. In this study, we have compared the transcriptional response of Mtb to hypoxia in cultures grown in both, a mix of even long-chain fatty acids and dextrose as carbon sources. Using RNA sequencing, we have identified the differential expressed genes in early and late hypoxia defined according to the in vitro Wayne model and compared the results with the exponential phase of growth in both carbon sources. Our results showed that, different to dextrose, the number of genes overexpressed in hypoxia in the lipid medium was quite low in both, early and late hypoxia in all functional categories describes for Mtb. The exception were the transcripts of stable and non-coding RNAs which were more expressed in the fatty acid medium. We found that SigB and SigE were overexpressed in the early phase of hypoxia, confirming their pivotal role in early adaptation to low oxygen concentration independently of the carbon source. A drastic contrast was found with the transcriptional regulatory factors at early hypoxia. Only 2 transcriptional factors were overexpressed in early hypoxia in the lipid medium compared to 37 that were overexpressed in the dextrose medium. Instead of Rv0081, known to be the central regulator of hypoxia in dextrose, Rv2745c, (ClgR), is playing a main role in hypoxia in the fatty acids medium. The low level of genes associated to stress-response, showed by Mtb during their adaptation to hypoxia in fatty acids, suggested that this lipid environment makes hypoxia a less stressful condition for the tubercle bacilli. Therefore, when the bacillus is surviving in that environment, its metabolism seemed to be already adapted to different stresses within the host, including hypoxia. This fact could explain the success of Mtb to establish long-term survival during latent infection.
2018-08-31 | GSE119225 | GEO
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.
2018-10-22 | PXD008587 | Pride
Project description:The normally virulent type-I RH parasite is rendered avirulent when lacking ROP5. The avirulent phenotype is a consequence of interaction with the host innate immune system. We sought to understand if ROP5 alters host gene expression in order to escape host defenses. We saw no gene expression differences between host cells infected with wt (RH∆ku80) or RH∆ku80∆rop5 parasites. We have included uninfected HFF samples that were harvested in parallel with the infected samples.
2012-09-13 | GSE32104 | GEO
Project description:We wanted to determine how type I ROP16 affect host gene expression We infected BMDM's from BALB/c with type I (RH) and type I (RH) ΔROP16
2011-05-29 | GSE29582 | GEO
Project description:The isogenic Mtb:ΔRv2745c mutant is significantly more sensitive normoxia conditions after a period of hypoxia, relative to wild-type Mtb, implicating a role for ClgR in response to reactivation, in vivo. Both hypoxia and reaeration treatment led to dysregulation of the σH regulon in the isogenic mutant, Mtb:ΔRv2745c. Induction of clgR in Mtb did lead to Clp protease induction, indicating that clgR plays a role in differntially activating downstream genes in a condition dependent manner. Disruption of genes involved in the dosR regulon, the Enduring Hypoxia Response, lipid synthesis, and mycolic acid synthesis also occurred in the knock out, implicating clgR as a possible regulator of downstream signaling cascades that facilitate Mtb survival. There was also a differnetial response of genes that are known Clp protease targets, in addition to potential Clp protease targets that had similar induction patterns as known Clp protease targets. At different time points, following hypoxia (day 1, day 5, and day 7) and reaeration (1 hour, 4 hour, 6 hour, 12 hour, 24 hour, and 48 hour) treatments M. tuberculosis CDC1551 cultures, RNA was extracted and labeled with Cy5. RNA was also extracted from pre-hypoxia (t=0) time points and labeled with Cy3. These samples were cohybridized on M. tuberculosis CDC1551 whole genome microarrays using biological triplicate samples (i.e. samples derived from three distinct cultures and treatments) and thus three unique datasets were generated for each of the three time points for Mtb. Similar experiments were performed for an isogenic Rv2745c (clgR) mutant in Mtb CDC1551 which was generated by allelic exchange.
2014-12-12 | E-GEOD-64065 | biostudies-arrayexpress