Background
Excessive Cytolytic Responses Predict Tuberculosis Relapse After Apparently Successful Treatment.
Time
View SamplesDespite wide scale vaccination with Mycobacterium bovis BCG, the prevalence of tuberculosis remains high, reflecting the global variable efficacy of this vaccine against adult pulmonary TB. Characterisation of different immune responses to M. tuberculosis and M. bovis BCG would increase understanding of pathology following M. tuberculosis infection or reactivation, and would facilitate the rational design of a new vaccine. Gene expression profiling was conducted on samples from diluted whole blood cultures from three healthy donors following incubation with live mycobacteria for six days. Approximately 8,000 gene entities were at least two-fold up- or down- regulated by the mycobacteria, and both mycobacteria induced similar expression changes in approximately 2,300 genes. Strikingly, many genes exhibited qualitatively different expression patterns, with over 1,000 genes up-regulated in response to M. bovis BCG but not changed by M. tuberculosis. Gene Ontology analysis revealed that the genes which failed to upregulate in M. tuberculosis-infected cultures included a large proportion of genes with lysosomal function. The inhibited up-regulation of expression of IFN--inducible protein 30, acid phosphatase 2, cathepsin B and GM2 ganglioside activator was verified in samples from six biologically independent donors by qRT-PCR. The failure to up-regulate these genes in response to M. tuberculosis may constitute an immune evasion mechanism, preventing intracellular killing and antigen presentation.
Excessive Cytolytic Responses Predict Tuberculosis Relapse After Apparently Successful Treatment.
Specimen part
View SamplesNeuronal, endocrine and exocrine cells exhibit regulated exocytosis but there is also a body of evidence for regulated exocytosis from other cell types. Myofibroblasts are a stromal cell type that secretes extracellular matrix proteins, growth factors and cytokines; they are important in wound healing and increasingly are recognised to play a role in modifying the cellular microenvironment in cancer. We have established calcium dependent regulated secretion in a subset of myofibroblasts from gastric cancers, adjacent tissue and from normal tissue. We have used microarrays to look for the expression of genes associated with the regulated secretory phenotype.
The neuroendocrine phenotype of gastric myofibroblasts and its loss with cancer progression.
Specimen part
View SamplesBackground Accurate assessment of treatment efficacy would facilitate clinical trials of new anti-tuberculosis drugs. TB patients exhibit altered peripheral immunity which reverts during successful treatment. We hypothesised that these changes could be observed in whole blood transcriptome profiles. Methods Ex vivo blood samples from 27 pulmonary TB patients were assayed at diagnosis and during conventional treatment. RNA was processed and hybridised to Affymetrix GeneChips, to determine expression of over 47,000 transcripts. Findings There were significant changes in expression of over 4,000 genes during treatment. Rapid, large scale changes were detected, with down-regulated expression of ~1,000 genes within the first week, including inflammatory markers such as the complement components C1q and C2. This was followed by slower changes in expression of different networks of genes, including a later increase in expression of B cell markers, transcription factors and signalling molecules. Interpretation The expression of many genes is drastically altered during TB disease, with components of the humoral immune response being markedly affected. The treatment-induced restoration reflects the simultaneous suppression and activation of different immune responses in TB. The rapid initial down-regulation of expression of inflammatory mediators coincides with rapid killing of actively dividing bacilli, whereas slower delayed changes occur as drugs act on dormant bacilli and as lung pathology resolves. Measurement of biosignatures during clinical trials of new drugs could be useful predictors of rapid bactericidal or sterilizing drug activity.
Distinct phases of blood gene expression pattern through tuberculosis treatment reflect modulation of the humoral immune response.
Specimen part, Disease, Subject, Time
View SamplesBackground Accurate assessment of treatment efficacy would facilitate clinical trials of new anti-tuberculosis drugs. TB patients exhibit altered peripheral immunity which reverts during successful treatment. We hypothesised that these changes could be observed in whole blood transcriptome profiles. Methods Ex vivo blood samples from 27 pulmonary TB patients were assayed at diagnosis and during conventional treatment. RNA was processed and hybridised to Affymetrix GeneChips, to determine expression of over 47,000 transcripts. Findings There were significant changes in expression of over 4,000 genes during treatment. Rapid, large scale changes were detected, with down-regulated expression of ~1,000 genes within the first week, including inflammatory markers such as the complement components C1q and C2. This was followed by slower changes in expression of different networks of genes, including a later increase in expression of B cell markers, transcription factors and signalling molecules. Interpretation The expression of many genes is drastically altered during TB disease, with components of the humoral immune response being markedly affected. The treatment-induced restoration reflects the simultaneous suppression and activation of different immune responses in TB. The rapid initial down-regulation of expression of inflammatory mediators coincides with rapid killing of actively dividing bacilli, whereas slower delayed changes occur as drugs act on dormant bacilli and as lung pathology resolves. Measurement of biosignatures during clinical trials of new drugs could be useful predictors of rapid bactericidal or sterilizing drug activity.
Distinct phases of blood gene expression pattern through tuberculosis treatment reflect modulation of the humoral immune response.
Specimen part, Subject, Time
View SamplesIn autoimmune diseases, accumulation of activated leukocytes correlates with inflammation and disease progression, and therefore, disruption of leukocyte trafficking is an active area of research. The protein kinase Tpl2 (MAP3K8) regulates leukocyte inflammatory responses and is also being investigated for therapeutic inhibition during autoimmunity. Herein, we addressed the contribution of Tpl2 to the regulation of macrophage chemokine and chemokine receptor expression and subsequent migration in vivo using a mouse model of Tpl2 ablation. We found that gene expression of the chemokine ligands CCL2, CCL7, CXCL2, and CXCL3 as well as the chemokine receptors CCR1 and CCR5 were reduced in macrophages from the bone marrow and peritoneal cavities of tpl2-/- mice following stimulation with LPS. LPS stimulation repressed chemokine receptor expression of CCR1, CCR2 and CCR5. Notably, LPS-induced repression of CCR1 and CCR5 was significantly enhanced in Tpl2-deficient macrophages and was observed to be dependent upon Erk activation and independent of PI3K and mTOR signaling. Consistent with alterations in chemokine and chemokine receptor expression, tpl2-/- macrophages were defective in trafficking to the peritoneal cavity following thioglycollate-induced inflammation. Overall, this study demonstrates a Tpl2-dependent mechanism for macrophage expression of both chemokine receptors and their ligands and provides further insight into how Tpl2 inhibition may disrupt inflammatory networks in vivo.
Tumor progression locus 2 (Tpl2) kinase promotes chemokine receptor expression and macrophage migration during acute inflammation.
Treatment
View SamplesNeutrophils were isolated form peripheral blood of wildtype and Phd3 null mice, cultured for 4 hours in hypoxia (3% O2) and micro array analysis performed
Prolyl hydroxylase 3 (PHD3) is essential for hypoxic regulation of neutrophilic inflammation in humans and mice.
Specimen part, Treatment
View SamplesMetformin, the most widely administered diabetes drug, has been proposed as a candidate for host directed therapy for tuberculosis although very little is known about its effects on human host responses to Mycobacterium tuberculosis. When added in vitro to PBMCs isolated from healthy non-diabetic volunteers, metformin increased glycolysis, inhibited the mTOR targets, strongly reduced M. tuberculosis induced production of TNF-alpha (-58%), IFN-gamma (-47%) and IL-beta (-20%), while increasing phagocytosis. In healthy subjects, in vivo metformin intake induced significant transcriptional changes in whole blood and isolated PBMCs, with substantial down-regulation of genes related to inflammation and the type 1 interferon response. Metformin intake also increased monocyte phagocytosis (by 1.5 to 2 fold) and ROS production (+20%). These results show that metformin in humans has a range of potentially beneficial effects on cellular metabolism, immune function and gene-transcriptional level, that affect innate host responses to M. tuberculosis. This underlines the importance of cellular metabolism for host immunity and supports a role for metformin as host-directed therapy for tuberculosis. Overall design: Peripheral Mononuclear Cells taken from 11 healthy donors, prior to administration of metformin and after 5 days of metformin. Samples were stimulated with Mycobacterium tuberculosis lysate or cultured unstimulated for 4 hours. Total 88 samples, with 11 clinical replicates.
Metformin Alters Human Host Responses to Mycobacterium tuberculosis in Healthy Subjects.
Specimen part, Disease, Disease stage, Treatment, Subject
View SamplesMetformin, the most widely administered diabetes drug, has been proposed as a candidate for host directed therapy for tuberculosis although very little is known about its effects on human host responses to Mycobacterium tuberculosis. When added in vitro to PBMCs isolated from healthy non-diabetic volunteers, metformin increased glycolysis, inhibited the mTOR targets, strongly reduced M. tuberculosis induced production of TNF-a (-58%), IFN-gamma (-47%) and IL-1ß (-20%), while increasing phagocytosis. In healthy subjects, in vivo metformin intake induced significant transcriptional changes in whole blood and isolated PBMCs, with substantial down-regulation of genes related to inflammation and the type 1 interferon response. Metformin intake also increased monocyte phagocytosis (by 1.5 to 2 fold) and ROS production (+20%). These results show that metformin in humans has a range of potentially beneficial effects on cellular metabolism, immune function and gene-transcriptional level, that affect innate host responses to M. tuberculosis. This underlines the importance of cellular metabolism for host immunity and supports a role for metformin as host-directed therapy for tuberculosis. Overall design: Ex vivo blood RNA samples analyzed from 11 healthy donors, prior to administration of metformin (control) and after 5 days of metformin (test). Total 22 samples, with 11 clinical replicates.
Metformin Alters Human Host Responses to Mycobacterium tuberculosis in Healthy Subjects.
Specimen part, Disease, Disease stage, Treatment, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Diagnosis of childhood tuberculosis and host RNA expression in Africa.
Disease
View Samples