399 research outputs found

    Positive Diagnosis of Ancient Leprosy and Tuberculosis Using Ancient DNA and Lipid Biomarkers

    Get PDF
    Diagnosis of leprosy and tuberculosis in archaeological material is most informative when based upon entire genomes. Ancient DNA (aDNA) is often degraded but amplification of specific fragments also provides reliable diagnoses. Cell wall lipid biomarkers can distinguish ancient leprosy from tuberculosis and DNA extraction residues can be utilized. The diagnostic power of combined aDNA and lipid biomarkers is illustrated by key cases of ancient leprosy and/or tuberculosis. Human tuberculosis was demonstrated in a woman and child from Atlit-Yam (~9 ka) in the Eastern Mediterranean and in the 600 BCE Egyptian ā€œGranvilleā€ mummy. Both aDNA and lipids confirmed Pleistocene tuberculosis in a ~17 ka bison from Natural Trap Cave, Wyoming. Leprosy is exemplified by cases from Winchester (10thā€“12th centuries CE) and Great Chesterford (5thā€“6th centuries CE). A mixed infection from Kiskundorozsma, Hungary (7th century CE) allowed lipid biomarkers to assess the relative load of leprosy and tuberculosis. Essential protocols for aDNA amplification and analysis of mycolic, mycolipenic, mycocerosic acid, and phthiocerol lipid biomarkers are summarized. Diagnoses of ancient mycobacterial disease can be extended beyond the reach of whole genomics by combinations of aDNA amplification and lipid biomarkers, with sole use of the latter having the potential to recognize even older cases

    Identification of 2-Aminothiazole-4-Carboxylate Derivatives Active against Mycobacterium tuberculosis H37Rv and the Ī²-Ketoacyl-ACP Synthase mtFabH

    Get PDF
    Background Tuberculosis (TB) is a disease which kills two million people every year and infects approximately over one-third of the world's population. The difficulty in managing tuberculosis is the prolonged treatment duration, the emergence of drug resistance and co-infection with HIV/AIDS. Tuberculosis control requires new drugs that act at novel drug targets to help combat resistant forms of Mycobacterium tuberculosis and reduce treatment duration. Methodology/Principal Findings Our approach was to modify the naturally occurring and synthetically challenging antibiotic thiolactomycin (TLM) to the more tractable 2-aminothiazole-4-carboxylate scaffold to generate compounds that mimic TLM's novel mode of action. We report here the identification of a series of compounds possessing excellent activity against M. tuberculosis H37Rv and, dissociatively, against the Ī²-ketoacyl synthase enzyme mtFabH which is targeted by TLM. Specifically, methyl 2-amino-5-benzylthiazole-4-carboxylate was found to inhibit M. tuberculosis H37Rv with an MIC of 0.06 Āµg/ml (240 nM), but showed no activity against mtFabH, whereas methyl 2-(2-bromoacetamido)-5-(3-chlorophenyl)tā€‹hiazole-4-carboxylateinhibited mtFabH with an IC50 of 0.95Ā±0.05 Āµg/ml (2.43Ā±0.13 ĀµM) but was not active against the whole cell organism. Conclusions/Significance These findings clearly identify the 2-aminothiazole-4-carboxylate scaffold as a promising new template towards the discovery of a new class of anti-tubercular agents

    Dimerization of inositol monophosphatase Mycobacterium tuberculosis SuhB is not constitutive, but induced by binding of the activator Mg2+

    Get PDF
    Background The cell wall of Mycobacterium tuberculosis contains a wide range of phosphatidyl inositol-based glycolipids that play critical structural roles and, in part, govern pathogen-host interactions. Synthesis of phosphatidyl inositol is dependent on free myo-inositol, generated through dephosphorylation of myo-inositol-1-phosphate by inositol monophosphatase (IMPase). Human IMPase, the putative target of lithium therapy, has been studied extensively, but the function of four IMPase-like genes in M. tuberculosis is unclear. Results We determined the crystal structure, to 2.6 ƅ resolution, of the IMPase M. tuberculosis SuhB in the apo form, and analysed self-assembly by analytical ultracentrifugation. Contrary to the paradigm of constitutive dimerization of IMPases, SuhB is predominantly monomeric in the absence of the physiological activator Mg2+, in spite of a conserved fold and apparent dimerization in the crystal. However, Mg2+ concentrations that result in enzymatic activation of SuhB decisively promote dimerization, with the inhibitor Li+ amplifying the effect of Mg2+, but failing to induce dimerization on its own. Conclusion The correlation of Mg2+-driven enzymatic activity with dimerization suggests that catalytic activity is linked to the dimer form. Current models of lithium inhibition of IMPases posit that Li+ competes for one of three catalytic Mg2+ sites in the active site, stabilized by a mobile loop at the dimer interface. Our data suggest that Mg2+/Li+-induced ordering of this loop may promote dimerization by expanding the dimer interface of SuhB. The dynamic nature of the monomer-dimer equilibrium may also explain the extended concentration range over which Mg2+ maintains SuhB activity

    Tuberculosis in Dr Granville's mummy: a molecular re-examination of the earliest known Egyptian mummy to be scientifically examined and given a medical diagnosis

    Get PDF
    ā€˜Dr Granville's mummyā€™ was described to the Royal Society of London in 1825 and was the first ancient Egyptian mummy to be subjected to a scientific autopsy. The remains are those of a woman, Irtyersenu, aged about 50, from the necropolis of Thebes and dated to about 600 BC. Augustus Bozzi Granville (1783ā€“1872), an eminent physician and obstetrician, described many organs still in situ and attributed the cause of death to a tumour of the ovary. However, subsequent histological investigations indicate that the tumour is a benign cystadenoma. Histology of the lungs demonstrated a potentially fatal pulmonary exudate and earlier studies attempted to associate this with particular disease conditions. Palaeopathology and ancient DNA analyses show that tuberculosis was widespread in ancient Egypt, so a systematic search for tuberculosis was made, using specific DNA and lipid biomarker analyses. Clear evidence for Mycobacterium tuberculosis complex DNA was obtained in lung tissue and gall bladder samples, based on nested PCR of the IS6110 locus. Lung and femurs were positive for specific M. tuberculosis complex cell-wall mycolic acids, demonstrated by high-performance liquid chromatography of pyrenebutyric acidā€“pentafluorobenzyl mycolates. Therefore, tuberculosis is likely to have been the major cause of death of Irtyersenu

    Osteological and Biomolecular Evidence of a 7000-Year-Old Case of Hypertrophic Pulmonary Osteopathy Secondary to Tuberculosis from Neolithic Hungary

    Get PDF
    Seventy-one individuals from the late Neolithic population of the 7000-year-old site of HĆ³dmezővĆ”sĆ”rhely-Gorzsa were examined for their skeletal palaeopathology. This revealed numerous cases of infections and non-specific stress indicators in juveniles and adults, metabolic diseases in juveniles, and evidence of trauma and mechanical changes in adults. Several cases showed potential signs of tuberculosis, particularly the remains of the individual HGO-53. This is an important finding that has significant implications for our understanding of this community. The aim of the present study was to seek biomolecular evidence to confirm this diagnosis. HGO-53 was a young male with a striking case of hypertrophic pulmonary osteopathy (HPO), revealing rib changes and cavitations in the vertebral bodies. The initial macroscopic diagnosis of HPO secondary to tuberculosis was confirmed by analysis of Mycobacterium tuberculosis complex specific cell wall lipid biomarkers and corroborated by ancient DNA (aDNA) analysis. This case is the earliest known classical case of HPO on an adult human skeleton and is one of the oldest palaeopathological and palaeomicrobiological tuberculosis cases to date

    Synthesis and biological activity of alpha-L-fucosyl ceramides, analogues of the potent agonist, alpha-D-galactosyl ceramide KRN7000

    Get PDF
    Several L-fucoglycolipids are associated with diseases such as cancer, cystic fibrosis and rheumatoid arthritis. Activation of iNKT cells is known to lead to the production of cytokines that can help alleviate or exacerbate these conditions. a-Galactosyl ceramide (a-GalCer) is a known agonist of iNKT cells and it is believed that its fucosyl counterpart might have similar immunogenic properties. We herein report the synthesis of a-L-fucosyl ceramide derivatives and describe their biological evaluation. The key challenge in the synthesis of the target molecules involved the stereoselective synthesis of the a-glycosidic linkage. Of the methods examined, the per-TMS-protected glycosyl iodide donor was completely aselective,and could be scaled up to provide gram quantities of the azide precursor 11, from which a range of N-acylated a-L-fucosyl ceramides were readily obtained and evaluated for ex vivo expansion of human iNKT cells

    Cytotoxic Mediators in Paradoxical HIV-Tuberculosis Immune Reconstitution Inflammatory Syndrome

    No full text
    Tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) frequently complicates combined antiretroviral therapy and antituberculosis therapy in HIV-1ā€“coinfected tuberculosis patients. The immunopathological mechanisms underlying TB-IRIS are incompletely defined, and improved understanding is required to derive new treatments and to reduce associated morbidity and mortality. We performed longitudinal and cross-sectional analyses of human PBMCs from paradoxical TB-IRIS patients and non-IRIS controls (HIV-TBā€“coinfected patients commencing antiretroviral therapy who did not develop TB-IRIS). Freshly isolated PBMC stimulated with heat-killed Mycobacterium tuberculosis H37Rv (hkH37Rv) were used for IFN-Ī³ ELISPOT and RNA extraction. Stored RNA was used for microarray and RT-PCR, whereas corresponding stored culture supernatants were used for ELISA. Stored PBMC were used for perforin and granzyme B ELISPOT and flow cytometry. There were significantly increased IFN-Ī³ responses to hkH37Rv in TB-IRIS, compared with non-IRIS PBMC (p = 0.035). Microarray analysis of hkH37Rv-stimulated PBMC indicated that perforin 1 was the most significantly upregulated gene, with granzyme B among the top five (log(2) fold difference 3.587 and 2.828, respectively), in TB-IRIS. Downstream experiments using RT-PCR, ELISA, and ELISPOT confirmed the increased expression and secretion of perforin and granzyme B. Moreover, granzyme B secretion reduced in PBMC from TB-IRIS patients during corticosteroid treatment. Invariant NKT cell (CD3(+)VĪ±24(+)) proportions were higher in TB-IRIS patients (p = 0.004) and were a source of perforin. Our data implicate the granule exocytosis pathway in TB-IRIS pathophysiology. Further understanding of the immunopathogenesis of this condition will facilitate development of specific diagnostic and improved therapeutic options

    The C-Type Lectin Receptor CLECSF8/CLEC4D Is a Key Component of Anti-Mycobacterial Immunity

    Get PDF
    Open Access funded by Wellcome Trust: Under a Creative Commons license Copyright Ā© 2015 The Authors. Published by Elsevier Inc. All rights reserved. Acknowledgments We would like to thank S. Hardison, P. Redelinghuys, J. Taylor, C. Wallace, A. Richmond, S. Hadebe, A. Plato, F. Abbass, L. Fick, N. Allie, R. Wilkinson, K. Wilkinson, S. Cooper, D. Lang, and V. Kumar for reagents and assistance, and the animal facility staff for the care of our animals. This work was supported by the MRC (UK) and Wellcome Trust (G.D.B.); MRC (South Africa) and Sydney Brenner Fellowship (M.J.M.); Vici (M.G.N.), Vidi (R.v.C.), and Veni grants (T.S.P.) from the Netherlands Organization for Scientific Research; the Royal Netherlands Academy of Arts and Sciences (T.H.M.O.); EC FP7 projects (NEWTBVAC, ADITEC; T.H.M.O.); Carnegie Corporation and CIDRI (J.C.H.); and the University of Aberdeen (B.K.).Peer reviewedPublisher PD

    Development of a novel secondary phenotypic screen to identify hits within the mycobacterial protein synthesis pipeline

    Get PDF
    Background Wholeā€cell phenotypic screening is the driving force behind modern antiā€tubercular drug discovery efforts. Focus has shifted from screening for bactericidal scaffolds to screens incorporating target deconvolution. Targetā€based screening aims to direct drug discovery toward known effective targets and avoid investing resources into unproductive lines of enquiry. The protein synthesis pipeline, including RNA polymerase and the ribosome, is a clinically proven target in Mycobacterium tuberculosis. Screening for new hits of this effective target pathway is an invaluable tool in the drug discovery arsenal. Methods Using M. tuberculosis H37Rv augmented with anhydrotetracyclineā€inducible expression of mCherry, a phenotypic screen was developed for the identification of protein synthesis inhibitors in a medium throughput screening format. Results The assay was validated using known inhibitors of protein synthesis to show a doseā€dependent reduction in mCherry fluorescence. This was expanded to a proprietary screen of hypothetical protein synthesis hits and modified to include quantitative viability measurement of cells using resazurin. Conclusion Following the success of the proprietary screen, a larger scale screen of the GlaxoSmithKline antiā€tubercular library containing 2799 compounds was conducted. Combined single shot and doseā€response screening yielded 18 hits, 0.64% of all screened compounds
    • ā€¦
    corecore