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Braian C, Karlsson L, Das J, Lerm M. Selected β-Glucans Act as Immune-Training Agents by Improving Anti-Mycobacterial Activity in Human Macrophages: A Pilot Study. J Innate Immun 2023; 15:751-764. [PMID: 37734337 PMCID: PMC10616672 DOI: 10.1159/000533873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 08/28/2023] [Indexed: 09/23/2023] Open
Abstract
Epigenetic reprogramming of innate immune cells by β-glucan in a process called trained immunity leads to an enhanced host response to a secondary infection. β-Glucans are structural components of plants, algae, fungi, and bacteria and thus recognized as non-self by human macrophages. We selected the β-glucan curdlan from Alcaligenes faecalis, WGP dispersible from Saccharomyces cerevisiae, and β-glucan-rich culture supernatant of Alternaria and investigated whether they could produce trained immunity effects leading to an increased control of virulent Mycobacterium tuberculosis. We observed a significant M. tuberculosis growth reduction in macrophages trained with curdlan and Alternaria, which also correlated with increased IL-6 and IL-1β release. WGP dispersible-trained macrophages were stratified into "non-responders" and "responders," according to their ability to control M. tuberculosis, with "responders" producing higher IL-6 levels. The addition of neutrophils to infected macrophage cultures further enhanced macrophage control of virulent M. tuberculosis, but not in a stimuli-dependent manner. Pathway enrichment analysis of DNA methylome data also highlighted hypomethylation of genes in pathways associated with signaling and cellular reorganization and motility, and "responders" to WGP training were enriched in the interferon-gamma signaling pathway. This study adds evidence that certain β-glucans show promise as immune-training agents.
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Affiliation(s)
- Clara Braian
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Faculty of Medicine, Linköping University, Linköping, Sweden,
| | - Lovisa Karlsson
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Faculty of Medicine, Linköping University, Linköping, Sweden
| | - Jyotirmoy Das
- Bioinformatics, Core Facility, Cell Biology, Faculty of Medical and Health Sciences, Linköping University, Linköping, Sweden
- Department of Biomedical and Clinical Sciences, Clinical Genomics Linköping, SciLife Laboratory, Linköping University, Linköping, Sweden
| | - Maria Lerm
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Faculty of Medicine, Linköping University, Linköping, Sweden
- SciLifeLab, CBCS, Linköping University, Linköping, Sweden
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Baatjies L, van Rensberg IC, Snyders C, Gutschmidt A, Loxton AG, Williams MJ. Investigating Mycobacterium tuberculosis sufR (rv1460) in vitro and ex vivo expression and immunogenicity. PLoS One 2023; 18:e0286965. [PMID: 37319185 PMCID: PMC10270350 DOI: 10.1371/journal.pone.0286965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 05/29/2023] [Indexed: 06/17/2023] Open
Abstract
Iron is vital metal for Mycobacterium tuberculosis infection, survival, and persistence within its human host. The mobilization of sulphur (SUF) operon encodes the primary iron-sulphur (Fe-S) biogenesis system in M. tuberculosis and is induced during iron limitation and intracellular growth of M. tuberculosis, pointing to its importance during infection. To study sufR expression at single cell level during intracellular growth of M. tuberculosis a fluorescent reporter was generated by cloning a 123 bp sufR promoter region upstream of a promotorless mcherry gene in an integrating vector. Expression analysis and fluorescence measurements during in vitro culture revealed that the reporter was useful for measuring induction of the promoter but was unable to detect subsequent repression due to the stability of mCherry. During intracellular growth in THP-1 macrophages, increased fluorescence was observed in the strain harbouring the reporter relative to the control strain, however this induction was only observed in a small sub-set of the population. Since SufR levels are predicted to be elevated during infection we hypothesize that it is immunogenic and may induce an immune response in M. tuberculosis infected individuals. The immune response elicited by SufR for both whole blood assay (WBA, a short term 12-hr stimulation to characterise the production of cytokines/growth factors suggestive of an effector response) and lymphocyte proliferation assay (LPA, a longer term 7-day stimulation to see if SufR induces a memory type immune response) were low and did not show a strong immune response for the selected Luminex analytes (MCP-1, RANTES, IL-1b, IL-8, MIP-1b, IFN-g, IL-6 and MMP-9) measured in three clinical groups, namely active TB, QuantiFERON positive (QFN pos) and QFN negative (QFN neg) individuals.
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Affiliation(s)
- Lucinda Baatjies
- Division of Molecular Biology and Human Genetics, Department of Science and Innovation (DSI)-National Research Foundation (NRF) Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Ilana C. van Rensberg
- Division of Molecular Biology and Human Genetics, Department of Science and Innovation (DSI)-National Research Foundation (NRF) Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Candice Snyders
- Division of Molecular Biology and Human Genetics, Department of Science and Innovation (DSI)-National Research Foundation (NRF) Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Andrea Gutschmidt
- Division of Molecular Biology and Human Genetics, Department of Science and Innovation (DSI)-National Research Foundation (NRF) Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Andre G. Loxton
- Division of Molecular Biology and Human Genetics, Department of Science and Innovation (DSI)-National Research Foundation (NRF) Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Monique J. Williams
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, South Africa
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Parbhoo T, Schurz H, Mouton JM, Sampson SL. Persistence of Mycobacterium tuberculosis in response to infection burden and host-induced stressors. Front Cell Infect Microbiol 2022; 12:981827. [PMID: 36530432 PMCID: PMC9755487 DOI: 10.3389/fcimb.2022.981827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 11/17/2022] [Indexed: 12/05/2022] Open
Abstract
Introduction As infection with Mycobacterium tuberculosis progresses, the bacilli experience various degrees of host stressors in the macrophage phagosome such as low pH, nutrient deprivation, or exposure to toxic agents, which promotes cell-to-cell phenotypic variation. This includes a physiologically viable but non- or slowly replicating persister subpopulation, which is characterised by a loss of growth on solid media, while remaining metabolically active. Persisters additionally evade the host immune response and macrophage antimicrobial processes by adapting their metabolic pathways to maintain survival and persistence in the host. Methods A flow cytometry-based dual-fluorescent replication reporter assay, termed fluorescence dilution, provided a culture-independent method to characterize the single-cell replication dynamics of M. tuberculosis persisters following macrophage infection. Fluorescence dilution in combination with reference counting beads and a metabolic esterase reactive probe, calcein violet AM, provided an effective approach to enumerate and characterize the phenotypic heterogeneity within M. tuberculosis following macrophage infection. Results Persister formation appeared dependent on the initial infection burden and intracellular bacterial burden. However, inhibition of phagocytosis by cytochalasin D treatment resulted in a significantly higher median percentage of persisters compared to inhibition of phagosome acidification by bafilomycin A1 treatment. Discussion Our results suggest that different host factors differentially impact the intracellular bacterial burden, adaptive mechanisms and entry into persistence in macrophages.
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Amaral EP, Foreman TW, Namasivayam S, Hilligan KL, Kauffman KD, Barbosa Bomfim CC, Costa DL, Barreto-Duarte B, Gurgel-Rocha C, Santana MF, Cordeiro-Santos M, Du Bruyn E, Riou C, Aberman K, Wilkinson RJ, Barber DL, Mayer-Barber KD, Andrade BB, Sher A. GPX4 regulates cellular necrosis and host resistance in Mycobacterium tuberculosis infection. J Exp Med 2022; 219:e20220504. [PMID: 36069923 PMCID: PMC9458471 DOI: 10.1084/jem.20220504] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 06/23/2022] [Accepted: 08/11/2022] [Indexed: 01/15/2023] Open
Abstract
Cellular necrosis during Mycobacterium tuberculosis (Mtb) infection promotes both immunopathology and bacterial dissemination. Glutathione peroxidase-4 (Gpx4) is an enzyme that plays a critical role in preventing iron-dependent lipid peroxidation-mediated cell death (ferroptosis), a process previously implicated in the necrotic pathology seen in Mtb-infected mice. Here, we document altered GPX4 expression, glutathione levels, and lipid peroxidation in patients with active tuberculosis and assess the role of this pathway in mice genetically deficient in or overexpressing Gpx4. We found that Gpx4-deficient mice infected with Mtb display substantially increased lung necrosis and bacterial burdens, while transgenic mice overexpressing the enzyme show decreased bacterial loads and necrosis. Moreover, Gpx4-deficient macrophages exhibited enhanced necrosis upon Mtb infection in vitro, an outcome suppressed by the lipid peroxidation inhibitor, ferrostatin-1. These findings provide support for the role of ferroptosis in Mtb-induced necrosis and implicate the Gpx4/GSH axis as a target for host-directed therapy of tuberculosis.
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Affiliation(s)
- Eduardo P. Amaral
- Immunobiology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD
| | - Taylor W. Foreman
- T Lymphocyte Biology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD
| | - Sivaranjani Namasivayam
- Immunobiology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD
| | - Kerry L. Hilligan
- Immunobiology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD
| | - Keith D. Kauffman
- T Lymphocyte Biology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD
| | - Caio Cesar Barbosa Bomfim
- Immunobiology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD
| | - Diego L. Costa
- Departmento de Bioquímica e Imunologia, Programa de Pós-Graduação em Imunologia Básica e Aplicada, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Beatriz Barreto-Duarte
- Laboratório de Inflamação e Biomarcadores, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Bahia, Brazil
- Multinational Organization Network Sponsoring Translational and Epidemiological Research Initiative, Salvador, Brazil
- Curso de Medicina, Universidade Salvador, Laureate Universities, Salvador, Brazil
| | - Clarissa Gurgel-Rocha
- Department of Pathology, School of Medicine of the Federal University of Bahia, Salvador, Bahia, Brazil
- Center for Biotechnology and Cell Therapy, D’Or Institute for Research and Education, Sao Rafael Hospital, Salvador, Bahia, Brazil
| | - Monique Freire Santana
- Departmento de Ensino e Pesquisa, Fundação Centro de Controle de Oncologia do Estado do Amazonas, Manaus, Brazil
- Fundação Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Brazil
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil
| | - Marcelo Cordeiro-Santos
- Fundação Medicina Tropical Doutor Heitor Vieira Dourado, Manaus, Brazil
- Programa de Pós-Graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil
- Faculdade de Medicina, Universidade Nilton Lins, Manaus, Brazil
| | - Elsa Du Bruyn
- Wellcome Centre for Infectious Disease Research in Africa, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Catherine Riou
- Wellcome Centre for Infectious Disease Research in Africa, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - Kate Aberman
- Immunobiology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD
| | - Robert John Wilkinson
- Wellcome Centre for Infectious Disease Research in Africa, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- The Francis Crick Institute, London, Northwick Park Hospital, Harrow, UK
- Department of Infectious Disease, Imperial College London, London, UK
| | - Daniel L. Barber
- T Lymphocyte Biology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD
| | - Katrin D. Mayer-Barber
- Inflammation and Innate Immunity Unit, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD
| | - Bruno B. Andrade
- Laboratório de Inflamação e Biomarcadores, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Bahia, Brazil
- Multinational Organization Network Sponsoring Translational and Epidemiological Research Initiative, Salvador, Brazil
- Curso de Medicina, Universidade Salvador, Laureate Universities, Salvador, Brazil
- Curso de Medicina, Escola Bahiana de Medicina e Saúde Pública, Salvador, Bahia, Brazil
- Faculdade de Medicina, Universidade Federal da Bahia, Salvador, Brazil
- Curso de Medicina, Universidade Faculdade de Tecnologia e Ciências, Salvador, Bahia, Brazil
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN
| | - Alan Sher
- Immunobiology Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD
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Samuels AN, Wang ER, Harrison GA, Valenta JC, Stallings CL. Understanding the contribution of metabolism to Mycobacterium tuberculosis drug tolerance. Front Cell Infect Microbiol 2022; 12:958555. [PMID: 36072222 PMCID: PMC9441742 DOI: 10.3389/fcimb.2022.958555] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 07/29/2022] [Indexed: 11/29/2022] Open
Abstract
Treatment of Mycobacterium tuberculosis (Mtb) infections is particularly arduous. One challenge to effectively treating tuberculosis is that drug efficacy in vivo often fails to match drug efficacy in vitro. This is due to multiple reasons, including inadequate drug concentrations reaching Mtb at the site of infection and physiological changes of Mtb in response to host derived stresses that render the bacteria more tolerant to antibiotics. To more effectively and efficiently treat tuberculosis, it is necessary to better understand the physiologic state of Mtb that promotes drug tolerance in the host. Towards this end, multiple studies have converged on bacterial central carbon metabolism as a critical contributor to Mtb drug tolerance. In this review, we present the evidence that changes in central carbon metabolism can promote drug tolerance, depending on the environment surrounding Mtb. We posit that these metabolic pathways could be potential drug targets to stymie the development of drug tolerance and enhance the efficacy of current antimicrobial therapy.
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Affiliation(s)
| | | | | | | | - Christina L. Stallings
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, United States
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Kalsum S, Otrocka M, Andersson B, Welin A, Schön T, Jenmalm-Jensen A, Lundbäck T, Lerm M. A high content screening assay for discovery of antimycobacterial compounds based on primary human macrophages infected with virulent Mycobacterium tuberculosis. Tuberculosis (Edinb) 2022; 135:102222. [PMID: 35738191 DOI: 10.1016/j.tube.2022.102222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 04/29/2022] [Accepted: 05/31/2022] [Indexed: 01/08/2023]
Abstract
Drug resistance in Mycobacterium tuberculosis is an emerging threat that makes the discovery of new candidate drugs a priority. In particular, drugs with high sterilizing activity within host cells are needed to improve efficacy and reduce treatment duration. We aimed to develope and validate a High Content Screening assay based on Mycobacterium tuberculosis-infected primary human monocyte-derived macrophages as its natural reservoir. Infected primary human monocyte-derived macrophages were exposed to control antibiotics or tested compounds on 384 well plates. Intracellular bacterial growth and macrophage numbers were evaluated using an ImageXpress High Content Screening system and Z'-factor was calculated to assess the reproducibility. The combination of isoniazid and rifampicin as a positive control rendered a Z'-factor above 0.4, demonstrating suitability of the assay for screening and compound profiling purposes. In a validation experiment, isoniazid, rifampicin, moxifloxacin and levofloxacin all effectively inhibited intracellular growth as expected. Finally, a pilot screening campaign including 5700 compounds from diverse libraries resulted in the identification of three compounds with confirmed antimycobacterial activity in the low micromolar range and low host cell toxicity. The assay represents an attractive screening platform for both academic research on host-pathogen mechanisms in tuberculosis and for the identification and characterization of novel antimycobacterial compounds.
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Affiliation(s)
- Sadaf Kalsum
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Linköping University, Sweden
| | - Magdalena Otrocka
- Chemical Biology Consortium Sweden, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Blanka Andersson
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Linköping University, Sweden
| | - Amanda Welin
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Linköping University, Sweden
| | - Thomas Schön
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Linköping University, Sweden; Departments of Infectious Diseases, Kalmar County Hospital, Kalmar Sweden and Linköping University Hospital, Linköping, Sweden
| | - Annika Jenmalm-Jensen
- Chemical Biology Consortium Sweden, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Thomas Lundbäck
- Chemical Biology Consortium Sweden, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Sweden
| | - Maria Lerm
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Linköping University, Sweden.
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Tanner L, Mashabela GT, Omollo CC, de Wet TJ, Parkinson CJ, Warner DF, Haynes RK, Wiesner L. Intracellular Accumulation of Novel and Clinically Used TB Drugs Potentiates Intracellular Synergy. Microbiol Spectr 2021; 9:e0043421. [PMID: 34585951 PMCID: PMC8557888 DOI: 10.1128/spectrum.00434-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 08/19/2021] [Indexed: 12/13/2022] Open
Abstract
The therapeutic repertoire for tuberculosis (TB) remains limited despite the existence of many TB drugs that are highly active in in vitro models and possess clinical utility. Underlying the lack of efficacy in vivo is the inability of TB drugs to penetrate microenvironments inhabited by the causative agent, Mycobacterium tuberculosis, including host alveolar macrophages. Here, we determined the ability of the phenoxazine PhX1 previously shown to be active against M. tuberculosis in vitro to differentially penetrate murine compartments, including plasma, epithelial lining fluid, and isolated epithelial lining fluid cells. We also investigated the extent of permeation into uninfected and M. tuberculosis-infected human macrophage-like Tamm-Horsfall protein 1 (THP-1) cells directly and by comparing to results obtained in vitro in synergy assays. Our data indicate that PhX1 (4,750 ± 127.2 ng/ml) penetrates more effectively into THP-1 cells than do the clinically used anti-TB agents, rifampin (3,050 ± 62.9 ng/ml), moxifloxacin (3,374 ± 48.7 ng/ml), bedaquiline (4,410 ± 190.9 ng/ml), and linezolid (770 ± 14.1 ng/ml). Compound efficacy in infected cells correlated with intracellular accumulation, reinforcing the perceived importance of intracellular penetration as a key drug property. Moreover, we detected synergies deriving from redox-stimulatory combinations of PhX1 or clofazimine with the novel prenylated amino-artemisinin WHN296. Finally, we used compound synergies to elucidate the relationship between compound intracellular accumulation and efficacy, with PhX1/WHN296 synergy levels shown to predict drug efficacy. Collectively, our data support the utility of the applied assays in identifying in vitro active compounds with the potential for clinical development. IMPORTANCE This study addresses the development of novel therapeutic compounds for the eventual treatment of drug-resistant tuberculosis. Tuberculosis continues to progress, with cases of Mycobacterium tuberculosis (M. tuberculosis) resistance to first-line medications increasing. We assess new combinations of drugs with both oxidant and redox properties coupled with a third partner drug, with the focus here being on the potentiation of M. tuberculosis-active combinations of compounds in the intracellular macrophage environment. Thus, we determined the ability of the phenoxazine PhX1, previously shown to be active against M. tuberculosis in vitro, to differentially penetrate murine compartments, including plasma, epithelial lining fluid, and isolated epithelial lining fluid cells. In addition, the extent of permeation into human macrophage-like THP-1 cells and H37Rv-infected THP-1 cells was measured via mass spectrometry and compared to in vitro two-dimensional synergy and subsequent intracellular efficacy. Collectively, our data indicate that development of new drugs will be facilitated using the methods described herein.
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Affiliation(s)
- Lloyd Tanner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Gabriel T. Mashabela
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Charles C. Omollo
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Timothy J. de Wet
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | | | - Digby F. Warner
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, DST/NRF Centre of Excellence for Biomedical TB Research, Department of Pathology and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Wellcome Centre for Infectious Diseases Research in Africa, University of Cape Town, Cape Town, South Africa
| | - Richard K. Haynes
- Centre of Excellence for Pharmaceutical Sciences, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa
| | - Lubbe Wiesner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town, South Africa
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Muliaditan M, Della Pasqua O. Bacterial growth dynamics and pharmacokinetic-pharmacodynamic relationships of rifampicin and bedaquiline in BALB/c mice. Br J Pharmacol 2021; 179:1251-1263. [PMID: 34599506 PMCID: PMC9303191 DOI: 10.1111/bph.15688] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 08/07/2021] [Accepted: 09/01/2021] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Translational efforts in the evaluation of novel anti-tubercular drugs demand better integration of pharmacokinetic-pharmacodynamic data arising from preclinical protocols. However, parametric approaches that discriminate drug effect from the underlying bacterial growth dynamics have not been fully explored, making it difficult to translate and/or extrapolate preclinical findings to humans. This analysis aims to develop a drug-disease model that allows distinction between drug- and system-specific properties. EXPERIMENTAL APPROACH Given their clinical relevance, rifampicin and bedaquiline were used as test compounds. A two-state model was used to describe bacterial growth dynamics. The approach assumes the existence of fast- and slow-growing bacterial populations. Drug effect on the growth dynamics of each subpopulation was characterised in terms of potency (EC50 -F and EC50 -S) and maximum killing rate. KEY RESULTS The doubling time of the fast- and slow-growing population was estimated to be 25 h and 42 days, respectively. Rifampicin was more potent against the fast-growing (EC50 -F = 4.8 mg·L-1 ), as compared with the slow-growing population (EC50 -S = 60.2 mg·L-1 ). Bedaquiline showed higher potency than rifampicin (EC50 -F = 0.19 mg·L-1 ; EC50 -S = 3.04 mg·L-1 ). External validation procedures revealed an effect of infection route on the apparent potency of rifampicin. CONCLUSION AND IMPLICATIONS Model parameter estimates suggest that nearly maximum killing rate is achieved against fast-growing, but not against slow-growing populations at the tested doses. Evidence of differences in drug potency for each subpopulation may facilitate the translation of preclinical findings and improve the dose rationale for anti-tubercular drugs in humans.
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Affiliation(s)
- Morris Muliaditan
- Clinical Pharmacology & Therapeutics Group, School of Life and Medical Sciences, University College London, London, UK
| | - Oscar Della Pasqua
- Clinical Pharmacology & Therapeutics Group, School of Life and Medical Sciences, University College London, London, UK.,Clinical Pharmacology, Modelling and Simulation, GlaxoSmithKline, Brentford, UK
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9
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Phosphoenolpyruvate depletion mediates both growth arrest and drug tolerance of Mycobacterium tuberculosis in hypoxia. Proc Natl Acad Sci U S A 2021; 118:2105800118. [PMID: 34426499 DOI: 10.1073/pnas.2105800118] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Mycobacterium tuberculosis (Mtb) infection is difficult to treat because Mtb spends the majority of its life cycle in a nonreplicating (NR) state. Since NR Mtb is highly tolerant to antibiotic effects and can mutate to become drug resistant (DR), our conventional tuberculosis (TB) treatment is not effective. Thus, a novel strategy to kill NR Mtb is required. Accumulating evidence has shown that repetitive exposure to sublethal doses of antibiotics enhances the level of drug tolerance, implying that NR Mtb is formed by adaptive metabolic remodeling. As such, metabolic modulation strategies to block the metabolic remodeling needed to form NR Mtb have emerged as new therapeutic options. Here, we modeled in vitro NR Mtb using hypoxia, applied isotope metabolomics, and revealed that phosphoenolpyruvate (PEP) is nearly completely depleted in NR Mtb. This near loss of PEP reduces PEP-carbon flux toward multiple pathways essential for replication and drug sensitivity. Inversely, supplementing with PEP restored the carbon flux and the activities of the foregoing pathways, resulting in growth and heightened drug susceptibility of NR Mtb, which ultimately prevented the development of DR. Taken together, PEP depletion in NR Mtb is associated with the acquisition of drug tolerance and subsequent emergence of DR, demonstrating that PEP treatment is a possible metabolic modulation strategy to resensitize NR Mtb to conventional TB treatment and prevent the emergence of DR.
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10
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Togarsimalemath SK, Pushpamithran G, Schön T, Stendahl O, Blomgran R. Helminth Antigen Exposure Enhances Early Immune Control of Mycobacterium tuberculosis in Monocytes and Macrophages. J Innate Immun 2020; 13:148-163. [PMID: 33333522 DOI: 10.1159/000512279] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 10/09/2020] [Indexed: 12/18/2022] Open
Abstract
Helminth and Mycobacterium tuberculosis (Mtb) coinfection is common and suggested to influence the risk of developing active tuberculosis (TB). It is known that helminths in contrast to TB induce a strong Th2 response in the host. However, the direct impact of helminth antigen exposure on host immunity against TB is largely unknown. Our aim was to explore the effects of helminth antigen exposure on the early immune control of Mtb in monocytes and macrophages. Ascaris lumbricoides (ASC) and Schistosoma mansoni (SM) protein antigens were used to study the immediate effect of helminth antigen exposure in monocytes, on monocyte-to-macrophage differentiation, or mature macrophages, in the control of virulent Mtb H37Rv. Pre-exposure of peripheral blood mononuclear cells reduced Mtb growth in monocytes, especially with SM, but no Th1/Th2 cytokines or activation markers indicated involvement of T cells. Monocytes exposed before maturing into macrophages reduced Mtb growth in macrophages (ASC), and pre-exposure of mature macrophages reduced (ASC) or kept Mtb growth at control levels (SM). This in vitro model shows how helminth infection directly affects the monocyte-macrophage axis at an early stage before cell-mediated immunity develops. During acute helminth coinfection or when helminth antigen concentration is elevated at the site of Mtb infection, these helminths provide an enhanced control and killing of Mtb owing to the direct stimulatory effect of helminth antigens on phagocytic cells.
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Affiliation(s)
- Shambhuprasad Kotresh Togarsimalemath
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden
| | - Giggil Pushpamithran
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden
| | - Thomas Schön
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden.,Department of Infectious Diseases and Clinical Microbiology, Kalmar County Hospital, Kalmar, Sweden
| | - Olle Stendahl
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden
| | - Robert Blomgran
- Division of Inflammation and Infection, Department of Biomedical and Clinical Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden,
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11
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Pitcher MJ, Bowness R, Dobson S, Eftimie R, Gillespie SH. Modelling the effects of environmental heterogeneity within the lung on the tuberculosis life-cycle. J Theor Biol 2020; 506:110381. [PMID: 32771534 PMCID: PMC7511696 DOI: 10.1016/j.jtbi.2020.110381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 05/24/2020] [Accepted: 06/15/2020] [Indexed: 11/28/2022]
Abstract
In silico model of TB in the lung incorporating environmental heterogeneity. Preferential conditions at the apex of lung localise post-primary disease there. Analysis of the key influences driving disease at different regions of the lung.
Progress in shortening the duration of tuberculosis (TB) treatment is hampered by the lack of a predictive model that accurately reflects the diverse environment within the lung. This is important as TB has been shown to produce distinct localisations to different areas of the lung during different disease stages, with the environmental heterogeneity within the lung of factors such as air ventilation, blood perfusion and oxygen tension believed to contribute to the apical localisation witnessed during the post-primary form of the disease. Building upon our previous model of environmental lung heterogeneity, we present a networked metapopulation model that simulates TB across the whole lung, incorporating these notions of environmental heterogeneity across the whole TB life-cycle to show how different stages of the disease are influenced by different environmental and immunological factors. The alveolar tissue in the lung is divided into distinct patches, with each patch representing a portion of the total tissue and containing environmental attributes that reflect the internal conditions at that location. We include populations of bacteria and immune cells in various states, and events are included which determine how the members of the model interact with each other and the environment. By allowing some of these events to be dependent on environmental attributes, we create a set of heterogeneous dynamics, whereby the location of the tissue within the lung determines the disease pathological events that occur there. Our results show that the environmental heterogeneity within the lung is a plausible driving force behind the apical localisation during post-primary disease. After initial infection, bacterial levels will grow in the initial infection location at the base of the lung until an adaptive immune response is initiated. During this period, bacteria are able to disseminate and create new lesions throughout the lung. During the latent stage, the lesions that are situated towards the apex are the largest in size, and once a post-primary immune-suppressing event occurs, it is the uppermost lesions that reach the highest levels of bacterial proliferation. Our sensitivity analysis also shows that it is the differential in blood perfusion, causing reduced immune activity towards the apex, which has the biggest influence of disease outputs.
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Affiliation(s)
- Michael J Pitcher
- School of Immunology and Microbial Sciences, King's College London, United Kingdom; School of Computer Science, University of St Andrews, United Kingdom.
| | - Ruth Bowness
- School of Medicine, University of St Andrews, United Kingdom
| | - Simon Dobson
- School of Computer Science, University of St Andrews, United Kingdom
| | - Raluca Eftimie
- School of Science and Engineering, University of Dundee, United Kingdom
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12
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Afkhami S, Villela AD, D’Agostino MR, Jeyanathan M, Gillgrass A, Xing Z. Advancing Immunotherapeutic Vaccine Strategies Against Pulmonary Tuberculosis. Front Immunol 2020; 11:557809. [PMID: 33013927 PMCID: PMC7509172 DOI: 10.3389/fimmu.2020.557809] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 08/18/2020] [Indexed: 12/21/2022] Open
Abstract
Chemotherapeutic intervention remains the primary strategy in treating and controlling tuberculosis (TB). However, a complex interplay between therapeutic and patient-related factors leads to poor treatment adherence. This in turn continues to give rise to unacceptably high rates of disease relapse and the growing emergence of drug-resistant forms of TB. As such, there is considerable interest in strategies that simultaneously improve treatment outcome and shorten chemotherapy duration. Therapeutic vaccines represent one such approach which aims to accomplish this through boosting and/or priming novel anti-TB immune responses to accelerate disease resolution, shorten treatment duration, and enhance treatment success rates. Numerous therapeutic vaccine candidates are currently undergoing pre-clinical and clinical assessment, showing varying degrees of efficacy. By dissecting the underlying mechanisms/correlates of their successes and/or shortcomings, strategies can be identified to improve existing and future vaccine candidates. This mini-review will discuss the current understanding of therapeutic TB vaccine candidates, and discuss major strategies that can be implemented in advancing their development.
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Affiliation(s)
- Sam Afkhami
- McMaster Immunology Research Center, McMaster University, Hamilton, ON, Canada
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Anne Drumond Villela
- McMaster Immunology Research Center, McMaster University, Hamilton, ON, Canada
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Michael R. D’Agostino
- McMaster Immunology Research Center, McMaster University, Hamilton, ON, Canada
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Mangalakumari Jeyanathan
- McMaster Immunology Research Center, McMaster University, Hamilton, ON, Canada
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Amy Gillgrass
- McMaster Immunology Research Center, McMaster University, Hamilton, ON, Canada
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Zhou Xing
- McMaster Immunology Research Center, McMaster University, Hamilton, ON, Canada
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
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13
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Džunková M, Moya A, Chen X, Kelly C, D’Auria G. Detection of mixed-strain infections by FACS and ultra-low input genome sequencing. Gut Microbes 2020; 11:305-309. [PMID: 30289342 PMCID: PMC7524272 DOI: 10.1080/19490976.2018.1526578] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The epidemiological tracking of a bacterial outbreak may be jeopardized by the presence of multiple pathogenic strains in one patient. Nevertheless, this fact is not considered in most of the epidemiological studies and only one colony per patient is sequenced. On the other hand, the routine whole genome sequencing of many isolates from each patient would be costly and unnecessary, because the number of strains in a patient is never known a priori. In addition, the result would be biased by microbial culture conditions. Herein we propose an approach for detecting mixed-strain infection, providing C. difficile infection as an example. The cells of the target pathogenic species are collected from the bacterial suspension by the fluorescence activated cell sorting (FACS) and a shallow genome sequencing is performed. A modified sequencing library preparation protocol for low-input DNA samples can be used for low prevalence gut pathogens (< 0.1% of the total microbiome). This FACS-seq approach reduces diagnostics time (no culture is needed) and may promote discoveries of novel strains. Methodological details, possible issues and future directions for the sequencing of these natural pan-genomes are herein discussed.
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Affiliation(s)
- Mária Džunková
- Department of Genomics and Health, Foundation for the Promotion of Health and Biomedical Research of Valencia Region (FISABIO-Public Health), València, Spain,CIBER in Epidemiology and Public Health (CIBEResp), Madrid, Spain,Institute for Integrative Systems Biology (I2SysBio), The University of Valencia and The Spanish National Research Council (CSIC)-UVEG), València, Spain,Australian Centre for Ecogenomics, The University of Queensland, St Lucia, Australia
| | - Andrés Moya
- Department of Genomics and Health, Foundation for the Promotion of Health and Biomedical Research of Valencia Region (FISABIO-Public Health), València, Spain,CIBER in Epidemiology and Public Health (CIBEResp), Madrid, Spain,Institute for Integrative Systems Biology (I2SysBio), The University of Valencia and The Spanish National Research Council (CSIC)-UVEG), València, Spain
| | - Xinhua Chen
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA
| | - Ciaran Kelly
- Division of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, USA
| | - Giuseppe D’Auria
- Department of Genomics and Health, Foundation for the Promotion of Health and Biomedical Research of Valencia Region (FISABIO-Public Health), València, Spain,CIBER in Epidemiology and Public Health (CIBEResp), Madrid, Spain,Institute for Integrative Systems Biology (I2SysBio), The University of Valencia and The Spanish National Research Council (CSIC)-UVEG), València, Spain,Sequencing and Bioinformatics Service of the Foundation for the Promotion of Health and Biomedical Research of Valencia Region (FISABIO-Public Health), València, Spain,CONTACT Giuseppe D’Auria
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14
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Das J, Verma D, Gustafsson M, Lerm M. Identification of DNA methylation patterns predisposing for an efficient response to BCG vaccination in healthy BCG-naïve subjects. Epigenetics 2019; 14:589-601. [PMID: 31010371 PMCID: PMC6557603 DOI: 10.1080/15592294.2019.1603963] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The protection against tuberculosis induced by the Bacille Calmette Guérin (BCG) vaccine is unpredictable. In our previous study, altered DNA methylation pattern in peripheral blood mononuclear cells (PBMCs) in response to BCG was observed in a subgroup of individuals, whose macrophages killed mycobacteria effectively (‘responders’). These macrophages also showed production of Interleukin-1β (IL-1β) in response to mycobacterial stimuli before vaccination. Here, we hypothesized that the propensity to respond to the BCG vaccine is reflected in the DNA methylome. We mapped the differentially methylated genes (DMGs) in PBMCs isolated from responders/non-responders at the time point before vaccination aiming to identify possible predictors of BCG responsiveness. We identified 43 DMGs and subsequent bioinformatic analyses showed that these were enriched for actin-modulating pathways, predicting differences in phagocytosis. This could be validated by experiments showing that phagocytosis of mycobacteria, which is an event preceding mycobacteria-induced IL-1β production, was strongly correlated with the DMG pattern.
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Affiliation(s)
- Jyotirmoy Das
- a Department of Clinical and Experimental Medicine (IKE), Faculty of Medicine and Health Sciences , Linköping University , Linköping , Sweden
| | - Deepti Verma
- b Department of Clinical and Experimental Medicine (IKE), Division of Cell Biology (CELLB) , Linköping University , Linköping , Sweden
| | - Mika Gustafsson
- c Department of Physics, Chemistry and Biology (IFM) Bioinformatics (BION) , Linköping University , Linköping , Sweden
| | - Maria Lerm
- a Department of Clinical and Experimental Medicine (IKE), Faculty of Medicine and Health Sciences , Linköping University , Linköping , Sweden
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15
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Tran T, Bonham AJ, Chan ED, Honda JR. A paucity of knowledge regarding nontuberculous mycobacterial lipids compared to the tubercle bacillus. Tuberculosis (Edinb) 2019; 115:96-107. [PMID: 30948183 DOI: 10.1016/j.tube.2019.02.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 01/29/2019] [Accepted: 02/25/2019] [Indexed: 10/27/2022]
Abstract
All mycobacteria, including nontuberculous mycobacteria (NTM), synthesize an array of lipids including phosphatidylinositol mannosides (PIM), lipomannan (LM), and lipoarabinomannan (LAM). While absent from Mycobacterium tuberculosis (M. tb), glycopeptidolipids (GPL) are critical to the biology of NTM. M. tb and some NTM also synthesize trehalose-containing glycolipids and phenolic glycolipids (PGL), key membrane constituents with essential roles in metabolism. While lipids facilitate immune evasion, they also induce host immunity against tuberculosis. However, much less is known about the significance of NTM-derived PIM, LM, LAM, GPL, trehalose-containing glycolipids, and PGL as virulence factors, warranting further investigation. While culling the scientific literature on NTM lipids, it's evident that such studies were relatively few in number with the overwhelming majority of prior work dedicated to understanding lipids from the saprophyte Mycobacterium smegmatis. The identification and functional analysis of immune reactive NTM-derived lipids remain challenging, but such work is likely to yield a greater understanding of the pathogenesis of NTM lung disease. In this review, we juxtapose the vast literature of what is currently known regarding M. tb lipids to the lesser number of studies for comparable NTM lipids. But because GPL is the most widely recognized NTM lipid, we highlight its role in disease pathogenesis.
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Affiliation(s)
- Tru Tran
- Department of Integrative Biology, University of Colorado Denver, Campus Box 171, PO Box 173364, Denver, CO, 80217-3364, USA.
| | - Andrew J Bonham
- Department of Chemistry, Metropolitan State University of Denver, Campus Box 52, P.O. Box 173362, Denver, CO, 80217-3362, USA.
| | - Edward D Chan
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA; Department of Medicine, Denver Veterans Affairs Medical Center, Denver, CO, USA; Academic Affairs, National Jewish Health, 1400 Jackson St. Neustadt D509, Denver, CO, 80206, USA.
| | - Jennifer R Honda
- Department of Biomedical Research and the Center for Genes, Environment, and Health, National Jewish Health, Denver, CO, USA.
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16
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Tenland E, Pochert A, Krishnan N, Umashankar Rao K, Kalsum S, Braun K, Glegola-Madejska I, Lerm M, Robertson BD, Lindén M, Godaly G. Effective delivery of the anti-mycobacterial peptide NZX in mesoporous silica nanoparticles. PLoS One 2019; 14:e0212858. [PMID: 30807612 PMCID: PMC6391042 DOI: 10.1371/journal.pone.0212858] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 02/12/2019] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Intracellular delivery of antimicrobial agents by nanoparticles, such as mesoporous silica particles (MSPs), offers an interesting strategy to treat intracellular infections. In tuberculosis (TB), Mycobacterium tuberculosis avoids components of the immune system by residing primarily inside alveolar macrophages, which are the desired target for TB therapy. METHODS AND FINDINGS We have previously identified a peptide, called NZX, capable of inhibiting both clinical and multi-drug resistant strains of M. tuberculosis at therapeutic concentrations. In this study we analysed the potential of MSPs containing NZX for the treatment of tuberculosis. The MSPs released functional NZX gradually into simulated lung fluid and the peptide filled MSPs were easily taken up by primary macrophages. In an intracellular infection model, the peptide containing particles showed increased mycobacterial killing compared to free peptide. The therapeutic potential of peptide containing MSPs was investigated in a murine infection model, showing that MSPs preserved the effect to eliminate M. tuberculosis in vivo. CONCLUSIONS In this study we found that loading the antimicrobial peptide NZX into MSPs increased the inhibition of intracellular mycobacteria in primary macrophages and preserved the ability to eliminate M. tuberculosis in vivo in a murine model. Our studies provide evidence for the feasibility of using MSPs for treatment of tuberculosis.
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Affiliation(s)
- Erik Tenland
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden
| | | | - Nitya Krishnan
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, United Kingdom
| | - Komal Umashankar Rao
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden
| | - Sadaf Kalsum
- Department of Clinical and Experimental Medicine, Faculty Medicine and Health Sciences, Linköping, Sweden
| | - Katharina Braun
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden
| | - Izabela Glegola-Madejska
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, United Kingdom
| | - Maria Lerm
- Department of Clinical and Experimental Medicine, Faculty Medicine and Health Sciences, Linköping, Sweden
| | - Brian D. Robertson
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, London, United Kingdom
| | - Mika Lindén
- Inorganic Chemistry II, Ulm University, Ulm, Germany
| | - Gabriela Godaly
- Department of Microbiology, Immunology and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden
- * E-mail:
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17
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Retention of EsxA in the Capsule-Like Layer of Mycobacterium tuberculosis Is Associated with Cytotoxicity and Is Counteracted by Lung Surfactant. Infect Immun 2019; 87:IAI.00803-18. [PMID: 30602503 DOI: 10.1128/iai.00803-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 12/18/2018] [Indexed: 12/18/2022] Open
Abstract
Mycobacterium tuberculosis, the pathogen that causes tuberculosis, primarily infects macrophages but withstands the host cell's bactericidal effects. EsxA, also called virulence factor 6-kDa early secretory antigenic target (ESAT-6), is involved in phagosomal rupture and cell death. We provide confocal and electron microscopy data showing that M. tuberculosis bacteria grown without detergent retain EsxA on their surface. Lung surfactant has detergent-like properties and effectively strips off this surface-associated EsxA, which advocates a novel mechanism of lung surfactant-mediated defense against pathogens. Upon challenge of human macrophages with these M. tuberculosis bacilli, the amount of surface-associated EsxA rapidly declines in a phagocytosis-independent manner. Furthermore, M. tuberculosis bacteria cultivated under exclusion of detergent exert potent cytotoxic activity associated with bacterial growth. Together, this study suggests that the surface retention of EsxA contributes to the cytotoxicity of M. tuberculosis and highlights how cultivation conditions affect the experimental outcome.
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18
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Tükenmez H, Edström I, Kalsum S, Braian C, Ummanni R, Fick SB, Sundin C, Lerm M, Elofsson M, Larsson C. Corticosteroids protect infected cells against mycobacterial killing in vitro. Biochem Biophys Res Commun 2019; 511:117-121. [PMID: 30773257 DOI: 10.1016/j.bbrc.2019.02.044] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 02/08/2019] [Indexed: 12/23/2022]
Abstract
The effect of corticosteroids on human physiology is complex and their use in tuberculosis patients remains controversial. In a high-throughput screening approach designed to discover virulence inhibitors, several corticosteroids were found to prevent cytolysis of fibroblasts infected with mycobacteria. Further experiments with Mycobacterium tuberculosis showed anti-cytolytic activity in the 10 nM range, but no effect on bacterial growth or survival in the absence of host cells at 20 μM. The results from a panel of corticosteroids with various affinities to the glucocorticoid- and mineralocorticoid receptors indicate that the inhibition of cytolysis most likely is mediated through the glucocorticoid receptor. Using live-imaging of M. tuberculosis-infected human monocyte-derived macrophages, we also show that corticosteroids to some extent control intracellular bacteria. In vitro systems with reduced complexity are to further study and understand the interactions between bacterial infection, immune defense and cell signaling.
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Affiliation(s)
- Hasan Tükenmez
- Department of Molecular Biology, Umeå University, SE-901 87, Umeå, Sweden
| | - Isabel Edström
- Department of Molecular Biology, Umeå University, SE-901 87, Umeå, Sweden
| | - Sadaf Kalsum
- Department of Clinical and Experimental Medicine, Linköping University, SE-581 83, Linköping, Sweden
| | - Clara Braian
- Department of Clinical and Experimental Medicine, Linköping University, SE-581 83, Linköping, Sweden
| | - Ramesh Ummanni
- Department of Applied Biology, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Tarnaka, Hyderabad, 500007, Telangana, India
| | - Stina Berglund Fick
- Chemical Biology Consortium Sweden (CBCS), Department of Chemistry, Umeå University, SE-901 87, Umeå, Sweden
| | - Charlotta Sundin
- Department of Chemistry, Umeå University, SE-901 87, Umeå, Sweden
| | - Maria Lerm
- Department of Clinical and Experimental Medicine, Linköping University, SE-581 83, Linköping, Sweden
| | - Mikael Elofsson
- Department of Chemistry, Umeå University, SE-901 87, Umeå, Sweden
| | - Christer Larsson
- Infectious Diseases Clinic, Umeå University Hospital, SE-901 85, Umeå, Sweden.
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19
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Singh SK, Larsson M, Schön T, Stendahl O, Blomgran R. HIV Interferes with the Dendritic Cell-T Cell Axis of Macrophage Activation by Shifting Mycobacterium tuberculosis-Specific CD4 T Cells into a Dysfunctional Phenotype. THE JOURNAL OF IMMUNOLOGY 2018; 202:816-826. [PMID: 30593540 DOI: 10.4049/jimmunol.1800523] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 11/26/2018] [Indexed: 02/07/2023]
Abstract
HIV coinfection is the greatest risk factor for transition of latent Mycobacterium tuberculosis infection into active tuberculosis (TB). Epidemiological data reveal both the reduction and the impairment of M. tuberculosis-specific CD4 T cells, although the cellular link and actual mechanisms resulting in immune impairment/suppression need further characterization. M. tuberculosis-specific CD4 T cells play a central role in development of protective immunity against TB, in which they participate in the activation of macrophages through the dendritic cell (DC)-T cell axis. Using an in vitro priming system for generating Ag-specific T cells, we explored if HIV-M. tuberculosis-infected (coinfected) human DCs can dysregulate the M. tuberculosis-specific CD4 T cell phenotype and functionality and subsequently mediate the failure to control M. tuberculosis infection in macrophages. After coculture with coinfected DCs, M. tuberculosis Ag-specific CD4 T cells lost their ability to enhance control of M. tuberculosis infection in infected macrophages. Coinfection of DCs reduced proliferation of M. tuberculosis Ag-specific CD4 T cells without affecting their viability, led to increased expression of coinhibitory factors CTLA-4, PD-1, and Blimp-1, and decreased expression of costimulatory molecules CD40L, CD28, and ICOS on the T cells. Expression of the regulatory T cell markers FOXP3 and CD25, together with the immunosuppressive cytokines TGF-β and IL-10, was also significantly increased by coinfection compared with M. tuberculosis single infection. Our data suggest a pattern in which HIV, through its effect on DCs, impairs the ability of M. tuberculosis-specific CD4 T cells to maintain a latent TB within human macrophages, which could play an early role in the subsequent development of TB.
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Affiliation(s)
- Susmita K Singh
- Division of Medical Microbiology, Department of Clinical and Experimental Medicine, Medical Faculty, Linköping University, 581 85 Linköping, Sweden
| | - Marie Larsson
- Division of Molecular Virology, Department of Clinical and Experimental Medicine, Medical Faculty, Linköping University, 581 85 Linköping, Sweden; and
| | - Thomas Schön
- Division of Medical Microbiology, Department of Clinical and Experimental Medicine, Medical Faculty, Linköping University, 581 85 Linköping, Sweden.,Department of Infectious Diseases and Clinical Microbiology, Kalmar County Hospital, 391 85 Kalmar, Sweden
| | - Olle Stendahl
- Division of Medical Microbiology, Department of Clinical and Experimental Medicine, Medical Faculty, Linköping University, 581 85 Linköping, Sweden
| | - Robert Blomgran
- Division of Medical Microbiology, Department of Clinical and Experimental Medicine, Medical Faculty, Linköping University, 581 85 Linköping, Sweden;
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20
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Tenland E, Krishnan N, Rönnholm A, Kalsum S, Puthia M, Mörgelin M, Davoudi M, Otrocka M, Alaridah N, Glegola-Madejska I, Sturegård E, Schmidtchen A, Lerm M, Robertson BD, Godaly G. A novel derivative of the fungal antimicrobial peptide plectasin is active against Mycobacterium tuberculosis. Tuberculosis (Edinb) 2018; 113:231-238. [PMID: 30514507 PMCID: PMC6289163 DOI: 10.1016/j.tube.2018.10.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 09/25/2018] [Accepted: 10/23/2018] [Indexed: 12/14/2022]
Abstract
Tuberculosis has been reaffirmed as the infectious disease causing most deaths in the world. Co-infection with HIV and the increase in multi-drug resistant Mycobacterium tuberculosis strains complicate treatment and increases mortality rates, making the development of new drugs an urgent priority. In this study we have identified a promising candidate by screening antimicrobial peptides for their capacity to inhibit mycobacterial growth. This non-toxic peptide, NZX, is capable of inhibiting both clinical strains of M. tuberculosis and an MDR strain at therapeutic concentrations. The therapeutic potential of NZX is further supported in vivo where NZX significantly lowered the bacterial load with only five days of treatment, comparable to rifampicin treatment over the same period. NZX possesses intracellular inhibitory capacity and co-localizes with intracellular bacteria in infected murine lungs. In conclusion, the data presented strongly supports the therapeutic potential of NZX in future anti-TB treatment.
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Affiliation(s)
- Erik Tenland
- Department of Microbiology, Immunology and Glycobiology, Institution of Laboratory Medicine, Lund University, Lund, Sweden
| | - Nitya Krishnan
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, UK
| | - Anna Rönnholm
- Department of Microbiology, Immunology and Glycobiology, Institution of Laboratory Medicine, Lund University, Lund, Sweden
| | - Sadaf Kalsum
- Department of Clinical and Experimental Medicine, Faculty Medicine and Health Sciences, Linköping, Sweden
| | - Manoj Puthia
- Department of Dermatology and Venereology, Institution of Clinical Sciences, Lund University, Lund, Sweden
| | | | - Mina Davoudi
- Department of Dermatology and Venereology, Institution of Clinical Sciences, Lund University, Lund, Sweden
| | - Magdalena Otrocka
- Chemical Biology Consortium Sweden, Science for Life Laboratory, Karolinska Institute, Stockholm, Sweden
| | - Nader Alaridah
- Department of Microbiology, Immunology and Glycobiology, Institution of Laboratory Medicine, Lund University, Lund, Sweden
| | - Izabela Glegola-Madejska
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, UK
| | - Erik Sturegård
- Department of Clinical Microbiology, Institution of Translational Medicine, Lund University, Malmö, Sweden
| | - Artur Schmidtchen
- Department of Dermatology and Venereology, Institution of Clinical Sciences, Lund University, Lund, Sweden
| | - Maria Lerm
- Department of Clinical and Experimental Medicine, Faculty Medicine and Health Sciences, Linköping, Sweden
| | - Brian D Robertson
- MRC Centre for Molecular Bacteriology and Infection, Department of Medicine, Imperial College London, UK
| | - Gabriela Godaly
- Department of Microbiology, Immunology and Glycobiology, Institution of Laboratory Medicine, Lund University, Lund, Sweden.
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21
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Tanner L, Denti P, Wiesner L, Warner DF. Drug permeation and metabolism in Mycobacterium tuberculosis: Prioritising local exposure as essential criterion in new TB drug development. IUBMB Life 2018; 70:926-937. [PMID: 29934964 PMCID: PMC6129860 DOI: 10.1002/iub.1866] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 04/11/2018] [Accepted: 04/11/2018] [Indexed: 12/22/2022]
Abstract
Anti-tuberculosis (TB) drugs possess diverse abilities to penetrate the different host tissues and cell types in which infecting Mycobacterium tuberculosis bacilli are located during active disease. This is important since there is increasing evidence that the respective "lesion-penetrating" properties of the front-line TB drugs appear to correlate well with their specific activity in standard combination therapy. In turn, these observations suggest that rational efforts to discover novel treatment-shortening drugs and drug combinations should incorporate knowledge about the comparative abilities of both existing and experimental anti-TB agents to access bacilli in defined physiological states at different sites of infection, as well as avoid elimination by efflux or inactivation by host or bacterial metabolism. However, while there is a fundamental requirement to understand the mode of action and pharmacological properties of any current or experimental anti-TB agent within the context of the obligate human host, this is complex and, until recently, has been severely limited by the available methodologies and models. Here, we discuss advances in analytical models and technologies which have enabled investigations of drug metabolism and pharmacokinetics (DMPK) for new TB drug development. In particular, we consider the potential to shift the focus of traditional pharmacokinetic-pharmacodynamic analyses away from plasma to a more specific "site of action" drug exposure as an essential criterion for drug development and the design of dosing strategies. Moreover, in summarising approaches to determine DMPK data for the "unit of infection" comprising host macrophage and intracellular bacillus, we evaluate the potential benefits of including these analyses at an early stage in the preclinical drug development algorithm. © 2018 IUBMB Life, 70(9):926-937, 2018.
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Affiliation(s)
- Lloyd Tanner
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, Department of Pathology and Institute of Infectious Disease & Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Observatory, South Africa
- Division of Clinical Pharmacology, Department of Medicine, Faculty of Health Sciences, University of Cape Town, Observatory, South Africa
| | - Paolo Denti
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, Department of Pathology and Institute of Infectious Disease & Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Observatory, South Africa
| | - Lubbe Wiesner
- SAMRC/NHLS/UCT Molecular Mycobacteriology Research Unit, Department of Pathology and Institute of Infectious Disease & Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Observatory, South Africa
| | - Digby F. Warner
- Division of Clinical Pharmacology, Department of Medicine, Faculty of Health Sciences, University of Cape Town, Observatory, South Africa
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22
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Antonova AV, Gryadunov DA, Zimenkov DV. Molecular Mechanisms of Drug Tolerance in Mycobacterium tuberculosis. Mol Biol 2018. [DOI: 10.1134/s0026893318030020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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23
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Abstract
Tuberculosis is a complex disease, which can affect many organs other than the lungs. Initial infection may be cleared without inducing immunological memory, or progress directly to primary disease. Alternatively, the infection may be controlled as latent TB infection, that may progress to active tuberculosis at a later stage. There is now a greater understanding that these infection states are part of a continuum, and studies using PET/CT imaging have shown that individual lung granulomas may respond to infection independently, in an un-synchronized manner. In addition, the Mycobacterium tuberculosis organisms themselves can exist in different states: as nonculturable forms, as 'persisters', as rapidly growing bacteria and a biofilm-forming cording phenotype. The 'omics' approaches of transcriptomics, metabolomics and proteomics can help reveal the mechanisms underlying these different infection states in the host, and identify biosignatures with diagnostic potential, that can predict the development of disease, in 'progressors' as early as 12-18 months before it can be detected clinically, or that can monitor the success of anti-TB therapy. Further insights can be obtained from studies of BCG vaccination and new TB vaccines. For example, epigenetic changes associated with trained immunity and a stronger immune responses following BCG vaccination can be identified. These omics approaches may be particularly valuable when linked to studies of mycobacterial growth inhibition, as a direct read-out of the ability to control mycobacterial growth. The second generation of omics studies is identifying much smaller signatures based on as few as 3 or 4 genes. Thus, narrowing down omics-derived biosignatures to a manageable set of markers now opens the way to field-friendly point of care assays.
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Affiliation(s)
- M Lerm
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden
| | - H M Dockrell
- Faculty of Infectious and Tropical Diseases, Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
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24
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Devalraju KP, Neela VSK, Gaddam R, Chaudhury A, Van A, Krovvidi SS, Vankayalapati R, Valluri VL. Defective MyD88 and IRAK4 but not TLR-2 expression in HIV+ individuals with latent tuberculosis infection. Cytokine 2018; 110:213-221. [PMID: 29778672 DOI: 10.1016/j.cyto.2018.05.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 04/17/2018] [Accepted: 05/07/2018] [Indexed: 01/02/2023]
Abstract
HIV infection markedly increases the likelihood of latent tuberculosis infection progressing to active TB. Information on expression of TLR-2, myeloid differentiation factor (MyD88), IL-1R- associated kinase-4 (IRAK4) and nuclear factor kappa B (NF-kB) in HIV+LTBI+ and HIV+ patients with active TB disease is limited. We found significantly higher percentages of CD14+TLR2+ cells in PBMCs of HIV+LTBI+ patients compared to HIV-LTBI+ individuals. γ-irradiated Mtb was unable to induce MyD88, IRAK4 expression and IL-1β, MCP-1, IP-10 production in HIV+LTBI+ patients. Pleural fluids from HIV+TB+ patients had low IL-1β, MCP-1, IP-10 and high IL-10, TNF-α production. γ-irradiated Mtb stimulated CD14+ cells from HIV+TB+ patients had low IL-1β, MCP-1, IP-10 production and MyD88, IRAK4 and similar NF-kB expression compared to those from of HIV-TB+ patients. Our results suggest defective MyD88, IRAK4 but not NF-kB inhibit IL-1β, MCP-1 and IP-10 production by CD14+ cells of HIV+ individuals with LTBI and active TB disease in peripheral blood and at the site of disease.
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Affiliation(s)
- Kamakshi Prudhula Devalraju
- Immunology and Molecular Biology Division, Blue Peter Public Health and Research Centre, LEPRA Society, Cherlapally, Hyderabad 501301, India
| | - Venkata Sanjeev Kumar Neela
- Immunology and Molecular Biology Division, Blue Peter Public Health and Research Centre, LEPRA Society, Cherlapally, Hyderabad 501301, India
| | - Ramulu Gaddam
- Department of Respiratory Medicine, AP Chest and General Hospital, Osmania Medical College, Erragadda, Hyderabad 500038, India
| | - Arunabala Chaudhury
- Clinical Division, Cheyutha, LEPRA Society, Cherlapally, Hyderabad 501301, India
| | - Abhinav Van
- Department of Pulmonary Immunology, Center for Biomedical Research, University of Texas Health Center, Tyler, TX 75708, United States
| | - Siva Sai Krovvidi
- Department of Biotechnology, Sreenidhi Institute of Science and Technology, Yamnampet, Ghatkesar, Hyderabad, Telangana 501301, India
| | - Ramakrishna Vankayalapati
- Department of Pulmonary Immunology, Center for Biomedical Research, University of Texas Health Center, Tyler, TX 75708, United States.
| | - Vijaya Lakshmi Valluri
- Immunology and Molecular Biology Division, Blue Peter Public Health and Research Centre, LEPRA Society, Cherlapally, Hyderabad 501301, India.
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25
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Vijay S, Vinh DN, Hai HT, Ha VTN, Dung VTM, Dinh TD, Nhung HN, Tram TTB, Aldridge BB, Hanh NT, Thu DDA, Phu NH, Thwaites GE, Thuong NTT. Influence of Stress and Antibiotic Resistance on Cell-Length Distribution in Mycobacterium tuberculosis Clinical Isolates. Front Microbiol 2017; 8:2296. [PMID: 29209302 PMCID: PMC5702322 DOI: 10.3389/fmicb.2017.02296] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 11/07/2017] [Indexed: 11/25/2022] Open
Abstract
Mycobacterial cellular variations in growth and division increase heterogeneity in cell length, possibly contributing to cell-to-cell variation in host and antibiotic stress tolerance. This may be one of the factors influencing Mycobacterium tuberculosis persistence to antibiotics. Tuberculosis (TB) is a major public health problem in developing countries, antibiotic persistence, and emergence of antibiotic resistance further complicates this problem. We wanted to investigate the factors influencing cell-length distribution in clinical M. tuberculosis strains. In parallel we examined M. tuberculosis cell-length distribution in a large set of clinical strains (n = 158) from ex vivo sputum samples, in vitro macrophage models, and in vitro cultures. Our aim was to understand the influence of clinically relevant factors such as host stresses, M. tuberculosis lineages, antibiotic resistance, antibiotic concentrations, and disease severity on the cell size distribution in clinical M. tuberculosis strains. Increased cell size and cell-to-cell variation in cell length were associated with bacteria in sputum and infected macrophages rather than liquid culture. Multidrug-resistant (MDR) strains displayed increased cell length heterogeneity compared to sensitive strains in infected macrophages and also during growth under rifampicin (RIF) treatment. Importantly, increased cell length was also associated with pulmonary TB disease severity. Supporting these findings, individual host stresses, such as oxidative stress and iron deficiency, increased cell-length heterogeneity of M. tuberculosis strains. In addition we also observed synergism between host stress and RIF treatment in increasing cell length in MDR-TB strains. This study has identified some clinical factors contributing to cell-length heterogeneity in clinical M. tuberculosis strains. The role of these cellular adaptations to host and antibiotic tolerance needs further investigation.
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Affiliation(s)
- Srinivasan Vijay
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Dao N Vinh
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Hoang T Hai
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Vu T N Ha
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Vu T M Dung
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Tran D Dinh
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Hoang N Nhung
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Trinh T B Tram
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Bree B Aldridge
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, United States.,Department of Biomedical Engineering, Tufts University School of Engineering, Medford, MA, United States
| | - Nguyen T Hanh
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Do D A Thu
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Nguyen H Phu
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Guy E Thwaites
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Nguyen T T Thuong
- Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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26
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Mvubu NE, Pillay B, McKinnon LR, Pillay M. Mycobacterium tuberculosis strains induce strain-specific cytokine and chemokine response in pulmonary epithelial cells. Cytokine 2017; 104:53-64. [PMID: 29032986 DOI: 10.1016/j.cyto.2017.09.027] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 09/23/2017] [Accepted: 09/23/2017] [Indexed: 02/07/2023]
Abstract
M. tuberculosis F15/LAM4/KZN has been associated with high transmission rates of drug resistant tuberculosis in the KwaZulu-Natal province of South Africa. The current study elucidated the cytokine/chemokine responses induced by representatives of the F15/LAM4/KZN and other dominant strain families in pulmonary epithelial cells. Multiplex cytokine analyses were performed at 24, 48 and 72h post infection of the A549 pulmonary epithelial cell line with the F15/LAM4/KZN, F28, F11, Beijing, Unique and H37Rv strains at an MOI of ∼10:1. Twenty-three anti- and pro-inflammatory cytokines/chemokines were detected at all-time intervals. Significantly high concentrations of IL-6, IFN-γ, TNF-α and G-CSF at 48h, and IL-8, IFN-γ, TNF-α, G-CSF and GM-CSF at 72h, were induced by the F28 and F15/LAM4/KZN strains, respectively. Lower levels of cytokines/chemokines were induced by either the Beijing or Unique strains at all three time intervals. All strains induced up-regulation of pathogen recognition receptors (PRRs) (TLR3 and TLR5) while only the F15/LAM4/KZN, F11 and F28 strains induced significant differential expression of TLR2 compared to the Beijing, Unique and H37Rv strains. The low induction of cytokines in epithelial cells by the Beijing strain correlates with its previously reported hypervirulent properties. High concentrations of cytokines and chemokines required for early protection against M. tuberculosis infections induced by the F15/LAM4/KZN and F28 strains suggests a lower virulence of these genotypes compared to the Beijing strain. These findings demonstrate the high diversity in host cytokine/chemokine response to early infection of pulmonary epithelial cells by different strains of M. tuberculosis.
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Affiliation(s)
- Nontobeko E Mvubu
- School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville 3630, South Africa.
| | - Balakrishna Pillay
- School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville 3630, South Africa.
| | - Lyle R McKinnon
- Centre for the AIDS Program of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa; Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada.
| | - Manormoney Pillay
- Medical Microbiology, School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, 719 Umbilo Road, South Africa.
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27
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Verma D, Parasa VR, Raffetseder J, Martis M, Mehta RB, Netea M, Lerm M. Anti-mycobacterial activity correlates with altered DNA methylation pattern in immune cells from BCG-vaccinated subjects. Sci Rep 2017; 7:12305. [PMID: 28951586 PMCID: PMC5615063 DOI: 10.1038/s41598-017-12110-2] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 09/05/2017] [Indexed: 12/28/2022] Open
Abstract
The reason for the largely variable protective effect against TB of the vaccine Bacille Calmette-Guerin (BCG) is not understood. In this study, we investigated whether epigenetic mechanisms are involved in the response of immune cells to the BCG vaccine. We isolated peripheral blood mononuclear cells (PBMCs) from BCG-vaccinated subjects and performed global DNA methylation analysis in combination with functional assays representative of innate immunity against Mycobacterium tuberculosis infection. Enhanced containment of replication was observed in monocyte-derived macrophages from a sub-group of BCG-vaccinated individuals (identified as ‘responders’). A stable and robust differential DNA methylation pattern in response to BCG could be observed in PBMCs isolated from the responders but not from the non-responders. Gene ontology analysis revealed that promoters with altered DNA methylation pattern were strongly enriched among genes belonging to immune pathways in responders, however no enrichments could be observed in the non-responders. Our findings suggest that BCG-induced epigenetic reprogramming of immune cell function can enhance anti-mycobacterial immunity in macrophages. Understanding why BCG induces this response in responders but not in non-responders could provide clues to improvement of TB vaccine efficacy.
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Affiliation(s)
- Deepti Verma
- Division of Microbiology and Molecular Medicine, Linköping University, SE-58185, Linköping, Sweden
| | - Venkata Ramanarao Parasa
- Division of Microbiology and Molecular Medicine, Linköping University, SE-58185, Linköping, Sweden
| | - Johanna Raffetseder
- Division of Microbiology and Molecular Medicine, Linköping University, SE-58185, Linköping, Sweden
| | - Mihaela Martis
- NBIS (National Bioinformatics Infrastructure Sweden), ScilifeLab, Division of Cell Biology, Department of Clinical and Experimental Medicine, Faculty of Medicine and Health Sciences, Linköping University, SE-581 85, Linköping, Sweden
| | - Ratnesh B Mehta
- Clinical Immunology, Department of Clinical and Experimental Medicine, Faculty of Medicine and Health Sciences, Linköping University, SE-58185, Linköping, Sweden
| | - Mihai Netea
- Department of Internal Medicine, Radboud University Medical Center, Geert Grooteplein 8, Nijmegen, The Netherlands
| | - Maria Lerm
- Division of Microbiology and Molecular Medicine, Linköping University, SE-58185, Linköping, Sweden.
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28
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Abstract
The interaction between the host and the pathogen is extremely complex and is affected by anatomical, physiological, and immunological diversity in the microenvironments, leading to phenotypic diversity of the pathogen. Phenotypic heterogeneity, defined as nongenetic variation observed in individual members of a clonal population, can have beneficial consequences especially in fluctuating stressful environmental conditions. This is all the more relevant in infections caused by Mycobacterium tuberculosis wherein the pathogen is able to survive and often establish a lifelong persistent infection in the host. Recent studies in tuberculosis patients and in animal models have documented the heterogeneous and diverging trajectories of individual lesions within a single host. Since the fate of the individual lesions appears to be determined by the local tissue environment rather than systemic response of the host, studying this heterogeneity is very relevant to ensure better control and complete eradication of the pathogen from individual lesions. The heterogeneous microenvironments greatly enhance M. tuberculosis heterogeneity influencing the growth rates, metabolic potential, stress responses, drug susceptibility, and eventual lesion resolution. Single-cell approaches such as time-lapse microscopy using microfluidic devices allow us to address cell-to-cell variations that are often lost in population-average measurements. In this review, we focus on some of the factors that could be considered as drivers of phenotypic heterogeneity in M. tuberculosis as well as highlight some of the techniques that are useful in addressing this issue.
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29
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Kalsum S, Braian C, Koeken VACM, Raffetseder J, Lindroth M, van Crevel R, Lerm M. The Cording Phenotype of Mycobacterium tuberculosis Induces the Formation of Extracellular Traps in Human Macrophages. Front Cell Infect Microbiol 2017; 7:278. [PMID: 28695112 PMCID: PMC5483443 DOI: 10.3389/fcimb.2017.00278] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 06/06/2017] [Indexed: 12/14/2022] Open
Abstract
The causative agent of tuberculosis, Mycobacterium tuberculosis, shares several characteristics with organisms that produce biofilms during infections. One of these is the ability to form tight bundles also known as cords. However, little is known of the physiological relevance of the cording phenotype. In this study, we investigated whether cord-forming M. tuberculosis induce the formation of macrophage extracellular traps (METs) in human monocyte-derived macrophages. Macrophages have previously been shown to produce extracellular traps in response to various stimuli. We optimized bacterial culturing conditions that favored the formation of the cord-forming phenotype as verified by scanning electron microscopy. Microscopy analysis of METs formation during experimental infection of macrophages with M. tuberculosis revealed that cord-forming M. tuberculosis induced significantly more METs compared to the non-cording phenotype. Deletion of early secreted antigenic target-6 which is an important virulence factor of M. tuberculosis, abrogated the ability of the bacteria to induce METs. The release of extracellular DNA from host cells during infection may represent a defense mechanism against pathogens that are difficult to internalize, including cord-forming M. tuberculosis.
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Affiliation(s)
- Sadaf Kalsum
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping UniversityLinköping, Sweden
| | - Clara Braian
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping UniversityLinköping, Sweden
| | - Valerie A C M Koeken
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping UniversityLinköping, Sweden.,Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical CenterNijmegen, Netherlands
| | - Johanna Raffetseder
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping UniversityLinköping, Sweden
| | - Margaretha Lindroth
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping UniversityLinköping, Sweden
| | - Reinout van Crevel
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical CenterNijmegen, Netherlands
| | - Maria Lerm
- Division of Microbiology and Molecular Medicine, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping UniversityLinköping, Sweden
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30
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Peddireddy V, Doddam SN, Ahmed N. Mycobacterial Dormancy Systems and Host Responses in Tuberculosis. Front Immunol 2017; 8:84. [PMID: 28261197 PMCID: PMC5309233 DOI: 10.3389/fimmu.2017.00084] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 01/18/2017] [Indexed: 12/15/2022] Open
Abstract
Tuberculosis (TB) caused by the intracellular pathogen, Mycobacterium tuberculosis (Mtb), claims more than 1.5 million lives worldwide annually. Despite promulgation of multipronged strategies to prevent and control TB, there is no significant downfall occurring in the number of new cases, and adding to this is the relapse of the disease due to the emergence of antibiotic resistance and the ability of Mtb to remain dormant after primary infection. The pathology of Mtb is complex and largely attributed to immune-evading strategies that this pathogen adopts to establish primary infection, its persistence in the host, and reactivation of pathogenicity under favorable conditions. In this review, we present various biochemical, immunological, and genetic strategies unleashed by Mtb inside the host for its survival. The bacterium enables itself to establish a niche by evading immune recognition via resorting to masking, establishment of dormancy by manipulating immune receptor responses, altering innate immune cell fate, enhancing granuloma formation, and developing antibiotic tolerance. Besides these, the regulatory entities, such as DosR and its regulon, encompassing various putative effector proteins play a vital role in maintaining the dormant nature of this pathogen. Further, reactivation of Mtb allows relapse of the disease and is favored by the genes of the Rtf family and the conditions that suppress the immune system of the host. Identification of target genes and characterizing the function of their respective antigens involved in primary infection, dormancy, and reactivation would likely provide vital clues to design novel drugs and/or vaccines for the control of dormant TB.
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Affiliation(s)
- Vidyullatha Peddireddy
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, University of Hyderabad , Hyderabad , India
| | - Sankara Narayana Doddam
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, University of Hyderabad , Hyderabad , India
| | - Niyaz Ahmed
- Pathogen Biology Laboratory, Department of Biotechnology and Bioinformatics, University of Hyderabad, Hyderabad, India; Laboratory Sciences and Services Division, International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), Dhaka, Bangladesh
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31
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Aira N, Andersson AM, Singh SK, McKay DM, Blomgran R. Species dependent impact of helminth-derived antigens on human macrophages infected with Mycobacterium tuberculosis: Direct effect on the innate anti-mycobacterial response. PLoS Negl Trop Dis 2017; 11:e0005390. [PMID: 28192437 PMCID: PMC5325601 DOI: 10.1371/journal.pntd.0005390] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 02/24/2017] [Accepted: 02/06/2017] [Indexed: 02/05/2023] Open
Abstract
Background In countries with a high prevalence of tuberculosis there is high coincident of helminth infections that might worsen disease outcome. While Mycobacterium tuberculosis (Mtb) gives rise to a pro-inflammatory Th1 response, a Th2 response is typical of helminth infections. A strong Th2 response has been associated with decreased protection against tuberculosis. Principal findings We investigated the direct effect of helminth-derived antigens on human macrophages, hypothesizing that helminths would render macrophages less capable of controlling Mtb. Measuring cytokine output, macrophage surface markers with flow cytometry, and assessing bacterial replication and phagosomal maturation revealed that antigens from different species of helminth directly affect macrophage responses to Mtb. Antigens from the tapeworm Hymenolepis diminuta and the nematode Trichuris muris caused an anti-inflammatory response with M2-type polarization, reduced macrophage phagosome maturation and ability to activate T cells, along with increased Mtb burden, especially in T. muris exposed cells which also induced the highest IL-10 production upon co-infection. However, antigens from the trematode Schistosoma mansoni had the opposite effect causing a decrease in IL-10 production, M1-type polarization and increased control of Mtb. Conclusion We conclude that, independent of any adaptive immune response, infection with helminth parasites, in a species-specific manner can influence the outcome of tuberculosis by either enhancing or diminishing the bactericidal function of macrophages. The innate immune system is the first response against invading pathogens like the bacterium Mycobacterium tuberculosis (Mtb) or parasitic worms (helminths). The adaptive immune response takes over after being primed by the innate immune response. Infection with Mycobacterium tuberculosis typically gives rise to a pro-inflammatory T-helper(Th)-1 response while helminths promote a Th2 response which is needed to combat the infection. Co-infection with both of these pathogens could lead to reduced immunity contributing to worsening of tuberculosis due to an increased Th2 response caused by helminths. We found that antigens from different helminth species (a nematode, a cestode and a trematode) caused different responses towards Mtb in macrophages. Depending on the helminth species, the macrophages can be more or less capable of combating Mtb infection and priming the adaptive immune response, which in turn would influence the outcome of tuberculosis. Thus, exposure to helminth antigens, in a species-dependent manner, could lead to a better control of Mtb infection or worsening of tuberculosis.
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Affiliation(s)
- Naomi Aira
- Division of Medical Microbiology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
| | - Anna-Maria Andersson
- Division of Medical Microbiology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
| | - Susmita K. Singh
- Division of Medical Microbiology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
| | - Derek M. McKay
- Gastrointestinal Research Group, Department of Physiology and Pharmacology, Snyder Institute for Chronic Disease, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Robert Blomgran
- Division of Medical Microbiology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
- * E-mail:
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32
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Giovagnoli S, Schoubben A, Ricci M. The long and winding road to inhaled TB therapy: not only the bug’s fault. Drug Dev Ind Pharm 2017; 43:347-363. [DOI: 10.1080/03639045.2016.1272119] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Stefano Giovagnoli
- Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| | - Aurelie Schoubben
- Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
| | - Maurizio Ricci
- Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy
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33
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Abstract
BACKGROUND Tuberculosis (TB) of the gastrointestinal tract and any other organ within the abdominal cavity is abdominal TB, and most guidelines recommend the same six-month regimen used for pulmonary TB for people with this diagnosis. However, some physicians are concerned whether a six-month treatment regimen is long enough to prevent relapse of the disease, particularly in people with gastrointestinal TB, which may sometimes cause antituberculous drugs to be poorly absorbed. On the other hand, longer regimens are associated with poor adherence, which could increase relapse, contribute to drug resistance developing, and increase costs to patients and health providers. OBJECTIVES To compare six-month versus longer drug regimens to treat people that have abdominal TB. SEARCH METHODS We searched the following electronic databases up to 2 September 2016: the Cochrane Infectious Diseases Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Embase (accessed via OvidSP), LILACS, INDMED, and the South Asian Database of Controlled Clinical Trials. We searched the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) and ClinicalTrials.gov for ongoing trials. We also checked article reference lists. SELECTION CRITERIA We included randomized controlled trials (RCTs) that compared six-month regimens versus longer regimens that consisted of isoniazid, rifampicin, pyrazinamide, and ethambutol to treat adults and children that had abdominal TB. The primary outcomes were relapse, with a minimum of six-month follow-up after completion of antituberculous treatment (ATT), and clinical cure at the end of ATT. DATA COLLECTION AND ANALYSIS Two review authors independently selected trials, extracted data, and assessed the risk of bias in the included trials. For analysis of dichotomous outcomes, we used risk ratios (RR) with 95% confidence intervals (CIs). Where appropriate, we pooled data from the included trials in meta-analyses. We assessed the quality of the evidence using the GRADE approach. MAIN RESULTS We included three RCTs, with 328 participants, that compared six-month regimens with nine-month regimens to treat adults with intestinal and peritoneal TB. All trials were conducted in Asia, and excluded people with HIV, those with co-morbidities and those who had received ATT in the previous five years. Antituberculous regimens were based on isoniazid, rifampicin, pyrazinamide, and ethambutol, and these drugs were administered daily or thrice weekly under a directly observed therapy programme. The median duration of follow-up after completion of treatment was between 12 and 39 months.Relapse was uncommon, with two cases among 140 participants treated for six months, and no events among 129 participants treated for nine months. The small number of participants means we do not know whether or not there is a difference in risk of relapse between the two regimens (very low quality evidence). At the end of therapy, there was probably no difference in the proportion of participants that achieved clinical cure between six-month and nine-month regimens (RR 1.02, 95% CI 0.97 to 1.08; 294 participants, 3 trials, moderate quality evidence). For death, there were 2/150 (1.3%) in the six-month group and 4/144 (2.8%) in the nine-month group. All deaths occurred in the first four months of treatment, so was not linked to the duration of treatment in the included trials. Similarly, the number of participants that defaulted from treatment was small in both groups, and there may be no difference between them (RR 0.50, 95% CI 0.10 to 2.59; 294 participants, 3 trials, low quality evidence). Only one trial reported on adherence to treatment, with only one participant allocated to the nine-month regimen presenting poor adherence to treatment. We do not know whether six-month regimens are associated with fewer people experiencing adverse events that lead to treatment interruption (RR 0.53, 95% CI 0.18 to 1.55; 318 participants, 3 trials, very low quality evidence). AUTHORS' CONCLUSIONS We found no evidence to suggest that six-month treatment regimens are inadequate for treating people that have intestinal and peritoneal TB, but numbers are small. We did not find any incremental benefits of nine-month regimens regarding relapse at the end of follow-up, or clinical cure at the end of therapy, but our confidence in the relapse estimate is very low because of size of the trials. Further research is required to make confident conclusions regarding the safety of six-month treatment for people with abdominal TB. Larger studies that include HIV-positive people, with long follow-up for detecting relapse with reliability, would help improve our knowledge around this therapeutic question.
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Affiliation(s)
- Sophie Jullien
- Liverpool School of Tropical MedicineDepartment of Clinical SciencesPembroke PlaceLiverpoolUK
| | - Siddharth Jain
- All India Institute of Medical SciencesDepartment of Internal MedicineNew DelhiIndia
| | - Hannah Ryan
- Liverpool School of Tropical MedicineDepartment of Clinical SciencesPembroke PlaceLiverpoolUK
| | - Vineet Ahuja
- All India Institute of Medical SciencesDepartment of GastroenterologyAnsari NagarNew DelhiIndia110029
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Autophagy induction targeting mTORC1 enhances Mycobacterium tuberculosis replication in HIV co-infected human macrophages. Sci Rep 2016; 6:28171. [PMID: 27302320 PMCID: PMC4908603 DOI: 10.1038/srep28171] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 05/31/2016] [Indexed: 12/30/2022] Open
Abstract
To survive and replicate in macrophages Mycobacterium tuberculosis (Mtb) has developed strategies to subvert host defence mechanisms, including autophagy. Autophagy induction has the potential to clear Mtb, but little is known about its effect during controlled tuberculosis and HIV co-infection. Mammalian target of rapamycin complex1 (mTORC1) inhibitors were used to induce autophagy in human macrophages pre-infected with HIV-1BaL and infected with a low dose of Mtb (co-infected), or single Mtb infected (single infected). The controlled Mtb infection was disrupted upon mTOR inhibition resulting in increased Mtb replication in a dose-dependent manner which was more pronounced during co-infection. The increased Mtb replication could be explained by the marked reduction in phagosome acidification upon mTOR inhibition. Autophagy stimulation targeting mTORC1 clearly induced a basal autophagy with flux that was unlinked to the subcellular environment of the Mtb vacuoles, which showed a concurrent suppression in acidification and maturation/flux. Overall our findings indicate that mTOR inhibition during Mtb or HIV/Mtb co-infection interferes with phagosomal maturation, thereby supporting mycobacterial growth during low-dose and controlled infection. Therefore pharmacological induction of autophagy through targeting of the canonical mTORC1-pathway should be handled with caution during controlled tuberculosis, since this could have serious consequences for patients with HIV/Mtb co-infection.
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McDaniel MM, Krishna N, Handagama WG, Eda S, Ganusov VV. Quantifying Limits on Replication, Death, and Quiescence of Mycobacterium tuberculosis in Mice. Front Microbiol 2016; 7:862. [PMID: 27379030 PMCID: PMC4906525 DOI: 10.3389/fmicb.2016.00862] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 05/23/2016] [Indexed: 02/02/2023] Open
Abstract
When an individual is exposed to Mycobacterium tuberculosis (Mtb) three outcomes are possible: bacterial clearance, active disease, or latent infection. It is generally believed that most individuals exposed to Mtb become latently infected and carry the mycobacteria for life. How Mtb is maintained during this latent infection remains largely unknown. During an Mtb infection in mice, there is a phase of rapid increase in bacterial numbers in the murine lungs within the first 3 weeks, and then bacterial numbers either stabilize or increase slowly over the period of many months. It has been debated whether the relatively constant numbers of bacteria in the chronic infection result from latent (dormant, quiescent), non-replicating bacteria, or whether the observed Mtb cell numbers are due to balance between rapid replication and death. A recent study of mice, infected with a Mtb strain carrying an unstable plasmid, showed that during the chronic phase, Mtb was replicating at significant rates. Using experimental data from this study and mathematical modeling we investigated the limits of the rates of bacterial replication, death, and quiescence during Mtb infection of mice. First, we found that to explain the data the rates of bacterial replication and death could not be constant and had to decrease with time since infection unless there were large changes in plasmid segregation probability over time. While a decrease in the rate of Mtb replication with time since infection was expected due to depletion of host's resources, a decrease in the Mtb death rate was counterintuitive since Mtb-specific immune response, appearing in the lungs 3–4 weeks after infection, should increase removal of bacteria. Interestingly, we found no significant correlation between estimated rates of Mtb replication and death suggesting the decline in these rates was driven by independent mechanisms. Second, we found that the data could not be explained by assuming that bacteria do not die, suggesting that some removal of bacteria from lungs of these mice had to occur even though the total bacterial counts in these mice always increased over time. Third and finally, we showed that to explain the data the majority of bacterial cells (at least ~60%) must be replicating in the chronic phase of infection further challenging widespread belief of nonreplicating Mtb in latency. Our predictions were robust to some changes in the structure of the model, for example, when the loss of plasmid-bearing cells was mainly due to high fitness cost of the plasmid. Further studies should determine if more mechanistic models for Mtb dynamics are also able to accurately explain these data.
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Affiliation(s)
- Margaret M McDaniel
- National Institute for Mathematical and Biological SynthesisKnoxville, TN, USA; Department of Biochemistry, Cellular and Molecular Biology, University of TennesseeKnoxville, TN, USA; Department of Mathematics, University of TennesseeKnoxville, TN, USA
| | - Nitin Krishna
- National Institute for Mathematical and Biological SynthesisKnoxville, TN, USA; The College at the University of ChicagoChicago, IL, USA
| | - Winode G Handagama
- National Institute for Mathematical and Biological SynthesisKnoxville, TN, USA; Departments of Chemistry and Mathematics, Maryville CollegeMaryville, TN, USA
| | - Shigetoshi Eda
- National Institute for Mathematical and Biological SynthesisKnoxville, TN, USA; Department of Forestry, Wildlife and Fisheries, University of TennesseeKnoxville, TN, USA
| | - Vitaly V Ganusov
- National Institute for Mathematical and Biological SynthesisKnoxville, TN, USA; Department of Mathematics, University of TennesseeKnoxville, TN, USA; Department of Microbiology, University of TennesseeKnoxville, TN, USA
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Jullien S, Jain S, Ryan H, Ahuja V. Six months therapy for abdominal tuberculosis. THE COCHRANE DATABASE OF SYSTEMATIC REVIEWS 2016. [DOI: 10.1002/14651858.cd012163] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Mouton JM, Helaine S, Holden DW, Sampson SL. Elucidating population-wide mycobacterial replication dynamics at the single-cell level. MICROBIOLOGY-SGM 2016; 162:966-978. [PMID: 27027532 PMCID: PMC5042079 DOI: 10.1099/mic.0.000288] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Mycobacterium tuberculosis infections result in a spectrum of clinical outcomes, and frequently the infection persists in a latent, clinically asymptomatic state. The within-host bacterial population is likely to be heterogeneous, and it is thought that persistent mycobacteria arise from a small population of viable, but non-replicating (VBNR) cells. These are likely to be antibiotic tolerant and necessitate prolonged treatment. Little is known about these persistent mycobacteria, since they are very difficult to isolate. To address this, we have successfully developed a replication reporter system for use in M. tuberculosis. This approach, termed fluorescence dilution, exploits two fluorescent reporters; a constitutive reporter allows the tracking of bacteria, while an inducible reporter enables the measurement of bacterial replication. The application of fluorescence single-cell analysis to characterize intracellular M. tuberculosis identified a distinct subpopulation of non-growing mycobacteria in murine macrophages. The presence of VBNR and actively replicating mycobacteria was observed within the same macrophage after 48 h of infection. Furthermore, our results suggest that macrophage uptake resulted in enrichment of non- or slowly replicating bacteria (as revealed by d-cycloserine treatment); this population is likely to be highly enriched for persisters, based on its drug-tolerant phenotype. These results demonstrate the successful application of the novel dual fluorescence reporter system both in vitro and in macrophage infection models to provide a window into mycobacterial population heterogeneity.
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Affiliation(s)
- Jacoba M Mouton
- DST/NRF Centre of Excellence for Biomedical Tuberculosis Research/SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Sophie Helaine
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - David W Holden
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Samantha L Sampson
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK.,DST/NRF Centre of Excellence for Biomedical Tuberculosis Research/SA MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
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