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Painter H, Harriss E, Fletcher HA, McShane H, Tanner R. Development and application of the direct mycobacterial growth inhibition assay: a systematic review. Front Immunol 2024; 15:1355983. [PMID: 38380319 PMCID: PMC10877019 DOI: 10.3389/fimmu.2024.1355983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 01/17/2024] [Indexed: 02/22/2024] Open
Abstract
Introduction First described by Wallis et al. in 2001 for the assessment of TB drugs, the direct mycobacterial growth inhibition assay (MGIA) offers a tractable ex vivo tool measuring the combined influences of host immunity, strain virulence and intervention effects. Over the past 13 years, we have led efforts to adapt the direct MGIA for the assessment of TB vaccines including optimisation, harmonisation and validation of BCG vaccine-induced responses as a benchmark, as well as assay transfer to institutes worldwide. Methods We have performed a systematic review on the primary published literature describing the development and applications of the direct MGIA from 2001 to June 2023 in accordance with the PRISMA reporting guidelines. Results We describe 63 studies in which the direct MGIA has been applied across species for the evaluation of TB drugs and novel TB vaccine candidates, the study of clinical cohorts including those with comorbidities, and to further understanding of potential immune correlates of protection from TB. We provide a comprehensive update on progress of the assay since its conception and critically evaluate current findings and evidence supporting its utility, highlighting priorities for future directions. Discussion While further standardisation and validation work is required, significant advancements have been made in the past two decades. The direct MGIA provides a potentially valuable tool for the early evaluation of TB drug and vaccine candidates, clinical cohorts, and immune mechanisms of mycobacterial control. Systematic review registration https://www.crd.york.ac.uk/prospero/, identifier CRD42023423491.
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Affiliation(s)
- Hannah Painter
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Eli Harriss
- Bodleian Health Care Libraries, University of Oxford, Oxford, United Kingdom
| | - Helen A. Fletcher
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Helen McShane
- Nuffield Department of Medicine, Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Rachel Tanner
- Department of Biology, University of Oxford, Oxford, United Kingdom
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2
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Venkataraman A, Shanmugam S, Balaji S, Mani K, Shanmugavel AK, Muthuramalingam K, Hissar S, Thiruvengadam K, Selladurai E, Smuk M, Hanna LE, Prendergast AJ. Comparison of two mycobacterial strains in performance of the whole blood mycobacterial growth inhibition assay in Indian children. Tuberculosis (Edinb) 2022; 137:102255. [PMID: 36252397 DOI: 10.1016/j.tube.2022.102255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 08/23/2022] [Accepted: 08/25/2022] [Indexed: 01/24/2023]
Abstract
A major challenge in tuberculosis is identifying correlates of a protective immune response. The Mycobacterial Growth Inhibition Assay (MGIA) is a functional assay providing an integrated measure of the host immune response to mycobacteria. However, its feasibility is limited by reliance on biosafety level 3 facilities, and its performance has not been widely evaluated in TB-endemic settings. Here, we compared two mycobacterial strains (M. tuberculosis H37Rv versus attenuated M. bovis BCG) in the performance of whole-blood MGIA in 30 TB-exposed children (median age 2 years) in Chennai, India. The time-to-positivity in both assays was similar (5.7 days vs 6 days) and the mycobacterial growth of M. tuberculosis H37Rv and M. bovis BCG were correlated (r = 0.64, p<0.0001). In Bland-Altman analysis, the bias was -0.54 days (95% limit of agreement -2.08, 0.99). Collectively, our results indicate that M. tuberculosis H37Rv can be substituted with the less virulent M. bovis BCG strain to improve feasibility of the MGIA assay, particularly in low-income settings.
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Affiliation(s)
- Aishwarya Venkataraman
- ICMR(-)National Institute for Research in Tuberculosis, Chennai, India; Blizard Institute, Queen Mary University of London, London, UK.
| | | | - Sarath Balaji
- Institute of Child Health, Madras Medical College, Chennai, India
| | - Karthick Mani
- ICMR(-)National Institute for Research in Tuberculosis, Chennai, India
| | | | | | - Syed Hissar
- ICMR(-)National Institute for Research in Tuberculosis, Chennai, India
| | | | | | - Melanie Smuk
- Blizard Institute, Queen Mary University of London, London, UK
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3
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Wallis RS, Ginindza S, Beattie T, Arjun N, Likoti M, Sebe M, Edward VA, Rassool M, Ahmed K, Fielding K, Ahidjo BA, Vangu MDT, Churchyard G. Lung and blood early biomarkers for host-directed tuberculosis therapies: Secondary outcome measures from a randomized controlled trial. PLoS One 2022; 17:e0252097. [PMID: 35120127 PMCID: PMC8815935 DOI: 10.1371/journal.pone.0252097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 05/03/2021] [Indexed: 11/18/2022] Open
Abstract
Background
Current tuberculosis treatments leave most patients with bronchiectasis and fibrosis, permanent conditions that impair lung function and increase all-cause post-TB mortality. Host-directed therapies (HDTs) may reduce lung inflammation and hasten eradication of infection. Biomarkers can accelerate tuberculosis regimen development, but no studies have yet examined early biomarkers of TB-HDTs.
Methods
Biomarkers of inflammation and microbicidal activity were evaluated as a part of a recent phase-2 randomized controlled trial of four HDTs in 200 patients with pulmonary tuberculosis and baseline predictors of poor outcome, including CC-11050 (PDE4i), everolimus (mTORi), auranofin (oral gold salt), and ergocalciferol (vitamin D). Two of the 4 arms (CC-11050 and everolimus) showed superior recovery of lung function at day 180 compared to control; none showed accelerated eradication of MTB infection. Patients underwent 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) on entry and day 56. PET signals were analyzed according to total, maximal, and peak glycolytic activity; CT was analyzed according to total modified Hounsfield units to assess radiodensity. Mycobactericidal activity in ex vivo whole blood culture was measured on days 42, 84, and 140. C-reactive protein (CRP) was measured at multiple time points.
Results
All PET/CT parameters showed highly significant reductions from baseline to day 56; however, only maximal or peak glycolytic activity showed further experimental reduction compared to controls, and only in everolimus recipients. CRP dropped precipitously during early treatment, but did so equally in all arms; over the entire period of treatment, the rate of decline of CRP tended to be greater in CC-11050 recipients than in controls but this fell short of statistical significance. Whole blood mycobactericidal activity in ex-vivo culture was enhanced by auranofin compared to controls, but not by other HDTs.
Conclusions
None of these early biomarkers correctly predicted HDT effects on inflammation or infection across all four experimental arms. Instead, they each appear to show highly specific responses related to HDT mechanisms of action.
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Affiliation(s)
- Robert S. Wallis
- Aurum Institute, Johannesburg, South Africa
- School of Medicine, Vanderbilt University, Nashville, Tennessee, United States of America
- School of Medicine, Case Western Reserve University, Cleveland, Ohio, United States of America
- * E-mail:
| | | | - Trevor Beattie
- Aurum Institute, Johannesburg, South Africa
- Department of Interdisciplinary Social Science, School of Public Health, Utrecht University, Utrecht, The Netherlands
| | | | | | | | - Vinodh A. Edward
- Aurum Institute, Johannesburg, South Africa
- Department of Interdisciplinary Social Science, School of Public Health, Utrecht University, Utrecht, The Netherlands
- Yale School of Public Health, Yale University, New Haven, Connecticut, United States of America
- Schools of Pathology (VAE) and Medicine (MDTV), University of the Witwatersrand, Johannesburg, South Africa
| | - Mohammed Rassool
- Schools of Pathology (VAE) and Medicine (MDTV), University of the Witwatersrand, Johannesburg, South Africa
- Clinical HIV Research Unit, Johannesburg, South Africa
| | | | - Katherine Fielding
- Department of Medical Statistics and Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Mboyo D. T. Vangu
- Schools of Pathology (VAE) and Medicine (MDTV), University of the Witwatersrand, Johannesburg, South Africa
| | - Gavin Churchyard
- Aurum Institute, Johannesburg, South Africa
- Department of Medical Statistics and Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
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4
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Setiabudiawan TP, Reurink RK, Hill PC, Netea MG, van Crevel R, Koeken VACM. Protection against tuberculosis by Bacillus Calmette-Guérin (BCG) vaccination: A historical perspective. MED 2022; 3:6-24. [PMID: 35590145 DOI: 10.1016/j.medj.2021.11.006] [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: 09/22/2021] [Revised: 11/17/2021] [Accepted: 11/18/2021] [Indexed: 01/23/2023]
Abstract
Bacillus Calmette-Guérin (BCG) was developed exactly 100 years ago, and it is still the only licensed tuberculosis (TB) vaccine and the most frequently administered of all vaccines worldwide. Despite universal vaccination policies in TB-endemic settings, the burden of TB remains high. Although BCG protects against Mycobacterium tuberculosis infection and TB disease, the level of protection varies greatly between age groups and settings. In this review, we present a historical perspective and describe the evidence for BCG's ability to protect against TB as well as the factors that influence protection. We also present the immunological mechanisms through which BCG vaccination induces protection, focusing on T cell, B cell, and innate immunity. Finally, we discuss several possibilities to boost BCG's efficacy, including alternative vaccination routes, BCG revaccination, and use of recombinant BCG vaccines, and describe the knowledge gaps that exist with respect to BCG's protection against TB.
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Affiliation(s)
- Todia P Setiabudiawan
- Department of Internal Medicine and Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, Gelderland 6525 GA, the Netherlands
| | - Remi K Reurink
- Department of Internal Medicine and Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, Gelderland 6525 GA, the Netherlands
| | - Philip C Hill
- Centre for International Health, University of Otago, Dunedin, North Dunedin 9016, New Zealand
| | - Mihai G Netea
- Department of Internal Medicine and Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, Gelderland 6525 GA, the Netherlands; Human Genomics Laboratory, Craiova University of Medicine and Pharmacy, Craiova, Județul Dolj 200349, Romania
| | - Reinout van Crevel
- Department of Internal Medicine and Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, Gelderland 6525 GA, the Netherlands; Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Valerie A C M Koeken
- Department of Internal Medicine and Radboud Center for Infectious Diseases (RCI), Radboud University Medical Center, Nijmegen, Gelderland 6525 GA, the Netherlands; Department of Computational Biology for Individualised Infection Medicine, Centre for Individualised Infection Medicine (CiiM), a joint venture between the Helmholtz-Centre for Infection Research (HZI) and the Hannover Medical School (MHH), Hannover 30625, Germany; TWINCORE, a joint venture between the Helmholtz-Centre for Infection Research (HZI) and the Hannover Medical School (MHH), Hannover 30625, Germany.
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5
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Stringari LL, Covre LP, da Silva FDC, de Oliveira VL, Campana MC, Hadad DJ, Palaci M, Salgame P, Dietze R, Gomes DCDO, Ribeiro-Rodrigues R. Increase of CD4+CD25highFoxP3+ cells impairs in vitro human microbicidal activity against Mycobacterium tuberculosis during latent and acute pulmonary tuberculosis. PLoS Negl Trop Dis 2021; 15:e0009605. [PMID: 34324509 PMCID: PMC8321116 DOI: 10.1371/journal.pntd.0009605] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 06/29/2021] [Indexed: 11/23/2022] Open
Abstract
Background Regulatory T cells (Tregs) play a critical role during Mycobacterium tuberculosis (Mtb) infection, modulating host responses while neutralizing excessive inflammation. However, their impact on regulating host protective immunity is not completely understood. Here, we demonstrate that Treg cells abrogate the in vitro microbicidal activity against Mtb. Methods We evaluated the in vitro microbicidal activity of peripheral blood mononuclear cells (PBMCs) from patients with active tuberculosis (TB), individuals with latent tuberculosis infection (LTBI, TST+/IGRA+) and healthy control (HC, TST-/IGRA-) volunteers. PBMCs, depleted or not of CD4+CD25+ T-cells, were analyzed to determine frequency and influence on microbicidal activity during in vitro Mtb infection with four clinical isolates (S1, S5, R3, and R6) and one reference strain (H37Rv). Results The frequency of CD4+CD25highFoxP3+ cells were significantly higher in Mtb infected whole blood cultures from both TB patients and LTBI individuals when compared to HC. Data from CD4+CD25+ T-cells depletion demonstrate that increase of CD4+CD25highFoxP3+ is associated with an impairment of Th-1 responses and a diminished in vitro microbicidal activity of LTBI and TB groups. Conclusions Tregs restrict host anti-mycobacterial immunity during active disease and latent infection and thereby may contribute to both disease progression and pathogen persistence. Our immune system has an enormous capacity of recognizing and responding to foreign antigens and, likewise, presents an extremely efficient mechanism of controlling these responses. Here, we investigated how a specific cell type with regulatory abilities can interfere in the immunological response against tuberculosis bacillus. For this, we used blood samples from individuals sensitized with the bacillus and patients with active pulmonary tuberculosis to understand how these cells act and their impact on the host/parasite relationship in the development of the disease. We could observe the negative impact that such regulatory cells cause during the immune response against Mycobacterium tuberculosis, decreasing the control/elimination of the bacillus in asymptomatic individuals and patients with tuberculosis. We also observed a recovery in the immune response when Treg cells were removed during in vitro challenge, restoring the capacity of Mtb clearance. Thus, these regulatory cells, when present, may represent a possible facilitator of the asymptomatic permanence of the bacillus, or even of the development of the disease itself. These data allowed us to see latency and tuberculosis from a new angle and thus postulate new approaches to fight tuberculosis.
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Affiliation(s)
- Lorenzzo Lyrio Stringari
- Núcleo de Doenças Infecciosas, Universidade Federal do Espírito Santo, Vitória, Brazil
- * E-mail: (LLS); (RR-R)
| | - Luciana Polaco Covre
- Núcleo de Doenças Infecciosas, Universidade Federal do Espírito Santo, Vitória, Brazil
| | | | | | | | - David Jamil Hadad
- Núcleo de Doenças Infecciosas, Universidade Federal do Espírito Santo, Vitória, Brazil
| | - Moisés Palaci
- Núcleo de Doenças Infecciosas, Universidade Federal do Espírito Santo, Vitória, Brazil
| | - Padmini Salgame
- Center for Emerging Pathogens, Rutgers-New Jersey Medical School, International Center for Public Health, Newark, New Jersey, United States of America
| | - Reynaldo Dietze
- Núcleo de Doenças Infecciosas, Universidade Federal do Espírito Santo, Vitória, Brazil
- Global Health & Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Daniel Cláudio de Oliveira Gomes
- Núcleo de Doenças Infecciosas, Universidade Federal do Espírito Santo, Vitória, Brazil
- Núcleo de Biotecnologia, Universidade Federal do Espírito Santo, Vitória, Brazil
| | - Rodrigo Ribeiro-Rodrigues
- Núcleo de Doenças Infecciosas, Universidade Federal do Espírito Santo, Vitória, Brazil
- * E-mail: (LLS); (RR-R)
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6
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Bobadilla-Del-Valle M, Leal-Vega F, Torres-Gonzalez P, Ordaz-Vazquez A, Garcia-Garcia MDL, Tovar-Vargas MDLA, Delgado-Sanchez G, Guerra De Blas PDC, Wallis RS, Ponce-De-León A, Sifuentes-Osornio J. Mycobacterial Growth Inhibition Assay (MGIA) as a Host Directed Diagnostic Tool for the Evaluation of the Immune Response in Subjects Living With Type 2 Diabetes Mellitus. Front Cell Infect Microbiol 2021; 11:640707. [PMID: 34084753 PMCID: PMC8167894 DOI: 10.3389/fcimb.2021.640707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 04/27/2021] [Indexed: 11/13/2022] Open
Abstract
The lack of efficient and cost-effective diagnostic tools contributes to poor control of tuberculosis in endemic countries. Moreover, host biological processes influence susceptibility, and infection resolution. It is well known that comorbidities such as type 2 diabetes mellitus (DM2) affect the host immune response, making individuals more susceptible to Mycobacterium tuberculosis infection. Currently, there are no laboratory tools that can identify those subjects who have a higher risk of developing the disease. In this study, we used a whole blood mycobacterial growth inhibition assay to assess the immune response capacity to inhibit mycobacterial growth between healthy subjects and those living with DM2 with optimal and poor glycemic control. We also measured cytokine levels in the culture supernatant by cytokine bead arrays. We included 89 patients with DM2: 54 patients with optimal control (mean age 56.2 ± 11.75 years) and 35 patients with poor control (mean age 52.05 ± 9.94 years). We also included 44 healthy subjects as controls (mean age 42.12 ± 11.75 years). We compared the Δlog UFC (a value that represents the difference between mycobacterial growth in the control tube versus the subject’s blood) between each group. Our results demonstrate that patients with DM2 had a lower capacity to inhibit M. tuberculosis growth (Δlog UFC DM2 subjects 0.9581 (-0.3897 to 2.495) vs Δlog UFC healthy subjects 0.7190 (-0.2678 to 2.098); p=0.013). Comparing subjects living with DM2 (optimal and poor glycemic control) vs healthy subjects, we found only significant differences between healthy subjects and patients poorly controlled (Δlog UFC optimal control group 0.876 (-0.3897 to 2.495); Δlog UFC poor control group 1.078 (0.068 to 2.33); Δlog UFC healthy subjects 0.7190 (-0.2678 to 2.098); p= 0.022). Therefore, glycemic control assessed by glycosylated hemoglobin values influences the capacity of the host to control the infection. Our results confirm that the whole blood mycobacterial growth inhibition assay has potential utility as an in vitro marker of M. tuberculosis immunological control in vivo in subjects living with DM2. This assay can be used to evaluate the immune response of each individual against M. tuberculosis, allowing clinicians to choose a more specific host-directed therapy.
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Affiliation(s)
- Miriam Bobadilla-Del-Valle
- Laboratorio de Microbiologia Clinica, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, Mexico
| | - Francisco Leal-Vega
- Laboratorio de Microbiologia Clinica, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, Mexico
| | - Pedro Torres-Gonzalez
- Laboratorio de Microbiologia Clinica, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, Mexico
| | - Anabel Ordaz-Vazquez
- Laboratorio de Microbiologia Clinica, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, Mexico
| | | | - Ma de Los Angeles Tovar-Vargas
- Laboratorio de Microbiologia Clinica, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, Mexico
| | - Guadalupe Delgado-Sanchez
- Centro de Investigación sobre Enfermedades Infecciosas, Instituto Nacional de Salud Publica, Cuernavaca, Mexico
| | - Paola Del Carmen Guerra De Blas
- Laboratorio de Microbiologia Clinica, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, Mexico.,LaRed- Coordinating Center, The Mexican Emerging Infectious Diseases Clinical Research Network (La Red), Mexico City, Mexico
| | | | - Alfredo Ponce-De-León
- Laboratorio de Microbiologia Clinica, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, Mexico
| | - José Sifuentes-Osornio
- Laboratorio de Microbiologia Clinica, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City, Mexico
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7
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Bok J, Hofland RW, Evans CA. Whole Blood Mycobacterial Growth Assays for Assessing Human Tuberculosis Susceptibility: A Systematic Review and Meta-Analysis. Front Immunol 2021; 12:641082. [PMID: 34046032 PMCID: PMC8144701 DOI: 10.3389/fimmu.2021.641082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 03/08/2021] [Indexed: 01/20/2023] Open
Abstract
Background Whole blood mycobacterial growth assays (WBMGA) quantify mycobacterial growth in fresh blood samples and may have potential for assessing tuberculosis vaccines and identifying individuals at risk of tuberculosis. We evaluated the evidence for the underlying assumption that in vitro WBMGA results can predict in vivo tuberculosis susceptibility. Methods A systematic search was done for studies assessing associations between WBMGA results and tuberculosis susceptibility. Meta-analyses were performed for eligible studies by calculating population-weighted averages. Results No studies directly assessed whether WBMGA results predicted tuberculosis susceptibility. 15 studies assessed associations between WBMGA results and proven correlates of tuberculosis susceptibility, which we divided in two categories. Firstly, WBMGA associations with factors believed to reduce tuberculosis susceptibility were statistically significant in all eight studies of: BCG vaccination; vitamin D supplementation; altitude; and HIV-negativity/therapy. Secondly, WBMGA associations with probable correlates of tuberculosis susceptibility were statistically significant in three studies of tuberculosis disease, in a parasitism study and in two of the five studies of latent tuberculosis infection. Meta-analyses for associations between WBMGA results and BCG vaccination, tuberculosis infection, tuberculosis disease and HIV infection revealed consistent effects. There was considerable methodological heterogeneity. Conclusions The study results generally showed significant associations between WBMGA results and correlates of tuberculosis susceptibility. However, no study directly assessed whether WBMGA results predicted actual susceptibility to tuberculosis infection or disease. We recommend optimization and standardization of WBMGA methodology and prospective studies to determine whether WBMGA predict susceptibility to tuberculosis disease.
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Affiliation(s)
- Jeroen Bok
- Department of Infectious Disease, Imperial College London, London, United Kingdom.,Innovation for Health and Development (IFHAD), Laboratory of Research and Development, Universidad Peruana Cayetano Heredia, Lima, Peru.,Innovacion Por la Salud Y el Desarrollo (IPSYD), Asociación Benéfica PRISMA, Lima, Peru.,Department of Pulmonology and Tuberculosis, University Medical Center Utrecht, Utrecht, Netherlands
| | - Regina W Hofland
- Department of Pulmonology and Tuberculosis, University Medical Center Utrecht, Utrecht, Netherlands
| | - Carlton A Evans
- Department of Infectious Disease, Imperial College London, London, United Kingdom.,Innovation for Health and Development (IFHAD), Laboratory of Research and Development, Universidad Peruana Cayetano Heredia, Lima, Peru.,Innovacion Por la Salud Y el Desarrollo (IPSYD), Asociación Benéfica PRISMA, Lima, Peru
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8
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Tanner R, Hoogkamer E, Bitencourt J, White A, Boot C, Sombroek CC, Harris SA, O'Shea MK, Wright D, Wittenberg R, Sarfas C, Satti I, Verreck FA, Sharpe SA, Fletcher HA, McShane H. The in vitro direct mycobacterial growth inhibition assay (MGIA) for the early evaluation of TB vaccine candidates and assessment of protective immunity: a protocol for non-human primate cells. F1000Res 2021; 10:257. [PMID: 33976866 PMCID: PMC8097740 DOI: 10.12688/f1000research.51640.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/17/2021] [Indexed: 04/04/2024] Open
Abstract
The only currently available approach to early efficacy testing of tuberculosis (TB) vaccine candidates is in vivo preclinical challenge models. These typically include mice, guinea pigs and non-human primates (NHPs), which must be exposed to virulent M.tb in a 'challenge' experiment following vaccination in order to evaluate protective efficacy. This procedure results in disease development and is classified as 'Moderate' in severity under EU legislation and UK ASPA licensure. Furthermore, experiments are relatively long and animals must be maintained in high containment level facilities, making them relatively costly. We describe an in vitro protocol for the direct mycobacterial growth inhibition assay (MGIA) for use in the macaque model of TB vaccine development with the aim of overcoming some of these limitations. Importantly, using an in vitro assay in place of in vivo M.tb challenge represents a significant refinement to the existing procedure for early vaccine efficacy testing. Peripheral blood mononuclear cell and autologous serum samples collected from vaccinated and unvaccinated control animals are co-cultured with mycobacteria in a 48-well plate format for 96 hours. Adherent monocytes are then lysed to release intracellular mycobacteria which is quantified using the BACTEC MGIT system and colony-forming units determined relative to an inoculum control and stock standard curve. We discuss related optimisation and characterisation experiments, and review evidence that the direct NHP MGIA provides a biologically relevant model of vaccine-induced protection. The potential end-users of the NHP MGIA are academic and industry organisations that conduct the assessment of TB vaccine candidates and associated protective immunity using the NHP model. This approach aims to provide a method for high-throughput down-selection of vaccine candidates going forward to in vivo efficacy testing, thus expediting the development of a more efficacious TB vaccine and offering potential refinement and reduction to the use of NHPs for this purpose.
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Affiliation(s)
- Rachel Tanner
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
| | - Emily Hoogkamer
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
- Public Health England, Salisbury, SP4 0JG, UK
| | - Julia Bitencourt
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
- Gonҫalo Moniz Institute, Oswaldo Cruz Foundation (FIOCRUZ), Salvador, 40296-710, Brazil
| | | | - Charelle Boot
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, 2288 GJ, The Netherlands
| | - Claudia C. Sombroek
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, 2288 GJ, The Netherlands
| | | | - Matthew K. O'Shea
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
- Institute of Immunology and Immunotherapy, University of Birmingham, UK, Birmingham, B15 2TH, UK
| | - Daniel Wright
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
| | - Rachel Wittenberg
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
| | | | - Iman Satti
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
| | - Frank A.W. Verreck
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, 2288 GJ, The Netherlands
| | | | - Helen A. Fletcher
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
- London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Helen McShane
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
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9
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Tanner R, Hoogkamer E, Bitencourt J, White A, Boot C, Sombroek CC, Harris SA, O'Shea MK, Wright D, Wittenberg R, Sarfas C, Satti I, Verreck FAW, Sharpe SA, Fletcher HA, McShane H. The in vitro direct mycobacterial growth inhibition assay (MGIA) for the early evaluation of TB vaccine candidates and assessment of protective immunity: a protocol for non-human primate cells. F1000Res 2021; 10:257. [PMID: 33976866 PMCID: PMC8097740.2 DOI: 10.12688/f1000research.51640.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/15/2021] [Indexed: 11/29/2022] Open
Abstract
The only currently available approach to early efficacy testing of tuberculosis (TB) vaccine candidates is in vivo preclinical challenge models. These typically include mice, guinea pigs and non-human primates (NHPs), which must be exposed to virulent M.tb in a 'challenge' experiment following vaccination in order to evaluate protective efficacy. This procedure results in disease development and is classified as 'Moderate' in severity under EU legislation and UK ASPA licensure. Furthermore, experiments are relatively long and animals must be maintained in high containment level facilities, making them relatively costly. We describe an in vitro protocol for the direct mycobacterial growth inhibition assay (MGIA) for use in the macaque model of TB vaccine development with the aim of overcoming some of these limitations. Importantly, using an in vitro assay in place of in vivo M.tb challenge represents a significant refinement to the existing procedure for early vaccine efficacy testing. Peripheral blood mononuclear cell and autologous serum samples collected from vaccinated and unvaccinated control animals are co-cultured with mycobacteria in a 48-well plate format for 96 hours. Adherent monocytes are then lysed to release intracellular mycobacteria which is quantified using the BACTEC MGIT system and colony-forming units determined relative to an inoculum control and stock standard curve. We discuss related optimisation and characterisation experiments, and review evidence that the direct NHP MGIA provides a biologically relevant model of vaccine-induced protection. The potential end-users of the NHP MGIA are academic and industry organisations that conduct the assessment of TB vaccine candidates and associated protective immunity using the NHP model. This approach aims to provide a method for high-throughput down-selection of vaccine candidates going forward to in vivo efficacy testing, thus expediting the development of a more efficacious TB vaccine and offering potential refinement and reduction to the use of NHPs for this purpose.
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Affiliation(s)
- Rachel Tanner
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
| | - Emily Hoogkamer
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
- Public Health England, Salisbury, SP4 0JG, UK
| | - Julia Bitencourt
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
- Gonҫalo Moniz Institute, Oswaldo Cruz Foundation (FIOCRUZ), Salvador, 40296-710, Brazil
| | | | - Charelle Boot
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, 2288 GJ, The Netherlands
| | - Claudia C Sombroek
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, 2288 GJ, The Netherlands
| | - Stephanie A Harris
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
| | - Matthew K O'Shea
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
- Institute of Immunology and Immunotherapy, University of Birmingham, UK, Birmingham, B15 2TH, UK
| | - Daniel Wright
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
| | - Rachel Wittenberg
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
| | | | - Iman Satti
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
| | - Frank A W Verreck
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, 2288 GJ, The Netherlands
| | | | - Helen A Fletcher
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
- London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Helen McShane
- Nuffield Department of Medicine, The Jenner Institute, Oxford, OX3 7DQ, UK
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10
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A non-human primate in vitro functional assay for the early evaluation of TB vaccine candidates. NPJ Vaccines 2021; 6:3. [PMID: 33397986 PMCID: PMC7782578 DOI: 10.1038/s41541-020-00263-7] [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: 07/23/2020] [Accepted: 11/23/2020] [Indexed: 01/29/2023] Open
Abstract
We present a non-human primate mycobacterial growth inhibition assay (MGIA) using in vitro blood or cell co-culture with the aim of refining and expediting early tuberculosis vaccine testing. We have taken steps to optimise the assay using cryopreserved peripheral blood mononuclear cells, transfer it to end-user institutes, and assess technical and biological validity. Increasing cell concentration or mycobacterial input and co-culturing in static 48-well plates compared with rotating tubes improved intra-assay repeatability and sensitivity. Standardisation and harmonisation efforts resulted in high consistency agreements, with repeatability and intermediate precision <10% coefficient of variation (CV) and inter-site reproducibility <20% CV; although some systematic differences were observed. As proof-of-concept, we demonstrated ability to detect a BCG vaccine-induced improvement in growth inhibition in macaque samples, and a correlation between MGIA outcome and measures of protection from in vivo disease development following challenge with either intradermal BCG or aerosol/endobronchial Mycobacterium tuberculosis (M.tb) at a group and individual animal level.
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11
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Kwan PKW, Lin W, Naim ANM, Periaswamy B, De Sessions PF, Hibberd ML, Paton NI. Gene expression responses to anti-tuberculous drugs in a whole blood model. BMC Microbiol 2020; 20:81. [PMID: 32264819 PMCID: PMC7140558 DOI: 10.1186/s12866-020-01766-y] [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] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 03/26/2020] [Indexed: 12/21/2022] Open
Abstract
Background There is a need for better tools to evaluate new or repurposed TB drugs. The whole blood bactericidal activity (WBA) assay has been advocated for this purpose. We investigated whether transcriptional responses in the WBA assay resemble TB responses in vivo, and whether the approach might additionally reveal mechanisms of action. Results 1422 of 1798 (79%) of differentially expressed genes in WBA incubated with the standard combination of rifampicin, isoniazid, pyrazinamide and ethambutol were also expressed in sputum (P < 0.0001) obtained from patients taking the same combination of drugs; these comprised well-established treatment-response genes. Gene expression profiles in WBA incubated with the standard drugs individually, or with moxifloxacin or faropenem (with amoxicillin and clavulanic acid) clustered by individual drug exposure. Distinct pathways were detected for individual drugs, although only with isoniazid did these relate to known mechanisms of drug action. Conclusions Substantial agreement between whole blood cultures and sputum and the ability to differentiate individual drugs suggest that transcriptomics may add value to the whole blood assay for evaluating new TB drugs.
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Affiliation(s)
- Philip Kam Weng Kwan
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, NUHS Tower Block Level 10, 1E Kent Ridge Road, Singapore, 119228, Singapore
| | - Wenwei Lin
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, NUHS Tower Block Level 10, 1E Kent Ridge Road, Singapore, 119228, Singapore
| | - Ahmad Nazri Mohamed Naim
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore
| | - Balamurugan Periaswamy
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore
| | - Paola Florez De Sessions
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore
| | - Martin L Hibberd
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore.,London School of Hygiene & Tropical Medicine, London, UK.,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Nicholas I Paton
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, NUHS Tower Block Level 10, 1E Kent Ridge Road, Singapore, 119228, Singapore. .,Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore, Singapore. .,London School of Hygiene & Tropical Medicine, London, UK. .,Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
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12
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Palucci I, Battah B, Salustri A, De Maio F, Petrone L, Ciccosanti F, Sali M, Bondet V, Duffy D, Fimia GM, Goletti D, Delogu G. IP-10 contributes to the inhibition of mycobacterial growth in an ex vivo whole blood assay. Int J Med Microbiol 2019; 309:299-306. [PMID: 31147175 DOI: 10.1016/j.ijmm.2019.05.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 04/17/2019] [Accepted: 05/21/2019] [Indexed: 02/05/2023] Open
Abstract
Interferon-γ inducible protein 10 (IP-10), is a potent chemoattractant that promotes migration of monocytes and activated T-cells to inflammation foci. IP-10 is elevated in serum of patients with chronic hepatitis C virus (HCV) and tuberculosis (TB) infections, although it remains to be determined the contribution of IP-10 in restricting Mycobacterium tuberculosis (Mtb) replication. Here, we investigated the impact of IP-10 on mycobacteria replication using the ex vivo model of human whole-blood (WB) assay. In particular, we compared the levels of IP-10 upon infection with different Mtb clinical strains and species of non-tuberculous mycobacteria (NTM) and evaluated how IP-10 may contain bacterial replication. Interestingly, we observed that the inhibition of the host enzyme dipeptidyl peptidase IV (DPP-IV), which inactivates IP-10 through cleavage of two amino acids at the chemokine N-terminus, restricted mycobacterial persistence in WB, supporting the critical role of full length IP-10 in mediating an anti-Mtb response. Addition of recombinant IP-10 expressed in eukaryotic cells enhanced the anti-mycobacterial activity in WB, although no differences were observed when IP-10 containing different proportions of cleaved and non-cleaved forms of the chemokine were added. Moreover, recombinant IP-10 did not exert a direct anti-mycobacterial effect. Our results underscore the clinical relevance of IP-10 in mycobacteria pathogenesis and support the potential outcomes that may derive by targeting the IP-10/CXCR3 pathway as host directed therapies for the treatment of Mtb or NTM infections.
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Affiliation(s)
- Ivana Palucci
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy; Università Cattolica del Sacro Cuore, Roma, Italy
| | - Basem Battah
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy; Università Cattolica del Sacro Cuore, Roma, Italy
| | | | - Flavio De Maio
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy
| | - Linda Petrone
- Translational Research Unit, Department of Epidemiology and Preclinical Research, National Institute for Infectious Diseases, L. Spallanzani IRCCS, Rome, Italy
| | - Fabiola Ciccosanti
- Cellular Biology Unit, Department of Epidemiology and Preclinical Research, National Institute for Infectious Diseases, L. Spallanzani IRCCS, Rome, Italy
| | - Michela Sali
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy; Università Cattolica del Sacro Cuore, Roma, Italy
| | - Vincent Bondet
- Institut Pasteur, Laboratoire Immunobiologie des Cellules Dendritiques, Département d'Immunologie, INSERM U1223, Institut Pasteur, Paris, France
| | - Darragh Duffy
- Institut Pasteur, Laboratoire Immunobiologie des Cellules Dendritiques, Département d'Immunologie, INSERM U1223, Institut Pasteur, Paris, France
| | - Gian Maria Fimia
- Cellular Biology Unit, Department of Epidemiology and Preclinical Research, National Institute for Infectious Diseases, L. Spallanzani IRCCS, Rome, Italy; Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, University of Salento, Lecce, 73100, Italy
| | - Delia Goletti
- Translational Research Unit, Department of Epidemiology and Preclinical Research, National Institute for Infectious Diseases, L. Spallanzani IRCCS, Rome, Italy
| | - Giovanni Delogu
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Roma, Italy; Università Cattolica del Sacro Cuore, Roma, Italy; Mater Olbia Hospital, Olbia, Italy.
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13
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Impact of selective immune-cell depletion on growth of Mycobacterium tuberculosis (Mtb) in a whole-blood bactericidal activity (WBA) assay. PLoS One 2019; 14:e0216616. [PMID: 31100071 PMCID: PMC6524797 DOI: 10.1371/journal.pone.0216616] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 04/24/2019] [Indexed: 01/08/2023] Open
Abstract
We investigated the contribution of host immune cells to bacterial killing in a whole-blood bactericidal activity (WBA) assay, an ex vivo model used to test efficacy of drugs against mycobacterium tuberculosis (Mtb). We performed WBA assays with immuno-magnetic depletion of specific cell types, in the presence or absence of rifampicin. Innate immune cells decreased Mtb growth in absence of drug, but appeared to diminish the cidal activity of rifampicin, possibly attributable to intracellular bacterial sequestration. Adaptive immune cells had no effect with or without drug. The WBA assay may have potential for testing adjunctive host-directed therapies acting on phagocytic cells.
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14
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Lee H, Kim J, Kang YA, Kim DR, Sim B, Zelmer A, Fletcher HA, Dockrell HM, Smith SG, Cho SN. In vitro Mycobacterial Growth Inhibition in South Korean Adults With Latent TB Infection. Front Immunol 2019; 10:896. [PMID: 31105706 PMCID: PMC6497970 DOI: 10.3389/fimmu.2019.00896] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 04/08/2019] [Indexed: 01/24/2023] Open
Abstract
Background: It is important to understand the ability to inhibit mycobacterial growth in healthy adults who would have been Bacillus Calmette-Guérin (BCG) vaccinated in childhood as this group will be the potential target population for novel booster TB vaccine trials. In this study we investigated not only the long-term immunity induced by childhood BCG vaccination but also protective immunity in terms of the ability to inhibit mycobacterial growth in those who were BCG vaccinated in childhood, with evidence of recent or remote TB infection. Methods: We measured the baseline immune response using a functional mycobacterial growth inhibition assay (MGIA) as a novel approach and an intracellular cytokine staining (ICS) assay as a reference approach in healthy adults, with different status of Mycobacterium tuberculosis (Mtb) infection. Results: Based on MGIA responses in historically BCG-vaccinated healthy adults, demographical characteristics including age, and gender did not affect mycobacterial growth inhibition in PBMC. However, the uninfected healthy control (HC) group showed a greater ability to inhibit mycobacterial growth compared with the latent TB infection (LTBI) group (P = 0.0005). In terms of the M. tuberculosis antigen-specific T-cell immune response in diluted whole blood quantitated using an ICS assay, the LTBI group had a higher frequency of polyfunctional CD 4+ T cells compared with the HC group (P = 0.0002), although there was no correlation between ICS and the MGIA assay. Conclusion: The Mtb infection status had a significant impact on mycobacterial growth inhibition in PBMC from healthy adults in South Korea, a country with an intermediate burden of tuberculosis, with healthy controls showing the greatest mycobacterial growth inhibition.
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Affiliation(s)
- Hyejon Lee
- Clinical Vaccine Research Section, International Tuberculosis Research Center, Seoul, South Korea
- Department of Microbiology, Institute of Immunology and Immunological Disease, Yonsei University College of Medicine, Seoul, South Korea
| | - Jungho Kim
- Clinical Vaccine Research Section, International Tuberculosis Research Center, Seoul, South Korea
- Department of Microbiology, Institute of Immunology and Immunological Disease, Yonsei University College of Medicine, Seoul, South Korea
| | - Young Ae Kang
- Division of Pulmonary, Department of Internal Medicine, Severance Hospital, Institute of Chest Diseases, Yonsei University College of Medicine, Seoul, South Korea
| | - Deok Ryun Kim
- Development and Delivery Unit, International Vaccine Institute, Seoul, South Korea
| | - Bora Sim
- Department of Microbiology, Institute of Immunology and Immunological Disease, Yonsei University College of Medicine, Seoul, South Korea
| | - Andrea Zelmer
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Helen A. Fletcher
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Hazel M. Dockrell
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Steven G. Smith
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Sang-Nae Cho
- Clinical Vaccine Research Section, International Tuberculosis Research Center, Seoul, South Korea
- Department of Microbiology, Institute of Immunology and Immunological Disease, Yonsei University College of Medicine, Seoul, South Korea
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15
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Liu D, Zhang T, Wang Y, Muhammad M, Xue W, Ju J, Zhao B. Knockout of alanine racemase gene attenuates the pathogenicity of Aeromonas hydrophila. BMC Microbiol 2019; 19:72. [PMID: 30940083 PMCID: PMC6444436 DOI: 10.1186/s12866-019-1437-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 03/17/2019] [Indexed: 11/10/2022] Open
Abstract
Background Aeromonas hydrophila is an opportunistic pathogen of poikilothermic and homoeothermic animals, including humans. In the present study, we described the role of Alanine racemase (alr-2) in the virulence of A. hydrophila using an alr-2 knockout mutant (A.H.Δalr). Results In mouse and common carp models, the survival of animals challenged with A.H.Δalr was significantly increased compared with the wild-type (WT), and the mutant was also impaired in its ability to replicate in the organs and blood of infected mice and fish. The A.H.Δalr significantly increased phagocytosis by macrophages of the mice and fish. These attenuation effects of alr-2 could be complemented by the addition of D-alanine to the A.H.Δalr strain. The histopathology results indicated that the extent of tissue injury in the WT-infected animals was more severe than in the A.H.Δalr-infected groups. The expression of 9 virulence genes was significantly down-regulated, and 3 outer membrane genes were significantly up-regulated in A.H.Δalr. Conclusions Our data suggest that alr-2 is essential for the virulence of A. hydrophila. Our findings suggested alanine racemase could be applied in the development of new antibiotics against A. hydrophila.
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Affiliation(s)
- Dong Liu
- College of Life Science, Hebei Normal University, Shijiazhuang, 050024, China
| | - Ting Zhang
- College of Life Science, Hebei Normal University, Shijiazhuang, 050024, China
| | - Yaping Wang
- College of Life Science, Hebei Normal University, Shijiazhuang, 050024, China
| | - Murtala Muhammad
- College of Life Science, Hebei Normal University, Shijiazhuang, 050024, China
| | - Wen Xue
- College of Life Science, Hebei Normal University, Shijiazhuang, 050024, China
| | - Jiansong Ju
- College of Life Science, Hebei Normal University, Shijiazhuang, 050024, China
| | - Baohua Zhao
- College of Life Science, Hebei Normal University, Shijiazhuang, 050024, China.
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16
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Historical BCG vaccination combined with drug treatment enhances inhibition of mycobacterial growth ex vivo in human peripheral blood cells. Sci Rep 2019; 9:4842. [PMID: 30890730 PMCID: PMC6425030 DOI: 10.1038/s41598-019-41008-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 02/20/2019] [Indexed: 12/24/2022] Open
Abstract
Tuberculosis (TB) is a leading infectious cause of death globally. Drug treatment and vaccination, in particular with Bacillus Calmette-Guérin (BCG), remain the main strategies to control TB. With the emergence of drug resistance, it has been proposed that a combination of TB vaccination with pharmacological treatment may provide a greater therapeutic value. We implemented an ex vivo mycobacterial growth inhibition assay (MGIA) to discriminate vaccine responses in historically BCG-vaccinated human volunteers and to assess the contribution of vaccine-mediated immune response towards the killing effect of mycobacteria in the presence of the antibiotics isoniazid (INH) and rifampicin (RIF), in an attempt to develop the assay as a screening tool for therapeutic TB vaccines. BCG vaccination significantly enhanced the ability of INH to control mycobacterial growth ex vivo. The BCG-vaccinated group displayed a higher production of IFN-γ and IP-10 when peripheral blood mononuclear cells (PBMC) were co-cultured with INH, with a similar trend during co-culture with RIF. A higher frequency of IFN-γ+ and TNF-α+ CD3− CD4− CD8− cells was observed, suggesting the contribution of Natural Killer (NK) cells in the combined effect between BCG vaccination and INH. Taken together, our data indicate the efficacy of INH can be augmented following historical BCG vaccination, which support findings from previous observational and animal studies.
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17
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Optimisation, harmonisation and standardisation of the direct mycobacterial growth inhibition assay using cryopreserved human peripheral blood mononuclear cells. J Immunol Methods 2019; 469:1-10. [PMID: 30710562 PMCID: PMC7926177 DOI: 10.1016/j.jim.2019.01.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 12/13/2018] [Accepted: 01/15/2019] [Indexed: 11/21/2022]
Abstract
A major challenge to tuberculosis (TB) vaccine development is the lack of a validated immune correlate of protection. Mycobacterial growth inhibition assays (MGIAs) represent an unbiased measure of the ability to control mycobacterial growth in vitro. A successful MGIA could be applied to preclinical and clinical post-vaccination samples to aid in the selection of novel vaccine candidates at an early stage and provide a relevant measure of immunogenicity and protection. However, assay harmonisation is critical to ensure that comparable information can be extracted from different vaccine studies. As part of the FP7 European Research Infrastructures for Poverty Related Diseases (EURIPRED) consortium, we aimed to optimise the direct MGIA, assess repeatability and reproducibility, and harmonise the assay across different laboratories. We observed an improvement in repeatability with increased cell number and increased mycobacterial input. Furthermore, we determined that co-culturing in static 48-well plates compared with rotating 2 ml tubes resulted in a 23% increase in cell viability and a 500-fold increase in interferon-gamma (IFN-γ) production on average, as well as improved reproducibility between replicates, assay runs and sites. Applying the optimised conditions, we report repeatability to be <5% coefficient of variation (CV), intermediate precision to be <20% CV, and inter-site reproducibility to be <30% CV; levels within acceptable limits for a functional cell-based assay. Using relevant clinical samples, we demonstrated comparable results across two shared sample sets at three sites. Based on these findings, we have established a standardised operating procedure (SOP) for the use of the direct PBMC MGIA in TB vaccine development.
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18
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Tanner R, Satti I, Harris SA, O'Shea MK, Cizmeci D, O'Connor D, Chomka A, Matsumiya M, Wittenberg R, Minassian AM, Meyer J, Fletcher HA, McShane H. Tools for Assessing the Protective Efficacy of TB Vaccines in Humans: in vitro Mycobacterial Growth Inhibition Predicts Outcome of in vivo Mycobacterial Infection. Front Immunol 2019; 10:2983. [PMID: 31998295 PMCID: PMC6968127 DOI: 10.3389/fimmu.2019.02983] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 12/05/2019] [Indexed: 12/16/2022] Open
Abstract
Tuberculosis (TB) remains a leading global cause of morbidity and mortality and an effective new vaccine is urgently needed. A major barrier to the rational development of novel TB vaccines is the lack of a validated immune correlate or biomarker of protection. Mycobacterial Growth Inhibition Assays (MGIAs) provide an unbiased measure of ability to control mycobacterial growth in vitro, and may represent a functional correlate of protection. However, the biological relevance of any potential correlate can only be assessed by determining the association with in vivo protection from either a controlled mycobacterial infection or natural development of TB disease. Our data demonstrate that the direct MGIA using peripheral blood mononuclear cells (PBMC) is measuring a biologically relevant response that correlates with protection from in vivo human BCG infection across two independent cohorts. This is the first report of an MGIA correlating with in vivo protection in the species-of-interest, humans, and furthermore on a per-individual as well as per-group basis. Control of mycobacterial growth in the MGIA is associated with a range of immune parameters measured post-BCG infection in vivo including the IFN-γ ELISpot response, frequency of PPD-specific IFN-γ or TNF-α producing CD4+ T cells and frequency of specific sub-populations of polyfunctional CD4+ T cells. Distinct transcriptomic profiles are associated with good vs. poor mycobacterial control in the MGIA, with good controllers showing enrichment for gene sets associated with antigen processing/presentation and the IL-23 pathway, and poor controllers showing enrichment for hypoxia-related pathways. This study represents an important step toward biologically validating the direct PBMC MGIA for use in TB vaccine development and furthermore demonstrates the utility of this assay in determining relevant immune mechanisms and pathways of protection.
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Affiliation(s)
- Rachel Tanner
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Iman Satti
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Stephanie A Harris
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Matthew K O'Shea
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.,Institute of Microbiology and Infection, College of Medical and Dental Sciences, The University of Birmingham, Birmingham, United Kingdom
| | - Deniz Cizmeci
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Daniel O'Connor
- Department of Paediatrics, University of Oxford, Oxford, United Kingdom
| | - Agnieszka Chomka
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Magali Matsumiya
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Rachel Wittenberg
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Angela M Minassian
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Joel Meyer
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Helen A Fletcher
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.,London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Helen McShane
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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19
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Basu Roy R, Sambou B, Uhía I, Roetynck S, Robertson BD, Kampmann B. An Auto-luminescent Fluorescent BCG Whole Blood Assay to Enable Evaluation of Paediatric Mycobacterial Responses Using Minimal Blood Volumes. Front Pediatr 2019; 7:151. [PMID: 31114771 PMCID: PMC6503113 DOI: 10.3389/fped.2019.00151] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Accepted: 04/01/2019] [Indexed: 12/15/2022] Open
Abstract
Introduction: Understanding protective human immunity against mycobacteria is critical to developing and evaluating new vaccines against tuberculosis. Children are the most susceptible population to infection, disease, and death from tuberculosis, but also have the strongest evidence of BCG-inducible protection. Limited amounts of blood can be obtained for research purposes in paediatrics and therefore there is a need for high-yield, low-volume, human immunology assays. Methods: We transformed BCG Danish with plasmids encoding luciferase full operon derived from Photorhabdus luminescens together with Green Fluorescent Protein and antibiotic selection markers. We characterised the luminescent and fluorescent properties of this recombinant BCG strain (BCG-GFP-LuxFO) using a luminometer and flow cytometry and developed a paediatric whole blood in vitro infection model. Results: Luminescence of BCG-GFP-LuxFO correlated with optical density (Spearman Rank Correlation coefficient r = 0.985, p < 0.0001) and colony forming units (CFUs) in liquid culture medium (r = 0.971, p < 0.0001). Fluorescence of BCG-GFP-LuxFO in paediatric whole blood was confirmed by flow cytometry in granulocytes and monocytes 1 h following infection. Luminescence of BCG-GFP-LuxFO in whole blood corresponded with CFUs (r = 0.7123, p < 0.0001). Conclusion: The BCG-GFP-LuxFO assay requires 225 μL whole blood per sample, from which serial luminescence measurements can be obtained, together with biochemical analysis of supernatants and cellular assay applications using its fluorescent properties. This offers the opportunity to study human-mycobacterial interactions using multiple experimental modalities with only minimal blood volumes. It is therefore a valuable method for investigating paediatric immunity to tuberculosis.
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Affiliation(s)
- Robindra Basu Roy
- Department of Paediatrics, Centre for International Child Health, Imperial College London, London, United Kingdom.,Vaccines & Immunity Theme, MRC Unit The Gambia at the London School of Hygiene and Tropical Medicine (LSHTM), Banjul, The Gambia
| | - Basil Sambou
- Vaccines & Immunity Theme, MRC Unit The Gambia at the London School of Hygiene and Tropical Medicine (LSHTM), Banjul, The Gambia
| | - Iria Uhía
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Sophie Roetynck
- Vaccines & Immunity Theme, MRC Unit The Gambia at the London School of Hygiene and Tropical Medicine (LSHTM), Banjul, The Gambia
| | - Brian D Robertson
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, United Kingdom
| | - Beate Kampmann
- Department of Paediatrics, Centre for International Child Health, Imperial College London, London, United Kingdom.,Vaccines & Immunity Theme, MRC Unit The Gambia at the London School of Hygiene and Tropical Medicine (LSHTM), Banjul, The Gambia.,Faculty of Infectious and Tropical Diseases, The Vaccine Centre, London School of Hygiene and Tropical Medicine, London, United Kingdom
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20
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Pedraza-Sánchez S, Méndez-León JI, Gonzalez Y, Ventura-Ayala ML, Herrera MT, Lezana-Fernández JL, Bellanti JA, Torres M. Oral Administration of Human Polyvalent IgG by Mouthwash as an Adjunctive Treatment of Chronic Oral Candidiasis. Front Immunol 2018; 9:2956. [PMID: 30627128 PMCID: PMC6309162 DOI: 10.3389/fimmu.2018.02956] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 11/30/2018] [Indexed: 12/02/2022] Open
Abstract
Candida albicans is a commensal fungus that can cause disease ranging in severity from moderate to severe mucosal infections to more serious life-threating disseminated infections in severely immunocompromised hosts. Chronic mucocutaneous candidiasis (CMC) occurs in patients with mutations in genes affecting IL-17-mediated immunity, such as STAT3, AIRE, RORC, CARD9, IL12B, and IL12RB1, or gain of function (GOF) mutations in STAT1. New strategies for the treatment of candidiasis are needed because of the increased burden of infections and the emergence of drug-resistant strains. In this study, we investigated an aspect of the role of antibodies in the control of C. albicans infection. We tested in vitro the effects of C. albicans opsonization with commercial human polyvalent intravenous IgG (IV IgG) on NADPH oxidase activity and killing of the fungi by blood leukocytes from 11 healthy donors and found a significant enhancement in both phenomena that was improved by IV IgG opsonization. Then, we hypothesized that the opsonization of Candida in vivo could help its elimination by mucosal phagocytes in human patients with mucocutaneous candidiasis. We tested a novel adjunctive treatment for oral candidiasis in humans based on topical treatment with IV IgG. For this purpose, we choose two pediatric patients with well-characterized primary immunodeficiencies who are susceptible to CMC. Two 8-year-old female patients with an autosomal recessive mutation in the IL12RB1 gene (P1, with oral candidiasis) and a GOF mutation in STAT1 (P2, with severe CMC persistent since the age of 8 months and resistant to pharmacological treatments) were treated with IV IgG administered daily three times a day as a mouthwash over the course of 2 weeks. The treatment with the IV IgG mouthwash reduced C. albicans mouth infection by 98 and 70% in P1 and P2, respectively, after 13 days, and complete fungal clearance was observed after complementary nystatin and caspofungin treatments, respectively. Therefore, treatment of oral candidiasis with human polyvalent IgG administered as a mouthwash helps eliminate mucosal infection in humans, circumventing drug resistance, and opening its potential use in patients with primary or transient immunodeficiency.
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Affiliation(s)
- Sigifredo Pedraza-Sánchez
- Unidad de Bioquímica, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | | | - Yolanda Gonzalez
- Departamento de Investigación en Microbiología, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico
| | - María Laura Ventura-Ayala
- Unidad de Bioquímica, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - María Teresa Herrera
- Departamento de Investigación en Microbiología, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico
| | | | - Joseph A Bellanti
- Department of Pediatrics and Microbiology-Immunology, Georgetown University Medical Center, Washington, DC, United States
| | - Martha Torres
- Departamento de Investigación en Microbiología, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, Mexico City, Mexico
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21
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Porter BW, Venkatappa TK. Uncloaking an ancient adversary: Can pathogen biomarker elicitors play a role in confirming extrapulmonary TB and latent TB infection? Tuberculosis (Edinb) 2018; 113:30-37. [PMID: 30514511 DOI: 10.1016/j.tube.2018.08.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 07/07/2018] [Accepted: 08/29/2018] [Indexed: 10/28/2022]
Abstract
Latent tuberculosis infection (LTBI) is diagnosed immunologically using the Mantoux tuberculin skin test (TST) or interferon-gamma release assays (IGRAs). While widely used, immunodiagnostics can produce false negative or false positive results. Pathogen biomarkers provide an alternative, but direct detection in LTBI and extrapulmonary TB cases is challenging. Mycobacterium tuberculosis grows slowly, has limited hematogenous movement, is protected by a lipid rich cell wall, and produces low levels of secreted factors. Here we discuss the potential of elicitors by first considering pathogen markers that may be released following the administration of isoniazid. Isoniazid targets the cell wall of mycobacteria found in extracellular compartments and within monocytes, macrophages, dendritic cells, and lymphatic endothelial cells. Isoniazid's dual-purpose potential as an antibiotic and elicitor is supported by knowledge of latent infection dynamics, time-kill kinetics, and new detection techniques. Within hours, the bactericidal action of isoniazid likely enriches plasma with M. tuberculosis DNA, RNA, proteins/peptides, and lipids. Undoubtedly a portion of these biomarkers are eliminated as some bacilli undergo phagocytosis and lysosomal destruction. However, advances in immunoprecipitation and nucleic acid amplification, combined with the use of larger blood volumes during assay development, may overcome these losses. Other anticipated challenges include determining optimal sample collection times and designing diagnostic workflows that minimize processing-associated marker loss and degradation. Conventional, commercial, and emerging technologies that address these variables are discussed. If realized, isoniazid associated markers could provide proof of concept for novel elicitor-based diagnostic approaches capable of confirming LTBI and empirically treated extrapulmonary TB.
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Affiliation(s)
- Brad W Porter
- Independent Researcher; P.O. Box 56224, Atlanta, GA 30343, USA.
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22
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Naftalin CM, Verma R, Gurumurthy M, Hee KH, Lu Q, Yeo BCM, Tan KH, Lin W, Yu B, Seng KY, Lee LSU, Paton NI. Adjunctive use of celecoxib with anti-tuberculosis drugs: evaluation in a whole-blood bactericidal activity model. Sci Rep 2018; 8:13491. [PMID: 30202030 PMCID: PMC6131161 DOI: 10.1038/s41598-018-31590-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 08/22/2018] [Indexed: 12/31/2022] Open
Abstract
COX-2 inhibition may be of benefit in the treatment of tuberculosis (TB) through a number of pathways including efflux pump inhibition (increasing intracellular TB drug levels) and diverse effects on inflammation and the immune response. We investigated celecoxib (a COX-2 inhibitor) alone and with standard anti-tuberculosis drugs in the whole-blood bactericidal activity (WBA) model. Healthy volunteers took a single dose of celecoxib (400 mg), followed (after 1 week) by a single dose of either rifampicin (10 mg/kg) or pyrazinamide (25 mg/kg), followed (after 2 or 7 days respectively) by the same anti-tuberculosis drug with celecoxib. WBA was measured at intervals until 8 hours post-dose (by inoculating blood samples with Mycobacterium tuberculosis and estimating the change in bacterial colony forming units after 72 hours incubation). Celecoxib had no activity alone in the WBA assay (cumulative WBA over 8 hours post-dose: 0.03 ± 0.01ΔlogCFU, p = 1.00 versus zero). Celecoxib did not increase cumulative WBA of standard TB drugs (mean cumulative WBA −0.10 ± 0.13ΔlogCFU versus −0.10 ± 0.12ΔlogCFU for TB drugs alone versus TB drugs and celecoxib; mean difference −0.01, 95% CI −0.02 to 0.00; p = 0.16). The lack of benefit of celecoxib suggests that efflux pump inhibition or eicosanoid pathway-related responses are of limited importance in mycobacterial killing in the WBA assay.
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Affiliation(s)
- Claire M Naftalin
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
| | - Rupangi Verma
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Meera Gurumurthy
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Kim Hor Hee
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Qingshu Lu
- Singapore Clinical Research Institute, Singapore, Singapore
| | - Benjamin Chaik Meng Yeo
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Kin Hup Tan
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Wenwei Lin
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Buduo Yu
- Investigational Medicine Unit, National University Health System, Singapore, Singapore
| | - Kok Yong Seng
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Lawrence Soon-U Lee
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Nicholas I Paton
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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23
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Story-Roller E, Lamichhane G. Have we realized the full potential of β-lactams for treating drug-resistant TB? IUBMB Life 2018; 70:881-888. [PMID: 29934998 PMCID: PMC6119476 DOI: 10.1002/iub.1875] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 04/27/2018] [Indexed: 12/30/2022]
Abstract
β-lactams are the most widely used antibiotics and are effective against a spectrum of pathogenic bacteria. Here, we focus on the state-of-the-art understanding of the molecular underpinnings that determine the overall efficacy of β-lactams against TB and include historical perspectives of this antibiotic class against this ancient disease. We summarize literature that describes why earlier generations of β-lactams are ineffective and the potential promise of newer β-lactams that exhibit improved efficacy against TB. Emerging evidence warrants renewed consideration of newer β-lactams in regimens for treatment of drug-resistant TB. © 2018 IUBMB Life, 70(9):881-888, 2018.
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Affiliation(s)
- Elizabeth Story-Roller
- Center for Tuberculosis Research, Division of Infectious Diseases, Department of Medicine, Johns Hopkins University, Baltimore, MD 21231
| | - Gyanu Lamichhane
- Center for Tuberculosis Research, Division of Infectious Diseases, Department of Medicine, Johns Hopkins University, Baltimore, MD 21231
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24
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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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25
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Wallis RS, Good CE, O'Riordan MA, Blumer JL, Jacobs MR, Griffiss JM, Healan A, Salata RA. Mycobactericidal activity of bedaquiline plus rifabutin or rifampin in ex vivo whole blood cultures of healthy volunteers: A randomized controlled trial. PLoS One 2018; 13:e0196756. [PMID: 29718967 PMCID: PMC5931679 DOI: 10.1371/journal.pone.0196756] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 04/18/2018] [Indexed: 11/28/2022] Open
Abstract
Background Bedaquiline, an antimycobacterial agent approved for drug-resistant tuberculosis, is metabolized by CYP3A4, an hepatic enzyme strongly induced by rifampin, an essential part of drug-sensitive tuberculosis treatment. We examined the pharmacokinetic interactions of bedaquiline plus either rifampin or rifabutin in 33 healthy volunteers. This sub-study of that trial examined the mycobactericidal activity of these drugs against intracellular Mycobacterium tuberculosis using ex vivo whole blood culture. Methods Subjects were randomly assigned to receive two single 400 mg doses of bedaquiline, alone, and, after a 4 week washout period, in combination with steady-state daily dosing of either rifabutin 300 mg or rifampin 600 mg. Blood samples were collected prior to dosing and at multiple time points subsequently, to measure plasma drug concentrations and bactericidal activity in ex vivo M tuberculosis-infected whole blood cultures (WBA). Results Single oral doses of bedaquiline produced readily detectable WBA ex vivo, reaching a maximal effect of -0.28 log/day, with negative values indicating bacterial killing. Plasma concentrations of 355 ng/ml were sufficient for intracellular mycobacteriostasis. Combined dosing with rifampin or rifabutin produced maximal effects of -0.91 and -0.79 log/d, respectively. However, the activity of the rifabutin combination was sustained throughout the dosing interval, thereby producing a greater cumulative or total effect. At low drug concentrations, rifabutin plus bedaquiline yielded greater mycobactericidal activity than the sum of their separate effects. Neither drug metabolites nor cellular drug accumulation could account for this observation. Conclusions The combination of rifabutin plus bedaquiline produces sustained intracellular mycobactericidal activity that is greater than the sum of their individual effects. Further studies of the treatment-shortening potential of this combination are warranted.
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Affiliation(s)
- Robert S Wallis
- Aurum Institute, Johannesburg, South Africa.,School of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, Ohio, United States of America.,ACT for TB/HIV, Johannesburg, South Africa
| | - Caryn E Good
- School of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, Ohio, United States of America
| | - Mary A O'Riordan
- School of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, Ohio, United States of America
| | | | - Michael R Jacobs
- School of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, Ohio, United States of America
| | - J McLeod Griffiss
- Clinical Research Management, Inc, Hinckley, Ohio, United States of America
| | - Amanda Healan
- School of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, Ohio, United States of America
| | - Robert A Salata
- School of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, Cleveland, Ohio, United States of America
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26
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Gurumurthy M, Verma R, Naftalin CM, Hee KH, Lu Q, Tan KH, Issac S, Lin W, Tan A, Seng KY, Lee LSU, Paton NI. Activity of faropenem with and without rifampicin against Mycobacterium tuberculosis: evaluation in a whole-blood bactericidal activity trial. J Antimicrob Chemother 2018; 72:2012-2019. [PMID: 28333342 DOI: 10.1093/jac/dkx081] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 02/20/2017] [Indexed: 11/13/2022] Open
Abstract
Background Faropenem has in vitro activity against Mycobacterium tuberculosis (Mtb) and shows synergy with rifampicin. We tested this in a whole-blood bactericidal activity (WBA) trial. Methods We randomized healthy volunteers to receive a single oral dose of faropenem (600 mg) with amoxicillin/clavulanic acid (500/125 mg) ( n = 8), rifampicin (10 mg/kg) ( n = 14) or the combination rifampicin + faropenem + amoxicillin/clavulanic acid ( n = 14). Blood was drawn at intervals to 8 h post-dose. Drug levels were measured using LC-tandem MS. WBA was measured by inoculating blood samples with Mtb and estimating the change in bacterial cfu after 72 h. Trial registration: ClinicalTrials.gov (NCT02393586). Results There was no activity in the faropenem + amoxicillin/clavulanic acid group (cumulative WBA 0.02 Δlog cfu; P = 0.99 versus zero change). There was a suggestion of a trend favouring the rifampicin + faropenem + amoxicillin/clavulanic acid group at 8 h (cumulative WBA -0.19 ± 0.03 and -0.26 ± 0.03 Δlog cfu in the rifampicin and rifampicin + faropenem + amoxicillin/clavulanic acid groups, respectively; P = 0.180), which was significant in the first hour post-dose ( P = 0.032). Faropenem C max and AUC were 5.4 mg/L and 16.2 mg·h/L, respectively, and MIC for Mtb H37Rv was 5-10 mg/L. Conclusions Faropenem is not active when used alone, possibly due to inadequate plasma levels relative to MIC. However, there was a suggestion of modest synergy with rifampicin that may merit further testing in clinical trials.
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Affiliation(s)
- Meera Gurumurthy
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Rupangi Verma
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Claire M Naftalin
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Kim Hor Hee
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Qingshu Lu
- Singapore Clinical Research Institute, Singapore
| | - Kin Hup Tan
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Simi Issac
- Dean's Office (BSL3 Core Facility), Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Wenwei Lin
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Angelia Tan
- Investigational Medicine Unit, National University Health System, Singapore
| | - Kok-Yong Seng
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Lawrence Soon-U Lee
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Nicholas I Paton
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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27
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Joosten SA, van Meijgaarden KE, Arend SM, Prins C, Oftung F, Korsvold GE, Kik SV, Arts RJ, van Crevel R, Netea MG, Ottenhoff TH. Mycobacterial growth inhibition is associated with trained innate immunity. J Clin Invest 2018; 128:1837-1851. [PMID: 29461976 DOI: 10.1172/jci97508] [Citation(s) in RCA: 108] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 02/13/2018] [Indexed: 12/29/2022] Open
Abstract
The lack of defined correlates of protection hampers development of vaccines against tuberculosis (TB). In vitro mycobacterial outgrowth assays are thought to better capture the complexity of the human host/Mycobacterium tuberculosis (Mtb) interaction. Here, we used a mycobacterial growth inhibition assay (MGIA) based on peripheral blood mononuclear cells to investigate the capacity to control outgrowth of bacille Calmette-Guérin (BCG). Interestingly, strong control of BCG outgrowth was observed almost exclusively in individuals with recent exposure to Mtb, but not in (long-term) latent TB infection, and only modestly in BCG vaccinees. Mechanistically, control of mycobacterial outgrowth strongly correlated with the presence of a CD14dim monocyte population, but also required the presence of T cells. The nonclassical monocytes produced CXCL10, and CXCR3 receptor blockade inhibited the capacity to control BCG outgrowth. Expression of CXCR3 splice variants was altered in recently Mtb-exposed individuals. Cytokines previously associated with trained immunity were detected in MGIA supernatants, and CXCL9, CXCL10, and CXCL11 represent new markers of trained immunity. These data indicate that CXCR3 ligands are associated with trained immunity and are critical factors in controlling mycobacterial outgrowth. In conclusion, control of mycobacterial outgrowth early after exposure to Mtb is the result of trained immunity mediated by a CXCL10-producing nonclassical CD14dim monocyte subset.
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Affiliation(s)
- Simone A Joosten
- Department of Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands
| | | | - Sandra M Arend
- Department of Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands
| | - Corine Prins
- Department of Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands
| | - Fredrik Oftung
- Division of Infection Control and Environmental Health, Department of Infectious Disease Immunology, Norwegian Institute of Public Health, Oslo, Norway
| | - Gro Ellen Korsvold
- Division of Infection Control and Environmental Health, Department of Infectious Disease Immunology, Norwegian Institute of Public Health, Oslo, Norway
| | - Sandra V Kik
- KNCV Tuberculosis Foundation, The Hague, Netherlands
| | - Rob Jw Arts
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, Netherlands
| | - Reinout van Crevel
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, Netherlands
| | - Mihai G Netea
- Department of Internal Medicine and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, Netherlands
| | - Tom Hm Ottenhoff
- Department of Infectious Diseases, Leiden University Medical Center, Leiden, Netherlands
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28
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Rivero-Lezcano OM, Blanco-Conde S, López-Medrano R, López-Fidalgo E, Caño-Herrero M, Nebreda-Mayoral T. Blood antimicrobial activity varies against different Mycobacterium spp. Tuberculosis (Edinb) 2017; 107:80-87. [PMID: 29050776 DOI: 10.1016/j.tube.2017.08.008] [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: 10/04/2016] [Revised: 08/17/2017] [Accepted: 08/23/2017] [Indexed: 11/17/2022]
Abstract
In vitro analysis of mycobacterial pathogenicity or host susceptibility has traditionally relied on the infection of macrophages, the target cell of mycobacteria, despite difficulties reproducing their antimycobacterial activity. We have employed alternative models, namely whole blood and leukocytes in plasma, from QuantiFERON negative individuals, and performed infections with the pathogenic M. tuberculosis, the less pathogenic M. avium, M. kansasii and M. chelonae and the occasionally pathogenic M. gordonae and M. bovis. The anticoagulant used in blood extraction, heparin or EDTA, had a major influence in the outcome of the infection. Thus, while in the heparinized models a similar number of bacteria were enumerated in the inoculum and after seven days, in the presence of EDTA a killing effect was observed, despite the inhibitory effect of EDTA on cellular functions like the production of cytokines or reactive oxygen species (ROS). A special case was the rapidly growing mycobacteria M. chelonae, that multiplied in heparinized models but was eliminated in models with EDTA. We verified that EDTA is not responsible for the bactericidal effect, but acts as a bacteriostatic agent. Further work will determine whether blood derived models are a better alternative to the classical macrophage.
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Affiliation(s)
- Octavio Miguel Rivero-Lezcano
- Unidad de Investigación, Complejo Asistencial Universitario de León (CAULE), Altos de Nava, s/n, 24008 León, Spain; Institute of Biomedicine (IBIOMED), Universidad de León, León, Spain; Fundación Instituto de Estudios de Ciencias de la Salud de Castilla y León (IECSCYL), Soria, Spain.
| | - Sara Blanco-Conde
- Servicio de Análisis Clínicos, Complejo Asistencial Universitario de León (CAULE), Altos de Nava, s/n, 24008 León, Spain
| | - Ramiro López-Medrano
- Servicio de Microbiología, Hospital del Bierzo, Médicos sin Fronteras, 7, Fuentesnuevas-Ponferrada, 24404 León, Spain
| | - Eduardo López-Fidalgo
- Unidad de Investigación, Complejo Asistencial Universitario de León (CAULE), Altos de Nava, s/n, 24008 León, Spain
| | - Manuela Caño-Herrero
- Servicio de Microbiología Clínica, Complejo Asistencial Universitario de León (CAULE), Altos de Nava, s/n, 24008 León, Spain
| | - Teresa Nebreda-Mayoral
- Servicio de Microbiología Clínica, Complejo Asistencial Universitario de León (CAULE), Altos de Nava, s/n, 24008 León, Spain
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29
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Gupta-Wright A, Tembo D, Jambo KC, Chimbayo E, Mvaya L, Caldwell S, Russell DG, Mwandumba HC. Functional Analysis of Phagocyte Activity in Whole Blood from HIV/Tuberculosis-Infected Individuals Using a Novel Flow Cytometry-Based Assay. Front Immunol 2017; 8:1222. [PMID: 29033941 PMCID: PMC5624998 DOI: 10.3389/fimmu.2017.01222] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 09/15/2017] [Indexed: 12/02/2022] Open
Abstract
The accurate assessment of immune competence through ex vivo analysis is paramount to our understanding of those immune mechanisms that lead to protection or susceptibility against a broad range of human pathogens. We have developed a flow cytometry-based, whole blood phagocyte functional assay that utilizes the inflammatory inducer zymosan, coupled to OxyBURST-SE, a fluorescent reporter of phagosomal oxidase activity. The assay measures both phagocytic uptake and the superoxide burst in the phagocyte populations in whole blood. We utilized this assay to demonstrate impaired superoxide burst activity in the phagocytes of hospitalized HIV-positive patients with laboratory-confirmed tuberculosis. These data validate the use of the assay to assess the immune competence of patients in a clinical setting. The method is highly reproducible with minimal intraindividual variation and opens opportunities for the rapid assessment of cellular immune competence in peripheral blood in a disease setting.
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Affiliation(s)
- Ankur Gupta-Wright
- College of Medicine, Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Clinical Research Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Dumizulu Tembo
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
| | - Kondwani C Jambo
- College of Medicine, Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Elizabeth Chimbayo
- College of Medicine, Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Leonard Mvaya
- College of Medicine, Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Shannon Caldwell
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
| | - David G Russell
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
| | - Henry C Mwandumba
- College of Medicine, Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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Coadministration of Allopurinol To Increase Antimycobacterial Efficacy of Pyrazinamide as Evaluated in a Whole-Blood Bactericidal Activity Model. Antimicrob Agents Chemother 2017; 61:AAC.00482-17. [PMID: 28739782 DOI: 10.1128/aac.00482-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 06/19/2017] [Indexed: 01/24/2023] Open
Abstract
Coadministering pyrazinamide (PZA) with the xanthine oxidase inhibitor allopurinol increases systemic levels of the active metabolite, pyrazinoic acid (POA), but the effects on bactericidal activity against tuberculosis are unknown. We randomized healthy volunteers to take a single dose of PZA (either 10 or 25 mg/kg of body weight) at the first visit and the same dose 7 days later, coadministered with allopurinol (100 mg daily; 2 days before to 1 day after the PZA dose). Blood was drawn at intervals until 48 h after each PZA dose, and drug levels were measured using liquid chromatography-tandem mass spectrometry. Whole-blood bactericidal activity (WBA) was measured by inoculating blood samples with Mycobacterium tuberculosis and estimating the change in bacterial CFU after 72 h of incubation. Allopurinol increased the POA area under the concentration-time curve from 0 to 8 h (AUC0-8) (18.32 h · μg/ml versus 24.63 h · μg/ml for PZA alone versus PZA plus allopurinol) (P < 0.001) and its peak plasma concentration (Cmax) (2.81 μg/ml versus 4.00 μg/ml) (P < 0.001). There was no effect of allopurinol on mean cumulative WBA (0.01 ± 0.02 ΔlogCFU versus 0.00 ± 0.02 ΔlogCFU for PZA alone versus PZA plus allopurinol) (P = 0.49). Higher systemic POA levels were associated with greater WBA levels (P < 0.001), but the relationship was evident only at low POA concentrations. The lack of an effect of allopurinol on WBA despite a significant increase in blood POA levels suggests that host-generated POA may be less effective than POA generated inside bacteria. Coadministration of allopurinol does not appear to be a useful strategy for increasing the efficacy of PZA in clinical practice. (This study has been registered at ClinicalTrials.gov under registration no. NCT02700347.).
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Application of a whole blood mycobacterial growth inhibition assay to study immunity against Mycobacterium tuberculosis in a high tuberculosis burden population. PLoS One 2017; 12:e0184563. [PMID: 28886145 PMCID: PMC5590973 DOI: 10.1371/journal.pone.0184563] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 08/25/2017] [Indexed: 11/19/2022] Open
Abstract
The determinants of immunological protection against Mycobacterium tuberculosis (M.tb) infection in humans are not known. Mycobacterial growth inhibition assays have potential utility as in vitro surrogates of in vivo immunological control of M.tb. We evaluated a whole blood growth inhibition assay in a setting with high burden of TB and aimed to identify immune responses that correlate with control of mycobacterial growth. We hypothesized that individuals with underlying M.tb infection will exhibit greater M.tb growth inhibition than uninfected individuals and that children aged 4 to 12 years, an age during which TB incidence is curiously low, will also exhibit greater M.tb growth inhibition than adolescents or adults. Neither M.tb infection status, age of the study participants, nor M.tb strain was associated with differential control of mycobacterial growth. Abundance and function of innate or T cell responses were also not associated with mycobacterial growth. Our data suggest that this assay does not provide a useful measure of age-associated differential host control of M.tb infection in a high TB burden setting. We propose that universally high levels of mycobacterial sensitization (through environmental non-tuberculous mycobacteria and/or universal BCG vaccination) in persons from high TB burden settings may impart broad inhibition of mycobacterial growth, irrespective of M.tb infection status. This sensitization may mask the augmentative effects of mycobacterial sensitization on M.tb growth inhibition that is typical in low burden settings.
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Brennan MJ, Tanner R, Morris S, Scriba TJ, Achkar JM, Zelmer A, Hokey DA, Izzo A, Sharpe S, Williams A, Penn-Nicholson A, Erasmus M, Stylianou E, Hoft DF, McShane H, Fletcher HA. The Cross-Species Mycobacterial Growth Inhibition Assay (MGIA) Project, 2010-2014. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2017; 24:e00142-17. [PMID: 28701467 PMCID: PMC5585695 DOI: 10.1128/cvi.00142-17] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The development of a functional biomarker assay in the tuberculosis (TB) field would be widely recognized as a major advance in efforts to develop and to test novel TB vaccine candidates efficiently. We present preliminary studies using mycobacterial growth inhibition assays (MGIAs) to detect Mycobacterium bovis BCG vaccine responses across species, and we extend this work to determine whether a standardized MGIA can be applied in characterizing new TB vaccines. The comparative MGIA studies reviewed here aimed to evaluate robustness, reproducibility, and ability to reflect in vivo responses. In doing so, they have laid the foundation for the development of a MGIA that can be standardized and potentially qualified. A major challenge ahead lies in better understanding the relationships between in vivo protection, in vitro growth inhibition, and the immune mechanisms involved. The final outcome would be a MGIA that could be used with confidence in TB vaccine trials. We summarize data arising from this project, present a strategy to meet the goals of developing a functional assay for TB vaccine testing, and describe some of the challenges encountered in performing and transferring such assays.
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Affiliation(s)
| | - Rachel Tanner
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Sheldon Morris
- Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, USA
| | - Thomas J Scriba
- South African Tuberculosis Vaccine Initiative and Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Jacqueline M Achkar
- Departments of Medicine, Microbiology, and Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Andrea Zelmer
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | | | - Angelo Izzo
- Colorado State University, Fort Collins, Colorado, USA
| | - Sally Sharpe
- Public Health England, Porton Down, Salisbury, United Kingdom
| | - Ann Williams
- Public Health England, Porton Down, Salisbury, United Kingdom
| | - Adam Penn-Nicholson
- South African Tuberculosis Vaccine Initiative and Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Mzwandile Erasmus
- South African Tuberculosis Vaccine Initiative and Division of Immunology, Department of Pathology, University of Cape Town, Cape Town, South Africa
| | - Elena Stylianou
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | | | - Helen McShane
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Helen A Fletcher
- Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, United Kingdom
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A mycobacterial growth inhibition assay (MGIA) for bovine TB vaccine development. Tuberculosis (Edinb) 2017; 106:118-122. [PMID: 28802398 PMCID: PMC5670120 DOI: 10.1016/j.tube.2017.07.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 07/18/2017] [Accepted: 07/19/2017] [Indexed: 11/23/2022]
Abstract
Human tuberculosis remains a significant cause of mortality and morbidity throughout the world. The global economic impact of bovine TB is considerable. An effective vaccine would be the most cost-effective way to control both epidemics, particularly in emerging economies. TB vaccine research would benefit from the identification of an immune correlate of protection with which vaccines could be gated at both preclinical and clinical levels. In-vitro mycobacterial growth inhibition assays (MGIA) are functional assays that include most aspects of the complex host immune response to mycobacteria, and they may serve as functional immune correlates for vaccine development. We applied to cattle an MGIA that was developed for use with human and murine samples. Several technical difficulties were encountered while transferring it to the cattle model. However, our data demonstrate that the assay was not discriminatory in cattle and further work is needed before using it for bovine TB vaccine development.
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Abstract
The global epidemic of multidrug-resistant tuberculosis (MDR-TB) caused by Mycobacterium tuberculosis strains resistant to at least isoniazid and rifampin was recently reported as larger than previously estimated, with at least 580,000 new cases reported in 2015. Extensively drug-resistant tuberculosis (XDR-TB), MDR-TB with additional resistance to a second-line fluoroquinolone and injectable, continues to account for nearly 10% of MDR cases globally. Cases in India, China, and the Russian Federation account for >45% of the cases of MDR-TB. Molecular testing helps identify MDR more quickly, and treatment options have expanded across the globe. Despite this, only 20% are in treatment, and treatment is challenging due to the toxicity of medications and the long duration. In 2016 the World Health Organization updated guidelines for the treatment of MDR-TB. A new short-course regimen is an option for those who qualify. Five effective drugs, including pyrazinamide (PZA) when possible, are recommended during the initial treatment phase and four drugs thereafter. Revised drug classifications include the use of linezolid and clofazimine as key second-line drugs and the option to use bedaquiline and delamanid to complete a five-drug regimen when needed due to poor medication tolerance or extensive resistance. Despite multiple drugs and long-duration treatment regimens, the outcomes for MDR and especially XDR-TB are much worse than for drug-susceptible disease. Better management of toxicity, prevention of transmission, and identification and appropriate management of infected contacts are important challenges for the future.
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Jensen C, Lindebo Holm L, Svensson E, Aagaard C, Ruhwald M. Optimisation of a murine splenocyte mycobacterial growth inhibition assay using virulent Mycobacterium tuberculosis. Sci Rep 2017; 7:2830. [PMID: 28588268 PMCID: PMC5460210 DOI: 10.1038/s41598-017-02116-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 04/05/2017] [Indexed: 11/21/2022] Open
Abstract
In the absence of a validated correlate of protection or robust animal models for human tuberculosis, Mycobacterial growth inhibition assays (MGIAs) aim to assess vaccines ability to inhibit mycobacterial growth in-vitro. We optimised a reproducible murine splenocyte MGIA based on in-vitro infection with virulent Mycobacterium tuberculosis (M.tb) Erdman. We identified splenocyte viability as a problem in state-of-art MGIA protocols, which can be improved by simple changes in culture conditions (viability increase from 21% to 46% at last day of culture). The growth inhibitory potential in mice immunised with either BCG, H56:CAF01 or H56:CAF01 administered side-by-side with BCG was significantly better compared to placebo in all groups (0.3 log10 CFU [±0.2, p = 0.049], 0.5 [±0.2, p = 0.016] and 0.6 [±0.1, p = 0.0007], respectively) corresponding to the levels of in-vivo protection. Unexpectedly the CAF01 adjuvant control group also induced significant growth inhibition of 0.3 log10 CFU (±0.2, p = 0.047). Finally, we explored vaccine-associated T cell effector functions. Despite presence of high levels of vaccine-specific T cells, we found no increase in CD4+ T cell number or cytokine expression profile, nor a difference in cytokine levels in the supernatant after four days culture with or without M.tb. Spontaneous IFN-γ release correlated with growth inhibition levels (p = 0.02), however the cellular source was not found.
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Affiliation(s)
- Christina Jensen
- Department of Infectious Disease Immunology, Statens Serum Institut, Copenhagen, Denmark
| | - Line Lindebo Holm
- Department of Infectious Disease Immunology, Statens Serum Institut, Copenhagen, Denmark
- Copenhagen University Hospitals, Hvidovre, Copenhagen, Denmark
| | - Erik Svensson
- International Reference Laboratory of Mycobacteriology, Statens Serum Institut, Copenhagen, Denmark
| | - Claus Aagaard
- Department of Infectious Disease Immunology, Statens Serum Institut, Copenhagen, Denmark
| | - Morten Ruhwald
- Department of Infectious Disease Immunology, Statens Serum Institut, Copenhagen, Denmark.
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Pilot studies of a human BCG challenge model. Tuberculosis (Edinb) 2017; 105:108-112. [PMID: 28610781 DOI: 10.1016/j.tube.2017.05.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 04/25/2017] [Accepted: 05/02/2017] [Indexed: 11/20/2022]
Abstract
Despite the great effort to develop an effective vaccine against tuberculosis (TB) there is currently no reliable and safe human challenge model that can be used for in vivo evaluation of new TB vaccine candidates and/or elucidation of the mechanisms of TB protective immunity. In this study, five volunteers were challenged with BCG intradermally (ID). Swab specimens were collected at multiple time points from the vaccination site pre- and post-vaccination to quantitate mycobacterial shedding as a surrogate of in vivo mycobacterial immunity. We compared the performance of the TaqMan qPCR assay against colony-forming unit cultures on 7H10 agar plates, and time to positivity (TTP) of mycobacterial growth indicator tubes (MGIT) in order to evaluate the reproducibility and sensitivity in measuring BCG burden in swab specimens. BCG was detected in swab specimens from all five volunteers by at least one method, and no single method was superior in terms of sensitivity and reproducibility. A comparison of all three methods showed significant correlations by Spearman's rank test between 7H10 agar plating and qPCR (R = 0.601, P = 0.00072), MGIT culture TTP and 7H10 agar plating (R = 0.412, P = 0.029) as well as MGIT culture TTP and qPCR (R = -0.708, P = 0.00003). However, the three methods were somewhat different with regard to early versus late detection of BCG shedding post-challenge. This ID BCG challenge model has unique potential to further explore correlations between reactogenicity and immune mechanisms involved in protection against mycobacterial infections, and could therefore become a reliable tool in the evaluation process of new TB vaccination strategies.
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le Roex N, Jolles A, Beechler B, van Helden P, Hoal E. Toll-like receptor (TLR) diversity influences mycobacterial growth in African buffalo. Tuberculosis (Edinb) 2017; 104:87-94. [PMID: 28454655 DOI: 10.1016/j.tube.2017.03.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 03/21/2017] [Accepted: 03/28/2017] [Indexed: 01/04/2023]
Abstract
Understanding the role of wildlife in the maintenance or spread of emerging infectious diseases is a growing priority across the world. Bovine tuberculosis (BTB) is a chronic, infectious disease caused by Mycobacterium bovis (M. bovis). BTB is widespread within game reserves in southern Africa, and within these ecosystems the primary wildlife host of this disease is the African buffalo. We used a modified bacterial killing assay for mycobacteria to investigate the effect of Toll-like receptor (TLR) genetic diversity and demographic parameters on the ability of African buffalo to restrict mycobacterial growth. Eosinophil count, time delay, bovine PPD response and avian PPD response were negatively correlated with mycobacterial growth. TLR6 diversity and the interaction of age group and sex were positively correlated with mycobacterial growth. Our results suggest that both demographic and individual immune parameters influence the ability to control mycobacterial infection in African buffalo. TLR6 diversity is particularly interesting as this locus has also shown associations with BTB in cattle, suggesting that further research into the effects, selection and role of TLR6 variants in bovine tuberculosis will be productive.
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Affiliation(s)
- Nikki le Roex
- DST/NRF Centre of Excellence for Biomedical Tuberculosis Research/ Medical Research Council (MRC) Centre for TB Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.
| | - Anna Jolles
- College of Veterinary Medicine, Oregon State University, Corvallis, OR, 97331, USA; Department of Integrative Biology, Oregon State University, Corvallis, OR, 97331, USA.
| | - Brianna Beechler
- College of Veterinary Medicine, Oregon State University, Corvallis, OR, 97331, USA.
| | - Paul van Helden
- DST/NRF Centre of Excellence for Biomedical Tuberculosis Research/ Medical Research Council (MRC) Centre for TB Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.
| | - Eileen Hoal
- DST/NRF Centre of Excellence for Biomedical Tuberculosis Research/ Medical Research Council (MRC) Centre for TB Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.
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Tanner R, O’Shea MK, White AD, Müller J, Harrington-Kandt R, Matsumiya M, Dennis MJ, Parizotto EA, Harris S, Stylianou E, Naranbhai V, Bettencourt P, Drakesmith H, Sharpe S, Fletcher HA, McShane H. The influence of haemoglobin and iron on in vitro mycobacterial growth inhibition assays. Sci Rep 2017; 7:43478. [PMID: 28256545 PMCID: PMC5335253 DOI: 10.1038/srep43478] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 01/24/2017] [Indexed: 01/04/2023] Open
Abstract
The current vaccine against tuberculosis, live attenuated Mycobacterium bovis BCG, has variable efficacy, but development of an effective alternative is severely hampered by the lack of an immune correlate of protection. There has been a recent resurgence of interest in functional in vitro mycobacterial growth inhibition assays (MGIAs), which provide a measure of a range of different immune mechanisms and their interactions. We identified a positive correlation between mean corpuscular haemoglobin and in vitro growth of BCG in whole blood from healthy UK human volunteers. Mycobacterial growth in peripheral blood mononuclear cells (PBMC) from both humans and macaques was increased following the experimental addition of haemoglobin (Hb) or ferric iron, and reduced following addition of the iron chelator deferoxamine (DFO). Expression of Hb genes correlated positively with mycobacterial growth in whole blood from UK/Asian adults and, to a lesser extent, in PBMC from South African infants. Taken together our data indicate an association between Hb/iron levels and BCG growth in vitro, which may in part explain differences in findings between whole blood and PBMC MGIAs and should be considered when using such assays.
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Affiliation(s)
- Rachel Tanner
- The Jenner Institute, University of Oxford, Oxford, UK
| | | | | | - Julius Müller
- The Jenner Institute, University of Oxford, Oxford, UK
| | | | | | | | | | | | | | | | | | - Hal Drakesmith
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Sally Sharpe
- Public Health England, Porton Down, Salisbury, UK
| | | | - Helen McShane
- The Jenner Institute, University of Oxford, Oxford, UK
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A novel mycobacterial In Vitro infection assay identifies differences of induced macrophage apoptosis between CD4+ and CD8+ T cells. PLoS One 2017; 12:e0171817. [PMID: 28199374 PMCID: PMC5310865 DOI: 10.1371/journal.pone.0171817] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 01/26/2017] [Indexed: 12/03/2022] Open
Abstract
Macrophages are natural host cells for pathogenic mycobacteria, like Mycobacterium tuberculosis (M.tb). Immune surveillance by T cells and interaction with M.tb infected macrophages is crucial for protection against M.tb reactivation and development of active tuberculosis. Several factors play a role in the control of M.tb infection but reliable biomarkers remain elusive. One major obstacle is the absence of functional in vitro assays which allow concomitant determination of i) mycobacterial eradication; ii) cytotoxic effects on host macrophages; and iii) effector T-cell functions. We established a novel functional in vitro assay based on flow cytometry analysis of monocyte-derived macrophages (MDM) infected with a Mycobacterium bovis BCG strain containing a tetracycline inducible live/dead reporter plasmid (LD-BCG). MDM of healthy human donors were generated in vitro and infected with defined LD-BCG numbers. After short-term MDM/LD-BCG co-incubation with autologous effector T cells or in the presence of antibiotics, proportions of MDM containing live or dead LD-BCG were determined by flow cytometry. Concomitant measure of defined numbers of added beads allowed comparison of absolute MDM numbers between samples. Differential effects of T-cell subpopulations on anti-mycobacterial cytotoxicity and on MDM apoptosis were determined. Flow cytometry measure of MDM/LD-BCG treated with rifampicin correlated well with mycobacterial colony forming units and fluorescence microscopy results. Co-culture with pre-activated effector T cells reduced viability of both, LD-BCG and MDM, in a concentration-dependent manner. M.tb protein specific CD4+ and CD8+ T-cells contributed similarly to anti-mycobacterial cytotoxicity but CD4+ T cells induced higher levels of apoptosis in infected MDMs. This novel assay enables rapid quantification of anti-mycobacterial cytotoxicity and characterization of effector functions. Our functional in vitro assay has the potential to contribute to the identification of biomarkers for protective T-cell responses against tuberculosis.
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Cardona PJ, Williams A. Experimental animal modelling for TB vaccine development. Int J Infect Dis 2017; 56:268-273. [PMID: 28163168 DOI: 10.1016/j.ijid.2017.01.030] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 01/24/2017] [Indexed: 11/18/2022] Open
Abstract
Research for a novel vaccine to prevent tuberculosis is an urgent medical need. The current vaccine, BCG, has demonstrated a non-homogenous efficacy in humans, but still is the gold standard to be improved upon. In general, the main indicator for testing the potency of new candidates in animal models is the reduction of the bacillary load in the lungs at the acute phase of the infection. Usually, this reduction is similar to that induced by BCG, although in some cases a weak but significant improvement can be detected, but none of candidates are able to prevent establishment of infection. The main characteristics of several laboratory animals are reviewed, reflecting that none are able to simulate the whole characteristics of human tuberculosis. As, so far, no surrogate of protection has been found, it is important to test new candidates in several models in order to generate convincing evidence of efficacy that might be better than that of BCG in humans. It is also important to investigate the use of "in silico" and "ex vivo" models to better understand experimental data and also to try to replace, or at least reduce and refine experimental models in animals.
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Affiliation(s)
- Pere-Joan Cardona
- Unitat de Tuberculosi Experimental, Universitat Autònoma de Barcelona, CIBERES, Fundació Institut Germans Trias i Pujol, Badalona, Catalonia.
| | - Ann Williams
- National Infections Service, Public Health England, Porton Down, Salisbury, UK
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Distinct Transcriptional and Anti-Mycobacterial Profiles of Peripheral Blood Monocytes Dependent on the Ratio of Monocytes: Lymphocytes. EBioMedicine 2016; 2:1619-26. [PMID: 26870787 PMCID: PMC4740301 DOI: 10.1016/j.ebiom.2015.09.027] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 09/04/2015] [Accepted: 09/15/2015] [Indexed: 01/03/2023] Open
Abstract
The ratio of monocytes and lymphocytes (ML ratio) in peripheral blood is associated with tuberculosis and malaria disease risk and cancer and cardiovascular disease outcomes. We studied anti-mycobacterial function and the transcriptome of monocytes in relation to the ML ratio. Mycobacterial growth inhibition assays of whole or sorted blood were performed and mycobacteria were enumerated by liquid culture. Transcriptomes of unstimulated CD14 + monocytes isolated by magnetic bead sorting were characterised by microarray. Transcript expression was tested for association with ML ratio calculated from leucocyte differential counts by linear regression. The ML ratio was associated with mycobacterial growth in vitro (β = 2.23, SE 0.91, p = 0.02). Using sorted monocytes and lymphocytes, in vivo ML ratio (% variance explained R2 = 11%, p = 0.02) dominated over in vitro ratios (R2 = 5%, p = 0.10) in explaining mycobacterial growth. Expression of 906 genes was associated with the ML ratio and 53 with monocyte count alone. ML-ratio associated genes were enriched for type-I and -II interferon signalling (p = 1.2 × 10− 8), and for genes under transcriptional control of IRF1, IRF2, RUNX1, RELA and ESRRB. The ML-ratio-associated gene set was enriched in TB disease (3.11-fold, 95% CI: 2.28–4.19, p = 5.7 × 10− 12) and other inflammatory diseases including atopy, HIV, IBD and SLE. The ML ratio is associated with distinct transcriptional and anti-mycobacterial profiles of monocytes that may explain the disease associations of the ML ratio. A pathophysiological basis for involvement of the ML ratio in infectious, malignant and cardiovascular diseases is unclear. Monocytes from individuals with high ML ratio have impaired control of mycobacterial growth and a distinctive transcriptome. These monocytes are characterised by enhanced interferon signalling, and intermediate transcription factors. The ML-ratio associated transcript signature is enriched in TB and other diseases including atopy, IBD and SLE. Ontogeny-specific function of monocytes may be the possible mechanism for the prognostic value of the ML ratio.
Enumeration of the absolute count of white blood cell subsets is one of the most frequently performed tests in clinical practice. Recently, elevation in the monocytes:lymphocytes (ML) ratio was linked to increased risk of tuberculosis and malaria disease, and poorer outcomes for many cancers and cardiovascular diseases. We sought to understand the mechanism of these disease associations. We found that the ML ratio reflects the functional capacity of monocytes and that genes that are differentially expressed in monocytes from donors with a high ML ratio are similar to those in other diseases such as HIV and inflammatory bowel disease. Because a specific type of blood-making stem cell regulates the ML ratio, it is plausible that the ratio reflects monocyte function because it is a clue to different monocyte origins. Our findings offer a mechanism for the predictive value of the ML ratio that may help improve its clinical utility.
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López-Medrano R, Guerra-Laso JM, López-Fidalgo E, Diez-Tascón C, García-García S, Blanco-Conde S, Rivero-Lezcano OM. Plasma contributes to the antimicrobial activity of whole blood against Mycobacterium tuberculosis. Innate Immun 2016; 22:557-66. [PMID: 27554054 DOI: 10.1177/1753425916663311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 06/29/2016] [Indexed: 11/16/2022] Open
Abstract
The whole blood model for infection has proven useful to analyze the immunological response to Mycobacterium tuberculosis, because it exerts a significant antimicrobial activity. Although this activity has been generally assumed to be cellular, we have found that the leukocyte fraction of blood from healthy volunteers did not kill the bacilli. We have discovered that plasma was responsible for a large proportion, but not all, of the antimicrobial activity. Furthermore, infected monocytes controlled the mycobacterial multiplication when cultivated in the presence of plasma. Intriguingly, serum from the same donors did not share this activity, although it was able to eliminate the non-pathogenic Mycobacterium gordonae To identify the remaining components that participate in the antimycobacterial activity we fractionated blood in leukocytes, plasma, erythrocytes and platelets, and analyzed the bactericidal power of each fraction and their combinations using a factorial design. We found that erythrocytes, but not platelets, participated and showed by flow cytometry that mycobacteria physically associated with erythrocytes. We propose that in exposed healthy individuals that show 'early clearance' of the mycobacteria, the innate response is predominantly humoral, probably through the effect of antimicrobial peptides and proteins.
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Affiliation(s)
| | - José Manuel Guerra-Laso
- Servicio de Medicina Interna, Complejo Asistencial Universitario de León, (CAULE), León, Spain
| | - Eduardo López-Fidalgo
- Unidad de Investigación, Complejo Asistencial Universitario de León (CAULE), León, Spain
| | - Cristina Diez-Tascón
- Servicio de Anatomía Patológica, Complejo Asistencial Universitario de León (CAULE), León, Spain Institute of Biomedicine (IBIOMED), Universidad de León, León, Spain
| | - Silvia García-García
- Servicio de Neumología, Complejo Asistencial Universitario de León (CAULE), León, Spain
| | - Sara Blanco-Conde
- Servicio de Análisis Clínicos, Complejo Asistencial Universitario de León (CAULE), León, Spain
| | - Octavio Miguel Rivero-Lezcano
- Unidad de Investigación, Complejo Asistencial Universitario de León (CAULE), León, Spain Institute of Biomedicine (IBIOMED), Universidad de León, León, Spain Fundación Instituto de Estudios de Ciencias de la Salud de Castilla y León (IECSCYL), León, Spain
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43
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Zelmer A, Tanner R, Stylianou E, Damelang T, Morris S, Izzo A, Williams A, Sharpe S, Pepponi I, Walker B, Hokey DA, McShane H, Brennan M, Fletcher H. A new tool for tuberculosis vaccine screening: Ex vivo Mycobacterial Growth Inhibition Assay indicates BCG-mediated protection in a murine model of tuberculosis. BMC Infect Dis 2016; 16:412. [PMID: 27519524 PMCID: PMC4983071 DOI: 10.1186/s12879-016-1751-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 08/03/2016] [Indexed: 11/30/2022] Open
Abstract
Background In the absence of a validated animal model and/or an immune correlate which predict vaccine-mediated protection, large-scale clinical trials are currently the only option to prove efficacy of new tuberculosis candidate vaccines. Tools to facilitate testing of new tuberculosis (TB) vaccines are therefore urgently needed. Methods We present here an optimized ex vivo mycobacterial growth inhibition assay (MGIA) using a murine Mycobacterium tuberculosis infection model. This assay assesses the combined ability of host immune cells to inhibit mycobacterial growth in response to vaccination. C57BL/6 mice were immunized with Bacillus Calmette-Guérin (BCG) and growth inhibition of mycobacteria by splenocytes was assessed. Mice were also challenged with Mycobacterium tuberculosis Erdman, and bacterial burden was assessed in lungs and spleen. Results Using the growth inhibition assay, we find a reduction in BCG CFU of 0.3–0.8 log10 after co-culture with murine splenocytes from BCG vaccinated versus naïve C57BL/6 mice. BCG vaccination in our hands led to a reduction in bacterial burden after challenge with Mycobacterium tuberculosis of approx. 0.7 log10 CFU in lung and approx. 1 log10 CFU in spleen. This effect was also seen when using Mycobacterium smegmatis as the target of growth inhibition. An increase in mycobacterial numbers was found when splenocytes from interferon gamma-deficient mice were used, compared to wild type controls, indicating that immune mechanisms may also be investigated using this assay. Conclusions We believe that the ex vivo mycobacterial growth inhibition assay could be a useful tool to help assess vaccine efficacy in future, alongside other established methods. It could also be a valuable tool for determination of underlying immune mechanisms. Electronic supplementary material The online version of this article (doi:10.1186/s12879-016-1751-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Andrea Zelmer
- London School of Hygiene and Tropical Medicine, London, UK.
| | | | | | - Timon Damelang
- London School of Hygiene and Tropical Medicine, London, UK
| | - Sheldon Morris
- Center for Biologics Evaluation and Research, Silver Spring, MD, USA
| | - Angelo Izzo
- Colorado State University, Fort Collins, CO, USA
| | | | | | - Ilaria Pepponi
- The Jenner Institute, Oxford University, Oxford, UK.,Animal and Plant Health Agency, Weybridge, UK.,Translational Research Unit, National Institute for Infectious Diseasess "Lazzaro Spallanzani", Rome, Italy
| | | | | | | | | | - Helen Fletcher
- London School of Hygiene and Tropical Medicine, London, UK
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Tanner R, O'Shea MK, Fletcher HA, McShane H. In vitro mycobacterial growth inhibition assays: A tool for the assessment of protective immunity and evaluation of tuberculosis vaccine efficacy. Vaccine 2016; 34:4656-4665. [PMID: 27527814 DOI: 10.1016/j.vaccine.2016.07.058] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 06/07/2016] [Accepted: 07/29/2016] [Indexed: 01/28/2023]
Abstract
Tuberculosis (TB) continues to pose a serious global health threat, and the current vaccine, BCG, has variable efficacy. However, the development of a more effective vaccine is severely hampered by the lack of an immune correlate of protection. Candidate vaccines are currently evaluated using preclinical animal models, but experiments are long and costly and it is unclear whether the outcomes are predictive of efficacy in humans. Unlike measurements of single immunological parameters, mycobacterial growth inhibition assays (MGIAs) represent an unbiased functional approach which takes into account a range of immune mechanisms and their complex interactions. Such a controlled system offers the potential to evaluate vaccine efficacy and study mediators of protective immunity against Mycobacterium tuberculosis (M.tb). This review discusses the underlying principles and relative merits and limitations of the different published MGIAs, their demonstrated abilities to measure mycobacterial growth inhibition and vaccine efficacy, and what has been learned about the immune mechanisms involved.
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Affiliation(s)
- Rachel Tanner
- The Jenner Institute, University of Oxford, Oxford, UK.
| | | | | | - Helen McShane
- The Jenner Institute, University of Oxford, Oxford, UK
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Harausz EP, Chervenak KA, Good CE, Jacobs MR, Wallis RS, Sanchez-Felix M, Boom WH. Activity of nitazoxanide and tizoxanide against Mycobacterium tuberculosis in vitro and in whole blood culture. Tuberculosis (Edinb) 2016; 98:92-6. [PMID: 27156623 DOI: 10.1016/j.tube.2016.03.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 03/08/2016] [Accepted: 03/15/2016] [Indexed: 11/18/2022]
Abstract
Nitazoxanide (NTZ) and its metabolite tizoxanide (TIZ) were studied as antimycobacterial agents in vitro (in mycobacterial growth indicator tube [MGIT] cultures) and in a whole blood bactericidal assay. Both NTZ and TIZ show high protein binding. In MGIT cultures (albumin concentration = 78 μM), inhibition of Mycobacterium tuberculosis growth occurred at total drug concentrations of ≥16 μg/ml, whereas in whole blood cultures (albumin concentration = 350 μM), ≥128 μg/ml was required. Free drug fractions at these two conditions were estimated to be 69% and 2%, respectively. Co-incubation of NTZ and TIZ in human plasma for 72 h nearly completely eliminated their ability to inhibit mycobacterial growth in MGIT. Interactions with plasma proteins may limit the potential of NTZ and TIZ as drugs for human tuberculosis.
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Affiliation(s)
- Elizabeth P Harausz
- Department of Medicine, Case Western Reserve University, University Hospitals Case Medical Center, 10900 Euclid Ave, Cleveland, OH 44106, USA.
| | - Keith A Chervenak
- Department of Medicine, Case Western Reserve University, University Hospitals Case Medical Center, 10900 Euclid Ave, Cleveland, OH 44106, USA.
| | - Caryn E Good
- Department of Pathology, Case Western Reserve University, University Hospitals Case Medical Center, 10900 Euclid Ave, Cleveland, OH 44106, USA.
| | - Michael R Jacobs
- Department of Pathology, Case Western Reserve University, University Hospitals Case Medical Center, 10900 Euclid Ave, Cleveland, OH 44106, USA.
| | - Robert S Wallis
- Aurum Institute, 29 Queens Rd, Parktown, Johannesburg, South Africa.
| | | | - W Henry Boom
- Department of Medicine, Case Western Reserve University, University Hospitals Case Medical Center, 10900 Euclid Ave, Cleveland, OH 44106, USA.
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Improvement in plasma drug activity during the early treatment interval among Tanzanian patients with multidrug-resistant tuberculosis. PLoS One 2015; 10:e0122769. [PMID: 25816161 PMCID: PMC4376785 DOI: 10.1371/journal.pone.0122769] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 02/17/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Individual pharmacokinetic variability may be common in patients treated for multidrug-resistant tuberculosis (MDR-TB) but data are sparse from resource-limited settings and across the early treatment interval. METHODS Plasma drug activity, as measured by the TB Drug Activity (TDA) assay at 2 and 4 weeks of treatment with a standardized MDR-TB regimen was performed in patients with pulmonary MDR-TB from Tanzania. TDA values were correlated with measures of early treatment outcome including every two week collection of sputum for time-to-positivity (TTP) in liquid culture from the MGIT 960 automated system. Patients were evaluated at 24 weeks and those surviving without delayed sputum culture conversion (>8 weeks), culture reversion after previously negative, or weight loss were defined as having a favorable outcome. RESULTS Twenty-five patients were enrolled with a mean age of 37 ±12 years. All were culture positive from the pretreatment sputum sample with a mean TTP in MGIT of 257 ±134 hours, and the median time to culture conversion on treatment was 6 weeks. Twenty patients (80%) had an increase in TDA, with the overall mean TDA at 2 weeks of 2.1 ±0.7 compared to 2.4 ±0.8 at 4 weeks (p = 0.005). At 2 weeks 13 subjects (52%) had a TDA value > 2-log killing against their own M. tuberculosis isolate compared to 17 subjects (68%) at 4 weeks (McNemar's exact test p = 0.29). An interim treatment outcome was able to be determined in 23 patients (92%), of whom 7 had a poor outcome (30%). An increase in TDA from week 2 to week 4 was associated with favorable outcome, [unadjusted OR = 20.0, 95% CI: 1.61-247.98, exact p = 0.017 and adjusted OR = 19.33, 95% CI: 1.55-241.5, exact p = 0.023]. CONCLUSIONS The majority of patients with MDR-TB in Tanzania had an increase in plasma drug activity from week 2 to week 4 of treatment as measured by the TDA assay. Understanding the etiology and full impact of this dynamic may inform therapeutic intervention.
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Herzmann C, Sotgiu G, Schaberg T, Ernst M, Stenger S, Lange C. Childhood BCG vaccination does not influence control of Mycobacterium tuberculosis growth by human bronchoalveolar lavage cells. Tuberculosis (Edinb) 2015; 95:321-7. [PMID: 25794470 DOI: 10.1016/j.tube.2015.02.044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 02/19/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Childhood vaccination with Mycobacterium bovis Bacille Calmette-Guérin (BCG) reduces the risk of infection with Mycobacterium tuberculosis and the risk of severe forms of tuberculosis in children. The protection of adults from pulmonary tuberculosis is doubtful. This study evaluated the effect of the vaccination on the growth of M. tuberculosis human bronchoalveolar mononuclear cells (BALMC). METHODS Healthy, adult healthcare workers who were regularly exposed to M. tuberculosis, household tuberculosis contacts, and cured tuberculosis patients were recruited in a multicentre study conducted in Germany. BALMC were co-cultured with different strains of M. tuberculosis in growth inhibition assays (MGIAs). RESULTS MGIAs on BALMC were conducted in 90 contact persons (known vaccination status, n = 75) and 62 former tuberculosis patients (known status, n = 22). Growth rates for M. tuberculosis H37Rv in BALMC were independent of the vaccination status, both in healthy contacts and in cured tuberculosis patients. This finding was validated in growth inhibition assays using two different Haarlem M. tuberculosis outbreak strains. Subgroup analyses based on the Interferon-gamma release assay status found no impact of the vaccination on mycobacterial growth. CONCLUSIONS This study suggests that M. bovis BCG vaccination does not alter the anti-mycobacterial capacity of BALMC as assessed in ex-vivo growth inhibition assays.
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Affiliation(s)
- Christian Herzmann
- Division of Clinical Infectious Diseases, Research Center Borstel, Borstel, Germany; Center for Clinical Studies, Research Center Borstel, Borstel, Germany.
| | - Giovanni Sotgiu
- Epidemiology and Medical Statistics Unit, Department of Biomedical Sciences, University of Sassari-Research, Medical Education and Professional Development Unit, AOU Sassari, Sassari, Italy.
| | - Tom Schaberg
- Center of Pneumology, Deaconess Hospital Rotenburg, Rotenburg, Germany.
| | - Martin Ernst
- Division of Immune-Cell Analytics, Research Center Borstel, Borstel, Germany.
| | - Steffen Stenger
- Institute for Medical Microbiology and Hygiene, University Hospital of Ulm, Ulm, Germany.
| | - Christoph Lange
- Division of Clinical Infectious Diseases, Research Center Borstel, Borstel, Germany; German Center for Infection Research (DZIF), Clinical Tuberculosis Unit, Germany; International Health/Infectious Diseases, University of Lübeck, Germany; Department of Internal Medicine, University of Namibia School of Medicine, Windhoek, Namibia; Department of Medicine, Karolinska Institute, Stockholm, Sweden.
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Larsson MC, Lerm M, Ängeby K, Nordvall M, Juréen P, Schön T. A luciferase-based assay for rapid assessment of drug activity against Mycobacterium tuberculosis including monitoring of macrophage viability. J Microbiol Methods 2014; 106:146-150. [PMID: 25194234 DOI: 10.1016/j.mimet.2014.08.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 08/07/2014] [Accepted: 08/26/2014] [Indexed: 10/24/2022]
Abstract
The intracellular (IC) effect of drugs against Mycobacterium tuberculosis (Mtb) is not well established but increasingly important to consider when combining current and future multidrug regimens into the best possible treatment strategies. For this purpose, we developed an IC model based on a genetically modified Mtb H37Rv strain, expressing the Vibrio harvei luciferase (H37Rv-lux) infecting the human macrophage like cell line THP-1. Cells were infected at a low multiplicity of infection (1:1) and subsequently exposed to isoniazid (INH), ethambutol (EMB), amikacin (AMI) or levofloxacin (LEV) for 5days in a 96-well format. Cell viability was evaluated by Calcein AM and was maintained throughout the experiment. The number of viable H37Rv-lux was determined by luminescence and verified by a colony forming unit analysis. The results were compared to the effects of the same drugs in broth cultures. AMI, EMB and LEV were significantly less effective intracellularly (MIC90: >4mg/L, 8mg/L and 2mg/L, respectively) compared to extracellularly (MIC90: 0.5mg/L for AMI and EMB; 0.25mg/L for LEV). The reverse was the case for INH (IC: 0.064mg/L vs EC: 0.25mg/L). In conclusion, this luciferase based method, in which monitoring of cell viability is included, has the potential to become a useful tool while evaluating the intracellular effects of anti-mycobacterial drugs.
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Affiliation(s)
- Marie C Larsson
- Department of Clinical Microbiology, Linköping University Hospital, Sweden
| | - Maria Lerm
- Department of Medical Microbiology, Linköping University, Sweden
| | - Kristian Ängeby
- Department of Clinical Microbiology, Karolinska University Hospital Department of Clinical Microbiology, MTC-Karolinska Institute, Karolinska University Hospital, Stockholm, Sweden; Department of Microbiology, The University of the West Indies, Kingston, Jamaica
| | - Michaela Nordvall
- Department of Clinical Microbiology, Linköping University Hospital, Sweden
| | | | - Thomas Schön
- Department of Medical Microbiology, Linköping University, Sweden; Department of Clinical Microbiology and Infectious Diseases, Kalmar County Hospital, Sweden; Department of Medicine and Optometry, Linnaeus University, Kalmar, Sweden.
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Ryndak MB, Singh KK, Peng Z, Zolla-Pazner S, Li H, Meng L, Laal S. Transcriptional profiling of Mycobacterium tuberculosis replicating ex vivo in blood from HIV- and HIV+ subjects. PLoS One 2014; 9:e94939. [PMID: 24755630 PMCID: PMC3995690 DOI: 10.1371/journal.pone.0094939] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 03/21/2014] [Indexed: 01/02/2023] Open
Abstract
Hematogenous dissemination of Mycobacterium tuberculosis (M. tb) occurs during both primary and reactivated tuberculosis (TB). Although hematogenous dissemination occurs in non-HIV TB patients, in ∼80% of these patients, TB manifests exclusively as pulmonary disease. In contrast, extrapulmonary, disseminated, and/or miliary TB is seen in 60–70% of HIV-infected TB patients, suggesting that hematogenous dissemination is likely more common in HIV+ patients. To understand M. tb adaptation to the blood environment during bacteremia, we have studied the transcriptome of M. tb replicating in human whole blood. To investigate if M. tb discriminates between the hematogenous environments of immunocompetent and immunodeficient individuals, we compared the M. tb transcriptional profiles during replication in blood from HIV- and HIV+ donors. Our results demonstrate that M. tb survives and replicates in blood from both HIV- and HIV+ donors and enhances its virulence/pathogenic potential in the hematogenous environment. The M. tb blood-specific transcriptome reflects suppression of dormancy, induction of cell-wall remodeling, alteration in mode of iron acquisition, potential evasion of immune surveillance, and enhanced expression of important virulence factors that drive active M. tb infection and dissemination. These changes are accentuated during bacterial replication in blood from HIV+ patients. Furthermore, the expression of ESAT-6, which participates in dissemination of M. tb from the lungs, is upregulated in M. tb growing in blood, especially during growth in blood from HIV+ patients. Preliminary experiments also demonstrate that ESAT-6 promotes HIV replication in U1 cells. These studies provide evidence, for the first time, that during bacteremia, M. tb can adapt to the blood environment by modifying its transcriptome in a manner indicative of an enhanced-virulence phenotype that favors active infection. Additionally, transcriptional modifications in HIV+ blood may further accentuate M. tb virulence and drive both M. tb and HIV infection.
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Affiliation(s)
- Michelle B. Ryndak
- Department of Pathology, New York University Langone Medical Center, New York, New York, United States of America
| | - Krishna K. Singh
- Department of Pathology, New York University Langone Medical Center, New York, New York, United States of America
| | - Zhengyu Peng
- Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Susan Zolla-Pazner
- Department of Pathology, New York University Langone Medical Center, New York, New York, United States of America
- Veterans Affairs New York Harbor Healthcare System, New York, New York, United States of America
| | - Hualin Li
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Lu Meng
- Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, China
| | - Suman Laal
- Department of Pathology, New York University Langone Medical Center, New York, New York, United States of America
- Veterans Affairs New York Harbor Healthcare System, New York, New York, United States of America
- * E-mail:
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50
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Population pharmacokinetic/pharmacodynamic analysis of the bactericidal activities of sutezolid (PNU-100480) and its major metabolite against intracellular Mycobacterium tuberculosis in ex vivo whole-blood cultures of patients with pulmonary tuberculosis. Antimicrob Agents Chemother 2014; 58:3306-11. [PMID: 24687496 DOI: 10.1128/aac.01920-13] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sutezolid (PNU-100480 [U-480]) is an oxazolidinone antimicrobial being developed for the treatment of tuberculosis. An active sulfoxide metabolite (PNU-101603 [U-603]), which reaches concentrations in plasma several times those of the parent, has been reported to drive the killing of extracellular Mycobacterium tuberculosis by sutezolid in hollow-fiber culture. However, the relative contributions of the parent and metabolite against intracellular M. tuberculosis in vivo are not fully understood. The relationships between the plasma concentrations of U-480 and U-603 and intracellular whole-blood bactericidal activity (WBA) in ex vivo cultures were examined using a direct competitive population pharmacokinetic (PK)/pharmacodynamic 4-parameter sigmoid model. The data set included 690 PK determinations and 345 WBA determinations from 50 tuberculosis patients enrolled in a phase 2a sutezolid trial. The model parameters were solved iteratively. The median U-603/U-480 concentration ratio was 7.1 (range, 1 to 28). The apparent 50% inhibitory concentration of U-603 for intracellular M. tuberculosis was 17-fold greater than that of U-480 (90% confidence interval [CI], 9.9- to 53-fold). Model parameters were used to simulate in vivo activity after oral dosing with sutezolid at 600 mg twice a day (BID) and 1,200 mg once a day (QD). Divided dosing resulted in greater cumulative activity (-0.269 log10 per day; 90% CI, -0.237 to -0.293 log10 per day) than single daily dosing (-0.186 log10 per day; 90% CI, -0.160 to -0.208 log10 per day). U-480 accounted for 84% and 78% of the activity for BID and QD dosing, respectively, despite the higher concentrations of U-603. Killing of intracellular M. tuberculosis by orally administered sutezolid is mainly due to the activity of the parent compound. Taken together with the findings of other studies in the hollow-fiber model, these findings suggest that sutezolid and its metabolite act on different mycobacterial subpopulations.
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