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Shaku MT, Um PK, Ocius KL, Apostolos AJ, Pires MM, Bishai WR, Kana BD. A modified BCG with depletion of enzymes associated with peptidoglycan amidation induces enhanced protection against tuberculosis in mice. eLife 2024; 13:e89157. [PMID: 38639995 PMCID: PMC11132681 DOI: 10.7554/elife.89157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 04/17/2024] [Indexed: 04/20/2024] Open
Abstract
Mechanisms by which Mycobacterium tuberculosis (Mtb) evades pathogen recognition receptor activation during infection may offer insights for the development of improved tuberculosis (TB) vaccines. Whilst Mtb elicits NOD-2 activation through host recognition of its peptidoglycan-derived muramyl dipeptide (MDP), it masks the endogenous NOD-1 ligand through amidation of glutamate at the second position in peptidoglycan side-chains. As the current BCG vaccine is derived from pathogenic mycobacteria, a similar situation prevails. To alleviate this masking ability and to potentially improve efficacy of the BCG vaccine, we used CRISPRi to inhibit expression of the essential enzyme pair, MurT-GatD, implicated in amidation of peptidoglycan side-chains. We demonstrate that depletion of these enzymes results in reduced growth, cell wall defects, increased susceptibility to antibiotics, altered spatial localization of new peptidoglycan and increased NOD-1 expression in macrophages. In cell culture experiments, training of a human monocyte cell line with this recombinant BCG yielded improved control of Mtb growth. In the murine model of TB infection, we demonstrate that depletion of MurT-GatD in BCG, which is expected to unmask the D-glutamate diaminopimelate (iE-DAP) NOD-1 ligand, yields superior prevention of TB disease compared to the standard BCG vaccine. In vitro and in vivo experiments in this study demonstrate the feasibility of gene regulation platforms such as CRISPRi to alter antigen presentation in BCG in a bespoke manner that tunes immunity towards more effective protection against TB disease.
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Affiliation(s)
- Moagi Tube Shaku
- DST/NRF Centre of Excellence for Biomedical TB Research, Faculty of Health Sciences, University of the Witwatersrand, National Health Laboratory ServiceJohannesburgSouth Africa
- Center for Tuberculosis Research, Department of Medicine, Johns Hopkins School of MedicineBaltimoreUnited States
| | - Peter K Um
- Center for Tuberculosis Research, Department of Medicine, Johns Hopkins School of MedicineBaltimoreUnited States
| | - Karl L Ocius
- Department of Chemistry, University of VirginiaCharlottesvilleUnited States
| | - Alexis J Apostolos
- Department of Chemistry, University of VirginiaCharlottesvilleUnited States
| | - Marcos M Pires
- Department of Chemistry, University of VirginiaCharlottesvilleUnited States
| | - William R Bishai
- Center for Tuberculosis Research, Department of Medicine, Johns Hopkins School of MedicineBaltimoreUnited States
| | - Bavesh D Kana
- DST/NRF Centre of Excellence for Biomedical TB Research, Faculty of Health Sciences, University of the Witwatersrand, National Health Laboratory ServiceJohannesburgSouth Africa
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2
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Omar S, Whitfield MG, Nolan MB, Ngom JT, Ismail N, Warren RM, Klopper M. Bedaquiline for treatment of non-tuberculous mycobacteria (NTM): a systematic review and meta-analysis. J Antimicrob Chemother 2024; 79:211-240. [PMID: 38134888 PMCID: PMC10832598 DOI: 10.1093/jac/dkad372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 11/21/2023] [Indexed: 12/24/2023] Open
Abstract
BACKGROUND Non-tuberculous mycobacteria (NTM) infections are increasing in incidence and associated mortality. NTM are naturally resistant to a variety of antibiotics, complicating treatment. We conducted a literature assessment on the efficacy of bedaquiline in treating NTM species in vitro and in vivo (animal models and humans); meta-analyses were performed where possible. METHOD Four databases were searched using specific terms. Publications were included according to predefined criteria. Bedaquiline's impact on NTM in vitro, MICs and epidemiological cut-off (ECOFF) values were evaluated. A meta-analysis of bedaquiline efficacy against NTM infections in animal models was performed. Culture conversion, cure and/or relapse-free cure were used to evaluate the efficacy of bedaquiline in treating NTM infection in humans. RESULTS Fifty studies met the inclusion criteria: 33 assessed bedaquiline's impact on NTM in vitro, 9 in animal models and 8 in humans. Three studies assessed bedaquiline's efficacy both in vitro and in vivo. Due to data paucity, an ECOFF value of 0.5 mg/mL was estimated for Mycobacterium abscessus only. Meta-analysis of animal studies showed a 1.86× reduction in bacterial load in bedaquiline-treated versus no treatment within 30 days. In humans, bedaquiline-including regimens were effective in treating NTM extrapulmonary infection but not pulmonary infection. CONCLUSIONS Bedaquiline demonstrated strong antibacterial activity against various NTM species and is a promising drug to treat NTM infections. However, data on the genomic mutations associated with bedaquiline resistance were scarce, preventing statistical analyses for most mutations and NTM species. Further studies are urgently needed to better inform treatment strategies.
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Affiliation(s)
- Shatha Omar
- DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council (SAMRC) Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Michael G Whitfield
- Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance, National Institute for Health Research, Imperial College London, London, UK
| | - Margaret B Nolan
- DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council (SAMRC) Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Justice T Ngom
- DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council (SAMRC) Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Nabila Ismail
- DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council (SAMRC) Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Rob M Warren
- DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council (SAMRC) Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Marisa Klopper
- DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council (SAMRC) Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
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3
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Kelley M, Sasaninia K, Abnousian A, Badaoui A, Owens J, Beever A, Kachour N, Tiwari RK, Venketaraman V. Additive Effects of Cyclic Peptide [R4W4] When Added Alongside Azithromycin and Rifampicin against Mycobacterium avium Infection. Pathogens 2023; 12:1057. [PMID: 37624017 PMCID: PMC10459066 DOI: 10.3390/pathogens12081057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 07/29/2023] [Accepted: 08/16/2023] [Indexed: 08/26/2023] Open
Abstract
Mycobacterium avium (M. avium), a type of nontuberculous mycobacteria (NTM), poses a risk for pulmonary infections and disseminated infections in immunocompromised individuals. Conventional treatment consists of a 12-month regimen of the first-line antibiotics rifampicin and azithromycin. However, the treatment duration and low antibiotic tolerability present challenges in the treatment of M. avium infection. Furthermore, the emergence of multidrug-resistant mycobacterium strains prompts a need for novel treatments against M. avium infection. This study aims to test the efficacy of a novel antimicrobial peptide, cyclic [R4W4], alongside the first-line antibiotics azithromycin and rifampicin in reducing M. avium survival. Colony-forming unit (CFU) counts were assessed after treating M. avium cultures with varying concentrations of cyclic [R4W4] alone or in conjunction with azithromycin or rifampicin 3 h and 4 days post-treatment. M. avium growth was significantly reduced 4 days after cyclic [R4W4] single treatment. Additionally, cyclic [R4W4]-azithromycin and cyclic [R4W4]-rifampicin combination treatments at specific concentrations significantly reduced M. avium survival 3 h and 4 days post-treatment compared with single antibiotic treatment alone. These findings demonstrate cyclic [R4W4] as a potent treatment method against M. avium and provide insight into novel therapeutic approaches against mycobacterium infections.
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Affiliation(s)
- Melissa Kelley
- Graduate College of Biomedical Sciences, Western University of Health Sciences, Pomona, CA 91766, USA
| | - Kayvan Sasaninia
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA; (K.S.); (A.A.); (J.O.)
| | - Arbi Abnousian
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA; (K.S.); (A.A.); (J.O.)
| | - Ali Badaoui
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA; (K.S.); (A.A.); (J.O.)
| | - James Owens
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA; (K.S.); (A.A.); (J.O.)
| | - Abrianna Beever
- College of Osteopathic Medicine, Kansas City University, Kansas City, MO 64106, USA
| | - Nala Kachour
- School of Medicine, University of California Riverside, Riverside, CA 92521, USA;
| | - Rakesh Kumar Tiwari
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA; (K.S.); (A.A.); (J.O.)
- Department of Biomedical and Pharmaceutical Sciences, Center for Targeted Drug Delivery, Chapman University School of Pharmacy, Harry and Diane Rinker Health Science Campus, Irvine, CA 92866, USA
| | - Vishwanath Venketaraman
- College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA 91766, USA; (K.S.); (A.A.); (J.O.)
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4
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Shaku MT, Um P, Ocius KL, Apostolos AJ, Pires MM, Bishai WR, Kana BD. A modified BCG with depletion of enzymes associated with peptidoglycan amidation induces enhanced protection against tuberculosis in mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.03.539199. [PMID: 37205421 PMCID: PMC10187164 DOI: 10.1101/2023.05.03.539199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Mechanisms by which Mycobacterium tuberculosis (Mtb) evades pathogen recognition receptor activation during infection may offer insights for the development of improved tuberculosis (TB) vaccines. Whilst Mtb elicits NOD-2 activation through host recognition of its peptidoglycan-derived muramyl dipeptide (MDP), it masks the endogenous NOD-1 ligand through amidation of glutamate at the second position in peptidoglycan sidechains. As the current BCG vaccine is derived from pathogenic mycobacteria, a similar situation prevails. To alleviate this masking ability and to potentially improve efficacy of the BCG vaccine, we used CRISPRi to inhibit expression of the essential enzyme pair, MurT-GatD, implicated in amidation of peptidoglycan sidechains. We demonstrate that depletion of these enzymes results in reduced growth, cell wall defects, increased susceptibility to antibiotics and altered spatial localization of new peptidoglycan. In cell culture experiments, training of monocytes with this recombinant BCG yielded improved control of Mtb growth. In the murine model of TB infection, we demonstrate that depletion of MurT-GatD in BCG, resulting in unmasking of the D-glutamate diaminopimelate (iE-DAP) NOD-1 ligand, yields superior prevention of TB disease compared to the standard BCG vaccine. This work demonstrates the feasibility of gene regulation platforms such as CRISPRi to alter antigen presentation in BCG in a bespoke manner that tunes immunity towards more effective protection against TB disease.
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5
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Intranasal multivalent adenoviral-vectored vaccine protects against replicating and dormant M.tb in conventional and humanized mice. NPJ Vaccines 2023; 8:25. [PMID: 36823425 PMCID: PMC9948798 DOI: 10.1038/s41541-023-00623-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 02/09/2023] [Indexed: 02/25/2023] Open
Abstract
Viral-vectored vaccines are highly amenable for respiratory mucosal delivery as a means of inducing much-needed mucosal immunity at the point of pathogen entry. Unfortunately, current monovalent viral-vectored tuberculosis (TB) vaccine candidates have failed to demonstrate satisfactory clinical protective efficacy. As such, there is a need to develop next-generation viral-vectored TB vaccine strategies which incorporate both vaccine antigen design and delivery route. In this study, we have developed a trivalent chimpanzee adenoviral-vectored vaccine to provide protective immunity against pulmonary TB through targeting antigens linked to the three different growth phases (acute/chronic/dormancy) of Mycobacterium tuberculosis (M.tb) by expressing an acute replication-associated antigen, Ag85A, a chronically expressed virulence-associated antigen, TB10.4, and a dormancy/resuscitation-associated antigen, RpfB. Single-dose respiratory mucosal immunization with our trivalent vaccine induced robust, sustained tissue-resident multifunctional CD4+ and CD8+ T-cell responses within the lung tissues and airways, which were further quantitatively and qualitatively improved following boosting of subcutaneously BCG-primed hosts. Prophylactic and therapeutic immunization with this multivalent trivalent vaccine in conventional BALB/c mice provided significant protection against not only actively replicating M.tb bacilli but also dormant, non-replicating persisters. Importantly, when used as a booster, it also provided marked protection in the highly susceptible C3HeB/FeJ mice, and a single respiratory mucosal inoculation was capable of significant protection in a humanized mouse model. Our findings indicate the great potential of this next-generation TB vaccine strategy and support its further clinical development for both prophylactic and therapeutic applications.
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Dutt TS, Karger BR, Fox A, Youssef N, Dadhwal R, Ali MZ, Patterson J, Creissen E, Rampacci E, Cooper SK, Podell BK, Gonzalez-Juarrero M, Obregon-Henao A, Henao-Tamayo M. Mucosal exposure to non-tuberculous mycobacteria elicits B cell-mediated immunity against pulmonary tuberculosis. Cell Rep 2022; 41:111783. [PMID: 36516760 DOI: 10.1016/j.celrep.2022.111783] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 10/09/2022] [Accepted: 11/15/2022] [Indexed: 12/15/2022] Open
Abstract
Bacille Calmette-Guerin (BCG) is the only licensed vaccine against Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB) disease. However, BCG has limited efficacy, necessitating the development of better vaccines. Non-tuberculous mycobacteria (NTMs) are opportunistic pathogens present ubiquitously in the environment. TB endemic countries experience higher exposure to NTMs, but previous studies have not elucidated the relationship between NTM exposure and BCG efficacy against TB. Therefore, we develop a mouse model (BCG + NTM) to simulate human BCG immunization regime and continuous NTM exposure. BCG + NTM mice exhibit superior and prolonged protection against pulmonary TB, with increased B cell influx and anti-Mtb antibodies in serum and airways, compared with BCG alone. Notably, spatial transcriptomics and immunohistochemistry reveal that BCG + NTM mice formed B cell aggregates with features of germinal center development, which correlate with reduced Mtb burden. Our studies suggest a direct relationship between NTM exposure and TB protection, with B cells playing a crucial role.
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Affiliation(s)
- Taru S Dutt
- Department of Microbiology, Immunology, and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, CO 80523, USA.
| | | | - Amy Fox
- Department of Microbiology, Immunology, and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, CO 80523, USA
| | | | - Rhythm Dadhwal
- College of Business, Colorado State University, Fort Collins, CO, USA
| | - Malik Zohaib Ali
- Department of Microbiology, Immunology, and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, CO 80523, USA; Cell and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Johnathan Patterson
- Department of Microbiology, Immunology, and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, CO 80523, USA
| | - Elizabeth Creissen
- Department of Microbiology, Immunology, and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, CO 80523, USA
| | - Elisa Rampacci
- Department of Veterinary Medicine, University of Perugia, Perugia, Italy
| | - Sarah K Cooper
- Department of Microbiology, Immunology, and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, CO 80523, USA
| | - Brendan K Podell
- Department of Microbiology, Immunology, and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, CO 80523, USA
| | - Mercedes Gonzalez-Juarrero
- Department of Microbiology, Immunology, and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, CO 80523, USA
| | - Andres Obregon-Henao
- Department of Microbiology, Immunology, and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, CO 80523, USA
| | - Marcela Henao-Tamayo
- Department of Microbiology, Immunology, and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, CO 80523, USA.
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7
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Korotetskaya M, Baikuzina P, Segura-Cerda CA, Aceves-Sánchez MDJ, Apt A, Flores-Valdez MA. BCG and BCGΔBCG1419c transiently protect hypersusceptible I/St mice and induce different influx of macrophages and neutrophils during pulmonary tuberculosis. J Med Microbiol 2022; 71. [PMID: 35037613 DOI: 10.1099/jmm.0.001485] [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] [Indexed: 12/15/2022] Open
Abstract
Background. Host genetic factors influence both susceptibility to Mycobacterium tuberculosis infection and immune responses generated by vaccination. Genetically susceptible mice help to study mechanisms of immune protection which may differ from those operating in more resistant models.Methods. In this work, we compared the efficacy of protection conferred by subcutaneous vaccination of hypersusceptible I/St mice with BCG and the first-generation, hygromycin resistant version of the vaccine candidate BCGΔBCG1419c, against tuberculosis (TB), measured as survival, weight loss and replication in lungs. We further characterized the relative presence of immune cells in lungs.Results. We found that in I/St mice, vaccination with BCG or BCGΔBCG1419c provided similar level of protection against TB-driven weight loss and M. tuberculosis replication in lungs, while prolonging median survival time compared with unvaccinated controls. Despite affording similar protection to parental BCG, BCGΔBCG1419c led to a reduced presence of macrophages in lungs during early TB and to an increased neutrophil recruitment to the lungs during chronic TB.Conclusions. BCGΔBCG1419c protects I/St mice in a different manner than wild-type BCG against pulmonary TB by promoting different influx of macrophages and neutrophils at distinct times post-infection. These findings prompt us to suggest that preclinical evaluation of novel TB vaccine candidates should include evaluation of efficacy not only in commonly used resistant inbred mice, but also in susceptible hosts, to further determine their potential application to populations varying in their genetic. This would likely impact their intended use depending on host resistance or susceptibility to TB.
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Affiliation(s)
- Maria Korotetskaya
- Central Institute for Tuberculosis, Department of Immunology, Laboratory of Immunogenetics, Moscow, Russia
| | - Polina Baikuzina
- Central Institute for Tuberculosis, Department of Immunology, Laboratory of Immunogenetics, Moscow, Russia
| | - Cristian Alfredo Segura-Cerda
- Biotecnología Médica y Farmacéutica, Centro de Investigación y Asistencia en Tecnología y diseño del Estado de Jalisco, A.C., Guadalajara, Jalisco, Mexico
| | - Michel de Jesús Aceves-Sánchez
- Biotecnología Médica y Farmacéutica, Centro de Investigación y Asistencia en Tecnología y diseño del Estado de Jalisco, A.C., Guadalajara, Jalisco, Mexico
| | - Alexander Apt
- Central Institute for Tuberculosis, Department of Immunology, Laboratory of Immunogenetics, Moscow, Russia
| | - Mario Alberto Flores-Valdez
- Biotecnología Médica y Farmacéutica, Centro de Investigación y Asistencia en Tecnología y diseño del Estado de Jalisco, A.C., Guadalajara, Jalisco, Mexico
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8
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Ahmed A, Rakshit S, Adiga V, Dias M, Dwarkanath P, D'Souza G, Vyakarnam A. A century of BCG: Impact on tuberculosis control and beyond. Immunol Rev 2021; 301:98-121. [PMID: 33955564 DOI: 10.1111/imr.12968] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/13/2021] [Accepted: 03/13/2021] [Indexed: 12/14/2022]
Abstract
BCG turns 100 this year and while it might not be the perfect vaccine, it has certainly contributed significantly towards eradication and prevention of spread of tuberculosis (TB). The search for newer and better vaccines for TB is an ongoing endeavor and latest results from trials of candidate TB vaccines such as M72AS01 look promising. However, recent encouraging data from BCG revaccination trials in adults combined with studies on mucosal and intravenous routes of BCG vaccination in non-human primate models have renewed interest in BCG for TB prevention. In addition, several well-demonstrated non-specific effects of BCG, for example, prevention of viral and respiratory infections, give BCG an added advantage. Also, BCG vaccination is currently being widely tested in human clinical trials to determine whether it protects against SARS-CoV-2 infection and/or death with detailed analyses and outcomes from several ongoing trials across the world awaited. Through this review, we attempt to bring together information on various aspects of the BCG-induced immune response, its efficacy in TB control, comparison with other candidate TB vaccines and strategies to improve its efficiency including revaccination and alternate routes of administration. Finally, we discuss the future relevance of BCG use especially in light of its several heterologous benefits.
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Affiliation(s)
- Asma Ahmed
- Laboratory of Immunology of HIV-TB co-infection, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
| | - Srabanti Rakshit
- Laboratory of Immunology of HIV-TB co-infection, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
| | - Vasista Adiga
- Laboratory of Immunology of HIV-TB co-infection, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India
| | - Mary Dias
- Division of Infectious Diseases, St John's Research Institute, Bangalore, India
| | | | - George D'Souza
- Division of Infectious Diseases, St John's Research Institute, Bangalore, India.,Department of Pulmonary Medicine, St John's Medical College, Bangalore, India
| | - Annapurna Vyakarnam
- Laboratory of Immunology of HIV-TB co-infection, Centre for Infectious Disease Research, Indian Institute of Science, Bangalore, India.,Peter Gorer Department of Immunobiology, School of Immunology and Microbial Sciences, Faculty of Life Sciences and Medicine, Guy's Hospital, King's College London, London, UK
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9
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Martinot AJ, Blass E, Yu J, Aid M, Mahrokhian SH, Cohen SB, Plumlee CR, Larocca RA, Siddiqi N, Wakabayashi S, Gardner M, Audette R, Devorak A, Urdahl KB, Rubin EJ, Barouch DH. Protective efficacy of an attenuated Mtb ΔLprG vaccine in mice. PLoS Pathog 2020; 16:e1009096. [PMID: 33315936 PMCID: PMC7769599 DOI: 10.1371/journal.ppat.1009096] [Citation(s) in RCA: 9] [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: 06/07/2020] [Revised: 12/28/2020] [Accepted: 10/26/2020] [Indexed: 01/14/2023] Open
Abstract
Bacille Calmette-Guerin (BCG), an attenuated whole cell vaccine based on Mycobacterium bovis, is the only licensed vaccine against Mycobacterium tuberculosis (Mtb), but its efficacy is suboptimal and it fails to protect against pulmonary tuberculosis. We previously reported that Mtb lacking the virulence genes lprG and rv1410c (ΔLprG) was highly attenuated in immune deficient mice. In this study, we show that attenuated ΔLprG Mtb protects C57BL/6J, Balb/cJ, and C3HeB/FeJ mice against Mtb challenge and is as attenuated as BCG in SCID mice. In C3HeB/FeJ mice, ΔLprG vaccination resulted in innate peripheral cytokine production and induced high polyclonal PPD-specific cytokine-secreting CD4+ T lymphocytes in peripheral blood. The ΔLprG vaccine afforded protective efficacy in the lungs of C3H/FeJ mice following both H37Rv and Erdman aerosolized Mtb challenges. Vaccine efficacy correlated with antigen-specific PD-1-negative CD4+ T lymphocytes as well as with serum IL-17 levels after vaccination. We hypothesize that induction of Th17 cells in lung is critical for vaccine protection, and we show a serum cytokine biomarker for IL-17 shortly after vaccination may predict protective efficacy. Many successful vaccines are based on attenuated human pathogens. The only licensed tuberculosis vaccine, BCG, is based on an attenuated version of live whole cell Mycobacterium bovis, the causative agent of tuberculosis (TB) in cattle. Advantages to using attenuated pathogens as vaccines include a broad antigen composition including proteins, lipids, carbohydrates and other molecules that can induce durable immune responses sometimes lasting decades. Here we test an attenuated Mycobacterium tuberculosis (Mtb), the causative agent of human TB, that lacks a key virulence factor as an alternative whole cell vaccine in mice. Attenuated Mtb lacking a key virulence protein, LprG, is immunogenic and protects mice against Mtb challenge. The LprG whole cell vaccine is protective in mice that develop lung pathology more similar to what is described in human TB and the LprG vaccine induces a key cytokine, IL-17, thought to be important for vaccine protection, in the peripheral blood early after vaccination. Together these data support the continued development of attenuated TB as a potential vaccine candidate. Furthermore our data suggests that serum IL-17 should be explored as a potential biomarker for vaccine efficacy in preclinical animal models.
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Affiliation(s)
- Amanda J. Martinot
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Infectious Diseases and Global Health, Tufts University Cummings School of Veterinary Medicine, North Grafton, Massachusetts, United States of America
| | - Eryn Blass
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jingyou Yu
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Malika Aid
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Shant H. Mahrokhian
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Sara B. Cohen
- Department of Immunology, Seattle Children’s Research Institute, Seattle, Washington, United States of America
| | - Courtney R. Plumlee
- Department of Immunology, Seattle Children’s Research Institute, Seattle, Washington, United States of America
| | - Rafael A. Larocca
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Noman Siddiqi
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Shoko Wakabayashi
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Michelle Gardner
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Rebecca Audette
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Anne Devorak
- Department of Infectious Diseases and Global Health, Tufts University Cummings School of Veterinary Medicine, North Grafton, Massachusetts, United States of America
| | - Kevin B. Urdahl
- Department of Immunology, Seattle Children’s Research Institute, Seattle, Washington, United States of America
- Departments of Pediatrics and Immunology, University of Washington, Seattle, Washington, United States of America
| | - Eric J. Rubin
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Dan H. Barouch
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
- Ragon Institute of MGH, MIT, and Harvard, Cambridge, Massachusetts, United States of America
- * E-mail:
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10
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Abstract
This manuscript describes the infection of mice and guinea pigs with mycobacteria via various routes, as well as necropsy methods for the determination of mycobacterial loads within target organs. Additionally, methods for cultivating mycobacteria and preparing stocks are described. The protocols outlined are primarily used for M. tuberculosis, but can also be used for the study of other non-tuberculosis mycobacterial species. A wide variety of animal models have been used to test new vaccines, drugs, and the impact of cigarette exposure. © 2020 Wiley Periodicals LLC. Basic Protocol 1: Aerosol infection of mice with mycobacteria Basic Protocol 2: Aerosol infection of guinea pig with mycobacteria using a Madison chamber Alternate Protocol 1: Cigarette exposure prior to infection of mice with mycobacteria Alternate Protocol 2: Intravenous infection of mice with mycobacteria Basic Protocol 3: Necropsy methods for animals experimentally infected with mycobacteria Basic Protocol 4: Following the course of infection Basic Protocol 5: Measuring the animal immune response to infection Support Protocol: Cultivation of mycobacteria for use in animal experiments.
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Affiliation(s)
- Edward D Chan
- Department of Medicine, Rocky Mountain Regional Veterans Affairs Medical Center, Departments of Medicine and Academic Affairs, National Jewish Health, Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Denver, Colorado
| | - Deepshikha Verma
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado
| | - Diane J Ordway
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado
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Ramos L, Lunney JK, Gonzalez-Juarrero M. Neonatal and infant immunity for tuberculosis vaccine development: importance of age-matched animal models. Dis Model Mech 2020; 13:dmm045740. [PMID: 32988990 PMCID: PMC7520460 DOI: 10.1242/dmm.045740] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Neonatal and infant immunity differs from that of adults in both the innate and adaptive arms, which are critical contributors to immune-mediated clearance of infection and memory responses elicited during vaccination. The tuberculosis (TB) research community has openly admitted to a vacuum of knowledge about neonatal and infant immune responses to Mycobacterium tuberculosis (Mtb) infection, especially in the functional and phenotypic attributes of memory T cell responses elicited by the only available vaccine for TB, the Bacillus Calmette-Guérin (BCG) vaccine. Although BCG vaccination has variable efficacy in preventing pulmonary TB during adolescence and adulthood, 80% of endemic TB countries still administer BCG at birth because it has a good safety profile and protects children from severe forms of TB. As such, new vaccines must work in conjunction with BCG at birth and, thus, it is essential to understand how BCG shapes the immune system during the first months of life. However, many aspects of the neonatal and infant immune response elicited by vaccination with BCG remain unknown, as only a handful of studies have followed BCG responses in infants. Furthermore, most animal models currently used to study TB vaccine candidates rely on adult-aged animals. This presents unique challenges when transitioning to human trials in neonates or infants. In this Review, we focus on vaccine development in the field of TB and compare the relative utility of animal models used thus far to study neonatal and infant immunity. We encourage the development of neonatal animal models for TB, especially the use of pigs.
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Affiliation(s)
- Laylaa Ramos
- Mycobacteria Research Laboratories, Microbiology Immunology and Pathology Department, Colorado State University, 1682 Campus Delivery, Fort Collins, CO 80523, USA
| | - Joan K Lunney
- Animal Parasitic Diseases Laboratory, BARC, NEA, ARS, USDA Building 1040, Room 103, Beltsville, MD 20705, USA
| | - Mercedes Gonzalez-Juarrero
- Mycobacteria Research Laboratories, Microbiology Immunology and Pathology Department, Colorado State University, 1682 Campus Delivery, Fort Collins, CO 80523, USA
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Verma D, Stapleton M, Gadwa J, Vongtongsalee K, Schenkel AR, Chan ED, Ordway D. Mycobacterium avium Infection in a C3HeB/FeJ Mouse Model. Front Microbiol 2019; 10:693. [PMID: 31001241 PMCID: PMC6456659 DOI: 10.3389/fmicb.2019.00693] [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: 06/28/2018] [Accepted: 03/19/2019] [Indexed: 01/08/2023] Open
Abstract
Infections caused by Mycobacterium avium complex (MAC) species are increasing worldwide, resulting in a serious public health problem. Patients with MAC lung disease face an arduous journey of a prolonged multidrug regimen that is often poorly tolerated and associated with relatively poor outcome. Identification of new animal models that demonstrate a similar pulmonary pathology as humans infected with MAC has the potential to significantly advance our understanding of nontuberculosis mycobacteria (NTM) pathogenesis as well as provide a tractable model for screening candidate compounds for therapy. One new mouse model is the C3HeB/FeJ which is similar to MAC patients in that these mice can form foci of necrosis in granulomas. In this study, we evaluated the ability of C3HeB/FeJ mice exposure to an aerosol infection of a rough strain of MAC 2285 to produce a progressive infection resulting in small necrotic foci during granuloma formation. C3HeB/FeJ mice were infected with MAC and demonstrated a progressive lung infection resulting in an increase in bacterial burden peaking around day 40, developed micronecrosis in granulomas and was associated with increased influx of CD4+ Th1, Th17, and Treg lymphocytes into the lungs. However, during chronic infection around day 50, the bacterial burden plateaued and was associated with the reduced influx of CD4+ Th1, Th17 cells, and increased numbers of Treg lymphocytes and necrotic foci during granuloma formation. These results suggest the C3HeB/FeJ MAC infection mouse model will be an important model to evaluate immune pathogenesis and compound efficacy.
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Affiliation(s)
- Deepshikha Verma
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, United States
| | - Megan Stapleton
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, United States
| | - Jake Gadwa
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, United States
| | - Kridakorn Vongtongsalee
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, United States
| | - Alan R Schenkel
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, United States
| | - Edward D Chan
- Department of Medicine, Denver Veterans Affairs Medical Center, Denver, CO, United States.,Departments of Medicine and Academic Affairs, National Jewish Health, Denver, CO, United States.,Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Diane Ordway
- Mycobacteria Research Laboratories, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, United States
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13
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Mantilla Galindo A, Ocampo M, Patarroyo MA. Experimental models used in evaluating anti-tuberculosis vaccines: the latest advances in the field. Expert Rev Vaccines 2019; 18:365-377. [PMID: 30773949 DOI: 10.1080/14760584.2019.1583558] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
INTRODUCTION Tuberculosis is an infectious disease which is caused by bacilli from the M. tuberculosis complex. The Mycobacterium bovis Bacillus Calmette-Guérin vaccine is currently available as a prophylactic tool for preventing the disease; it has been shown to be efficient in preventing disseminated forms of tuberculosis during early ages; however, its efficiency is limited in areas where individuals have had prior exposure to environmental mycobacteria, and its efficacy decreases with a host's age. AREAS COVERED Following a comprehensive search of the available literature, this review describes some of the most frequently used animal models, the most frequently used methods for evaluating efficacy in animal models and some in vitro strategies as alternatives for evaluating vaccines. EXPERT OPINION Identifying the animal models used up to now for evaluating vaccines during their development stages, their characteristics and limitations, as well as knowledge regarding strategies for evaluating promising vaccine candidate efficacy, will ensure more efficient, reliable and reproducible pre-clinical trials. Although much of the knowledge accrued to date concerning vaccine effectiveness against tuberculosis has been based on animal models, it is clear that large questions still need to be resolved and that extrapolation of such efficacy to humans has yet to be achieved.
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Affiliation(s)
| | - Marisol Ocampo
- b Basic Sciences Department, School of Medicine and Health Sciences , Universidad del Rosario , Bogotá , Colombia.,c Department of Tuberculosis and Molecular Biology , Fundación Instituto de Inmunología de Colombia (FIDIC) , Bogotá , Colombia
| | - Manuel Alfonso Patarroyo
- b Basic Sciences Department, School of Medicine and Health Sciences , Universidad del Rosario , Bogotá , Colombia.,c Department of Tuberculosis and Molecular Biology , Fundación Instituto de Inmunología de Colombia (FIDIC) , Bogotá , Colombia
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Abstract
Immunity against Mycobacterium tuberculosis requires a balance between adaptive immune responses to constrain bacterial replication and the prevention of potentially damaging immune activation. Regulatory T (Treg) cells express the transcription factor Foxp3+ and constitute an essential counterbalance of inflammatory Th1 responses and are required to maintain immune homeostasis. The first reports describing the presence of Foxp3-expressing CD4+ Treg cells in tuberculosis (TB) emerged in 2006. Different Treg cell subsets, most likely specialized for different tissues and microenvironments, have been shown to expand in both human TB and animal models of TB. Recently, additional functional roles for Treg cells have been demonstrated during different stages and spectrums of TB disease. Foxp3+ regulatory cells can quickly expand during early infection and impede the onset of cellular immunity and persist during chronic TB infection. Increased frequencies of Treg cells have been associated with a detrimental outcome of active TB, and may be dependent on the M. tuberculosis strain, animal model, local environment, and the stage of infection. Some investigations also suggest that Treg cells are required together with effector T cell responses to obtain reduced pathology and sterilizing immunity. In this review, we will first provide an overview of the regulatory cells and mechanisms that control immune homeostasis. Then, we will review what is known about the phenotype and function of Treg cells from studies in human TB and experimental animal models of TB. We will discuss the potential role of Treg cells in the progression of TB disease and the relevance of this knowledge for future efforts to prevent, modulate, and treat TB.
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15
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Zhan L, Tang J, Sun M, Qin C. Animal Models for Tuberculosis in Translational and Precision Medicine. Front Microbiol 2017; 8:717. [PMID: 28522990 PMCID: PMC5415616 DOI: 10.3389/fmicb.2017.00717] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 04/06/2017] [Indexed: 12/12/2022] Open
Abstract
Tuberculosis (TB) is a health threat to the global population. Anti-TB drugs and vaccines are key approaches for TB prevention and control. TB animal models are basic tools for developing biomarkers of diagnosis, drugs for therapy, vaccines for prevention and researching pathogenic mechanisms for identification of targets; thus, they serve as the cornerstone of comparative medicine, translational medicine, and precision medicine. In this review, we discuss the current use of TB animal models and their problems, as well as offering perspectives on the future of these models.
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Affiliation(s)
- Lingjun Zhan
- Key Laboratory of Human Disease Comparative Medicine, Ministry of HealthBeijing, China.,Institution of Laboratory Animal Sciences, Centre for Tuberculosis, Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing, China.,Beijing Key Laboratory for Animal Models of Emerging and Reemerging InfectiousBeijing, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijing, China.,Key Laboratory of Human Diseases Animal Model, State Administration of Traditional Chinese MedicineBeijing, China
| | - Jun Tang
- Key Laboratory of Human Disease Comparative Medicine, Ministry of HealthBeijing, China.,Institution of Laboratory Animal Sciences, Centre for Tuberculosis, Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing, China.,Beijing Key Laboratory for Animal Models of Emerging and Reemerging InfectiousBeijing, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijing, China.,Key Laboratory of Human Diseases Animal Model, State Administration of Traditional Chinese MedicineBeijing, China
| | - Mengmeng Sun
- Key Laboratory of Human Disease Comparative Medicine, Ministry of HealthBeijing, China.,Institution of Laboratory Animal Sciences, Centre for Tuberculosis, Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing, China.,Beijing Key Laboratory for Animal Models of Emerging and Reemerging InfectiousBeijing, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijing, China.,Key Laboratory of Human Diseases Animal Model, State Administration of Traditional Chinese MedicineBeijing, China
| | - Chuan Qin
- Key Laboratory of Human Disease Comparative Medicine, Ministry of HealthBeijing, China.,Institution of Laboratory Animal Sciences, Centre for Tuberculosis, Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing, China.,Beijing Key Laboratory for Animal Models of Emerging and Reemerging InfectiousBeijing, China.,Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijing, China.,Key Laboratory of Human Diseases Animal Model, State Administration of Traditional Chinese MedicineBeijing, China
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Moliva JI, Turner J, Torrelles JB. Immune Responses to Bacillus Calmette-Guérin Vaccination: Why Do They Fail to Protect against Mycobacterium tuberculosis? Front Immunol 2017; 8:407. [PMID: 28424703 PMCID: PMC5380737 DOI: 10.3389/fimmu.2017.00407] [Citation(s) in RCA: 99] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 03/22/2017] [Indexed: 12/11/2022] Open
Abstract
Mycobacterium tuberculosis (M.tb), the causative agent of tuberculosis (TB), is the current leading cause of death due to a single infectious organism. Although curable, the broad emergence of multi-, extensive-, extreme-, and total-drug resistant strains of M.tb has hindered eradication efforts of this pathogen. Furthermore, computational models predict a quarter of the world’s population is infected with M.tb in a latent state, effectively serving as the largest reservoir for any human pathogen with the ability to cause significant morbidity and mortality. The World Health Organization has prioritized new strategies for improved vaccination programs; however, the lack of understanding of mycobacterial immunity has made it difficult to develop new successful vaccines. Currently, Mycobacterium bovis bacillus Calmette–Guérin (BCG) is the only vaccine approved for use to prevent TB. BCG is highly efficacious at preventing meningeal and miliary TB, but is at best 60% effective against the development of pulmonary TB in adults and wanes as we age. In this review, we provide a detailed summary on the innate immune response of macrophages, dendritic cells, and neutrophils in response to BCG vaccination. Additionally, we discuss adaptive immune responses generated by BCG vaccination, emphasizing their specific contributions to mycobacterial immunity. The success of future vaccines against TB will directly depend on our understanding of mycobacterial immunity.
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Affiliation(s)
- Juan I Moliva
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Joanne Turner
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH, USA.,Center for Microbial Interface Biology, The Ohio State University, Columbus, OH, USA
| | - Jordi B Torrelles
- Department of Microbial Infection and Immunity, College of Medicine, The Ohio State University, Columbus, OH, USA.,Center for Microbial Interface Biology, The Ohio State University, Columbus, OH, USA
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Novel vaccine potential of Rv3131, a DosR regulon-encoded putative nitroreductase, against hyper-virulent Mycobacterium tuberculosis strain K. Sci Rep 2017; 7:44151. [PMID: 28272457 PMCID: PMC5341159 DOI: 10.1038/srep44151] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 02/03/2017] [Indexed: 12/12/2022] Open
Abstract
Accumulating evidence indicates that latency-associated Mycobacterium tuberculosis (Mtb)-specific antigens from the dormancy survival regulator regulon (DosR) may be promising novel vaccine target antigens for the development of an improved tuberculosis vaccine. After transcriptional profiling of DosR-related genes in the hyper-virulent Beijing Mtb strain K and the reference Mtb strain H37Rv, we selected Rv3131, a hypothetical nitroreductase, as a vaccine antigen and evaluated its vaccine efficacy against Mtb K. Mtb K exhibited stable and constitutive up-regulation of rv3131 relative to Mtb H37Rv under three different growth conditions (at least 2-fold induction) including exponential growth in normal culture conditions, hypoxia, and inside macrophages. Mice immunised with Rv3131 formulated in GLA-SE, a well-defined TLR4 adjuvant, displayed enhanced Rv3131-specific IFN-γ and serum IgG2c responses along with effector/memory T cell expansion and remarkable generation of Rv3131-specific multifunctional CD4+ T cells co-producing TNF-α, IFN-γ and IL-2 in both spleen and lung. Following challenge with Mtb K, the Rv3131/GLA-SE-immunised group exhibited a significant reduction in bacterial number and less extensive lung inflammation accompanied by the obvious persistence of Rv3131-specific multifunctional CD4+ T cells. These results suggest that Rv3131 could be an excellent candidate for potential use in a multi-antigenic Mtb subunit vaccine, especially against Mtb Beijing strains.
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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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Tuberculosis Susceptibility and Vaccine Protection Are Independently Controlled by Host Genotype. mBio 2016; 7:mBio.01516-16. [PMID: 27651361 PMCID: PMC5030360 DOI: 10.1128/mbio.01516-16] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
UNLABELLED The outcome of Mycobacterium tuberculosis infection and the immunological response to the bacillus Calmette-Guerin (BCG) vaccine are highly variable in humans. Deciphering the relative importance of host genetics, environment, and vaccine preparation for the efficacy of BCG has proven difficult in natural populations. We developed a model system that captures the breadth of immunological responses observed in outbred individual mice, which can be used to understand the contribution of host genetics to vaccine efficacy. This system employs a panel of highly diverse inbred mouse strains, consisting of the founders and recombinant progeny of the "Collaborative Cross" project. Unlike natural populations, the structure of this panel allows the serial evaluation of genetically identical individuals and the quantification of genotype-specific effects of interventions such as vaccination. When analyzed in the aggregate, our panel resembled natural populations in several important respects: the animals displayed a broad range of susceptibility to M. tuberculosis, differed in their immunological responses to infection, and were not durably protected by BCG vaccination. However, when analyzed at the genotype level, we found that these phenotypic differences were heritable. M. tuberculosis susceptibility varied between lines, from extreme sensitivity to progressive M. tuberculosis clearance. Similarly, only a minority of the genotypes was protected by vaccination. The efficacy of BCG was genetically separable from susceptibility to M. tuberculosis, and the lack of efficacy in the aggregate analysis was driven by nonresponsive lines that mounted a qualitatively distinct response to infection. These observations support an important role for host genetic diversity in determining BCG efficacy and provide a new resource to rationally develop more broadly efficacious vaccines. IMPORTANCE Tuberculosis (TB) remains an urgent global health crisis, and the efficacy of the currently used TB vaccine, M. bovis BCG, is highly variable. The design of more broadly efficacious vaccines depends on understanding the factors that limit the protection imparted by BCG. While these complex factors are difficult to disentangle in natural populations, we used a model population of mice to understand the role of host genetic composition in BCG efficacy. We found that the ability of BCG to protect mice with different genotypes was remarkably variable. The efficacy of BCG did not depend on the intrinsic susceptibility of the animal but, instead, correlated with qualitative differences in the immune responses to the pathogen. These studies suggest that host genetic polymorphism is a critical determinant of vaccine efficacy and provide a model system to develop interventions that will be useful in genetically diverse populations.
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Mouse models of human TB pathology: roles in the analysis of necrosis and the development of host-directed therapies. Semin Immunopathol 2015; 38:221-37. [PMID: 26542392 PMCID: PMC4779126 DOI: 10.1007/s00281-015-0538-9] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 10/22/2015] [Indexed: 12/28/2022]
Abstract
A key aspect of TB pathogenesis that maintains Mycobacterium tuberculosis in the human population is the ability to cause necrosis in pulmonary lesions. As co-evolution shaped M. tuberculosis (M.tb) and human responses, the complete TB disease profile and lesion manifestation are not fully reproduced by any animal model. However, animal models are absolutely critical to understand how infection with virulent M.tb generates outcomes necessary for the pathogen transmission and evolutionary success. In humans, a wide spectrum of TB outcomes has been recognized based on clinical and epidemiological data. In mice, there is clear genetic basis for susceptibility. Although the spectra of human and mouse TB do not completely overlap, comparison of human TB with mouse lesions across genetically diverse strains firmly establishes points of convergence. By embracing the genetic heterogeneity of the mouse population, we gain tremendous advantage in the quest for suitable in vivo models. Below, we review genetically defined mouse models that recapitulate a key element of M.tb pathogenesis—induction of necrotic TB lesions in the lungs—and discuss how these models may reflect TB stratification and pathogenesis in humans. The approach ensures that roles that mouse models play in basic and translational TB research will continue to increase allowing researchers to address fundamental questions of TB pathogenesis and bacterial physiology in vivo using this well-defined, reproducible, and cost-efficient system. Combination of the new generation mouse models with advanced imaging technologies will also allow rapid and inexpensive assessment of experimental vaccines and therapies prior to testing in larger animals and clinical trials.
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Susceptibility of Mycobacterium abscessus to antimycobacterial drugs in preclinical models. Antimicrob Agents Chemother 2015; 59:6904-12. [PMID: 26303795 DOI: 10.1128/aac.00459-15] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 08/15/2015] [Indexed: 12/11/2022] Open
Abstract
Over the last 10 years, Mycobacterium abscessus group strains have emerged as important human pathogens, which are associated with significantly higher fatality rates than any other rapidly growing mycobacteria. These opportunistic pathogens are widespread in the environment and can cause a wide range of clinical diseases, including skin, soft tissue, central nervous system, and disseminated infections; by far, the most difficult to treat is the pulmonary form. Infections with M. abscessus are often multidrug-resistant (MDR) and require prolonged treatment with various regimens and, many times, result in high mortality despite maximal therapy. We report here the evaluation of diverse mouse infection models for their ability to produce a progressive high level of infection with M. abscessus. The nude (nu/nu), SCID (severe combined immunodeficiency), gamma interferon knockout (GKO), and granulocyte-macrophage colony-stimulating factor (GMCSF) knockout mice fulfilled the criteria for an optimal model for compound screening. Thus, we set out to assess the antimycobacterial activity of clarithromycin, clofazimine, bedaquiline, and clofazimine-bedaquiline combinations against M. abscessus-infected GKO and SCID murine infection models. Treatment of GKO and SCID mice with a combination of clofazimine and bedaquiline was the most effective in decreasing the M. abscessus organ burden.
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