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Stampolaki M, Malwal SR, Alvarez-Cabrera N, Gao Z, Moniruzzaman M, Babii SO, Naziris N, Rey-Cibati A, Valladares-Delgado M, Turcu AL, Baek KH, Phan TN, Lee H, Alcaraz M, Watson S, van der Watt M, Coertzen D, Efstathiou N, Chountoulesi M, Shoen CM, Papanastasiou IP, Brea J, Cynamon MH, Birkholtz LM, Kremer L, No JH, Vázquez S, Benaim G, Demetzos C, Zgurskaya HI, Dick T, Oldfield E, D. Kolocouris A. Synthesis and Testing of Analogs of the Tuberculosis Drug Candidate SQ109 against Bacteria and Protozoa: Identification of Lead Compounds against Mycobacterium abscessus and Malaria Parasites. ACS Infect Dis 2023; 9:342-364. [PMID: 36706233 PMCID: PMC10615177 DOI: 10.1021/acsinfecdis.2c00537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
SQ109 is a tuberculosis drug candidate that has high potency against Mycobacterium tuberculosis and is thought to function at least in part by blocking cell wall biosynthesis by inhibiting the MmpL3 transporter. It also has activity against bacteria and protozoan parasites that lack MmpL3, where it can act as an uncoupler, targeting lipid membranes and Ca2+ homeostasis. Here, we synthesized 18 analogs of SQ109 and tested them against M. smegmatis, M. tuberculosis, M. abscessus, Bacillus subtilis, and Escherichia coli, as well as against the protozoan parasites Trypanosoma brucei, T. cruzi, Leishmania donovani, L. mexicana, and Plasmodium falciparum. Activity against the mycobacteria was generally less than with SQ109 and was reduced by increasing the size of the alkyl adduct, but two analogs were ∼4-8-fold more active than SQ109 against M. abscessus, including a highly drug-resistant strain harboring an A309P mutation in MmpL3. There was also better activity than found with SQ109 with other bacteria and protozoa. Of particular interest, we found that the adamantyl C-2 ethyl, butyl, phenyl, and benzyl analogs had 4-10× increased activity against P. falciparum asexual blood stages, together with low toxicity to a human HepG2 cell line, making them of interest as new antimalarial drug leads. We also used surface plasmon resonance to investigate the binding of inhibitors to MmpL3 and differential scanning calorimetry to investigate binding to lipid membranes. There was no correlation between MmpL3 binding and M. tuberculosis or M. smegmatis cell activity, suggesting that MmpL3 is not a major target in mycobacteria. However, some of the more active species decreased lipid phase transition temperatures, indicating increased accumulation in membranes, which is expected to lead to enhanced uncoupler activity.
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Affiliation(s)
- Marianna Stampolaki
- Laboratory of Medicinal Chemistry, Section of Pharmaceutical Chemistry, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou, Athens 15771, Greece
| | - Satish R. Malwal
- Department of Chemistry, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801, USA
| | | | - Zijun Gao
- Department of Chemistry, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801, USA
| | - Mohammad Moniruzzaman
- University of Oklahoma, Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, 101 Stephenson Parkway, Norman, OK 73019-5251, USA
| | - Svitlana O. Babii
- University of Oklahoma, Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, 101 Stephenson Parkway, Norman, OK 73019-5251, USA
| | - Nikolaos Naziris
- Section of Pharmaceutical Technology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou, Athens 15771, Greece
| | - André Rey-Cibati
- Instituto de Estudios Avanzados, Caracas, Venezuela Instituto de Biología Experimental, Facultad de Ciencias, Universidad Central de Venezuela (UCV), Caracas, Venezuela
| | - Mariana Valladares-Delgado
- Instituto de Estudios Avanzados, Caracas, Venezuela Instituto de Biología Experimental, Facultad de Ciencias, Universidad Central de Venezuela (UCV), Caracas, Venezuela
| | - Andreea L. Turcu
- Laboratori de Química Farmacèutica (Unitat Associada al CSIC), Departament de Farmacologia, Toxicologia i Química Terapèutica, Facultat de Farmàcia i Ciències de l’Alimentació, and Institute of Biomedicine (IBUB), Universitat de Barcelona, Av. Joan XXIII, 27-31, Barcelona, E-08028, Spain
| | - Kyung-Hwa Baek
- Host-Parasite Research Laboratory, Institut Pasteur Korea, Seongnam-si, Republic of Korea
| | - Trong-Nhat Phan
- Host-Parasite Research Laboratory, Institut Pasteur Korea, Seongnam-si, Republic of Korea
| | - Hyeryon Lee
- Host-Parasite Research Laboratory, Institut Pasteur Korea, Seongnam-si, Republic of Korea
| | - Mattheo Alcaraz
- Institut de Recherche en Infectiologie de Montpellier, CNRS UMR9004, Université de Montpellier, 1919 route de Mende, 34293, Montpellier, France
| | - Savannah Watson
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, Pretoria, 0028, South Africa
| | - Mariette van der Watt
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, Pretoria, 0028, South Africa
| | - Dina Coertzen
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, Pretoria, 0028, South Africa
| | - Natasa Efstathiou
- Laboratory of Medicinal Chemistry, Section of Pharmaceutical Chemistry, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou, Athens 15771, Greece
| | - Maria Chountoulesi
- Section of Pharmaceutical Technology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou, Athens 15771, Greece
| | - Carolyn M. Shoen
- Central New York Research Corporation, Veterans Affairs Medical Center, Syracuse, NY 13210, U
| | - Ioannis P. Papanastasiou
- Laboratory of Medicinal Chemistry, Section of Pharmaceutical Chemistry, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou, Athens 15771, Greece
| | - Jose Brea
- Drug Screening Platform/Biofarma Research Group, CIMUS Research Center, Departamento de Farmacoloxía, Farmacia e Tecnoloxía Farmacéutica, University of Santiago de Compostela (USC), 15782 Santiago de Compostela, Spain
| | - Michael H. Cynamon
- Central New York Research Corporation, Veterans Affairs Medical Center, Syracuse, NY 13210, U
| | - Lyn-Marié Birkholtz
- Department of Biochemistry, Genetics and Microbiology, Institute for Sustainable Malaria Control, University of Pretoria, Hatfield, Pretoria, 0028, South Africa
| | - Laurent Kremer
- Institut de Recherche en Infectiologie de Montpellier, CNRS UMR9004, Université de Montpellier, 1919 route de Mende, 34293, Montpellier, France
- INSERM, IRIM, Montpellier, France
| | - Joo Hwan No
- Host-Parasite Research Laboratory, Institut Pasteur Korea, Seongnam-si, Republic of Korea
| | - Santiago Vázquez
- Laboratori de Química Farmacèutica (Unitat Associada al CSIC), Departament de Farmacologia, Toxicologia i Química Terapèutica, Facultat de Farmàcia i Ciències de l’Alimentació, and Institute of Biomedicine (IBUB), Universitat de Barcelona, Av. Joan XXIII, 27-31, Barcelona, E-08028, Spain
| | - Gustavo Benaim
- Instituto de Estudios Avanzados, Caracas, Venezuela Instituto de Biología Experimental, Facultad de Ciencias, Universidad Central de Venezuela (UCV), Caracas, Venezuela
| | - Costas Demetzos
- Section of Pharmaceutical Technology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou, Athens 15771, Greece
| | - Helen I. Zgurskaya
- University of Oklahoma, Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, 101 Stephenson Parkway, Norman, OK 73019-5251, USA
| | - Thomas Dick
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA
- Department of Medical Sciences, Hackensack Meridian School of Medicine, Nutley, NJ 07110, USA
- Department of Microbiology and Immunology, Georgetown University, Washington, DC 20007, USA
| | - Eric Oldfield
- Department of Chemistry, University of Illinois at Urbana–Champaign, Urbana, Illinois 61801, USA
| | - Antonios D. Kolocouris
- Laboratory of Medicinal Chemistry, Section of Pharmaceutical Chemistry, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis-Zografou, Athens 15771, Greece
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DeStefano MS, Shoen CM, Alley MRK, Cynamon MH. 1712. In Vitro Activity of Epetraborole, a Novel Bacterial Leucyl-tRNA Synthetase Inhibitor, in Drug Combinations Against Nontuberculous Mycobacteria Including Resistance Frequency and MIC Characterization of Mycobacterium avium ATCC 700898 Epetraborole-resistant Mutants. Open Forum Infect Dis 2022. [DOI: 10.1093/ofid/ofac492.1342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Abstract
Background
Epetraborole (EBO) is a boron-containing, oral inhibitor of bacterial leucyl-tRNA synthetase, an essential enzyme in protein synthesis; EBO demonstrates potent activity against nontuberculous mycobacteria (NTM). The standard of care therapy for Mycobacterium avium complex (MAC) lung disease consists of a combination of a macrolide, ethambutol (EMB) and a rifamycin. A total of 5 strains of MAC, M. abscessus ATCC 19977 and M. peregrinum ATCC 700686 were tested in checkerboard assays to evaluate the effects of combining EBO with other agents. The spontaneous resistance frequency (RF) was determined for EBO singly and in combination against M. avium ATCC 700898.
Methods
The effects of combining EBO with clarithromycin (CLR), rifabutin (RBT), EMB, amikacin (AMK) or bedaquiline (BDQ) were evaluated in 7 strains of NTM. Synergy, additive effects, indifference or antagonism was characterized in the checkerboard assay using EUCAST criteria. The RF of M. avium ATCC 700898 at 2x, 4x and 8x the MIC (8 mg/L) of EBO was determined, as was the RF of EBO combined with CLR, RBT, AMK or EMB. MICs of selected EBO mutants were determined against AMK, BDQ, CLR, RBT, EMB, and clofazimine (CFZ) and the mutants were further characterized.
Results
The RF of EBO ranged from 1.58x10-7 to 8.48x10-9 when selected on 2 - 8x agar MIC. The MIC for EBO increased 32- > 256-fold for the resistant mutants; however, the MICs for the other drugs tested against EBO-resistant strains did not change significantly. The activity of EBO was not antagonized, and was mainly indifferent to the addition of CLR, RBT, AMK, or BDQ for all the NTM strains tested. Synergy with EMB was observed with 2 strains and additivity with 2 additional strains of MAC. The addition of EMB (24 mg/L), CLR (32 mg/L), RFB (2 mg/L) or AMK (128 mg/L) to agar plates containing 2x MIC of EBO lowered the RF to at least < 2.13x10-10 (Table 1). Table 1.In Vitro Resistance Frequency for the Components of SOC with and without EBO in Mycobacterium avium ATCC 700898
Conclusion
In the checkerboard studies, no evidence of antagonism was observed with any strain or EBO combination; interactions were largely indifferent. EBO combined with EMB in MAC resulted in synergy or additive effects in the checkerboard assay. The addition of EMB, CLR, RFB or AMK to EBO led to a > 700-fold reduction in RF. Activity of other drugs was not impacted by EBO resistance suggesting that cross-resistance did not occur.
Disclosures
Michelle S. DeStefano, n/a, AN2 Therapeutics: Grant/Research Support Carolyn M. Shoen, PhD, AN2 Therapeutics: Grant/Research Support MRK Alley, PhD, ABBOTT LABS: Stocks/Bonds|ABBVIE: Stocks/Bonds|AN2 Therapeutics: Author on epetraborole patent|AN2 Therapeutics: Salary|AN2 Therapeutics: Ownership Interest|AVANOS MED INC: Stocks/Bonds|NABRIVA THERAPEUTICS PLC: Stocks/Bonds|NOVARTIS AG: Stocks/Bonds Michael H. Cynamon, MD, AN2: Grant/Research Support|AN2: Grant/Research Support.
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DeStefano MS, Shoen CM, Alley MRK, Cynamon MH. 1713. In Vitro Activities of Epetraborole, a Novel Bacterial Leucyl-tRNA Synthetase Inhibitor, Against Mycobacterium avium Complex Isolates. Open Forum Infect Dis 2022. [DOI: 10.1093/ofid/ofac492.1343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Abstract
Background
Epetraborole (EBO) is a boron-containing, oral inhibitor of bacterial leucyl-tRNA synthetase, an essential enzyme in protein synthesis; EBO demonstrates potent activity against nontuberculous mycobacteria. We evaluated the effects of select culture conditions on MIC determinations of EBO against isolates of M. avium complex (MAC), as well as EBO MIC90 results with Middlebrook 7H9 broth compared to those with cation-adjusted Mueller Hinton Broth (CAMHB) for 51 MAC isolates.
Methods
Six strains of MAC were used to test the in vitro activity of EBO in different conditions in a broth microdilution (BMD) assay. Activity was compared in Middlebrook 7H9 and CAMHB with 5% OADC from different manufacturers. The effects of glycerol, cations, oxyrase, varying pH levels, and increasing inoculum sizes were tested. Finally, EBO in vitro activity was tested for 51 MAC isolates in a BMD assay in both Middlebrook 7H9 and CAMHB with 5% OADC.
Results
In general, manipulation of select culture conditions caused very little variation in EBO MIC values for the 6 MAC strains except for increasing the inoculum from ∼105 to 107 CFU/mL, which caused an approximately 64x increase in the MIC. Since 1 MAC isolate out of 6 was affected by the addition of casitone, we tested 51 MAC isolates in both the minimal media Middlebrook 7H9 and the complex media CAMHB. EBO had a narrow MIC range in both broths, 0.25-8 mg/L for all isolates. The EBO modal MIC, MIC50 and MIC90 for the entire MAC panel of 51 isolates was 2 mg/L, 2 mg/L, and 8 mg/L for CAMHB and 1 mg/L, 1 mg/L, and 4 mg/L for Middlebrook 7H9, respectively (Table 1). Three clarithromycin-resistant isolates had EBO MIC values of 0.5 mg/L, 1 mg/L, and 2 mg/L suggesting that clarithromycin resistance does not affect EBO in vitro activity. In addition, amikacin resistance as determined using the Clinical Laboratory Standards Institute (CLSI) IV amikacin breakpoint (MIC ≥ 64 mg/L) had no noticeable effect on EBO MIC values. Table 1EBO In Vitro Activity Against 51 Isolates of Mycobacterium avium complex
Conclusion
The MIC distribution for the 51 MAC isolates tested was similar in both media types, indicating that CAMHB can be used to test EBO MAC susceptibilities per CLSI guidelines. Clarithromycin- and amikacin-resistant isolates demonstrated no cross-resistance with EBO.
Disclosures
Michelle S. DeStefano, n/a, AN2 Therapeutics: Grant/Research Support Carolyn M. Shoen, PhD, AN2 Therapeutics: Grant/Research Support MRK Alley, PhD, ABBOTT LABS: Stocks/Bonds|ABBVIE: Stocks/Bonds|AN2 Therapeutics: Author on epetraborole patent|AN2 Therapeutics: Salary|AN2 Therapeutics: Ownership Interest|AVANOS MED INC: Stocks/Bonds|NABRIVA THERAPEUTICS PLC: Stocks/Bonds|NOVARTIS AG: Stocks/Bonds Michael H. Cynamon, MD, AN2: Grant/Research Support|AN2: Grant/Research Support.
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Evangelopoulos D, Shoen CM, Honeyborne I, Clark S, Williams A, Mukamolova GV, Cynamon MH, McHugh TD. Culture-Free Enumeration of Mycobacterium tuberculosis in Mouse Tissues Using the Molecular Bacterial Load Assay for Preclinical Drug Development. Microorganisms 2022; 10:microorganisms10020460. [PMID: 35208914 PMCID: PMC8876813 DOI: 10.3390/microorganisms10020460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/10/2022] [Accepted: 02/11/2022] [Indexed: 12/04/2022] Open
Abstract
Background: The turnaround times for phenotypic tests used to monitor the bacterial load of Mycobacterium tuberculosis, in both clinical and preclinical studies, are delayed by the organism’s slow growth in culture media. The existence of differentially culturable populations of M.tuberculosis may result in an underestimate of the true number. Moreover, culture methods are susceptible to contamination resulting in loss of critical data points. Objectives: We report the adaptation of our robust, culture-free assay utilising 16S ribosomal RNA, developed for sputum, to enumerate the number of bacteria present in animal tissues as a tool to improve the read-outs in preclinical drug efficacy studies. Methods: Initial assay adaptation was performed using naïve mouse lungs spiked with known quantities of M. tuberculosis and an internal RNA control. Tissues were homogenised, total RNA extracted, and enumeration performed using RT-qPCR. We then evaluated the utility of the assay, in comparison to bacterial counts estimated using growth assays on solid and liquid media, to accurately inform bacterial load in tissues from M. tuberculosis-infected mice before and during treatment with a panel of drug combinations. Results: When tested on lung tissues derived from infected mice, the MBL assay produced comparable results to the bacterial counts in solid culture (colony forming units: CFU). Notably, under specific drug treatments, the MBL assay was able to detect a significantly higher number of M. tuberculosis compared to CFU, likely indicating the presence of bacteria that were unable to produce colonies in solid-based culture. Additionally, growth recovery in liquid media using the most probable number (MPN) assay was able to account for the discrepancy between the MBL assay and CFU number, suggesting that the MBL assay detects differentially culturable sub-populations of M. tuberculosis. Conclusions: The MBL assay can enumerate the bacterial load in animal tissues in real time without the need to wait for extended periods for cultures to grow. The readout correlates well with CFUs. Importantly, we have shown that the MBL is able to measure specific populations of bacteria not cultured on solid agar. The adaptation of this assay for preclinical studies has the potential to decrease the readout time of data acquisition from animal experiments and could represent a valuable tool for tuberculosis drug discovery and development.
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Affiliation(s)
- Dimitrios Evangelopoulos
- Department of Microbial Diseases, UCL Eastman Dental Institute, University College London, London NW3 2PF, UK
- UCL Centre for Clinical Microbiology, University College London, London NW3 2PF, UK; (I.H.); (T.D.M.)
- Correspondence:
| | - Carolyn M. Shoen
- Veterans Administration Medical Center, Syracuse, NY 13210, USA; (C.M.S.); (M.H.C.)
- Veterans Health Research Institute, Syracuse, NY 13210, USA
| | - Isobella Honeyborne
- UCL Centre for Clinical Microbiology, University College London, London NW3 2PF, UK; (I.H.); (T.D.M.)
| | - Simon Clark
- UK Health Security Agency, Porton Down, Salisbury SP4 OJG, UK; (S.C.); (A.W.)
| | - Ann Williams
- UK Health Security Agency, Porton Down, Salisbury SP4 OJG, UK; (S.C.); (A.W.)
| | - Galina V. Mukamolova
- Leicester Tuberculosis Research Group, Department of Respiratory Sciences, University of Leicester, Leicester LE1 7RH, UK;
| | - Michael H. Cynamon
- Veterans Administration Medical Center, Syracuse, NY 13210, USA; (C.M.S.); (M.H.C.)
- Veterans Health Research Institute, Syracuse, NY 13210, USA
| | - Timothy D. McHugh
- UCL Centre for Clinical Microbiology, University College London, London NW3 2PF, UK; (I.H.); (T.D.M.)
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Abstract
The current standard of care therapy for pulmonary Mycobacterium kansasii infection is isoniazid (300 mg/day), rifampin (600 mg/day), and ethambutol (15 mg/kg/day) for 12 months after achieving sputum culture negativity. Rifampin is the key drug in this regimen. The contribution of isoniazid is unclear since its in vitro MICs against M. kansasii are near the peak achievable serum levels and more than 100-fold greater than the MICs for Mycobacterium tuberculosis. Ethambutol likely decreases the emergence of rifampin resistant organisms. There are several new drug classes (e.g., quinolones, macrolides, nitroimidazoles, diarylquinolines, and clofazimine) that exhibit antimycobacterial activities against M. tuberculosis but have not yet been adequately studied against M. kansasii infections. The evaluation of in vitro activities of these agents as well as their study in new regimens in comparison to the standard of care regimen in mouse infection models should be undertaken. This knowledge will inform development of human clinical trials of new regimens in comparison to the current standard of care regimen. It is likely that shorter and more effective therapy is achievable with currently available drugs.
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Affiliation(s)
| | - Carolyn M Shoen
- Central New York Research Corporation, Syracuse, NY, United States
| | - Michael H Cynamon
- Central New York Research Corporation, Syracuse, NY, United States.,Veterans Affairs Medical Center, Syracuse, NY, United States
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Shoen CM, DeStefano MS, Hager CC, Tham KT, Braunstein M, Allen AD, Gates HO, Cynamon MH, Kernodle DS. A Modified Bacillus Calmette-Guérin (BCG) Vaccine with Reduced Activity of Antioxidants and Glutamine Synthetase Exhibits Enhanced Protection of Mice despite Diminished in Vivo Persistence. Vaccines (Basel) 2013; 1:34-57. [PMID: 26343849 PMCID: PMC4552197 DOI: 10.3390/vaccines1010034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Revised: 12/18/2012] [Accepted: 01/05/2013] [Indexed: 01/02/2023] Open
Abstract
Early attempts to improve BCG have focused on increasing the expression of prominent antigens and adding recombinant toxins or cytokines to influence antigen presentation. One such modified BCG vaccine candidate has been withdrawn from human clinical trials due to adverse effects. BCG was derived from virulent Mycobacterium bovis and retains much of its capacity for suppressing host immune responses. Accordingly, we have used a different strategy for improving BCG based on reducing its immune suppressive capacity. We made four modifications to BCG Tice to produce 4dBCG and compared it to the parent vaccine in C57Bl/6 mice. The modifications included elimination of the oxidative stress sigma factor SigH, elimination of the SecA2 secretion channel, and reductions in the activity of iron co-factored superoxide dismutase and glutamine synthetase. After IV inoculation of 4dBCG, 95% of vaccine bacilli were eradicated from the spleens of mice within 60 days whereas the titer of BCG Tice was not significantly reduced. Subcutaneous vaccination with 4dBCG produced greater protection than vaccination with BCG against dissemination of an aerosolized challenge of M. tuberculosis to the spleen at 8 weeks post-challenge. At this time, 4dBCG-vaccinated mice also exhibited altered lung histopathology compared to BCG-vaccinated mice and control mice with less well-developed lymphohistiocytic nodules in the lung parenchyma. At 26 weeks post-challenge, 4dBCG-vaccinated mice but not BCG-vaccinated mice had significantly fewer challenge bacilli in the lungs than control mice. In conclusion, despite reduced persistence in mice a modified BCG vaccine with diminished antioxidants and glutamine synthetase is superior to the parent vaccine in conferring protection against M. tuberculosis. The targeting of multiple immune suppressive factors produced by BCG is a promising strategy for simultaneously improving vaccine safety and effectiveness.
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Affiliation(s)
| | | | - Cynthia C Hager
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
| | - Kyi-Toe Tham
- Department of Pathology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
- Veterans Affairs Medical Center, Nashville, TN 37212, USA.
| | - Miriam Braunstein
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Alexandria D Allen
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
| | - Hiriam O Gates
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
| | | | - Douglas S Kernodle
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
- Veterans Affairs Medical Center, Nashville, TN 37212, USA.
- Department of Microbiology, Immunology and Pathology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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Shoen CM, DeStefano MS, Sklaney MR, Monica BJ, Slee AM, Cynamon MH. Short-course treatment regimen to identify potential antituberculous agents in a murine model of tuberculosis. J Antimicrob Chemother 2004; 53:641-5. [PMID: 14973154 DOI: 10.1093/jac/dkh124] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE Designing a more rapid method to test antimycobacterial agents in a murine model would significantly improve the drug development process. We describe a short-course in vivo treatment model that could be used to screen potential antituberculous drugs. METHODS In this model, C57BL/6 mice were infected intranasally with approximately 10(6) viable Mycobacterium tuberculosis organisms. Treatment began 1 day post-infection and was administered for 2 days. Mice were euthanized 3 days post-infection and their right lungs were removed and cell counts determined. Several antimycobacterial agents with superior in vivo activity in a 4 week treatment model were tested to evaluate the short-course treatment model. RESULTS Two days of isoniazid (25 mg/kg), rifampicin (20 mg/kg), PNU-100480 (100 mg/kg), gatifloxacin (100 mg/kg), levofloxacin (100 mg/kg) and sparfloxacin (100 mg/kg) were all able to significantly reduce the mycobacterial load in the lungs compared with the untreated control mice. CONCLUSIONS Use of this model to screen potential chemotherapeutic agents will save time and resources.
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Affiliation(s)
- Carolyn M Shoen
- Central New York Research Corporation, Syracuse, NY 13210, USA
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Abstract
ABT-773, a new ketolide antimicrobial agent, was evaluated in comparison to clarithromycin (CLA) in vitro against Mycobacterium avium complex (MAC) and in a beige mouse model of disseminated MAC infection. The MICs at which 50 and 90% of the isolates tested were inhibited were 2 and 4 microg/ml, respectively, for CLA and 8 and 16 microg/ml, respectively, for ABT-773. Eight CLA-resistant isolates were found to be resistant to ABT-773 (MICs > 64 microg/ml). In the in vivo study mice were treated with ABT-773 (50, 100, and 200 mg/kg of body weight) or CLA (200 mg/kg). Both ABT-773 (100 and 200 mg/kg) and CLA significantly decreased the viable cell counts in spleens and lungs. ABT-773 (200 mg/kg) and CLA had similar activities in lungs, but the former was more active in spleens.
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Affiliation(s)
- M H Cynamon
- Veterans Affairs Medical Center and State University of New York, Upstate Medical University, Syracuse, New York 12310, USA.
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Shoen CM, Chase SE, DeStefano MS, Harpster TS, Chmielewski AJ, Cynamon MH. Evaluation of rifalazil in long-term treatment regimens for tuberculosis in mice. Antimicrob Agents Chemother 2000; 44:1458-62. [PMID: 10817693 PMCID: PMC89897 DOI: 10.1128/aac.44.6.1458-1462.2000] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previous experiments with rifalazil (RLZ) (also known as KRM-1648) in combination with isoniazid (INH) demonstrated its potential for short-course treatment of Mycobacterium tuberculosis infection. In this study we investigated the minimum RLZ-INH treatment time required to eradicate M. tuberculosis in a murine model. RLZ-INH treatment for 6 weeks or longer led to a nonculturable state. Groups of mice treated in parallel were killed following an observation period to evaluate regrowth. RLZ-INH treatment for a minimum of 10 weeks was necessary to maintain a nonculturable state through the observation period. Pyrazinamide (PZA) was added to this regimen to determine whether the treatment duration could be further reduced. In this model, the addition of PZA did not shorten the duration of RLZ-INH treatment required to eradicate M. tuberculosis from mice. The addition of PZA reduced the number of mice in which regrowth occurred, although the reduction was not statistically significant.
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Affiliation(s)
- C M Shoen
- State University of New York Upstate Medical University, Veterans Affairs Medical Center, Syracuse, New York, USA
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Shoen CM, DeStefano MS, Cynamon MH. Durable cure for tuberculosis: rifalazil in combination with isoniazid in a murine model of Mycobacterium tuberculosis infection. Clin Infect Dis 2000; 30 Suppl 3:S288-90. [PMID: 10875802 DOI: 10.1086/313876] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Rifalazil (formerly known as KRM-1648) in combination with isoniazid has been found to be more active than rifampin/isoniazid. Administration of rifalazil/isoniazid for 12 weeks resulted in continued apparent sterilization of organs 6 months after cessation of therapy. In this study we evaluated the durability of rifalazil/isoniazid treatment. Female CD-1 mice were infected with Mycobacterium tuberculosis ATCC 35801 (strain Erdman). Rifalazil and isoniazid were given in combination for 6 and 12 weeks; no mycobacteria could be cultured from spleens and lungs at both the 6-week and 12-week time points. After completing treatment, groups of mice treated with rifalazil/isoniazid for 6 or 12 weeks were observed without any additional treatment. These observation groups were compared to groups of rifalazil/isoniazid-treated mice (6 and 12 weeks) given dexamethasone for 7 and 8 weeks, respectively. Modest regrowth was noted in the spleens and lungs of the group treated with rifalazil/isoniazid for 6 weeks. Regrowth in the 6-weeks group was enhanced slightly by treatment with dexamethasone. In contrast, no regrowth was noted in the 12-weeks rifalazil/isoniazid group, and treatment with dexamethasone did not result in any regrowth.
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Affiliation(s)
- C M Shoen
- State University of New York Upstate Medical University, Syracuse, NY, USA
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Shoen CM, Choromanska O, Reynolds RC, Piper JR, Johnson CA, Cynamon MH. In vitro activities of several diaminomethylpyridopyrimidines against Mycobacterium avium complex. Antimicrob Agents Chemother 1998; 42:3315-6. [PMID: 9835537 PMCID: PMC106045 DOI: 10.1128/aac.42.12.3315] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Three recently synthesized dihydrofolate reductase (DHFR) inhibitors designated SoRI 8890, 8895, and 8897 were evaluated for their in vitro activities against 25 isolates of Mycobacterium avium complex. The MICs at which 50 and 90% of isolates were inhibited were 1 and 2, 4 and 8, and 4 and 8 microgram/ml for SoRI 8890, 8895, and 8897, respectively. Although the addition of dapsone at 0.5 microgram/ml did not significantly enhance the in vitro activities of these compounds, their activities alone were comparable to, if not better than, results seen with other DHFR inhibitors, such as pyrimethamine or WR99210.
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Affiliation(s)
- C M Shoen
- Department of Medicine, Veterans Affairs Medical Center, Syracuse, New York, USA
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