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Tkaczyk C, Newton M, Patnaik MM, Thom G, Strain M, Gamson A, Daramola O, Murthy A, Douthwaite J, Stepanov O, Boger E, Yang H, Esser MT, Lidwell A, DiGiandomenico A, Santos L, Sellman BR. In vivo mRNA expression of a multi-mechanistic mAb combination protects against Staphylococcus aureus infection. Mol Ther 2024; 32:2505-2518. [PMID: 38822525 PMCID: PMC11405172 DOI: 10.1016/j.ymthe.2024.05.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 04/30/2024] [Accepted: 05/29/2024] [Indexed: 06/03/2024] Open
Abstract
Single monoclonal antibodies (mAbs) can be expressed in vivo through gene delivery of their mRNA formulated with lipid nanoparticles (LNPs). However, delivery of a mAb combination could be challenging due to the risk of heavy and light variable chain mispairing. We evaluated the pharmacokinetics of a three mAb combination against Staphylococcus aureus first in single chain variable fragment scFv-Fc and then in immunoglobulin G 1 (IgG1) format in mice. Intravenous delivery of each mRNA/LNP or the trio (1 mg/kg each) induced functional antibody expression after 24 h (10-100 μg/mL) with 64%-78% cognate-chain paired IgG expression after 3 days, and an absence of non-cognate chain pairing for scFv-Fc. We did not observe reduced neutralizing activity for each mAb compared with the level of expression of chain-paired mAbs. Delivery of the trio mRNA protected mice in an S. aureus-induced dermonecrosis model. Intravenous administration of the three mRNA in non-human primates achieved peak serum IgG levels ranging between 2.9 and 13.7 μg/mL with a half-life of 11.8-15.4 days. These results suggest nucleic acid delivery of mAb combinations holds promise and may be a viable option to streamline the development of therapeutic antibodies.
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Affiliation(s)
- Christine Tkaczyk
- AstraZeneca, Early Vaccines & Immune Therapies, Gaithersburg, MD 20878, USA.
| | - Michael Newton
- AstraZeneca, BioPharmaceutical Development, BioPharmaceuticals R&D, Gaithersburg, MD 20878, USA
| | - Mun Mun Patnaik
- AstraZeneca, Early Vaccines & Immune Therapies, Gaithersburg, MD 20878, USA
| | - George Thom
- AstraZeneca, Discovery Sciences, BioPharmaceuticals R&D, Cambridge CB21 6GH, UK
| | - Martin Strain
- AstraZeneca, Biologics Engineering, BioPharmaceuticals R&D, Cambridge CB216GH, UK
| | - Adam Gamson
- AstraZeneca, Early Vaccines & Immune Therapies, Gaithersburg, MD 20878, USA
| | - Olalekan Daramola
- AstraZeneca, BioPharmaceutical Development, BioPharmaceuticals R&D, Cambridge CB21 6GH, UK
| | - Andal Murthy
- AstraZeneca, BioPharmaceutical Development, BioPharmaceuticals R&D, Cambridge CB21 6GH, UK
| | - Julie Douthwaite
- AstraZeneca, Discovery Sciences, BioPharmaceuticals R&D, Cambridge CB21 6GH, UK
| | - Oleg Stepanov
- Clinical Pharmacology and Pharmacometrics, BioPharmaceuticals R&D, AstraZeneca, Cambridge CB2 8PA, UK
| | - Elin Boger
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Respirator & immunology, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Haitao Yang
- Clinical Pharmacology and Pharmacometrics, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD 20878, USA
| | - Mark T Esser
- AstraZeneca, Early Vaccines & Immune Therapies, Gaithersburg, MD 20878, USA
| | - Ashley Lidwell
- AstraZeneca, Early Vaccines & Immune Therapies, Gaithersburg, MD 20878, USA
| | | | - Luis Santos
- AstraZeneca, BioPharmaceutical Development, BioPharmaceuticals R&D, Gaithersburg, MD 20878, USA
| | - Bret R Sellman
- AstraZeneca, Early Vaccines & Immune Therapies, Gaithersburg, MD 20878, USA
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2
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Hibbert T, Krpetic Z, Latimer J, Leighton H, McHugh R, Pottenger S, Wragg C, James CE. Antimicrobials: An update on new strategies to diversify treatment for bacterial infections. Adv Microb Physiol 2024; 84:135-241. [PMID: 38821632 DOI: 10.1016/bs.ampbs.2023.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2024]
Abstract
Ninety-five years after Fleming's discovery of penicillin, a bounty of antibiotic compounds have been discovered, modified, or synthesised. Diversification of target sites, improved stability and altered activity spectra have enabled continued antibiotic efficacy, but overwhelming reliance and misuse has fuelled the global spread of antimicrobial resistance (AMR). An estimated 1.27 million deaths were attributable to antibiotic resistant bacteria in 2019, representing a major threat to modern medicine. Although antibiotics remain at the heart of strategies for treatment and control of bacterial diseases, the threat of AMR has reached catastrophic proportions urgently calling for fresh innovation. The last decade has been peppered with ground-breaking developments in genome sequencing, high throughput screening technologies and machine learning. These advances have opened new doors for bioprospecting for novel antimicrobials. They have also enabled more thorough exploration of complex and polymicrobial infections and interactions with the healthy microbiome. Using models of infection that more closely resemble the infection state in vivo, we are now beginning to measure the impacts of antimicrobial therapy on host/microbiota/pathogen interactions. However new approaches are needed for developing and standardising appropriate methods to measure efficacy of novel antimicrobial combinations in these contexts. A battery of promising new antimicrobials is now in various stages of development including co-administered inhibitors, phages, nanoparticles, immunotherapy, anti-biofilm and anti-virulence agents. These novel therapeutics need multidisciplinary collaboration and new ways of thinking to bring them into large scale clinical use.
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Affiliation(s)
- Tegan Hibbert
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences (IVES), University of Liverpool, Liverpool, UK
| | - Zeljka Krpetic
- School of Science, Engineering, and Environment, University of Salford, Salford, UK
| | - Joe Latimer
- School of Science, Engineering, and Environment, University of Salford, Salford, UK
| | - Hollie Leighton
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences (IVES), University of Liverpool, Liverpool, UK
| | - Rebecca McHugh
- School of Infection and Immunity, University of Glasgow, Glasgow, UK
| | - Sian Pottenger
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences (IVES), University of Liverpool, Liverpool, UK
| | - Charlotte Wragg
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences (IVES), University of Liverpool, Liverpool, UK
| | - Chloë E James
- School of Science, Engineering, and Environment, University of Salford, Salford, UK.
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3
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Kim NH, Choi Y, Kwon K, Park JS, Park KU, Moon SM, Song KH, Kim ES, Park WB, Kim HB. Anti-Alpha-Toxin Antibody Responses and Clinical Outcomes of Staphylococcus aureus Bacteremia. J Korean Med Sci 2023; 38:e129. [PMID: 37096312 PMCID: PMC10125797 DOI: 10.3346/jkms.2023.38.e129] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 01/09/2023] [Indexed: 04/26/2023] Open
Abstract
BACKGROUND Alpha-toxin (AT), a major virulence factor of Staphylococcus aureus, is an important immunotherapeutic target to prevent or treat invasive S. aureus infections. Previous studies have suggested that anti-AT antibodies (Abs) may have a protective role against S. aureus bacteremia (SAB), but their function remains unclear. Therefore, we aimed to investigate the association between serum anti-AT Ab levels and clinical outcomes of SAB. METHODS Patients from a prospective SAB cohort at a tertiary-care medical center (n = 51) were enrolled in the study from July 2016 to January 2019. Patients without symptoms or signs of infection were enrolled as controls (n = 100). Blood samples were collected before the onset of SAB and at 2- and 4-weeks post-bacteremia. Anti-AT immunoglobin G (IgG) levels were measured using an enzyme-linked immunosorbent assay. All clinical S. aureus isolates were tested for the presence of hla using polymerase chain reaction. RESULTS Anti-AT IgG levels in patients with SAB before the onset of bacteremia did not differ significantly from those in non-infectious controls. Pre-bacteremic anti-AT IgG levels tended to be lower in patients with worse clinical outcomes (7-day mortality, persistent bacteremia, metastatic infection, septic shock), although the differences were not statistically significant. Patients who needed intensive care unit care had significantly lower anti-AT IgG levels at 2 weeks post-bacteremia (P = 0.020). CONCLUSION The study findings suggest that lower anti-AT Ab responses before and during SAB, reflective of immune dysfunction, are associated with more severe clinical presentations of infection.
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Affiliation(s)
- Nak-Hyun Kim
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Yunjung Choi
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Kyungmi Kwon
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Jeong Su Park
- Department of Laboratory Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Kyoung Un Park
- Department of Laboratory Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Song Mi Moon
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Kyoung-Ho Song
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Eu Suk Kim
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Wan Beom Park
- Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
| | - Hong Bin Kim
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
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4
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Targeting the Inside of Cells with Biologicals: Toxin Routes in a Therapeutic Context. BioDrugs 2023; 37:181-203. [PMID: 36729328 PMCID: PMC9893211 DOI: 10.1007/s40259-023-00580-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/12/2023] [Indexed: 02/03/2023]
Abstract
Numerous toxins translocate to the cytosol in order to fulfil their function. This demonstrates the existence of routes for proteins from the extracellular space to the cytosol. Understanding these routes is relevant to multiple aspects related to therapeutic applications. These include the development of anti-toxin treatments, the potential use of toxins as shuttles for delivering macromolecular cargo to the cytosol or the use of drugs based on toxins. Compared with other strategies for delivery, such as chemicals as carriers for macromolecular delivery or physical methods like electroporation, toxin routes present paths into the cell that potentially cause less damage and can be specifically targeted. The efficiency of delivery via toxin routes is limited. However, low-delivery efficiencies can be entirely sufficient, if delivered cargoes possess an amplification effect or if very few molecules are sufficient for inducing the desired effects. This is known for example from RNA-based vaccines that have been developed during the coronavirus disease 2019 pandemic as well as for other approved RNA-based drugs, which elicited the desired effect despite their typically low delivery efficiencies. The different mechanisms by which toxins enter cells may have implications for their technological utility. We review the mechanistic principles of the translocation pathway of toxins from the extracellular space to the cytosol, the delivery efficiencies, and therapeutic strategies or applications that exploit toxin routes for intracellular delivery.
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5
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Zhang W, Gong Q, Tang Z, Ma X, Wang Z, Guan J, Wang L, Zhao Y, Yan M. The natural product, echinatin, protects mice from methicillin-resistant Staphylococcus aureus pneumonia by inhibition of alpha-hemolysin expression. Front Microbiol 2023; 14:1128144. [PMID: 37125192 PMCID: PMC10140358 DOI: 10.3389/fmicb.2023.1128144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 03/06/2023] [Indexed: 05/02/2023] Open
Abstract
Antimicrobial resistance (AMR) is a global, multifaceted crisis that poses significant challenges to the successful eradication of devastating pathogens, particularly methicillin-resistant Staphylococcus aureus (MRSA), a persistent superbug that causes devastating infections. The scarcity of new antibacterial drugs is obvious, and antivirulence strategies that reduce the pathogenicity of bacteria by weakening their virulence have become the subject of intense investigation. Alpha-hemolysin (Hla), a cytolytic pore-forming toxin, has a pivotal role in S. aureus pathogenesis. Here, we demonstrated that echinatin, a natural compound isolated from licorice, effectively inhibited the hemolytic activity of MRSA at 32 μg/mL. In addition, echinatin did not interfere with bacterial growth and had no significant cytotoxicity at the inhibitory concentration of S. aureus hemolysis. Heptamer formation tightly correlated with Hla-mediated cell invasion, whereas echinatin did not affect deoxycholic acid-induced oligomerization of Hla. Echinatin affected hemolytic activity through indirect binding to Hla as confirmed by the neutralization assay and cellular thermal shift assay (CETSA). Furthermore, qRT-PCR and western blot analyses revealed that echinatin suppressed Hla expression at both the mRNA and protein levels as well as the transcript levels of Agr quorum-sensing system-related genes. Additionally, when echinatin was added to a coculture system of A549 cells and S. aureus, it significantly reduced cell damage. Importantly, echinatin exhibited a significant therapeutic effect in an MRSA-induced mouse pneumonia model. In conclusion, the present findings demonstrated that echinatin significantly inhibits the hemolysin effect and may be a potential candidate compound for combating drug-resistant MRSA infections.
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Affiliation(s)
- Wei Zhang
- The Third Affiliated Hospital of Changchun University of Chinese Medicine, Changchun, China
| | - Qing Gong
- The Affiliated Hospital of Changchun University of Chinese Medicine, Changchun, China
| | - Zhitong Tang
- The Affiliated Hospital of Changchun University of Chinese Medicine, Changchun, China
| | - Xin Ma
- Jilin Provincial Cancer Hospital, Changchun, China
| | - Zhuoer Wang
- Changchun University of Chinese Medicine, Changchun, China
| | - Jiyu Guan
- Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Li Wang
- Changchun University of Chinese Medicine, Changchun, China
| | - Yicheng Zhao
- Changchun University of Chinese Medicine, Changchun, China
| | - Ming Yan
- The Third Affiliated Hospital of Changchun University of Chinese Medicine, Changchun, China
- College of Integrated Traditional Chinese and Western Medicine, Changchun University of Chinese Medicine, Changchun, China
- *Correspondence: Ming Yan,
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6
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Walesch S, Birkelbach J, Jézéquel G, Haeckl FPJ, Hegemann JD, Hesterkamp T, Hirsch AKH, Hammann P, Müller R. Fighting antibiotic resistance-strategies and (pre)clinical developments to find new antibacterials. EMBO Rep 2022; 24:e56033. [PMID: 36533629 PMCID: PMC9827564 DOI: 10.15252/embr.202256033] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 11/23/2022] [Accepted: 11/25/2022] [Indexed: 12/23/2022] Open
Abstract
Antibacterial resistance is one of the greatest threats to human health. The development of new therapeutics against bacterial pathogens has slowed drastically since the approvals of the first antibiotics in the early and mid-20th century. Most of the currently investigated drug leads are modifications of approved antibacterials, many of which are derived from natural products. In this review, we highlight the challenges, advancements and current standing of the clinical and preclinical antibacterial research pipeline. Additionally, we present novel strategies for rejuvenating the discovery process and advocate for renewed and enthusiastic investment in the antibacterial discovery pipeline.
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Affiliation(s)
- Sebastian Walesch
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS)SaarbrückenGermany,Department of PharmacySaarland UniversitySaarbrückenGermany,Helmholtz Centre for Infection research (HZI)BraunschweigGermany,German Center for infection research (DZIF)BraunschweigGermany
| | - Joy Birkelbach
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS)SaarbrückenGermany,Department of PharmacySaarland UniversitySaarbrückenGermany,Helmholtz Centre for Infection research (HZI)BraunschweigGermany,German Center for infection research (DZIF)BraunschweigGermany
| | - Gwenaëlle Jézéquel
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS)SaarbrückenGermany,Helmholtz Centre for Infection research (HZI)BraunschweigGermany
| | - F P Jake Haeckl
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS)SaarbrückenGermany,Department of PharmacySaarland UniversitySaarbrückenGermany,Helmholtz Centre for Infection research (HZI)BraunschweigGermany,German Center for infection research (DZIF)BraunschweigGermany
| | - Julian D Hegemann
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS)SaarbrückenGermany,Department of PharmacySaarland UniversitySaarbrückenGermany,Helmholtz Centre for Infection research (HZI)BraunschweigGermany,German Center for infection research (DZIF)BraunschweigGermany
| | - Thomas Hesterkamp
- Helmholtz Centre for Infection research (HZI)BraunschweigGermany,German Center for infection research (DZIF)BraunschweigGermany
| | - Anna K H Hirsch
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS)SaarbrückenGermany,Department of PharmacySaarland UniversitySaarbrückenGermany,Helmholtz Centre for Infection research (HZI)BraunschweigGermany,German Center for infection research (DZIF)BraunschweigGermany,Helmholtz International Lab for Anti‐InfectivesSaarbrückenGermany
| | - Peter Hammann
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS)SaarbrückenGermany,Department of PharmacySaarland UniversitySaarbrückenGermany,Helmholtz Centre for Infection research (HZI)BraunschweigGermany,German Center for infection research (DZIF)BraunschweigGermany
| | - Rolf Müller
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS)SaarbrückenGermany,Department of PharmacySaarland UniversitySaarbrückenGermany,Helmholtz Centre for Infection research (HZI)BraunschweigGermany,German Center for infection research (DZIF)BraunschweigGermany,Helmholtz International Lab for Anti‐InfectivesSaarbrückenGermany
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7
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Yu H, Liu J, Wang L, Guan S, Jin Y, Zheng J, Xiang H, Wang D, Liu D. 2,3-Dehydrokievitone combats methicillin-resistant Staphylococcus aureus infection by reducing alpha-hemolysin expression. Front Microbiol 2022; 13:969215. [PMID: 36090058 PMCID: PMC9454091 DOI: 10.3389/fmicb.2022.969215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 08/02/2022] [Indexed: 11/21/2022] Open
Abstract
Due to powerful drug resistance and fatal toxicity of methicillin-resistant Staphylococcus aureus (MRSA), therapeutic strategies against virulence factors present obvious advantages since no evolutionary pressure will induce bacterial resistance. Alpha-hemolysin (Hla) is an extracellular toxin secreted by Staphylococcus aureus and contributes to bacterial pathogenicity. Herein, we identified a natural product 2,3-dehydrokievitone (2,3-DHKV) for inhibiting Hla activity of MRSA strain USA300 but not affecting bacteria growth. 2,3-DHKV significantly decreased hemolysin expression in a dose-dependent manner, but it did not potently neutralize hemolysin activity. Subsequently, cellular thermal shift and heptamer formation assays confirmed that 2,3-DHK affects hemolytic activity through indirect binding to Hla. RT-qPCR and western blot revealed that 2,3-DHKV suppressed Hla expression at the mRNA and protein levels, and further decreased accessory gene regulator A (agrA) transcription levels. We also observed that 2,3-DHK significantly attenuated the damage of A549 cells by S. aureus and reduced the release of lactate dehydrogenase (LDH). Moreover, in the MRSA-induced pneumonia mouse model, 2,3-DHK treatment prolonged the life span of mice and reduced the bacterial load in the lungs, which significantly alleviated the damage to the lungs. In summary, this study proved that 2,3-DHK as a Hla inhibitor is a potential antivirulence agent against MRSA infection.
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Affiliation(s)
- Hangqian Yu
- College of Animal Science, Jilin University, Changchun, China
| | - Jingyu Liu
- College of Animal Science, Jilin University, Changchun, China
| | - Li Wang
- College of Animal Science, Jilin University, Changchun, China
- Changchun University of Chinese Medicine, Changchun, China
| | - Shuhan Guan
- College of Animal Science, Jilin University, Changchun, China
| | - Yajing Jin
- College of Animal Science, Jilin University, Changchun, China
| | - Jianze Zheng
- College of Animal Science, Jilin University, Changchun, China
| | - Hua Xiang
- College of Animal Medicine, Jilin Agricultural University, Changchun, China
| | - Dacheng Wang
- College of Animal Science, Jilin University, Changchun, China
| | - Dianfeng Liu
- College of Animal Science, Jilin University, Changchun, China
- *Correspondence: Dianfeng Liu,
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8
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Han J, Poma A. Molecular Targets for Antibody-Based Anti-Biofilm Therapy in Infective Endocarditis. Polymers (Basel) 2022; 14:3198. [PMID: 35956712 PMCID: PMC9370930 DOI: 10.3390/polym14153198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/25/2022] [Accepted: 07/29/2022] [Indexed: 11/16/2022] Open
Abstract
Infective endocarditis (IE) is a heart disease caused by the infection of heart valves, majorly caused by Staphilococcus aureus. IE is initiated by bacteria entering the blood circulation in favouring conditions (e.g., during invasive procedures). So far, the conventional antimicrobial strategies based on the usage of antibiotics remain the major intervention for treating IE. Nevertheless, the therapeutic efficacy of antibiotics in IE is limited not only by the bacterial drug resistance, but also by the formation of biofilms, which resist the penetration of antibiotics into bacterial cells. To overcome these drawbacks, the development of anti-biofilm treatments that can expose bacteria and make them more susceptible to the action of antibiotics, therefore resulting in reduced antimicrobial resistance, is urgently required. A series of anti-biofilm strategies have been developed, and this review will focus in particular on the development of anti-biofilm antibodies. Based on the results previously reported in the literature, several potential anti-biofilm targets are discussed, such as bacterial adhesins, biofilm matrix and bacterial toxins, covering their antigenic properties (with the identification of potential promising epitopes), functional mechanisms, as well as the antibodies already developed against these targets and, where feasible, their clinical translation.
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Affiliation(s)
- Jiahe Han
- UCL Institute of Cardiovascular Science, The Rayne Building, 5 University Street, London WC1E 6JF, UK
| | - Alessandro Poma
- Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, Royal Free Hospital, UCL Medical School, Rowland Hill Street, London NW3 2PF, UK
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9
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Xu W, Peng L, Li C, Wu T, Chen H, Zhang H, Yu H, Ye Y, Wu Y, Yuan Q, Nian S. A novel fully human recombinant antibody neutralizing the α-hemolysin of Staphylococcus aureus. APMIS 2022; 130:578-589. [PMID: 35751523 DOI: 10.1111/apm.13258] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 06/23/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND Methicillin-resistant Staphylococcus aureus (MRSA) is resistant to almost all β-lactam antibiotics. Hence, new ways to control MRSA infection, such as antibacterial antibodies, need to be explored. α-hemolysin is the most important virulence factor widely expressed in S. aureus. This study aimed to develop a new fully human antibody against α-hemolysin of S. aureus and research its neutralizing effect. RESULTS The single-chain antibody fragments(scFvs)against S. aureus were screened from a fully human scFv library using phage display technology. The selected scFvs had good binding affinities to α-hemolysin and S. aureus. The IgG-like scFv-Fc inserted into the pcDNA3.1 or pMH3 vector was expressed in HEK293F suspension cells to extend the half-life and restore Fc function. The size of purified scFv-Fc was about 55 kDa. The functions of expressed scFv-Fcs against α-hemolysin were validated. The cytotoxicity assays showed that scFv555-Fc had better protective effects on A549 cells than other scFv-Fcs. The results of anti-rabbit erythrocyte lysis and A549 cell apoptosis assay confirmed that scFv555-Fc had a significant neutralizing effect on α-hemolysin. The scFv555-Fc was used to construct the docking model of antigen-antibody complexes using Discovery Studio software. It predicted that the key binding sites of α-hemolysin were TYR28, LYS37, PHE39, ARG56, and LYS58, which might be the key toxic sites of α-hemolysin. CONCLUSION A novel fully human scFv-Fc antibody neutralizing the α-hemolysin toxin of S. aureus was successfully developed. The findings might provide a new theoretical basis and treatment method for preventing MRSA infection.
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Affiliation(s)
- Wenfeng Xu
- Immune Mechanism and Therapy of Major Diseases of Luzhou Key Laboratory, Public Center of Experimental Technology, School of Basic Medical Sciences, Southwest Medical University, Luzhou 646000, China
| | - Lei Peng
- Immune Mechanism and Therapy of Major Diseases of Luzhou Key Laboratory, Public Center of Experimental Technology, School of Basic Medical Sciences, Southwest Medical University, Luzhou 646000, China
| | - Chun Li
- Clinical pharmacy & GCP center, the Affiliated Traditional Chinese Medicine Hospital of Southwest Medical University, Luzhou, Sichuan Province, 646000, China
| | - Tong Wu
- Immune Mechanism and Therapy of Major Diseases of Luzhou Key Laboratory, Public Center of Experimental Technology, School of Basic Medical Sciences, Southwest Medical University, Luzhou 646000, China
| | - Han Chen
- Immune Mechanism and Therapy of Major Diseases of Luzhou Key Laboratory, Public Center of Experimental Technology, School of Basic Medical Sciences, Southwest Medical University, Luzhou 646000, China
| | | | - Hong Yu
- Immune Mechanism and Therapy of Major Diseases of Luzhou Key Laboratory, Public Center of Experimental Technology, School of Basic Medical Sciences, Southwest Medical University, Luzhou 646000, China
| | - Yingchun Ye
- Immune Mechanism and Therapy of Major Diseases of Luzhou Key Laboratory, Public Center of Experimental Technology, School of Basic Medical Sciences, Southwest Medical University, Luzhou 646000, China
| | - Yuchuan Wu
- Immune Mechanism and Therapy of Major Diseases of Luzhou Key Laboratory, Public Center of Experimental Technology, School of Basic Medical Sciences, Southwest Medical University, Luzhou 646000, China
| | - Qing Yuan
- Immune Mechanism and Therapy of Major Diseases of Luzhou Key Laboratory, Public Center of Experimental Technology, School of Basic Medical Sciences, Southwest Medical University, Luzhou 646000, China
| | - Siji Nian
- Immune Mechanism and Therapy of Major Diseases of Luzhou Key Laboratory, Public Center of Experimental Technology, School of Basic Medical Sciences, Southwest Medical University, Luzhou 646000, China
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10
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Wang H, Chen D, Lu H. Anti-bacterial monoclonal antibodies: next generation therapy against superbugs. Appl Microbiol Biotechnol 2022; 106:3957-3972. [PMID: 35648146 DOI: 10.1007/s00253-022-11989-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 05/12/2022] [Accepted: 05/16/2022] [Indexed: 12/19/2022]
Abstract
Prior to the nineteenth century, infectious disease was one of the leading causes of death. Human life expectancy has roughly doubled over the past century as a result of the development of antibiotics and vaccines. However, the emergence of antibiotic-resistant superbugs brings new challenges. The side effects of broad-spectrum antibiotics, such as causing antimicrobial resistance and destroying the normal flora, often limit their applications. Furthermore, the development of new antibiotics has lagged far behind the emergence and spread of antibiotic resistance. On the other hand, the genome complexity of bacteria makes it difficult to create effective vaccines. Therefore, novel therapeutic agents in supplement to antibiotics and vaccines are urgently needed to improve the treatment of infections. In recent years, monoclonal antibodies (mAbs) have achieved remarkable clinical success in a variety of fields. In the treatment of infectious diseases, mAbs can play functions through multiple mechanisms, including toxins neutralization, virulence factors inhibition, complement-mediated killing activity, and opsonic phagocytosis. Toxins and bacterial surface components are good targets to generate antibodies against. The U.S. FDA has approved three monoclonal antibody drugs, and there are numerous candidates in the preclinical or clinical trial stages. This article reviews recent advances in the research and development of anti-bacterial monoclonal antibody drugs in order to provide a valuable reference for future studies in this area. KEY POINTS: • Novel drugs against antibiotic-resistant superbugs are urgently required • Monoclonal antibodies can treat bacterial infections through multiple mechanisms • There are many anti-bacterial monoclonal antibodies developed in recent years and some candidates have entered the preclinical or clinical stages of development.
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Affiliation(s)
- Hui Wang
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
- School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Daijie Chen
- School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Huili Lu
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
- School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
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11
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Mindt BC, DiGiandomenico A. Microbiome Modulation as a Novel Strategy to Treat and Prevent Respiratory Infections. Antibiotics (Basel) 2022; 11:antibiotics11040474. [PMID: 35453224 PMCID: PMC9029693 DOI: 10.3390/antibiotics11040474] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 03/26/2022] [Accepted: 03/28/2022] [Indexed: 02/06/2023] Open
Abstract
Acute and chronic lower airway disease still represent a major cause of morbidity and mortality on a global scale. With the steady rise of multidrug-resistant respiratory pathogens, such as Pseudomonas aeruginosa and Klebsiella pneumoniae, we are rapidly approaching the advent of a post-antibiotic era. In addition, potentially detrimental novel variants of respiratory viruses continuously emerge with the most prominent recent example being severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To this end, alternative preventive and therapeutic intervention strategies will be critical to combat airway infections in the future. Chronic respiratory diseases are associated with alterations in the lung and gut microbiome, which is thought to contribute to disease progression and increased susceptibility to infection with respiratory pathogens. In this review we will focus on how modulating and harnessing the microbiome may pose a novel strategy to prevent and treat pulmonary infections as well as chronic respiratory disease.
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12
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Abstract
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The paradigm of antivirulence
therapy dictates that bacterial pathogens
are specifically disarmed but not killed by neutralizing their virulence
factors. Clearance of the invading pathogen by the immune system is
promoted. As compared to antibiotics, the pathogen-selective antivirulence
drugs hold promise to minimize collateral damage to the beneficial
microbiome. Also, selective pressure for resistance is expected to
be lower because bacterial viability is not directly affected. Antivirulence
drugs are being developed for stand-alone prophylactic and therapeutic
treatments but also for combinatorial use with antibiotics. This Review
focuses on drug modalities that target bacterial exotoxins after the
secretion or release-upon-lysis. Exotoxins have a significant and
sometimes the primary role as the disease-causing virulence factor,
and thereby they are attractive targets for drug development. We describe
the key pre-clinical and clinical trial data that have led to the
approval of currently used exotoxin-targeted drugs, namely the monoclonal
antibodies bezlotoxumab (toxin B/TcdB, Clostridioides difficile), raxibacumab (anthrax toxin, Bacillus anthracis), and obiltoxaximab (anthrax toxin, Bacillus anthracis), but also to challenges with some of the promising leads. We also
highlight the recent developments in pre-clinical research sector
to develop exotoxin-targeted drug modalities, i.e., monoclonal antibodies,
antibody fragments, antibody mimetics, receptor analogs, neutralizing
scaffolds, dominant-negative mutants, and small molecules. We describe
how these exotoxin-targeted drug modalities work with high-resolution
structural knowledge and highlight their advantages and disadvantages
as antibiotic alternatives.
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Affiliation(s)
- Moona Sakari
- Institute of Biomedicine, Research Unit for Infection and Immunity, University of Turku, Kiinamyllynkatu 10, FI-20520 Turku, Finland
| | - Arttu Laisi
- Institute of Biomedicine, Research Unit for Infection and Immunity, University of Turku, Kiinamyllynkatu 10, FI-20520 Turku, Finland
| | - Arto T. Pulliainen
- Institute of Biomedicine, Research Unit for Infection and Immunity, University of Turku, Kiinamyllynkatu 10, FI-20520 Turku, Finland
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13
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Kailasan S, Kant R, Noonan-Shueh M, Kanipakala T, Liao G, Shulenin S, Leung DW, Alm RA, Adhikari RP, Amarasinghe GK, Gross ML, Aman MJ. Antigenic landscapes on Staphylococcus aureus pore-forming toxins reveal insights into specificity and cross-neutralization. MAbs 2022; 14:2083467. [PMID: 35730685 PMCID: PMC9225675 DOI: 10.1080/19420862.2022.2083467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Staphylococcus aureus carries an exceptional repertoire of virulence factors that aid in immune evasion. Previous single-target approaches for S. aureus-specific vaccines and monoclonal antibodies (mAbs) have failed in clinical trials due to the multitude of virulence factors released during infection. Emergence of antibiotic-resistant strains demands a multi-target approach involving neutralization of different, non-overlapping pathogenic factors. Of the several pore-forming toxins that contribute to S. aureus pathogenesis, efforts have largely focused on mAbs that neutralize α-hemolysin (Hla) and target the receptor-binding site. Here, we isolated two anti-Hla and three anti-Panton-Valentine Leukocidin (LukSF-PV) mAbs, and used a combination of hydrogen deuterium exchange mass spectrometry (HDX-MS) and alanine scanning mutagenesis to delineate and validate the toxins’ epitope landscape. Our studies identified two novel, neutralizing epitopes targeted by 2B6 and CAN6 on Hla that provided protection from hemolytic activity in vitro and showed synergy in rodent pneumonia model against lethal challenge. Of the anti-LukF mAbs, SA02 and SA131 showed specific neutralization activity to LukSF-PV while SA185 showed cross-neutralization activity to LukSF-PV, γ-hemolysin HlgAB, and leukotoxin ED. We further compared these antigen-specific mAbs to two broadly neutralizing mAbs, H5 (targets Hla, LukSF-PV, HlgAB, HlgCB, and LukED) and SA185 (targeting LukSF-PV, HlgAB, and LukED), and identified molecular level markers for broad-spectrum reactivity among the pore-forming toxins by HDX-MS. To further underscore the need to target the cross-reactive epitopes on leukocidins for the development of broad-spectrum therapies, we annotated Hla sequences isolated from patients in multiple countries for genomic variations within the perspective of our defined epitopes.
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Affiliation(s)
| | - Ravi Kant
- Department of Chemistry, Washington University in St. Louis, St. Louis, USA
| | | | | | - Grant Liao
- Integrated BioTherapeutics, Rockville, USA
| | | | - Daisy W Leung
- Department of Medicine, Washington University in St. Louis, St. Louis, USA
| | - Richard A Alm
- Boston University School of Law, Boston University, Boston, USA
| | | | - Gaya K Amarasinghe
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, USA
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14
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Ahmad-Mansour N, Loubet P, Pouget C, Dunyach-Remy C, Sotto A, Lavigne JP, Molle V. Staphylococcus aureus Toxins: An Update on Their Pathogenic Properties and Potential Treatments. Toxins (Basel) 2021; 13:677. [PMID: 34678970 PMCID: PMC8540901 DOI: 10.3390/toxins13100677] [Citation(s) in RCA: 109] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 09/18/2021] [Accepted: 09/21/2021] [Indexed: 01/12/2023] Open
Abstract
Staphylococcus aureus is a clinically important pathogen that causes a wide range of human infections, from minor skin infections to severe tissue infection and sepsis. S. aureus has a high level of antibiotic resistance and is a common cause of infections in hospitals and the community. The rising prevalence of community-acquired methicillin-resistant S. aureus (CA-MRSA), combined with the important severity of S. aureus infections in general, has resulted in the frequent use of anti-staphylococcal antibiotics, leading to increasing resistance rates. Antibiotic-resistant S. aureus continues to be a major health concern, necessitating the development of novel therapeutic strategies. S. aureus uses a wide range of virulence factors, such as toxins, to develop an infection in the host. Recently, anti-virulence treatments that directly or indirectly neutralize S. aureus toxins have showed promise. In this review, we provide an update on toxin pathogenic characteristics, as well as anti-toxin therapeutical strategies.
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Affiliation(s)
- Nour Ahmad-Mansour
- Laboratory of Pathogen Host Interactions, CNRS UMR5235, Université de Montpellier, 34000 Montpellier, France;
| | - Paul Loubet
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Department of Infectious and Tropical Diseases, Université de Montpellier, 30908 Nîmes, France; (P.L.); (A.S.)
| | - Cassandra Pouget
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Université de Montpellier, 30908 Nîmes, France;
| | - Catherine Dunyach-Remy
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Department of Microbiology and Hospital Hygiene, Université de Montpellier, 30908 Nîmes, France; (C.D.-R.); (J.-P.L.)
| | - Albert Sotto
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Department of Infectious and Tropical Diseases, Université de Montpellier, 30908 Nîmes, France; (P.L.); (A.S.)
| | - Jean-Philippe Lavigne
- Virulence Bactérienne et Infections Chroniques, INSERM U1047, Department of Microbiology and Hospital Hygiene, Université de Montpellier, 30908 Nîmes, France; (C.D.-R.); (J.-P.L.)
| | - Virginie Molle
- Laboratory of Pathogen Host Interactions, CNRS UMR5235, Université de Montpellier, 34000 Montpellier, France;
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15
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Liu F, Guan Z, Liu Y, Li J, Liu C, Gao Y, Ma Y, Feng J, Shen B, Yang G. Identification of a Human Anti-Alpha-Toxin Monoclonal Antibody Against Staphylococcus aureus Infection. Front Microbiol 2021; 12:692279. [PMID: 34335518 PMCID: PMC8319846 DOI: 10.3389/fmicb.2021.692279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 06/14/2021] [Indexed: 11/13/2022] Open
Abstract
Staphylococcus aureus is a major pathogenic bacterium that causes a variety of clinical infections. The emergence of multi-drug resistant mechanisms requires novel strategies to mitigate S. aureus infection. Alpha-hemolysin (Hla) is a key virulence factor that is believed to play a significant role in the pathogenesis of S. aureus infections. In this study, we screened a naïve human Fab library for identification of monoclonal antibodies targeting Hla by phage display technology. We found that the monoclonal antibody YG1 blocked the Hla-mediated lysis of rabbit red blood cells and inhibited Hla binding to A549 cells in a concentration-dependent manner. YG1 also provided protection against acute peritoneal infection, bacteremia, and pneumonia in murine models. We further characterized its epitope using different Hla variants and found that the amino acids N209 and F210 of Hla were functionally and structurally important for YG1 binding. Overall, these results indicated that targeting Hla with YG1 could serve as a promising protective strategy against S. aureus infection.
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Affiliation(s)
- Fangjie Liu
- Beijing Institute of Pharmacology and Toxicology, Beijing, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Zhangchun Guan
- Beijing Institute of Pharmacology and Toxicology, Beijing, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Yu Liu
- Beijing Institute of Pharmacology and Toxicology, Beijing, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Jingjing Li
- Beijing Institute of Pharmacology and Toxicology, Beijing, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Chenghua Liu
- Beijing Institute of Pharmacology and Toxicology, Beijing, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Yaping Gao
- Beijing Institute of Pharmacology and Toxicology, Beijing, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Yuanfang Ma
- Laboratory of Cellular and Molecular Immunology, Institute of Immunology, Henan University, Kaifeng, China
| | - Jiannan Feng
- Beijing Institute of Pharmacology and Toxicology, Beijing, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Beifen Shen
- Beijing Institute of Pharmacology and Toxicology, Beijing, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
| | - Guang Yang
- Beijing Institute of Pharmacology and Toxicology, Beijing, China.,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China
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16
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Development of combination vaccine conferring optimal protection against six pore-forming toxins of Staphylococcus aureus. Infect Immun 2021; 89:e0034221. [PMID: 34227839 DOI: 10.1128/iai.00342-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Gram-positive pathogen Staphylococcus aureus, pore-forming toxins (PFTs) such as leukocidins and hemolysins play prominent roles in staphylococcal pathogenesis by killing host immune cells and red blood cells (RBCs). However, it remains unknown which combination of toxin antigens would induce the broadest protective immune response against those toxins. In this study, by targeting six major staphylococcal PFTs (i.e., HlgAB, HlgCB, LukAB, LukED, LukSF-PV, and Hla), we generated ten recombinant toxins or toxin-subunits, three toxoids, and their rabbit antibodies. Using the cytolytic assay for RBCs and polymorphonuclear cells (PMNs), we determined the best combination of toxin antibodies conferring the broadest protection against those staphylococcal PFTs. Although anti-HlgA IgG (HlgA-IgG) showed low cross-reactivity to other toxin components, it was essential to protect rabbit and human RBCs and human PMNs. For the protection of rabbit RBCs, HlaH35L toxoid-IgG was also required, whereas, for human PMNs, LukS-IgG and LukAE323AB-IgG were essential too. When the toxin/toxoid antigens HlgA, LukS-PV, HlaH35L, and LukAE323AB were used to immunize rabbits, they increased rabbit survival; however, they did not block staphylococcal abscess formation in kidneys. Based on these results, we proposed that the combination of HlgA, LukS, HlaH35L, and LukAE323AB is the optimal vaccine component to protect human RBCs and PMNs from staphylococcal PFTs. We also concluded that a successful S. aureus vaccine requires not only those toxin antigens but also other antigens that can induce immune response blocking staphylococcal colonization.
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17
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Zheng D, Chen Y, Wan S, Jiang J, Chen S, Zheng C, Zhou H, Xu G, Zhang H, Xu H. Polycyclic polyprenylated acylphloroglucinol congeners from Garcinia yunnanensis Hu with inhibitory effect on α-hemolysin production in Staphylococcus aureus. Bioorg Chem 2021; 114:105074. [PMID: 34174629 DOI: 10.1016/j.bioorg.2021.105074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/04/2021] [Accepted: 06/06/2021] [Indexed: 12/22/2022]
Abstract
α-Hemolysin (Hla) is an extracellular protein secreted by methicillin-resistant Staphylococcus aureus (MRSA) strains that plays a critical role in the pathogenesis of pulmonary, intraperitoneal, intramammary, and corneal infections, rendering Hla a potential therapeutic target. In this study, 10 unreported polycyclic polyprenylated acylphloroglucinol (PPAP) derivatives, garciyunnanins C-L (1-10), with diverse skeletons, were isolated from Garcinia yunnanensis Hu. The structures of these new compounds were determined by HRMS, NMR, electronic circular dichroism (ECD) calculations, single-crystal X-ray diffraction, and biomimetic transformation. Garciyunnanins C and D (1 and 2) were found to be potent Hla inhibitors in the anti-virulence efficacy evaluation against MRSA strain.
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Affiliation(s)
- Dan Zheng
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China; Center for Translational Medicine and Shanghai Key Laboratory of Diabetes Mellitus, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
| | - Yuyu Chen
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Shijie Wan
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Jiaming Jiang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Simin Chen
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Changwu Zheng
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Hua Zhou
- Institute of Cardiovascular Disease of Integrated Traditional Chinese and Western Medicine, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Gang Xu
- State Key Laboratory of Phytochemistry and Plant Resources in West China and Yunnan Key Laboratory of Natural Medicinal Chemistry, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Hong Zhang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
| | - Hongxi Xu
- Institute of Cardiovascular Disease of Integrated Traditional Chinese and Western Medicine, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
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18
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Monoclonal Antibodies Targeting Surface-Exposed and Secreted Proteins from Staphylococci. Vaccines (Basel) 2021; 9:vaccines9050459. [PMID: 34064471 PMCID: PMC8147999 DOI: 10.3390/vaccines9050459] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/14/2021] [Accepted: 04/30/2021] [Indexed: 02/01/2023] Open
Abstract
Staphylococci (specifically Staphylococcus aureus and Staphylococcus epidermidis) are the causative agents of diseases ranging from superficial skin and soft tissue infections to severe conditions such as fatal pneumonia, bacteremia, sepsis and endocarditis. The widespread and indiscriminate use of antibiotics has led to serious problems of resistance to staphylococcal disease and has generated a renewed interest in alternative therapeutic agents such as vaccines and antibodies. Staphylococci express a large repertoire of surface and secreted virulence factors, which provide mechanisms (adhesion, invasion and biofilm development among others) for both bacterial survival in the host and evasion from innate and adaptive immunity. Consequently, the development of antibodies that target specific antigens would provide an effective protective strategy against staphylococcal infections. In this review, we report an update on efforts to develop anti-staphylococci monoclonal antibodies (and their derivatives: minibodies, antibody–antibiotic conjugates) and the mechanism by which such antibodies can help fight infections. We also provide an overview of mAbs used in clinical trials and highlight their therapeutic potential in various infectious contexts.
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19
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François B, Jafri HS, Chastre J, Sánchez-García M, Eggimann P, Dequin PF, Huberlant V, Viña Soria L, Boulain T, Bretonnière C, Pugin J, Trenado J, Hernandez Padilla AC, Ali O, Shoemaker K, Ren P, Coenjaerts FE, Ruzin A, Barraud O, Timbermont L, Lammens C, Pierre V, Wu Y, Vignaud J, Colbert S, Bellamy T, Esser MT, Dubovsky F, Bonten MJ, Goossens H, Laterre PF. Efficacy and safety of suvratoxumab for prevention of Staphylococcus aureus ventilator-associated pneumonia (SAATELLITE): a multicentre, randomised, double-blind, placebo-controlled, parallel-group, phase 2 pilot trial. THE LANCET. INFECTIOUS DISEASES 2021; 21:1313-1323. [PMID: 33894131 DOI: 10.1016/s1473-3099(20)30995-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 11/18/2020] [Accepted: 12/17/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND Staphylococcus aureus remains a common cause of ventilator-associated pneumonia, with little change in incidence over the past 15 years. We aimed to evaluate the efficacy of suvratoxumab, a monoclonal antibody targeting the α toxin, in reducing the incidence of S aureus pneumonia in patients in the intensive care unit (ICU) who are on mechanical ventilation. METHODS We did a multicentre, randomised, double-blind, placebo-controlled, parallel-group, phase 2 pilot trial at 31 hospitals in Belgium, the Czech Republic, France, Germany, Greece, Hungary, Portugal, Spain, and Switzerland. Eligible patients were in the ICU, aged ≥18 years, were intubated and on mechanical ventilation, were positive for S aureus colonisation of the lower respiratory tract, as assessed by quantitative PCR (qPCR) analysis of endotracheal aspirate, and had not been diagnosed with new-onset pneumonia. Patients were excluded if they had confirmed or suspected acute ongoing staphylococcal disease; had received antibiotics for S aureus infection for more than 48 h within 72 h of randomisation; had a Clinical Pulmonary Infection Score of 6 or higher; had an acute physiology and chronic health evaluation II score of 25 or higher with a Glasgow coma scale (GCS) score of more than 5, or an acute physiology and chronic health evaluation II score of at least 30 with a GCS score of 5 or less; had a Sequential Organ Failure Assessment score of 9 or higher; or had active pulmonary disease that would impair the ability to diagnose pneumonia. Colonised patients were randomly assigned (1:1:1), by use of an interactive voice or web response system, to receive either a single intravenous infusion of suvratoxumab 2000 mg, suvratoxumab 5000 mg, or placebo. Randomisation was done in blocks of size four, stratified by country and by whether patients had received systemic antibiotics for S aureus infection. Patients, investigators, and study staff involved in the treatment or clinical evaluation of patients were masked to patient assignment. The primary efficacy endpoint was the incidence of S aureus pneumonia at 30 days, as determined by a masked independent endpoint adjudication committee, in all patients who received their assigned treatment (modified intention-to-treat [ITT] population). Primary safety endpoints were the incidence of treatment-emergent adverse events at 30 days, 90 days, and 190 days after treatment, and the incidence of treatment-emergent serious adverse events, adverse events of special interest, and new-onset chronic disease at 190 days after treatment. All primary safety endpoints were assessed in the modified ITT population. This trial is registered with ClinicalTrials.gov (NCT02296320) and the EudraCT database (2014-001097-34). FINDINGS Between Oct 10, 2014, and April 1, 2018, 767 patients were screened, of whom 213 patients with confirmed S aureus colonisation of the lower respiratory tract were randomly assigned to the suvratoxumab 2000 mg group (n=15), the suvratoxumab 5000 mg group (n=96), or the placebo group (n=102). Two patients in the placebo group did not receive treatment after randomisation because their clinical conditions changed and they no longer met the eligibility criteria for dosing. As adjudicated by the data monitoring committee at an interim analysis, the suvratoxumab 2000 mg group was discontinued on the basis of predefined pharmacokinetic criteria. At 30 days after treatment, 17 (18%) of 96 patients in the suvratoxumab 5000 mg group and 26 (26%) of 100 patients in the placebo group had developed S aureus pneumonia (relative risk reduction 31·9% [90% CI -7·5 to 56·8], p=0·17). The incidence of treatment-emergent adverse events at 30 days were similar between the suvratoxumab 5000 mg group (87 [91%]) and the placebo group (90 [90%]). The incidence of treatment-emergent serious adverse events at 30 days were also similar between the suvratoxumab 5000 mg group (36 [38%]) and the placebo group (32 [32%]). No significant difference in the incidence of treatment-emergent adverse events between the two groups at 90 days (89 [93%] in the suvratoxumab 5000 mg group vs 92 [92%] in the placebo group) and at 190 days (93 [94%] vs 93 [93%]) was observed. 40 (40%) patients in the placebo group and 50 (52%) in the suvratoxumab 5000 mg group had a serious adverse event at 190 days. In the suvratoxumab 5000 mg group, one (1%) patient reported at least one treatment-emergent serious adverse event related to treatment, two (2%) patients reported an adverse event of special interest, and two (2%) reported a new-onset chronic disease. INTERPRETATION In patients in the ICU receiving mechanical ventilation with qPCR-confirmed S aureus colonisation of the lower respiratory tract, the incidence of S aureus pneumonia at 30 days was not significantly lower following treatment with 5000 mg suvratoxumab than with placebo. Despite these negative results, monoclonal antibodies still represent one promising therapeutic option to reduce antibiotic consumption that require further exploration and studies. FUNDING AstraZeneca, with support from the Innovative Medicines Initiative Joint Undertaking.
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Affiliation(s)
- Bruno François
- ICU Department, Inserm CIC-1435 and UMR-1092, CRICS-TRIGGERSEP Network, CHU Dupuytren, Limoges, France.
| | - Hasan S Jafri
- BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA.
| | - Jean Chastre
- Institut de Cardiologie, Service de Réanimation Médicale, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, Paris, France
| | | | - Philippe Eggimann
- Department of Critical Care, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Pierre-François Dequin
- CHRU de Tours, Service de Médecine Intensive Réanimation, Inserm CIC 1415 and UMR-1100, and CRICS-TRIGGERSEP Network, Tours, France
| | | | | | - Thierry Boulain
- Centre Hospitalier Régional d'Orléans, Médecine Intensive Réanimation, Orleans, France
| | - Cédric Bretonnière
- Service de Soins Intensifs-Pneumologie, Hôpital Guillaume et René Laennec, Nantes, France
| | - Jérôme Pugin
- Département d'Anesthésiologie, Pharmacologie, Soins Intensifs et Urgences, Université de Genève, Geneva, Switzerland
| | - Josep Trenado
- Intensive Care Department, Hospital Universitari Mutua de Terrassa, Terrassa, Spain
| | | | - Omar Ali
- BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | | | - Pin Ren
- BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | - Frank E Coenjaerts
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, Netherlands
| | - Alexey Ruzin
- BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | | | - Leen Timbermont
- Laboratory of Medical Microbiology, Vaccine and Infectious Disease Institute, Antwerp University Hospital, Antwerp, Belgium
| | - Christine Lammens
- Laboratory of Medical Microbiology, Vaccine and Infectious Disease Institute, Antwerp University Hospital, Antwerp, Belgium
| | - Vadryn Pierre
- BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | - Yuling Wu
- BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | | | - Susan Colbert
- BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | | | - Mark T Esser
- BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | - Filip Dubovsky
- BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, MD, USA
| | - Marc J Bonten
- Department of Medical Microbiology and Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, Netherlands
| | - Herman Goossens
- Laboratory of Medical Microbiology, Vaccine and Infectious Disease Institute, Antwerp University Hospital, Antwerp, Belgium
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20
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Wächter H, Yörük E, Becker K, Görlich D, Kahl BC. Correlations of Host and Bacterial Characteristics with Clinical Parameters and Survival in Staphylococcus aureus Bacteremia. J Clin Med 2021; 10:1371. [PMID: 33800644 PMCID: PMC8037130 DOI: 10.3390/jcm10071371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 03/19/2021] [Accepted: 03/24/2021] [Indexed: 01/14/2023] Open
Abstract
Staphylococcus aureus bacteremia (SAB) is a frequent, severe condition that occurs in patients of all age groups and affects clinical departments of all medical fields. It is associated with a high mortality rate of 20-30%. In this study, we analyzed patient mortality associated with SAB at our tertiary care university hospital, assessed the clinical management in terms of administered antimicrobial therapy, and determined which factors have an impact on the clinical course and outcome of patients with this disease. We collected clinical data and blood culture isolates of 178 patients diagnosed with SAB between May 2013 and July 2015. For this study, bacteria were cultured and analyzed concerning their phenotype, hemolysis activity, biofilm formation, nuclease activity, prevalence of toxin genes, spa and agr type. Overall mortality was 24.2% and 30-day mortality was 14.6%. Inadequate initial therapy was administered to 26.2% of patients and was associated with decreased survival (p = 0.041). Other factors associated with poor survival were patient age (p = 0.003), agr type 4 (p ≤ 0.001) and pathological leukocyte counts (p = 0.029 if elevated and p = 0.003 if lowered). The type of infection focus, spa clonal complex and enterotoxin genes seg and sei had an impact on severity of inflammation. Our results indicate that mortality and burden of disease posed by SAB are high at our university hospital.
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Affiliation(s)
- Hannah Wächter
- Institute of Medical Microbiology, University Hospital Münster, 48149 Münster, Germany; (H.W.); (E.Y.); (K.B.)
| | - Erdal Yörük
- Institute of Medical Microbiology, University Hospital Münster, 48149 Münster, Germany; (H.W.); (E.Y.); (K.B.)
| | - Karsten Becker
- Institute of Medical Microbiology, University Hospital Münster, 48149 Münster, Germany; (H.W.); (E.Y.); (K.B.)
- Friedrich Loeffler-Institute of Medical Microbiology, University Medicine Greifswald, 17475 Greifswald, Germany
| | - Dennis Görlich
- Institute of Biostatistics and Clinical Research, University Hospital Münster, 48149 Münster, Germany;
| | - Barbara C. Kahl
- Institute of Medical Microbiology, University Hospital Münster, 48149 Münster, Germany; (H.W.); (E.Y.); (K.B.)
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21
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Streicher LM. Exploring the future of infectious disease treatment in a post-antibiotic era: A comparative review of alternative therapeutics. J Glob Antimicrob Resist 2021; 24:285-295. [PMID: 33484895 DOI: 10.1016/j.jgar.2020.12.025] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/19/2020] [Accepted: 12/26/2020] [Indexed: 12/23/2022] Open
Abstract
Antibiotic resistance is projected to be one of the greatest healthcare challenges of the 21st century. As the efficacy of these critical drugs wanes and the discovery of new antibiotics stagnates, exploration of alternative therapies could offer a much needed solution. Although numerous alternative therapies are currently under investigation, three in particular appear poised for long-term success, namely antimicrobial oligonucleotides, monoclonal antibodies and phage therapy. Antimicrobial oligonucleotides could conceivably offer the greatest spectrum of activity while having the lowest chance of unrecoverable resistance. Bacteriophages, while most susceptible to resistance, are inexhaustible, inexpensive and exceptionally adept at eliminating biofilm-associated infections. And although monoclonal antibodies may have limited access to such recalcitrant bacteria, these agents are uniquely able to neutralise exotoxins and other diffusible virulence factors. This comparative review seeks to illuminate these promising therapies and to encourage the scientific and financial support necessary to usher in the next generation of infectious disease treatment.
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22
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Ford CA, Hurford IM, Cassat JE. Antivirulence Strategies for the Treatment of Staphylococcus aureus Infections: A Mini Review. Front Microbiol 2021; 11:632706. [PMID: 33519793 PMCID: PMC7840885 DOI: 10.3389/fmicb.2020.632706] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 12/22/2020] [Indexed: 12/11/2022] Open
Abstract
Staphylococcus aureus is a Gram-positive bacterium capable of infecting nearly all host tissues, causing severe morbidity and mortality. Widespread antimicrobial resistance has emerged among S. aureus clinical isolates, which are now the most frequent causes of nosocomial infection among drug-resistant pathogens. S. aureus produces an array of virulence factors that enhance in vivo fitness by liberating nutrients from the host or evading host immune responses. Staphylococcal virulence factors have been identified as viable therapeutic targets for treatment, as they contribute to disease pathogenesis, tissue injury, and treatment failure. Antivirulence strategies, or treatments targeting virulence without direct toxicity to the inciting pathogen, show promise as an adjunctive therapy to traditional antimicrobials. This Mini Review examines recent research on S. aureus antivirulence strategies, with an emphasis on translational studies. While many different virulence factors have been investigated as therapeutic targets, this review focuses on strategies targeting three virulence categories: pore-forming toxins, immune evasion mechanisms, and the S. aureus quorum sensing system. These major areas of S. aureus antivirulence research demonstrate broad principles that may apply to other human pathogens. Finally, challenges of antivirulence research are outlined including the potential for resistance, the need to investigate multiple infection models, and the importance of studying antivirulence in conjunction with traditional antimicrobial treatments.
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Affiliation(s)
- Caleb A. Ford
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
| | - Ian M. Hurford
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN, United States
| | - James E. Cassat
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN, United States
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN, United States
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, United States
- Vanderbilt Center for Bone Biology, Vanderbilt University Medical Center, Nashville, TN, United States
- Vanderbilt Institute for Infection, Immunology, and Inflammation (VI4), Vanderbilt University Medical Center, Nashville, TN, United States
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23
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Wang Z, Chen W, Machiesky L, Sun J, Christian E, Parthemore C, Martinelli M, Lin S. Development of a mechanism of action reflective and robust potency assay for a therapeutic antibody against alpha toxin using rabbit erythrocytes. J Immunol Methods 2020; 488:112903. [PMID: 33075362 DOI: 10.1016/j.jim.2020.112903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 10/03/2020] [Accepted: 10/13/2020] [Indexed: 11/15/2022]
Affiliation(s)
- Zheng Wang
- Bioassay, Impurities & Quality, AstraZeneca, Gaithersburg, USA
| | - Weimin Chen
- Bioassay, Impurities & Quality, AstraZeneca, Gaithersburg, USA
| | | | - Jenny Sun
- Physiochemical Analytical Sciences, AstraZeneca, Gaithersburg, USA
| | | | | | | | - Shihua Lin
- Bioassay, Impurities & Quality, AstraZeneca, Gaithersburg, USA.
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24
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Zeng H, Zhang J, Song X, Zeng J, Yuan Y, Chen Z, Xu L, Gou Q, Yang F, Zeng N, Zhang Y, Peng L, Zhao L, Zhu J, Liu Y, Luo P, Zou Q, Zhao Z. An Immunodominant Epitope-Specific Monoclonal Antibody Cocktail Improves Survival in a Mouse Model of Staphylococcus aureus Bacteremia. J Infect Dis 2020; 223:1743-1752. [PMID: 32959055 DOI: 10.1093/infdis/jiaa602] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 09/18/2020] [Indexed: 01/22/2023] Open
Abstract
To date, no vaccine or monoclonal antibody (mAb) against Staphylococcus aureus has been approved for use in humans. Our laboratory has developed a 5-antigen S. aureus vaccine (rFSAV), which is now under efficacy evaluation in a phase 2 clinical trial. In the current study, using overlapping peptides and antiserum from rFSAV-immunized volunteers, we identified 7 B-cell immunodominant epitopes on 4 antigens in rFSAV, including 5 novel epitopes (Hla48-65, IsdB402-419, IsdB432-449, SEB78-95, and MntC7-24). Ten immunodominant epitope mAbs were generated against these epitopes, and all of them exhibited partial protection in a mouse sepsis model. Four robust mAbs were used together as an mAb cocktail to prevent methicillin-resistant S. aureus strain 252 infection. The results showed that the mAb cocktail was efficient in combating S. aureus infection and that its protective efficacy correlated with a reduced bacterial burden and decreased infection pathology, which demonstrates that the mAb cocktail is a promising S. aureus vaccine candidate.
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Affiliation(s)
- Hao Zeng
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, Chongqing, People's Republic of China
| | - Jinyong Zhang
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, Chongqing, People's Republic of China
| | - Xu Song
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, Chongqing, People's Republic of China
| | - Jiangmin Zeng
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, Chongqing, People's Republic of China
| | - Yue Yuan
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, Chongqing, People's Republic of China
| | - Zhifu Chen
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, Chongqing, People's Republic of China
| | - Limin Xu
- Chengdu Olymvax Biotechnology Co, Ltd, Chengdu, Sichuan, People's Republic of China
| | - Qiang Gou
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, Chongqing, People's Republic of China
| | - Feng Yang
- Chengdu Olymvax Biotechnology Co, Ltd, Chengdu, Sichuan, People's Republic of China
| | - Ni Zeng
- Chengdu Olymvax Biotechnology Co, Ltd, Chengdu, Sichuan, People's Republic of China
| | - Yi Zhang
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, Chongqing, People's Republic of China
| | - Liusheng Peng
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, Chongqing, People's Republic of China
| | - Liqun Zhao
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, Chongqing, People's Republic of China
| | - Jiang Zhu
- Department of Pathology, Southwest Hospital, Army Medical University, Chongqing, People's Republic of China
| | - Yuanyuan Liu
- Medical Corps Department, Unit 69016, Chinese People's Liberation Army, Xinjiang, People's Republic of China
| | - Ping Luo
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, Chongqing, People's Republic of China
| | - Quanming Zou
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, Chongqing, People's Republic of China
| | - Zhuo Zhao
- National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, Chongqing, People's Republic of China
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25
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Generation and Characterization of Typhoid Toxin-Neutralizing Human Monoclonal Antibodies. Infect Immun 2020; 88:IAI.00292-20. [PMID: 32661121 DOI: 10.1128/iai.00292-20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 07/06/2020] [Indexed: 11/20/2022] Open
Abstract
Typhoid toxin is a virulence factor of Salmonella enterica serovar Typhi, the causative agent of typhoid fever, and is thought to be responsible for the symptoms of severe disease. This toxin has a unique A2B5 architecture with two active subunits, the ADP ribosyl transferase PltA and the DNase CdtB, linked to a pentameric B subunit, which is alternatively made of PltB or PltC. Here, we describe the generation and characterization of typhoid toxin-neutralizing human monoclonal antibodies by immunizing genetically engineered mice that have a full set of human immunoglobulin variable region genes. We identified several monoclonal antibodies with strong in vitro and in vivo toxin-neutralizing activity and different mechanisms of toxin neutralization. These antibodies could serve as the basis for the development of novel therapeutic strategies against typhoid fever.
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26
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Possible drugs for the treatment of bacterial infections in the future: anti-virulence drugs. J Antibiot (Tokyo) 2020; 74:24-41. [PMID: 32647212 DOI: 10.1038/s41429-020-0344-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/26/2020] [Accepted: 05/29/2020] [Indexed: 12/19/2022]
Abstract
Antibiotic resistance is a global threat that should be urgently resolved. Finding a new antibiotic is one way, whereas the repression of the dissemination of virulent pathogenic bacteria is another. From this point of view, this paper summarizes first the mechanisms of conjugation and transformation, two important processes of horizontal gene transfer, and then discusses the approaches for disarming virulent pathogenic bacteria, that is, virulence factor inhibitors. In contrast to antibiotics, anti-virulence drugs do not impose a high selective pressure on a bacterial population, and repress the dissemination of antibiotic resistance and virulence genes. Disarmed virulence factors make virulent pathogens avirulent bacteria or pathobionts, so that we human will be able to coexist with these disarmed bacteria peacefully.
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27
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Tsai CN, MacNair CR, Cao MPT, Perry JN, Magolan J, Brown ED, Coombes BK. Targeting Two-Component Systems Uncovers a Small-Molecule Inhibitor of Salmonella Virulence. Cell Chem Biol 2020; 27:793-805.e7. [PMID: 32413287 DOI: 10.1016/j.chembiol.2020.04.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/27/2020] [Accepted: 04/06/2020] [Indexed: 12/27/2022]
Abstract
Salmonella serovars are leading causes of gastrointestinal disease and have become increasingly resistant to fluoroquinolone and cephalosporin antibiotics. Overcoming this healthcare crisis requires new approaches in antibiotic discovery and the identification of unique bacterial targets. In this work, we describe a chemical genomics approach to identify inhibitors of Salmonella virulence. From a cell-based, promoter reporter screen of ∼50,000 small molecules, we identified dephostatin as a non-antibiotic compound that inhibits intracellular virulence factors and polymyxin resistance genes. Dephostatin disrupts signaling through both the SsrA-SsrB and PmrB-PmrA two-component regulatory systems and restores sensitivity to the last-resort antibiotic, colistin. Cell-based experiments and mouse models of infection demonstrate that dephostatin attenuates Salmonella virulence in vitro and in vivo, suggesting that perturbing regulatory networks is a promising strategy for the development of anti-infectives.
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Affiliation(s)
- Caressa N Tsai
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada; Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Craig R MacNair
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada; Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - My P T Cao
- Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON L8S 4L8, Canada; Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Jordyn N Perry
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada; Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Jakob Magolan
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada; Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON L8S 4L8, Canada; Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Eric D Brown
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada; Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Brian K Coombes
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4L8, Canada; Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON L8S 4L8, Canada.
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28
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Robinson KM, Ramanan K, Tobin JM, Nickolich KL, Pilewski MJ, Kallewaard NL, Sellman BR, Cohen TS, Alcorn JF. Survival during influenza-associated bacterial superinfection improves following viral- and bacterial-specific monoclonal antibody treatment. JCI Insight 2019; 4:125554. [PMID: 31341107 DOI: 10.1172/jci.insight.125554] [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] [Received: 10/15/2018] [Accepted: 06/05/2019] [Indexed: 12/27/2022] Open
Abstract
Postinfluenza bacterial superinfections cause increased morbidity and mortality compared with singular infection with influenza during both pandemics and seasonal epidemics. Vaccines and current treatments provide limited benefit, a rationale to conduct studies utilizing alternative therapies. FY1 and an optimized version, MEDI8852, anti-influenza HA mAbs, have been shown to neutralize influenza virus during singular influenza infection. MEDI4893*, an anti-Staphylococcus aureus α-toxin mAb, has been shown to improve survival when administered prophylactically prior to S. aureus pneumonia. Our objective was to determine if mAbs can improve survival during postinfluenza bacterial pneumonia. We administered FY1 in a murine model of postinfluenza methicillin-resistant S. aureus (MRSA) pneumonia and observed improved survival rates when given early during the course of influenza infection. Our findings indicate decreased lung injury and increased uptake and binding of bacteria by macrophages in the mice that received FY1 earlier in the course of influenza infection, corresponding to decreased bacterial burden. We also observed improved survival when mice were treated with a combination of FY1 and MEDI4893* late during the course of postinfluenza MRSA pneumonia. In conclusion, both FY1 and MEDI4893* prolong survival when used in a murine model of postinfluenza MRSA pneumonia, suggesting pathogen-specific mAbs as a possible therapeutic in the context of bacterial superinfection.
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Affiliation(s)
- Keven M Robinson
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Krishnaveni Ramanan
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Joshua M Tobin
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Kara L Nickolich
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Matthew J Pilewski
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | | | - Bret R Sellman
- Department of Microbial Sciences, MedImmune, Gaithersburg, Maryland, USA
| | - Taylor S Cohen
- Department of Microbial Sciences, MedImmune, Gaithersburg, Maryland, USA
| | - John F Alcorn
- Division of Pulmonary Medicine, Department of Pediatrics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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29
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Masters EA, Trombetta RP, de Mesy Bentley KL, Boyce BF, Gill AL, Gill SR, Nishitani K, Ishikawa M, Morita Y, Ito H, Bello-Irizarry SN, Ninomiya M, Brodell JD, Lee CC, Hao SP, Oh I, Xie C, Awad HA, Daiss JL, Owen JR, Kates SL, Schwarz EM, Muthukrishnan G. Evolving concepts in bone infection: redefining "biofilm", "acute vs. chronic osteomyelitis", "the immune proteome" and "local antibiotic therapy". Bone Res 2019; 7:20. [PMID: 31646012 PMCID: PMC6804538 DOI: 10.1038/s41413-019-0061-z] [Citation(s) in RCA: 273] [Impact Index Per Article: 54.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 06/17/2019] [Accepted: 06/21/2019] [Indexed: 02/08/2023] Open
Abstract
Osteomyelitis is a devastating disease caused by microbial infection of bone. While the frequency of infection following elective orthopedic surgery is low, rates of reinfection are disturbingly high. Staphylococcus aureus is responsible for the majority of chronic osteomyelitis cases and is often considered to be incurable due to bacterial persistence deep within bone. Unfortunately, there is no consensus on clinical classifications of osteomyelitis and the ensuing treatment algorithm. Given the high patient morbidity, mortality, and economic burden caused by osteomyelitis, it is important to elucidate mechanisms of bone infection to inform novel strategies for prevention and curative treatment. Recent discoveries in this field have identified three distinct reservoirs of bacterial biofilm including: Staphylococcal abscess communities in the local soft tissue and bone marrow, glycocalyx formation on implant hardware and necrotic tissue, and colonization of the osteocyte-lacuno canalicular network (OLCN) of cortical bone. In contrast, S. aureus intracellular persistence in bone cells has not been substantiated in vivo, which challenges this mode of chronic osteomyelitis. There have also been major advances in our understanding of the immune proteome against S. aureus, from clinical studies of serum antibodies and media enriched for newly synthesized antibodies (MENSA), which may provide new opportunities for osteomyelitis diagnosis, prognosis, and vaccine development. Finally, novel therapies such as antimicrobial implant coatings and antibiotic impregnated 3D-printed scaffolds represent promising strategies for preventing and managing this devastating disease. Here, we review these recent advances and highlight translational opportunities towards a cure.
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Affiliation(s)
- Elysia A. Masters
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY USA
| | - Ryan P. Trombetta
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY USA
| | - Karen L. de Mesy Bentley
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY USA
| | - Brendan F Boyce
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY USA
| | - Ann Lindley Gill
- Department of Microbiology & Immunology, University of Rochester Medical Center, Rochester, NY USA
| | - Steven R. Gill
- Department of Microbiology & Immunology, University of Rochester Medical Center, Rochester, NY USA
| | - Kohei Nishitani
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedic Surgery, Kyoto University, Kyoto, Japan
| | - Masahiro Ishikawa
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedic Surgery, Kyoto University, Kyoto, Japan
| | - Yugo Morita
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedic Surgery, Kyoto University, Kyoto, Japan
| | - Hiromu Ito
- Department of Orthopaedic Surgery, Kyoto University, Kyoto, Japan
| | | | - Mark Ninomiya
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
| | - James D. Brodell
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
| | - Charles C. Lee
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
| | - Stephanie P. Hao
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
| | - Irvin Oh
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY USA
| | - Chao Xie
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY USA
| | - Hani A. Awad
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY USA
| | - John L. Daiss
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY USA
| | - John R. Owen
- Department of Orthopaedic Surgery, Virginia Commonwealth University Medical Center, Richmond, VA USA
| | - Stephen L. Kates
- Department of Orthopaedic Surgery, Virginia Commonwealth University Medical Center, Richmond, VA USA
| | - Edward M. Schwarz
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY USA
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY USA
- Department of Microbiology & Immunology, University of Rochester Medical Center, Rochester, NY USA
| | - Gowrishankar Muthukrishnan
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY USA
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY USA
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30
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Candida albicans Augments Staphylococcus aureus Virulence by Engaging the Staphylococcal agr Quorum Sensing System. mBio 2019; 10:mBio.00910-19. [PMID: 31164467 PMCID: PMC6550526 DOI: 10.1128/mbio.00910-19] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Relatively little is known about the complex interactions and signaling events that occur between microbes and even less so about how microbial “cross talk” shapes human health and disease. Candida albicans (a fungus) and Staphylococcus aureus (a bacterium) are formidable human nosocomial pathogens, causing severe morbidity and mortality. Moreover, they are frequently coisolated from central venous catheters and deep-seated infections, including intra-abdominal sepsis. In this work, we have shown that coinfection with C. albicans and S. aureus is highly lethal, leading to >80% mortality by day 1 postinfection, whereas monoinfection with C. albicans or S. aureus does not cause mortality. This infectious synergism is dependent on the expression of staphylococcal alpha-toxin, and secretion of this potent virulence factor is actually augmented by C. albicans via an agr-dependent mechanism. Moreover, prophylactic neutralization of alpha-toxin with a monoclonal antibody is sufficient to elicit protection during coinfection. Therefore, we have demonstrated that a pathogenic fungus can enhance virulence determinants of a bacterium in vivo with devastating consequences to the host. These results have important implications in the surveillance and treatment of polymicrobial disease and highlight the dynamic intersection of environment, pathogens, and host. Candida albicans and Staphylococcus aureus are among the most prevalent nosocomial pathogens that are responsible for severe morbidity and mortality, even with appropriate treatment. Using a murine model of polymicrobial intra-abdominal infection (IAI), we have previously shown that coinfection with these pathogens results in synergistic lethality that is partially dependent on exacerbated prostaglandin signaling, while monomicrobial infection is nonlethal. Therefore, the objective of this study was to identify staphylococcal virulence determinants that drive lethal synergism during polymicrobial IAI. Using the toxigenic S. aureus strain JE2, we observed that coinfection with C. albicans led to a striking 80 to 100% mortality rate within 20 h postinoculation (p.i.) while monomicrobial infections were nonlethal. Use of a green fluorescent protein (GFP)-P3 promoter S. aureus reporter strain revealed enhanced activation of the staphylococcal agr quorum sensing system during in vitro polymicrobial versus monomicrobial growth. Analyses by quantitative real-time PCR (qPCR), Western blot, and toxin functional assays confirmed enhanced agr-associated gene transcription and increases in secreted alpha- and delta-toxins. C. albicans-mediated elevated toxin production and hemolytic activity were determined to be agrA dependent, and genetic knockout and complementation of hla identified alpha-toxin as the key staphylococcal virulence factor driving lethal synergism. Analysis of mono- and polymicrobial infections 8 h p.i. demonstrated equivalent bacterial burdens in the peritoneal cavity but significantly elevated levels of alpha-toxin (3-fold) and the eicosanoid prostaglandin E2 (PGE2) (4-fold) during coinfection. Importantly, prophylactic passive immunization using the monoclonal anti-alpha-toxin antibody MEDI4893* led to significantly improved survival rates compared to those following treatment with isotype control antibody. Collectively, these results define alpha-toxin as an essential virulence determinant during C. albicans-S. aureus IAI and describe a novel mechanism by which a human-pathogenic fungus can augment the virulence of a highly pathogenic bacterium in vivo.
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Tam K, Torres VJ. Staphylococcus aureus Secreted Toxins and Extracellular Enzymes. Microbiol Spectr 2019; 7:10.1128/microbiolspec.GPP3-0039-2018. [PMID: 30873936 PMCID: PMC6422052 DOI: 10.1128/microbiolspec.gpp3-0039-2018] [Citation(s) in RCA: 201] [Impact Index Per Article: 40.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Indexed: 02/06/2023] Open
Abstract
Staphylococcus aureus is a formidable pathogen capable of causing infections in different sites of the body in a variety of vertebrate animals, including humans and livestock. A major contribution to the success of S. aureus as a pathogen is the plethora of virulence factors that manipulate the host's innate and adaptive immune responses. Many of these immune modulating virulence factors are secreted toxins, cofactors for activating host zymogens, and exoenzymes. Secreted toxins such as pore-forming toxins and superantigens are highly inflammatory and can cause leukocyte cell death by cytolysis and clonal deletion, respectively. Coagulases and staphylokinases are cofactors that hijack the host's coagulation system. Exoenzymes, including nucleases and proteases, cleave and inactivate various immune defense and surveillance molecules, such as complement factors, antimicrobial peptides, and surface receptors that are important for leukocyte chemotaxis. Additionally, some of these secreted toxins and exoenzymes can cause disruption of endothelial and epithelial barriers through cell lysis and cleavage of junction proteins. A unique feature when examining the repertoire of S. aureus secreted virulence factors is the apparent functional redundancy exhibited by the majority of the toxins and exoenzymes. However, closer examination of each virulence factor revealed that each has unique properties that have important functional consequences. This chapter provides a brief overview of our current understanding of the major secreted virulence factors critical for S. aureus pathogenesis.
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Affiliation(s)
- Kayan Tam
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, New York, NY 10016
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, Alexandria Center for Life Science, New York, NY 10016
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Raafat D, Otto M, Reppschläger K, Iqbal J, Holtfreter S. Fighting Staphylococcus aureus Biofilms with Monoclonal Antibodies. Trends Microbiol 2019; 27:303-322. [PMID: 30665698 DOI: 10.1016/j.tim.2018.12.009] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 12/10/2018] [Accepted: 12/18/2018] [Indexed: 02/07/2023]
Abstract
Staphylococcus aureus (S. aureus) is a notorious pathogen and one of the most frequent causes of biofilm-related infections. The treatment of S. aureus biofilms is hampered by the ability of the biofilm structure to shield bacteria from antibiotics as well as the host's immune system. Therefore, new preventive and/or therapeutic interventions, including the use of antibody-based approaches, are urgently required. In this review, we describe the mechanisms by which anti-S. aureus antibodies can help in combating biofilms, including an up-to-date overview of monoclonal antibodies currently in clinical trials. Moreover, we highlight ongoing efforts in passive vaccination against S. aureus biofilm infections, with special emphasis on promising targets, and finally indicate the direction into which future research could be heading.
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Affiliation(s)
- Dina Raafat
- Department of Microbiology and Immunology, Faculty of Pharmacy, Alexandria University, Egypt; Current affiliation: Department of Immunology, University Medicine Greifswald, Greifswald, Germany
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, US National Institutes of Health, Bethesda, MD, USA
| | - Kevin Reppschläger
- Department of Immunology, University Medicine Greifswald, Greifswald, Germany
| | - Jawad Iqbal
- Department of Immunology, University Medicine Greifswald, Greifswald, Germany
| | - Silva Holtfreter
- Department of Immunology, University Medicine Greifswald, Greifswald, Germany.
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Naran K, Nundalall T, Chetty S, Barth S. Principles of Immunotherapy: Implications for Treatment Strategies in Cancer and Infectious Diseases. Front Microbiol 2018; 9:3158. [PMID: 30622524 PMCID: PMC6308495 DOI: 10.3389/fmicb.2018.03158] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 12/05/2018] [Indexed: 12/13/2022] Open
Abstract
The advances in cancer biology and pathogenesis during the past two decades, have resulted in immunotherapeutic strategies that have revolutionized the treatment of malignancies, from relatively non-selective toxic agents to specific, mechanism-based therapies. Despite extensive global efforts, infectious diseases remain a leading cause of morbidity and mortality worldwide, necessitating novel, innovative therapeutics that address the current challenges of increasing antimicrobial resistance. Similar to cancer pathogenesis, infectious pathogens successfully fashion a hospitable environment within the host and modulate host metabolic functions to support their nutritional requirements, while suppressing host defenses by altering regulatory mechanisms. These parallels, and the advances made in targeted therapy in cancer, may inform the rational development of therapeutic interventions for infectious diseases. Although "immunotherapy" is habitually associated with the treatment of cancer, this review accentuates the evolving role of key targeted immune interventions that are approved, as well as those in development, for various cancers and infectious diseases. The general features of adoptive therapies, those that enhance T cell effector function, and ligand-based therapies, that neutralize or eliminate diseased cells, are discussed in the context of specific diseases that, to date, lack appropriate remedial treatment; cancer, HIV, TB, and drug-resistant bacterial and fungal infections. The remarkable diversity and versatility that distinguishes immunotherapy is emphasized, consequently establishing this approach within the armory of curative therapeutics, applicable across the disease spectrum.
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Affiliation(s)
- Krupa Naran
- Medical Biotechnology and Immunotherapy Unit, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Trishana Nundalall
- Medical Biotechnology and Immunotherapy Unit, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Shivan Chetty
- Medical Biotechnology and Immunotherapy Unit, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Stefan Barth
- Medical Biotechnology and Immunotherapy Unit, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- South African Research Chair in Cancer Biotechnology, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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Pharmacological Targeting of Pore-Forming Toxins as Adjunctive Therapy for Invasive Bacterial Infection. Toxins (Basel) 2018; 10:toxins10120542. [PMID: 30562923 PMCID: PMC6316385 DOI: 10.3390/toxins10120542] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 12/10/2018] [Accepted: 12/14/2018] [Indexed: 12/23/2022] Open
Abstract
For many of the most important human bacterial infections, invasive disease severity is fueled by the cell damaging and pro-inflammatory effects of secreted pore-forming toxins (PFTs). Isogenic PFT-knockout mutants, e.g., Staphylococcus aureus lacking α-toxin or Streptococcus pneumoniae deficient in pneumolysin, show attenuation in animal infection models. This knowledge has inspired multi-model investigations of strategies to neutralize PFTs or counteract their toxicity as a novel pharmacological approach to ameliorate disease pathogenesis in clinical disease. Promising examples of small molecule, antibody or nanotherapeutic drug candidates that directly bind and neutralize PFTs, block their oligomerization or membrane receptor interactions, plug establishment membrane pores, or boost host cell resiliency to withstand PFT action have emerged. The present review highlights these new concepts, with a special focus on β-PFTs produced by leading invasive human Gram-positive bacterial pathogens. Such anti-virulence therapies could be applied as an adjunctive therapy to antibiotic-sensitive and -resistant strains alike, and further could be free of deleterious effects that deplete the normal microflora.
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Jing C, Liu C, Liu F, Gao Y, Liu Y, Guan Z, Xuan B, Yu Y, Yang G. Novel human monoclonal antibodies targeting the F subunit of leukocidins reduce disease progression and mortality caused by Staphylococcus aureus. BMC Microbiol 2018; 18:181. [PMID: 30419818 PMCID: PMC6233355 DOI: 10.1186/s12866-018-1312-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 10/11/2018] [Indexed: 01/17/2023] Open
Abstract
Background Staphylococcus aureus is a leading cause of Gram-positive bacterial infections worldwide; however, the treatment of S. aureus infection has become increasingly difficult due to the prevalence of methicillin-resistant S. aureus strains, highlighting the urgent need for the development of novel strategies. The complexity of S. aureus pathogenesis relies on virulence factors. Recent studies have demonstrated that leukocidins expressed by the majority of clinical isolates play important roles in the pathogenesis of S. aureus. Results In this study, we developed three human monoclonal antibodies against all F-components of leukocidins HlgABC, LukSF, and LukED with high affinity. These antibodies were found to be capable of blocking leukocidin-mediated cell lysis in vitro. Furthermore, the antibodies dramatically reduced disease progression and mortality after S. aureus infection in vivo. Conclusions Our findings revealed that neutralizing bicomponent leukocidins may be a promising strategy to combat infections caused by S. aureus. Electronic supplementary material The online version of this article (10.1186/s12866-018-1312-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chendi Jing
- Department of Infectious Diseases, Peking University First Hospital, Beijing, 100034, China
| | - Chenghua Liu
- Beijing Institute of Basic Medical Sciences, Beijing, 100850, China
| | - Fangjie Liu
- Beijing Institute of Basic Medical Sciences, Beijing, 100850, China
| | - Yaping Gao
- Beijing Institute of Basic Medical Sciences, Beijing, 100850, China
| | - Yu Liu
- Beijing Institute of Basic Medical Sciences, Beijing, 100850, China
| | - Zhangchun Guan
- Beijing Institute of Basic Medical Sciences, Beijing, 100850, China
| | - Bo Xuan
- Beijing Institute of Basic Medical Sciences, Beijing, 100850, China
| | - Yanyan Yu
- Department of Infectious Diseases, Peking University First Hospital, Beijing, 100034, China.
| | - Guang Yang
- Beijing Institute of Basic Medical Sciences, Beijing, 100850, China. .,State Key Laboratory of Toxicology and Medical Countermeasures, Beijing, China.
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Alanine Scanning Mutagenesis of the MEDI4893 (Suvratoxumab) Epitope Reduces Alpha Toxin Lytic Activity In Vitro and Staphylococcus aureus Fitness in Infection Models. Antimicrob Agents Chemother 2018; 62:AAC.01033-18. [PMID: 30150481 PMCID: PMC6201083 DOI: 10.1128/aac.01033-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Accepted: 08/18/2018] [Indexed: 02/06/2023] Open
Abstract
Alpha toxin (AT) is a cytolytic pore-forming toxin that plays a key role in Staphylococcus aureus pathogenesis; consequently, extensive research was undertaken to understand the AT mechanism of action and its utility as a target for novel prophylaxis and treatment strategies against S. aureus infections. MEDI4893 (suvratoxumab) is a human anti-AT IgG1 monoclonal antibody (MAb) that targets AT and is currently in phase 2 clinical development. Alpha toxin (AT) is a cytolytic pore-forming toxin that plays a key role in Staphylococcus aureus pathogenesis; consequently, extensive research was undertaken to understand the AT mechanism of action and its utility as a target for novel prophylaxis and treatment strategies against S. aureus infections. MEDI4893 (suvratoxumab) is a human anti-AT IgG1 monoclonal antibody (MAb) that targets AT and is currently in phase 2 clinical development. As shown previously, the MEDI4893-binding epitope on AT is comprised of the highly conserved amino acid regions 177 to 200 and 261 to 271, suggesting these amino acids are important for AT function. To test this hypothesis and gain insight into the effect of mutations in the epitope on AT neutralization by MEDI4893, nine MEDI4893 contact residues in AT were individually mutated to alanine. Consistent with our hypothesis, 8 out of 9 mutants exhibited >2-fold loss in lytic activity resulting from a defect in cell binding and pore formation. MEDI4893 binding affinity was reduced >2-fold (2- to 27-fold) for 7 out of 9 mutants, and no binding was detected for the W187A mutant. MEDI4893 effectively neutralized all of the lytic mutants in vitro and in vivo. When the defective mutants were introduced into an S. aureus clinical isolate, the mutant-expressing strains exhibited less severe disease in mouse models and were effectively neutralized by MEDI4893. These results indicate the MEDI4893 epitope is highly conserved due in part to its role in AT pore formation and bacterial fitness, thereby decreasing the likelihood for the emergence of MAb-resistant variants.
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Acquaye-Seedah E, Huang Y, Sutherland JN, DiVenere AM, Maynard JA. Humanised monoclonal antibodies neutralise pertussis toxin by receptor blockade and reduced retrograde trafficking. Cell Microbiol 2018; 20:e12948. [PMID: 30152075 PMCID: PMC6519169 DOI: 10.1111/cmi.12948] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 08/02/2018] [Accepted: 08/20/2018] [Indexed: 12/12/2022]
Abstract
Pertussis toxin (PTx) is a major protective antigen produced by Bordetella pertussis that is included in all current acellular vaccines. Of several well‐characterized monoclonal antibodies binding this toxin, the humanised hu1B7 and hu11E6 antibodies are highly protective in multiple in vitro and in vivo assays. In this study, we determine the molecular mechanisms of protection mediated by these antibodies. Neither antibody directly binds the B. pertussis bacterium nor supports antibody‐dependent complement cytotoxicity. Both antibodies, either individually or as a cocktail, form multivalent complexes with soluble PTx that bind the FcγRIIb receptor more tightly than antibody alone, suggesting that the antibodies may accelerate PTx clearance via immune complex formation. However, a receptor binding assay and cellular imaging indicate that the main mechanism used by hu11E6 is competitive inhibition of PTx binding to its cellular receptor. In contrast, the main hu1B7 neutralising mechanism appears to be inhibition of PTx internalisation and retrograde trafficking. We assessed the effects of hu1B7 on PTx retrograde trafficking in CHO‐K1 cells using quantitative immunofluorescence microscopy. In the absence of hu1B7 or after incubation with an isotype control antibody, PTx colocalizes to organelles in a manner consistent with retrograde transport. However, after preincubation with hu1B7, PTx appears restricted to the membrane surface with colocalization to organelles associated with retrograde transport significantly reduced. Together, these data support a model whereby hu11E6 and hu1B7 interfere with PTx receptor binding and PTx retrograde trafficking, respectively.
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Affiliation(s)
- Edith Acquaye-Seedah
- Department of Biochemistry, The University of Texas at Austin, Austin, Texas.,Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas
| | - Yimin Huang
- Department of Cell and Molecular Biology, The University of Texas at Austin, Austin, Texas.,Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas
| | - Jamie N Sutherland
- Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas
| | - Andrea M DiVenere
- Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas
| | - Jennifer A Maynard
- Department of Biochemistry, The University of Texas at Austin, Austin, Texas.,Department of Cell and Molecular Biology, The University of Texas at Austin, Austin, Texas.,Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas
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Nagy E, Nagy G, Power CA, Badarau A, Szijártó V. Anti-bacterial Monoclonal Antibodies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1053:119-153. [PMID: 29549638 DOI: 10.1007/978-3-319-72077-7_7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The failing efficacy of antibiotics and the high mortality rate among high-risk patients calls for new treatment modalities for bacterial infections. Due to the vastly divergent pathogenesis of human pathogens, each microbe requires a tailored approach. The main modes of action of anti-bacterial antibodies are virulence factor neutralization, complement-mediated bacterial lysis and enhancement of opsonophagocytic uptake and killing (OPK). Gram-positive bacteria cannot be lysed by complement and their pathogenesis often involves secreted toxins, therefore typically toxin-neutralization and OPK activity are required to prevent and ameliorate disease. In fact, the success stories in terms of approved products, in the anti-bacterial mAb field are based on toxin neutralization (Bacillus anthracis, Clostridium difficile). In contrast, Gram-negative bacteria are vulnerable to antibody-dependent complement-mediated lysis, while their pathogenesis rarely relies on secreted exotoxins, and involves the pro-inflammatory endotoxin (lipopolysaccharide). Given the complexity of bacterial pathogenesis, antibody therapeutics are expected to be most efficient upon targeting more than one virulence factor and/or combining different modes of action. The improved understanding of bacterial pathogenesis combined with the versatility and maturity of antibody discovery technologies available today are pivotal for the design of novel anti-bacterial therapeutics. The intensified research generating promising proof-of-concept data, and the increasing number of clinical programs with anti-bacterial mAbs, indicate that the field is ready to fulfill its promise in the coming years.
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Affiliation(s)
- Eszter Nagy
- Arsanis Biosciences GmbH/Arsanis, Inc, Vienna, Austria.
| | - Gábor Nagy
- Arsanis Biosciences GmbH/Arsanis, Inc, Vienna, Austria
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Fong R, Kajihara K, Chen M, Hotzel I, Mariathasan S, Hazenbos WL, Lupardus PJ. Structural investigation of human S. aureus-targeting antibodies that bind wall teichoic acid. MAbs 2018; 10:979-991. [PMID: 30102105 PMCID: PMC6204806 DOI: 10.1080/19420862.2018.1501252] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are a growing health threat worldwide. Efforts to identify novel antibodies that target S. aureus cell surface antigens are a promising direction in the development of antibiotics that can halt MRSA infection. We biochemically and structurally characterized three patient-derived MRSA-targeting antibodies that bind to wall teichoic acid (WTA), which is a polyanionic surface glycopolymer. In S. aureus, WTA exists in both α- and β-forms, based on the stereochemistry of attachment of a N-acetylglucosamine residue to the repeating phosphoribitol sugar unit. We identified a panel of antibodies cloned from human patients that specifically recognize the α or β form of WTA, and can bind with high affinity to pathogenic wild-type strains of S. aureus bacteria. To investigate how the β-WTA specific antibodies interact with their target epitope, we determined the X-ray crystal structures of the three β-WTA specific antibodies, 4462, 4497, and 6078 (Protein Data Bank IDs 6DWI, 6DWA, and 6DW2, respectively), bound to a synthetic WTA epitope. These structures reveal that all three of these antibodies, while utilizing distinct antibody complementarity-determining region sequences and conformations to interact with β-WTA, fulfill two recognition principles: binding to the β-GlcNAc pyranose core and triangulation of WTA phosphate residues with polar contacts. These studies reveal the molecular basis for targeting a unique S. aureus cell surface epitope and highlight the power of human patient-based antibody discovery techniques for finding novel pathogen-targeting therapeutics.
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Affiliation(s)
- Rina Fong
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Kimberly Kajihara
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Matthew Chen
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Isidro Hotzel
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Sanjeev Mariathasan
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Wouter L.W. Hazenbos
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA
| | - Patrick J. Lupardus
- Department of Structural Biology, Genentech, South San Francisco, CA, USA,Departments of Infectious Diseases, Genentech, South San Francisco, CA, USA,Departments of Antibody Engineering, Genentech, South San Francisco, CA, USA,CONTACT Patrick J. Lupardus Department of Structural Biology, Genentech, South San Francisco, CA, USA
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Lin LCW, Chattopadhyay S, Lin JC, Hu CMJ. Advances and Opportunities in Nanoparticle- and Nanomaterial-Based Vaccines against Bacterial Infections. Adv Healthc Mater 2018; 7:e1701395. [PMID: 29508547 DOI: 10.1002/adhm.201701395] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 01/22/2018] [Indexed: 02/06/2023]
Abstract
As the dawn of the postantibiotic era we approach, antibacterial vaccines are becoming increasingly important for managing bacterial infection and reducing the need for antibiotics. Despite the success of vaccination, vaccines remain unavailable for many pressing microbial diseases, including tuberculosis, chlamydia, and staphylococcus infections. Amid continuing research efforts in antibacterial vaccine development, the advancement of nanomaterial engineering has brought forth new opportunities in vaccine designs. With increasing knowledge in antibacterial immunity and immunologic adjuvants, innovative nanoparticles are designed to elicit the appropriate immune responses for effective antimicrobial defense. Rationally designed nanoparticles are demonstrated to overcome delivery barriers to shape the adaptive immunity. This article reviews the advances in nanoparticle- and nanomaterial-based antibacterial vaccines and summarizes the development of nanoparticulate adjuvants for immune potentiation against microbial pathogens. In addition, challenges and progress in ongoing antibacterial vaccine development are discussed to highlight the opportunities for future vaccine designs.
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Affiliation(s)
- Leon Chien-Wei Lin
- Institute of Biomedical Sciences; Academia Sinica; 128, Sec. 2, Academia Road Nangang District Taipei 11529 Taiwan
| | - Saborni Chattopadhyay
- Institute of Biomedical Sciences; Academia Sinica; 128, Sec. 2, Academia Road Nangang District Taipei 11529 Taiwan
| | - Jung-Chen Lin
- Institute of Biomedical Sciences; Academia Sinica; 128, Sec. 2, Academia Road Nangang District Taipei 11529 Taiwan
| | - Che-Ming Jack Hu
- Institute of Biomedical Sciences; Academia Sinica; 128, Sec. 2, Academia Road Nangang District Taipei 11529 Taiwan
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Alpha-Toxin Contributes to Biofilm Formation among Staphylococcus aureus Wound Isolates. Toxins (Basel) 2018; 10:toxins10040157. [PMID: 29659477 PMCID: PMC5923323 DOI: 10.3390/toxins10040157] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 04/03/2018] [Accepted: 04/04/2018] [Indexed: 01/03/2023] Open
Abstract
Biofilms complicate treatment of Staphylococcus aureus (SA) wound infections. Previously, we determined alpha-toxin (AT)-promoted SA biofilm formation on mucosal tissue. Therefore, we evaluated SA wound isolates for AT production and biofilm formation on epithelium and assessed the role of AT in biofilm formation. Thirty-eight wound isolates were molecularly typed by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (ST), and spa typing. We measured biofilm formation of these SA isolates in vitro and ex vivo and quantified ex vivo AT production. We also investigated the effect of an anti-AT monoclonal antibody (MEDI4893*) on ex vivo biofilm formation by methicillin-resistant SA (USA 300 LAC) and tested whether purified AT rescued the biofilm defect of hla mutant SA strains. The predominant PFGE/ST combinations were USA100/ST5 (50%) and USA300/ST8 (33%) for methicillin-resistant SA (MRSA, n = 18), and USA200/ST30 (20%) for methicillin-susceptible SA (MSSA, n = 20). Ex vivo AT production correlated significantly with ex vivo SA wound isolate biofilm formation. Anti-alpha-toxin monoclonal antibody (MEDI4893*) prevented ex vivo biofilm formation by MRSA USA300 strain LAC. Wild-type AT rescued the ex vivo biofilm defect of non-AT producing SA strains. These findings provide evidence that AT plays a role in SA biofilm formation on epithelial surfaces and suggest that neutralization of AT may be useful in preventing and treating SA infections.
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Speziale P, Rindi S, Pietrocola G. Antibody-Based Agents in the Management of Antibiotic-Resistant Staphylococcus aureus Diseases. Microorganisms 2018. [PMID: 29533985 PMCID: PMC5874639 DOI: 10.3390/microorganisms6010025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Staphylococcus aureus is a human pathogen that can cause a wide spectrum of diseases, including sepsis, pneumonia, arthritis, and endocarditis. Ineffective treatment of a number of staphylococcal infections with antibiotics is due to the development and spread of antibiotic-resistant strains following decades of antibiotic usage. This has generated renewed interest within the scientific community in alternative therapeutic agents, such as anti-S. aureus antibodies. Although the role of antibodies in the management of S. aureus diseases is controversial, the success of this pathogen in neutralizing humoral immunity clearly indicates that antibodies offer the host extensive protection. In this review, we report an update on efforts to develop antibody-based agents, particularly monoclonal antibodies, and their therapeutic potential in the passive immunization approach to the treatment and prevention of S. aureus infections.
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Affiliation(s)
- Pietro Speziale
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy.
- Department of Industrial and Information Engineering, University of Pavia, 27100 Pavia, Italy.
| | - Simonetta Rindi
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy.
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Wagner EK, Maynard JA. Engineering therapeutic antibodies to combat infectious diseases. Curr Opin Chem Eng 2018; 19:131-141. [PMID: 29911002 DOI: 10.1016/j.coche.2018.01.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Serum therapy fell out of favor 80 years ago, but antibodies against infectious diseases are now experiencing a renaissance. With the evolution of antibiotic-resistant bacteria, the emergence of new pathogens, and a growing population of immunocompromised individuals coupled with improvements in antibody manufacturing and biological efficacy, antibodies are an increasingly attractive therapeutic option. In this review, we highlight successful clinical strategies and discuss recent applications of advanced antibody engineering approaches to combat infectious diseases. Case studies include antibody mixtures to neutralize Staphylococcus aureus; bispecific antibodies promoting Pseudomonas aeruginosa clearance; antibody-antibiotic conjugates to eradicate S. aureus from protected intracellular niches; and novel anti-RSV antibodies with extended serum half-life. These new designs are powerful strategies for targeting infectious diseases due to their abilities to target multiple antigens and induce novel clearance mechanisms.
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Affiliation(s)
- Ellen K Wagner
- Department of Chemical Engineering, The University of Texas at Austin, Austin TX USA, 78712
| | - Jennifer A Maynard
- Department of Chemical Engineering, The University of Texas at Austin, Austin TX USA, 78712
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Neutralizing Alpha-Toxin Accelerates Healing of Staphylococcus aureus-Infected Wounds in Nondiabetic and Diabetic Mice. Antimicrob Agents Chemother 2018; 62:AAC.02288-17. [PMID: 29311091 DOI: 10.1128/aac.02288-17] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 01/03/2018] [Indexed: 12/26/2022] Open
Abstract
Staphylococcus aureus wound infections delay healing and result in invasive complications such as osteomyelitis, especially in the setting of diabetic foot ulcers. In preclinical animal models of S. aureus skin infection, antibody neutralization of alpha-toxin (AT), an S. aureus-secreted pore-forming cytolytic toxin, reduces disease severity by inhibiting skin necrosis and restoring effective host immune responses. However, whether therapeutic neutralization of alpha-toxin is effective against S. aureus-infected wounds is unclear. Herein, the efficacy of prophylactic treatment with a human neutralizing anti-AT monoclonal antibody (MAb) was evaluated in an S. aureus skin wound infection model in nondiabetic and diabetic mice. In both nondiabetic and diabetic mice, anti-AT MAb treatment decreased wound size and bacterial burden and enhanced reepithelialization and wound resolution compared to control MAb treatment. Anti-AT MAb had distinctive effects on the host immune response, including decreased neutrophil and increased monocyte and macrophage infiltrates in nondiabetic mice and decreased neutrophil extracellular traps (NETs) in diabetic mice. Similar therapeutic efficacy was achieved with an active vaccine targeting AT. Taken together, neutralization of AT had a therapeutic effect against S. aureus-infected wounds in both nondiabetic and diabetic mice that was associated with differential effects on the host immune response.
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Prevalence of IgG and Neutralizing Antibodies against Staphylococcus aureus Alpha-Toxin in Healthy Human Subjects and Diverse Patient Populations. Infect Immun 2018; 86:IAI.00671-17. [PMID: 29263109 DOI: 10.1128/iai.00671-17] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 12/17/2017] [Indexed: 02/02/2023] Open
Abstract
Staphylococcus aureus causes an array of serious infections resulting in high morbidity and mortality worldwide. This study evaluated naturally occurring serum anti-alpha-toxin (anti-AT) antibody levels in human subjects from various age groups, individuals with S. aureus dialysis and surgical-site infections, and S. aureus-colonized versus noncolonized subjects. Anti-AT immunoglobulin G (IgG) and neutralizing antibody (NAb) levels in infants (aged ≤1 year) were significantly lower than those in other populations. In comparison to adolescent, adult, and elderly populations, young children (aged 2 to 10 years) had equivalent anti-AT IgG levels but significantly lower anti-AT NAb levels. Therefore, the development of anti-AT NAbs appears to occur later than that of AT-specific IgG, suggesting a maturation of the immune response to AT. Anti-AT IgG levels were slightly higher in S. aureus-colonized subjects than in noncolonized subjects. The methicillin susceptibility status of colonizing isolates had no effect on anti-AT antibody levels in S. aureus-colonized subjects. The highest anti-AT IgG and NAb levels were observed in dialysis patients with acute S. aureus infection. Anti-AT IgG and NAb levels were well correlated in subjects aged >10 years, regardless of colonization or infection status. These data demonstrate that AT elicits a robust IgG humoral response in infants and young children that becomes stable prior to adolescence, matures into higher levels of NAbs in healthy adolescents, and becomes elevated during S. aureus infection. These findings may assist in identifying subjects and patient populations that could benefit from vaccination or immunoprophylaxis with anti-AT monoclonal antibodies.
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Ruzin A, Wu Y, Yu L, Yu XQ, Tabor DE, Mok H, Tkaczyk C, Jensen K, Bellamy T, Roskos L, Esser MT, Jafri HS. Characterisation of anti-alpha toxin antibody levels and colonisation status after administration of an investigational human monoclonal antibody, MEDI4893, against Staphylococcus aureus alpha toxin. Clin Transl Immunology 2018; 7:e1009. [PMID: 29484186 PMCID: PMC5822409 DOI: 10.1002/cti2.1009] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 12/20/2017] [Accepted: 12/29/2017] [Indexed: 01/07/2023] Open
Abstract
Objectives MEDI4893 is a novel, long‐acting human monoclonal antibody targeting Staphylococcus aureus (SA) alpha toxin (AT). This report presents the results of the exploratory analyses from a randomised phase 1 dose‐escalation study in healthy human subjects receiving single intravenous MEDI4893 doses or placebo. Methods Anti‐AT antibodies and AT expression were measured as described previously. Nasal swabs were analysed by culture and PCR. Data were summarised by treatment groups and visits by using SAS System Version 9.3. Results Subjects receiving 2250 or 5000 mg of MEDI4893 had the highest serum anti‐AT neutralising antibody (NAb) levels: approximately 180‐ to 240‐, 70‐ to 100‐ and sevenfold to 10‐fold higher than respective baseline levels at peak, 30 and 360 days, respectively. In these subjects, levels of serum anti‐AT NAbs were >3.2 International Units (IU) mL−1 for at least 211 days. In the upper respiratory tract, anti‐AT NAb levels increased with MEDI4893 dose. No apparent effect of MEDI4893 on SA nasal colonisation, hla gene sequence or AT expression was observed. Five AT variants were detected, their lytic activity was fully neutralised by MEDI4893. Discussion Our results indicate that (1) MEDI4893 administration at 2250 and 5000 mg would provide effective immunoprophylaxis against systemic SA disease; (2) MEDI4983 distributes to the upper respiratory tract and retains neutralising activity against AT; and (3) potential for emergence of MEDI4893 resistance is low. Conclusion Intravenous administration of MEDI4893 maintained levels of anti‐AT NAbs in serum and nasal mucosa that may provide effective immunoprophylaxis against SA disease and support continued clinical development of MEDI4893.
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Affiliation(s)
| | | | - Li Yu
- MedImmune Gaithersburg MD USA
| | - Xiang-Qing Yu
- MedImmune Gaithersburg MD USA.,Present address: Janssen Pharmaceuticals, Inc. Johnson & Johnson Spring House PA USA
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Kroh HK, Chandrasekaran R, Zhang Z, Rosenthal K, Woods R, Jin X, Nyborg AC, Rainey GJ, Warrener P, Melnyk RA, Spiller BW, Lacy DB. A neutralizing antibody that blocks delivery of the enzymatic cargo of Clostridium difficile toxin TcdB into host cells. J Biol Chem 2017; 293:941-952. [PMID: 29180448 DOI: 10.1074/jbc.m117.813428] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 11/08/2017] [Indexed: 12/14/2022] Open
Abstract
Clostridium difficile infection is the leading cause of hospital-acquired diarrhea and is mediated by the actions of two toxins, TcdA and TcdB. The toxins perturb host cell function through a multistep process of receptor binding, endocytosis, low pH-induced pore formation, and the translocation and delivery of an N-terminal glucosyltransferase domain that inactivates host GTPases. Infection studies with isogenic strains having defined toxin deletions have established TcdB as an important target for therapeutic development. Monoclonal antibodies that neutralize TcdB function have been shown to protect against C. difficile infection in animal models and reduce recurrence in humans. Here, we report the mechanism of TcdB neutralization by PA41, a humanized monoclonal antibody capable of neutralizing TcdB from a diverse array of C. difficile strains. Through a combination of structural, biochemical, and cell functional studies, involving X-ray crystallography and EM, we show that PA41 recognizes a single, highly conserved epitope on the TcdB glucosyltransferase domain and blocks productive translocation and delivery of the enzymatic cargo into the host cell. Our study reveals a unique mechanism of C. difficile toxin neutralization by a monoclonal antibody, which involves targeting a process that is conserved across the large clostridial glucosylating toxins. The PA41 antibody described here provides a valuable tool for dissecting the mechanism of toxin pore formation and translocation across the endosomal membrane.
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Affiliation(s)
- Heather K Kroh
- From the Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2363
| | - Ramyavardhanee Chandrasekaran
- From the Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2363
| | - Zhifen Zhang
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada.,Molecular Structure and Function, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | | | - Rob Woods
- MedImmune LLC, Gaithersburg, Maryland 20878-2204
| | - Xiaofang Jin
- MedImmune LLC, Gaithersburg, Maryland 20878-2204
| | | | | | | | - Roman A Melnyk
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada.,Molecular Structure and Function, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada
| | - Benjamin W Spiller
- From the Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2363.,Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232-6600, and
| | - D Borden Lacy
- From the Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-2363, .,Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee 37212-2637
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Dickey SW, Cheung GYC, Otto M. Different drugs for bad bugs: antivirulence strategies in the age of antibiotic resistance. Nat Rev Drug Discov 2017; 16:457-471. [PMID: 28337021 DOI: 10.1038/nrd.2017.23] [Citation(s) in RCA: 470] [Impact Index Per Article: 67.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The rapid evolution and dissemination of antibiotic resistance among bacterial pathogens are outpacing the development of new antibiotics, but antivirulence agents provide an alternative. These agents can circumvent antibiotic resistance by disarming pathogens of virulence factors that facilitate human disease while leaving bacterial growth pathways - the target of traditional antibiotics - intact. Either as stand-alone medications or together with antibiotics, these drugs are intended to treat bacterial infections in a largely pathogen-specific manner. Notably, development of antivirulence drugs requires an in-depth understanding of the roles that diverse virulence factors have in disease processes. In this Review, we outline the theory behind antivirulence strategies and provide examples of bacterial features that can be targeted by antivirulence approaches. Furthermore, we discuss the recent successes and failures of this paradigm, and new developments that are in the pipeline.
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Affiliation(s)
- Seth W Dickey
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland 20814, USA
| | - Gordon Y C Cheung
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland 20814, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland 20814, USA
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Conroy PJ, Law RH, Caradoc-Davies TT, Whisstock JC. Antibodies: From novel repertoires to defining and refining the structure of biologically important targets. Methods 2017; 116:12-22. [DOI: 10.1016/j.ymeth.2017.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Revised: 01/10/2017] [Accepted: 01/10/2017] [Indexed: 01/02/2023] Open
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Structure and Function of the Two-Component Cytotoxins of Staphylococcus aureus - Learnings for Designing Novel Therapeutics. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 966:15-35. [PMID: 28455832 DOI: 10.1007/5584_2016_200] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Staphylococcus aureus can produce up to five different bi-component cytotoxins: two gamma-hemolysins HlgAB and HlgCB, and leukocidins SF-PV (Panton Valentine leukocidin), ED (LukED) and GH (LukGH, also called LukAB). Their major function in S. aureus pathogenesis is to evade innate immunity by attacking phagocytic cells and to support bacterial growth by lysing red blood cells. The five cytotoxins display different levels of amino acid sequence conservation (30-82%), but all form a remarkably similar beta-barrel type pore structure (greatly resembling the mono-component toxin alpha-hemolysin) that inserts into the target cell membrane leading to necrotic cell death. This review provides an overview of the culmination of decades of research on the structure of these toxins, their unique sequence and structural features that helps to explain the observed functional differences, such as toxin potency towards different cell types and species, receptor specificity and formation of functional non-cognate toxin pairs. The vast knowledge accumulated in this field supports novel approaches and the design of therapeutics targeting these cytotoxins to tame virulence and fight S. aureus infections.
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