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Cima-Cabal MD, Vázquez-Espinosa E, Vazquez F, García-Suárez MDM. Detection of Streptococcus pneumoniae in Urine by Loop-Mediated Isothermal Amplification. J PEDIAT INF DIS-GER 2020. [DOI: 10.1055/s-0040-1719164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Abstract
Objective To assess the loop-mediated isothermal amplification (LAMP) to detect cell-free DNA from Streptococcus pneumoniae in urine samples from children with pneumococcal pneumonia.
Methods LAMP reactions using four primers (backward inner primer, forward inner primer, B3, and F3) targeting conserved regions of the S. pneumoniae ply gene and DNA from the recombinant plasmid pTrc99A-ply were optimized for temperature (65°C) and MgSO4 concentration (8 mM) conditions. Urine samples from 71 patients with symptoms of pneumonia and from 17 healthy children were tested side by side using the isothermal methodology LAMP and the commercial urinary antigen test, BinaxNOW S. pneumoniae assay. Percentages of sensitivity, specificity, positive predictive value (PPV), negative predictive value, and positive (LR) were calculated to compare both tests.
Results The specificity of the LAMP reaction was confirmed against several species of bacteria and yeast that can cause pneumonia or urine infections. The suitability of the LAMP assay was evaluated in urine samples from 71 patients and 17 healthy children. All patients (100%) with confirmed pneumococcal pneumonia were positive for the LAMP assay. Among patients with possible/probable pneumonia, 74.1% were identified as positive using the LAMP test. Notably, a higher specificity (95.4%), PPV (94.1%) and positive LR (21.7) were found compared with the urinary antigen test.
Conclusion The presence of S. pneumoniae cell-free DNA in urine samples of pediatric patients can be used as a specific diagnostic biomarker for community-acquired pneumonia by using the LAMP methodology.
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Affiliation(s)
- María Dolores Cima-Cabal
- Escuela Superior de Ingeniería y Tecnología (ESIT), Universidad Internacional de La Rioja (UNIR), Logroño, Spain
| | | | - Fernando Vazquez
- Servicio de Microbiología, Hospital Universitario Central de Asturias, Oviedo, Spain
- Departamento de Biología Funcional, Área de Microbiología, Universidad de Oviedo, Oviedo, Spain
- Fundación de Investigación Oftalmológica, Instituto Oftalmológico Fernández-Vega, Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
| | - María del Mar García-Suárez
- Escuela Superior de Ingeniería y Tecnología (ESIT), Universidad Internacional de La Rioja (UNIR), Logroño, Spain
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2
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Badgujar DC, Anil A, Green AE, Surve MV, Madhavan S, Beckett A, Prior IA, Godsora BK, Patil SB, More PK, Sarkar SG, Mitchell A, Banerjee R, Phale PS, Mitchell TJ, Neill DR, Bhaumik P, Banerjee A. Structural insights into loss of function of a pore forming toxin and its role in pneumococcal adaptation to an intracellular lifestyle. PLoS Pathog 2020; 16:e1009016. [PMID: 33216805 PMCID: PMC7717573 DOI: 10.1371/journal.ppat.1009016] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 12/04/2020] [Accepted: 09/24/2020] [Indexed: 12/14/2022] Open
Abstract
The opportunistic pathogen Streptococcus pneumoniae has dual lifestyles: one of an asymptomatic colonizer in the human nasopharynx and the other of a deadly pathogen invading sterile host compartments. The latter triggers an overwhelming inflammatory response, partly driven via pore forming activity of the cholesterol dependent cytolysin (CDC), pneumolysin. Although pneumolysin-induced inflammation drives person-to-person transmission from nasopharynx, the primary reservoir for pneumococcus, it also contributes to high mortality rates, creating a bottleneck that hampers widespread bacterial dissemination, thus acting as a double-edged sword. Serotype 1 ST306, a widespread pneumococcal clone, harbours a non-hemolytic variant of pneumolysin (Ply-NH). Performing crystal structure analysis of Ply-NH, we identified Y150H and T172I as key substitutions responsible for loss of its pore forming activity. We uncovered a novel inter-molecular cation-π interaction, governing formation of the transmembrane β-hairpins (TMH) in the pore state of Ply, which can be extended to other CDCs. H150 in Ply-NH disrupts this interaction, while I172 provides structural rigidity to domain-3, through hydrophobic interactions, inhibiting TMH formation. Loss of pore forming activity enabled improved cellular invasion and autophagy evasion, promoting an atypical intracellular lifestyle for pneumococcus, a finding that was corroborated in in vivo infection models. Attenuation of inflammatory responses and tissue damage promoted tolerance of Ply-NH-expressing pneumococcus in the lower respiratory tract. Adoption of this altered lifestyle may be necessary for ST306 due to its limited nasopharyngeal carriage, with Ply-NH, aided partly by loss of its pore forming ability, facilitating a benign association of SPN in an alternative, intracellular host niche.
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Affiliation(s)
- Dilip C. Badgujar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India
| | - Anjali Anil
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India
| | - Angharad E. Green
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Manalee Vishnu Surve
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India
| | - Shilpa Madhavan
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India
| | - Alison Beckett
- Division of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Ian A. Prior
- Division of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool, United Kingdom
| | - Barsa K. Godsora
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India
| | - Sanket B. Patil
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India
| | - Prachi Kadam More
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India
| | - Shruti Guha Sarkar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India
| | - Andrea Mitchell
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Rinti Banerjee
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India
| | - Prashant S. Phale
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India
| | - Timothy J. Mitchell
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Daniel R. Neill
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Prasenjit Bhaumik
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India
| | - Anirban Banerjee
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, Maharashtra, India
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3
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Panagiotou S, Chaguza C, Yahya R, Audshasai T, Baltazar M, Ressel L, Khandaker S, Alsahag M, Mitchell TJ, Prudhomme M, Kadioglu A, Yang M. Hypervirulent pneumococcal serotype 1 harbours two pneumolysin variants with differential haemolytic activity. Sci Rep 2020; 10:17313. [PMID: 33057054 PMCID: PMC7560715 DOI: 10.1038/s41598-020-73454-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/14/2020] [Indexed: 12/13/2022] Open
Abstract
Streptococcus pneumoniae is a devastating global pathogen. Prevalent in sub-Saharan Africa, pneumococcal serotype 1 is atypical in that it is rarely found as a nasopharyngeal coloniser, yet is described as one of the most common causes of invasive pneumococcal disease. Clonal sequence type (ST)-306 and ST615 are representative of the two major serotype 1 lineages A and C, respectively. Here we investigated the virulence properties and haemolytic activities of these 2 clonal types using in vivo mouse models and in vitro assays. A lethal dose of ST615 administered intranasally to mice led to the rapid onset of disease symptoms and resulted in 90% mortality. In contrast, mice exposed to the same infection dose of ST306 or a pneumolysin (Ply)-deficient ST615 failed to develop any disease symptoms. Interestingly, the 2 strains did not differ in their ability to bind the immune complement or to undergo neutrophil-mediated phagocytosis. Upon comparative genomic analysis, we found higher within-ST sequence diversity in ST615 compared with ST306 and determined that ZmpA, ZmpD proteins, and IgA protease, were uniquely found in ST615. Using cell fractionation and cell contact-dependent assay, we made the unexpected finding that ST615 harbours the expression of two haemolytic variants of Ply: a cell-wall restricted fully haemolytic Ply, and a cytosolic pool of Ply void of any detectable haemolytic activity. This is the first time such a phenomenon has been described. We discuss the biological significance of our observation in relation to the aptitude of the pneumococcus for sustaining its human reservoir.
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Affiliation(s)
- Stavros Panagiotou
- Department of Clinical Infection Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, The Ronald Ross Building, 8 West Derby St, Liverpool, L69 7BE, UK
| | - Chrispin Chaguza
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, CB10 1SA, UK
- Darwin College, University of Cambridge, Silver Street, Cambridge, CB3 9EU, UK
| | - Reham Yahya
- College of sciences and health professions, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
- King Abdullah International Medical Research Center, Riyadh, Saudi Arabia
| | - Teerawit Audshasai
- Department of Clinical Infection Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, The Ronald Ross Building, 8 West Derby St, Liverpool, L69 7BE, UK
| | - Murielle Baltazar
- Department of Clinical Infection Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, The Ronald Ross Building, 8 West Derby St, Liverpool, L69 7BE, UK
| | - Lorenzo Ressel
- Department of Veterinary Pathology and Public Health, Institute of Veterinary Science, University of Liverpool, Leahurst Campus, Neston, CH64 7TE, UK
| | - Shadia Khandaker
- Department of Clinical Infection Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, The Ronald Ross Building, 8 West Derby St, Liverpool, L69 7BE, UK
| | - Mansoor Alsahag
- Department of Clinical Infection Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, The Ronald Ross Building, 8 West Derby St, Liverpool, L69 7BE, UK
- Faculty of Applied Medical Sciences, Albaha University, Albaha, Kingdom of Saudi Arabia
| | - Tim J Mitchell
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
| | - Marc Prudhomme
- Université Paul Sabatier, Centre National de la Recherche Scientifique, 118 Route de Narbonne, 31062, Toulouse Cedex 9, France
| | - Aras Kadioglu
- Department of Clinical Infection Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, The Ronald Ross Building, 8 West Derby St, Liverpool, L69 7BE, UK.
| | - Marie Yang
- Department of Clinical Infection Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, The Ronald Ross Building, 8 West Derby St, Liverpool, L69 7BE, UK.
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4
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Li S, Lv Q, Sun X, Tang T, Deng X, Yin Y, Li L. Acacetin inhibits Streptococcus pneumoniae virulence by targeting pneumolysin. ACTA ACUST UNITED AC 2020; 72:1092-1100. [PMID: 32390150 DOI: 10.1111/jphp.13279] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 04/04/2020] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Streptococcus pneumoniae (S. pneumoniae) is an important commensal and pathogenic bacterium responsible for pneumonia, meningitis and other invasive diseases. Pneumolysin (PLY) is the major virulence factor that contributes significantly to the interaction between S. pneumoniae and the host. KEY FINDINGS In this study, the results of antibacterial analysis, the haemolysis test and the Western blotting assay showed that acacetin inhibited PLY-mediated pore-forming activity caused by S. pneumoniae culture precipitates and purified PLY without anti-S. pneumoniae activity. In addition, acacetin treatment inhibited PLY oligomerization without affecting the expression of PLY in S. pneumoniae culture supernatants. Live/dead cells and cytotoxicity assays suggested that acacetin significantly enhanced the survival rate of injured cells by inhibiting the biological toxicity of PLY without cytotoxicity in the coculture system. The in vivo mouse model of S. pneumoniae infection further demonstrated that acacetin treatment could significantly reduce the levels of inflammatory factors (INF-γ and IL-β) in bronchoalveolar lavage fluid (BALF) and alleviate the pathological damage of lung injury. CONCLUSIONS Taken together, the results presented in this study indicated that acacetin inhibited the pore-forming activity of PLY and reduced the virulence of S. pneumoniae in vivo and in vitro, which may provide a leading compound for the treatment of S. pneumoniae infection.
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Affiliation(s)
- Shufang Li
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Qianghua Lv
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Xiaodi Sun
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Tianzhong Tang
- Hubei Wudang Animal Pharmaceutical Co., Ltd, Shiyan, Hubei, China
| | - Xuming Deng
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Yunhou Yin
- School of Communication, GuizhouMinzu University, Guiyang, China
| | - Li Li
- Key Laboratory of Zoonosis Research, Ministry of Education, Institute of Zoonosis, College of Veterinary Medicine, Jilin University, Changchun, China
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5
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Lucas R, Hadizamani Y, Gonzales J, Gorshkov B, Bodmer T, Berthiaume Y, Moehrlen U, Lode H, Huwer H, Hudel M, Mraheil MA, Toque HAF, Chakraborty T, Hamacher J. Impact of Bacterial Toxins in the Lungs. Toxins (Basel) 2020; 12:toxins12040223. [PMID: 32252376 PMCID: PMC7232160 DOI: 10.3390/toxins12040223] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
Bacterial toxins play a key role in the pathogenesis of lung disease. Based on their structural and functional properties, they employ various strategies to modulate lung barrier function and to impair host defense in order to promote infection. Although in general, these toxins target common cellular signaling pathways and host compartments, toxin- and cell-specific effects have also been reported. Toxins can affect resident pulmonary cells involved in alveolar fluid clearance (AFC) and barrier function through impairing vectorial Na+ transport and through cytoskeletal collapse, as such, destroying cell-cell adhesions. The resulting loss of alveolar-capillary barrier integrity and fluid clearance capacity will induce capillary leak and foster edema formation, which will in turn impair gas exchange and endanger the survival of the host. Toxins modulate or neutralize protective host cell mechanisms of both the innate and adaptive immunity response during chronic infection. In particular, toxins can either recruit or kill central players of the lung's innate immune responses to pathogenic attacks, i.e., alveolar macrophages (AMs) and neutrophils. Pulmonary disorders resulting from these toxin actions include, e.g., acute lung injury (ALI), the acute respiratory syndrome (ARDS), and severe pneumonia. When acute infection converts to persistence, i.e., colonization and chronic infection, lung diseases, such as bronchitis, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF) can arise. The aim of this review is to discuss the impact of bacterial toxins in the lungs and the resulting outcomes for pathogenesis, their roles in promoting bacterial dissemination, and bacterial survival in disease progression.
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Affiliation(s)
- Rudolf Lucas
- Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Department of Medicine and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Correspondence: (R.L.); (J.H.); Tel.: +41-31-300-35-00 (J.H.)
| | - Yalda Hadizamani
- Lungen-und Atmungsstiftung, Bern, 3012 Bern, Switzerland;
- Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, 3012 Bern, Switzerland
| | - Joyce Gonzales
- Department of Medicine and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Boris Gorshkov
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Thomas Bodmer
- Labormedizinisches Zentrum Dr. Risch, Waldeggstr. 37 CH-3097 Liebefeld, Switzerland;
| | - Yves Berthiaume
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada;
| | - Ueli Moehrlen
- Pediatric Surgery, University Children’s Hospital, Zürich, Steinwiesstrasse 75, CH-8032 Zürch, Switzerland;
| | - Hartmut Lode
- Insitut für klinische Pharmakologie, Charité, Universitätsklinikum Berlin, Reichsstrasse 2, D-14052 Berlin, Germany;
| | - Hanno Huwer
- Department of Cardiothoracic Surgery, Voelklingen Heart Center, 66333 Voelklingen/Saar, Germany;
| | - Martina Hudel
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Mobarak Abu Mraheil
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Haroldo Alfredo Flores Toque
- Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Trinad Chakraborty
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Jürg Hamacher
- Lungen-und Atmungsstiftung, Bern, 3012 Bern, Switzerland;
- Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, 3012 Bern, Switzerland
- Medical Clinic V-Pneumology, Allergology, Intensive Care Medicine and Environmental Medicine, Faculty of Medicine, Saarland University, University Medical Centre of the Saarland, D-66421 Homburg, Germany
- Institute for Clinical & Experimental Surgery, Faculty of Medicine, Saarland University, D-66421 Homburg, Germany
- Correspondence: (R.L.); (J.H.); Tel.: +41-31-300-35-00 (J.H.)
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6
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Han C, Zhang M. Genetic diversity and antigenicity analysis of Streptococcus pneumoniae pneumolysin isolated from children with pneumococcal infection. Int J Infect Dis 2019; 86:57-64. [DOI: 10.1016/j.ijid.2019.06.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 06/13/2019] [Accepted: 06/21/2019] [Indexed: 12/18/2022] Open
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Domain 4 of pneumolysin from Streptococcus pneumoniae is a multifunctional domain contributing TLR4 activating and hemolytic activity. Biochem Biophys Res Commun 2019; 517:596-602. [PMID: 31395343 DOI: 10.1016/j.bbrc.2019.07.063] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 07/18/2019] [Indexed: 11/21/2022]
Abstract
The pneumolysin (Ply) protein of Streptococcus pneumoniae is composed of four domains and possesses several different but related activities. In this study, recombinant Ply and two truncated forms, Ply domain 1-3 and Ply domain 4 (rPly4), were expressed and characterized regarding their participation in apoptosis, the stimulation of cytokine production, hemolytic activity and virulence. rPly4 activated murine bone marrow-derived dendritic cells in a Toll-like receptor (TLR) 4-dependent manner. The rPly4 alone was able to produce hemolytic activity at high concertation and penetrate the lipid bilayer. We further demonstrated that domain 4 of Ply involved in the virulence of the bacteria in mouse model. In the absence of apoptotic activity, the virulence level caused by rPly4 was similar to that of full length Ply. Our data suggested that domain 4 of Ply alone with TLR4 agonist and hemolytic activity may play roles in virulence of Streptococcus pneumoniae.
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8
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Janesch P, Rouha H, Badarau A, Stulik L, Mirkina I, Caccamo M, Havlicek K, Maierhofer B, Weber S, Groß K, Steinhäuser J, Zerbs M, Varga C, Dolezilkova I, Maier S, Zauner G, Nielson N, Power CA, Nagy E. Assessing the function of pneumococcal neuraminidases NanA, NanB and NanC in in vitro and in vivo lung infection models using monoclonal antibodies. Virulence 2019; 9:1521-1538. [PMID: 30289054 PMCID: PMC6177239 DOI: 10.1080/21505594.2018.1520545] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Streptococcus pneumoniae isolates express up to three neuraminidases (sialidases), NanA, NanB and NanC, all of which cleave the terminal sialic acid of glycan-structures that decorate host cell surfaces. Most research has focused on the role of NanA with limited investigations evaluating the roles of all three neuraminidases in host-pathogen interactions. We generated two highly potent monoclonal antibodies (mAbs), one that blocks the enzymatic activity of NanA and one cross-neutralizing NanB and NanC. Total neuraminidase activity of clinical S. pneumoniae isolates could be inhibited by this mAb combination in enzymatic assays. To detect desialylation of cell surfaces by pneumococcal neuraminidases, primary human tracheal/bronchial mucocilial epithelial tissues were infected with S. pneumoniae and stained with peanut lectin. Simultaneous targeting of the neuraminidases was required to prevent desialylation, suggesting that inhibition of NanA alone is not sufficient to preserve terminal lung glycans. Importantly, we also found that all three neuraminidases increased the interaction of S. pneumoniae with human airway epithelial cells. Lectin-staining of lung tissues of mice pre-treated with mAbs before intranasal challenge with S. pneumoniae confirmed that both anti-NanA and anti-NanBC mAbs were required to effectively block desialylation of the respiratory epithelium in vivo. Despite this, no effect on survival, reduction in pulmonary bacterial load, or significant changes in cytokine responses were observed. This suggests that neuraminidases have no pivotal role in this murine pneumonia model that is induced by high bacterial challenge inocula and does not progress from colonization as it happens in the human host.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Karin Groß
- a Arsanis Biosciences , Vienna , Austria
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9
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Immunodominance in T cell responses elicited against different domains of detoxified pneumolysin PlyD1. PLoS One 2018; 13:e0193650. [PMID: 29509778 PMCID: PMC5839544 DOI: 10.1371/journal.pone.0193650] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 02/15/2018] [Indexed: 12/05/2022] Open
Abstract
Detoxified pneumolysin, PlyD1, is a protein vaccine candidate that induces protection against infections with Streptococcus pneumoniae in mouse models. Despite extensive knowledge on antibody responses against PlyD1, limited information is available about PlyD1 induced T cell recognition. Here we interrogated epitope breadth and functional characteristics of the T cell response to PlyD1 in two mouse strains. BALB/c (H-2d) and C57BL/6 (H-2b) mice were vaccinated with Al(OH)3-adjuvanted or non-adjuvanted PlyD1, or placebo, on day 0, 21 and 42 and were sacrificed at day 56 for collection of sera and spleens. Vaccination with adjuvanted and non-adjuvanted PlyD1 induced anti-pneumolysin IgG antibodies with neutralizing capacity in both mouse strains. Adjuvantation of PlyD1 enhanced the serological responses in both strains. In vitro restimulation of splenocytes with PlyD1 and 18-mer synthetic peptides derived from pneumolysin revealed specific proliferative and cytokine responses. For both mouse strains, one immunodominant and three subdominant natural epitopes were identified. Overlap between H-2d and H-2b restricted T cell epitopes was limited, yet similarities were found between epitopes processed in mice and predicted to be immunogenic in humans. H-2d restricted T cell epitopes were localized in pneumolysin domains 2 and 3, whereas H-2b epitopes were scattered over the protein. Cytokine responses show mostly a Th2 profile, with low levels of Th1 cytokines, in both mouse strains. In conclusion, PlyD1 evokes T cell responses in mice directed against multiple epitope regions, that is dependent on Major Histocompatibility Complex (MHC) background. These results are important to understand human PlyD1 T cell immunogenicity, to guide cell mediated immunity studies in the context of vaccine development.
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10
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Hermand P, Vandercammen A, Mertens E, Di Paolo E, Verlant V, Denoël P, Godfroid F. Preclinical evaluation of a chemically detoxified pneumolysin as pneumococcal vaccine antigen. Hum Vaccin Immunother 2016; 13:220-228. [PMID: 27768518 PMCID: PMC5287308 DOI: 10.1080/21645515.2016.1234553] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The use of protein antigens able to protect against the majority of Streptococcus pneumoniae serotypes is envisaged as stand-alone and/or complement to the current capsular polysaccharide-based pneumococcal vaccines. Pneumolysin (Ply) is a key virulence factor that is highly conserved in amino acid sequence across pneumococcal serotypes, and therefore may be considered as a vaccine target. However, native Ply cannot be used in vaccines due to its intrinsic cytolytic activity. In the present work a completely, irreversibly detoxified pneumolysin (dPly) has been generated using an optimized formaldehyde treatment. Detoxi-fication was confirmed by dPly challenge in mice and histological analysis of the injection site in rats. Immunization with dPly elicited Ply-specific functional antibodies that were able to inhibit Ply activity in a hemolysis assay. In addition, immunization with dPly protected mice against lethal intranasal challenge with Ply, and intranasal immunization inhibited nasopharyngeal colonization after intranasal challenge with homologous or heterologous pneumococcal strain. Our findings supported dPly as a valid candidate antigen for further pneumococcal vaccine development.
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11
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Morales M, Martín-Galiano AJ, Domenech M, García E. Insights into the Evolutionary Relationships of LytA Autolysin and Ply Pneumolysin-Like Genes in Streptococcus pneumoniae and Related Streptococci. Genome Biol Evol 2015; 7:2747-61. [PMID: 26349755 PMCID: PMC4607534 DOI: 10.1093/gbe/evv178] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Streptococcus pneumoniae (pneumococcus) is a major human pathogen. The main pneumococcal autolysin LytA and the pneumolysin Ply are two of the bacterium's most important virulence factors. The lytA- and ply-related genes are also found in other streptococci of the Mitis group (SMG). The precise characteristics of the lytA-related-but not the ply-related-genes of SMG and their prophages have been previously described. A search of the more than 400 SMG genomic sequences available in public databases (ca. 300 for S. pneumoniae), showed Streptococcus pseudopneumoniae IS7493 to harbor four ply-related genes, two of which (plyA and plyB) have 98% identical nucleotides. The plyA homolog of S. pseudopneumoniae is conserved in all S. pneumoniae strains, and seems to be included in a pathogenicity island together with the lytA gene. However, only nonencapsulated S. pneumoniae strains possess a plyB gene, which is part of an integrative and conjugative element. Notably, the existence of a bacterial lytA-related gene in a genome is linked to the presence of plyA and vice versa. The present analysis also shows there are eight main types of plyA-lytA genomic islands. A possible stepwise scenario for the evolution of the plyA-lytA island in S. pneumoniae is proposed.
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Affiliation(s)
- María Morales
- Departamento de Microbiología Molecular y Biología de las Infecciones, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain Unidad de Genética Bacteriana, Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Antonio J Martín-Galiano
- Unidad de Genética Bacteriana, Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III (ISCIII), Madrid, Spain Centro Nacional de Microbiología, ISCIII, Majadahonda, Madrid, Spain
| | - Mirian Domenech
- Departamento de Microbiología Molecular y Biología de las Infecciones, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain Unidad de Genética Bacteriana, Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
| | - Ernesto García
- Departamento de Microbiología Molecular y Biología de las Infecciones, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain Unidad de Genética Bacteriana, Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III (ISCIII), Madrid, Spain
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Diversity of Pneumolysin and Pneumococcal Histidine Triad Protein D of Streptococcus pneumoniae Isolated from Invasive Diseases in Korean Children. PLoS One 2015; 10:e0134055. [PMID: 26252211 PMCID: PMC4529296 DOI: 10.1371/journal.pone.0134055] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 07/04/2015] [Indexed: 01/07/2023] Open
Abstract
Pneumolysin (Ply) and pneumococcal histidine triad protein D (PhtD) are candidate proteins for a next-generation pneumococcal vaccine. We aimed to analyze the genetic diversity and antigenic heterogeneity of Ply and PhtD for 173 pneumococci isolated from invasive diseases in Korean children. Allele was designated based on the variation of amino acid sequence. Antigenicity was predicted by the amino acid hydrophobicity of the region. There were seven and 39 allele types for the ply and phtD genes, respectively. The nucleotide sequence identity was 97.2%-99.9% for ply and 91.4%-98.0% for phtD gene. Only minor variations in hydrophobicity were noted among the antigenicity plots of Ply and PhtD. Overall, the allele types of the ply and phtD genes were remarkably homogeneous, and the antigenic diversity of the corresponding proteins was very limited. The Ply and PhtD could be useful antigens for universal pneumococcal vaccines.
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13
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Sun T, Hou H, Lu J, Xu M, Gu T, Wang D, Dong Y, Jiang C, Kong W, Wu Y. Detection and comparison of structure and function of wild-type pneumolysin and its novel mutant PlyM2. Chem Res Chin Univ 2015. [DOI: 10.1007/s40242-015-5105-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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14
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Vaccination in Southeast Asia--reducing meningitis, sepsis and pneumonia with new and existing vaccines. Vaccine 2014; 32:4119-23. [PMID: 24907487 DOI: 10.1016/j.vaccine.2014.05.062] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 04/30/2014] [Accepted: 05/20/2014] [Indexed: 11/23/2022]
Abstract
Streptococcus pneumoniae, Haemophilus influenzae type b and Neisseria meningitidis are leading causes of vaccine-preventable diseases such as meningitis, sepsis and pneumonia. Although there has been much progress in the introduction of vaccines against these pathogens, access to vaccines remains elusive in some countries. This review highlights the current S. pneumoniae, H. influenzae type b, and N. meningitidis immunization schedules in the 10 countries belonging to the Association of Southeast Asian Nations (ASEAN). Epidemiologic studies may be useful for informing vaccine policy in these countries, particularly when determining the cost-effectiveness of introducing new vaccines.
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Tocheva AS, Jefferies JMC, Christodoulides M, Faust SN, Clarke SC. Distribution of carried pneumococcal clones in UK children following the introduction of the 7-valent pneumococcal conjugate vaccine: a 3-year cross-sectional population based analysis. Vaccine 2013; 31:3187-90. [PMID: 23680442 DOI: 10.1016/j.vaccine.2013.04.075] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 04/03/2013] [Accepted: 04/26/2013] [Indexed: 11/18/2022]
Abstract
The success of Streptococcus pneumoniae (pneumococcus) in both colonisation and disease is associated with the increased prevalence of genetic clones expressing virulence factors that assist host invasion. We studied the distribution of pneumococcal clones in paediatric carriage as part of an ongoing longitudinal study of pneumococcal carriage in children less than 5 years of age. Across three years, 87 different sequence types (STs) were found amongst 310 pneumococci. A decline in PCV-7 related STs was observed during the study period. STs 62, 199, 433 and 1692 increased after the implementation of PCV-7 and were related to increases in serotypes 11A, 19A, 22F, and to serotype 6C, respectively. Overall, a strong correlation was observed between ST and serotype. Thirteen STs contained multiple serotypes and 74 STs were associated with only one serotype. On-going molecular epidemiological surveillance of pneumococcal carriage is warranted during the implementation of pneumococcal conjugate vaccines.
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Affiliation(s)
- Anna S Tocheva
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, UK
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Neutralizing antibodies elicited by a novel detoxified pneumolysin derivative, PlyD1, provide protection against both pneumococcal infection and lung injury. Infect Immun 2012; 80:2212-20. [PMID: 22473606 DOI: 10.1128/iai.06348-11] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Streptococcus pneumoniae pneumolysin (PLY) is a virulence factor that causes toxic effects contributing to pneumococcal pneumonia. To date, deriving a PLY candidate vaccine with the appropriate detoxification and immune profile has been challenging. A pneumolysin protein that is appropriately detoxified and that retains its immunogenicity is a desirable vaccine candidate. In this study, we assessed the protective efficacy of our novel PlyD1 detoxified PLY variant and investigated its underlying mechanism of protection. Results have shown that PlyD1 immunization protected mice against lethal intranasal (i.n.) challenge with pneumococci and lung injury mediated by PLY challenge. Protection was associated with PlyD1-specific IgG titers and in vitro neutralization titers. Pretreatment of PLY with PlyD1-specific rat polyclonal antiserum prior to i.n. delivery of toxin reduced PLY-mediated lung lesions, interleukin-6 (IL-6) production, and neutrophil infiltration into lungs, indicating that protection from lung lesions induced by PLY is antibody mediated. Preincubation of PLY with a neutralizing monoclonal PLY antibody also specifically reduced the cytotoxic effects of PLY after i.n. inoculation in comparison to nonneutralizing monoclonal antibodies. These results indicate that the induction of neutralizing antibodies against PLY can contribute to protection against bacterial pneumonia by preventing the development of PLY-induced lung lesions and inflammation. Our detoxified PlyD1 antigen elicits such PLY neutralizing antibodies, thus serving as a candidate vaccine antigen for the prevention of pneumococcal pneumonia.
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