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Oh MW, Lin J, Chong SY, Lew SQ, Alam T, Lau GW. Time-resolved RNA-seq analysis to unravel the in vivo competence induction by Streptococcus pneumoniae during pneumonia-derived sepsis. Microbiol Spectr 2024; 12:e0305023. [PMID: 38305162 PMCID: PMC10913500 DOI: 10.1128/spectrum.03050-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 01/09/2024] [Indexed: 02/03/2024] Open
Abstract
Competence development in Streptococcus pneumoniae (pneumococcus) is tightly intertwined with virulence. In addition to genes encoding genetic transformation machinery, the competence regulon also regulates the expression of allolytic factors, bacteriocins, and cytotoxins. Pneumococcal competence system has been extensively interrogated in vitro where the short transient competent state upregulates the expression of three distinct phases of "early," "late," and "delayed" genes. Recently, we have demonstrated that the pneumococcal competent state develops naturally in mouse models of pneumonia-derived sepsis. To unravel the underlying adaptive mechanisms driving the development of the competent state, we conducted a time-resolved transcriptomic analysis guided by the spatiotemporal live in vivo imaging system of competence induction during pneumonia-derived sepsis. Mouse lungs infected by the serotype 2 strain D39 expressing a competent state-specific reporter gene (D39-ssbB-luc) were subjected to RNA sequencing guided by monitoring the competence development at 0, 12, 24, and, at the moribund state, >40 hours post-infection (hpi). Transcriptomic analysis revealed that the competence-specific gene expression patterns in vivo were distinct from those under in vitro conditions. There was significant upregulation of early, late, and some delayed phase competence-specific genes as early as 12 hpi, suggesting that the pneumococcal competence regulon is important for adaptation to the lung environment. Additionally, members of the histidine triad (pht) gene family were sharply upregulated at 12 hpi followed by a steep decline throughout the rest of the infection cycle, suggesting that Pht proteins participate in the early adaptation to the lung environment. Further analysis revealed that Pht proteins execute a metal ion-dependent regulatory role in competence induction.IMPORTANCEThe induction of pneumococcal competence for genetic transformation has been extensively studied in vitro but poorly understood during lung infection. We utilized a combination of live imaging and RNA sequencing to monitor the development of a competent state during acute pneumonia. Upregulation of competence-specific genes was observed as early as 12 hour post-infection, suggesting that the pneumococcal competence regulon plays an important role in adapting pneumococcus to the stressful lung environment. Among others, we report novel finding that the pneumococcal histidine triad (pht) family of genes participates in the adaptation to the lung environment and regulates pneumococcal competence induction.
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Affiliation(s)
- Myung Whan Oh
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Jingjun Lin
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Sook Yin Chong
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Shi Qian Lew
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Tauqeer Alam
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Gee W. Lau
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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Bahadori Z, Shafaghi M, Sabzevari J, Madanchi H, Ranjbar MM, Mousavi SF, Shabani AA. Design, development, and assessment of a novel multi-peptide vaccine targeting PspC, PsaA, and PhtD proteins of Streptococcus pneumoniae. Int J Biol Macromol 2024; 258:128924. [PMID: 38143051 DOI: 10.1016/j.ijbiomac.2023.128924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 12/15/2023] [Accepted: 12/18/2023] [Indexed: 12/26/2023]
Abstract
Pneumococcus is the top cause of diseases such as pneumonia/meningitis, and of secondary infections after viral respiratory diseases like COVID-19/flu. Pneumococcal protein-based vaccines consisting of proteins with various functions in virulence might provide a qualified alternative for present vaccines. In this project, PspC, PsaA, and PhtD proteins were considered to anticipate B/T-cell epitopes using immunoinformatics to develop 4 multi-peptide constructs (C, A, and D individual constructs, and a fusion construct CAD). We tested whether vaccination with CAD is able to elicit more efficient protective responses against infection than vaccination with the individual constructs or combination of C + A + D. Based on the in silico results, the constructs were predicted to be antigenic, soluble, non-toxic, and stable, and also be able to provoke humoral/cellular immune reactions. When mice were immunized with the fusion protein, significantly higher levels of IgG and cytokines were induced in serum. The IgG in the fusion group had an effective bioactivity for pneumococcus clearance utilizing the complement pathway. The mice immunized with fusion protein were the most protected from challenge. This report for the first time presents a novel multi-peptide vaccine composed of immunodominant peptides of PspC, PsaA, and PhtD. In general, the experimental results supported the immunoinformatics predictions.
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Affiliation(s)
- Zohreh Bahadori
- Department of Medical Biotechnology, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran; Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran.
| | - Mona Shafaghi
- Department of Medical Biotechnology, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran; Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran.
| | - Jahangir Sabzevari
- Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
| | - Hamid Madanchi
- Department of Medical Biotechnology, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran; Drug Design and Bioinformatics Unit, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran; Nervous System Stem Cells Research Center, Semnan University of Medical Sciences, Semnan, Iran
| | - Mohammad Mehdi Ranjbar
- Razi Vaccine and Serum Research Institute, Agricultural Research, Education, and Extension Organization (AREEO), Karaj, Iran
| | | | - Ali Akbar Shabani
- Department of Medical Biotechnology, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran.
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3
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Shafaghi M, Bahadori Z, Barzi SM, Afshari E, Madanchi H, Mousavi SF, Shabani AA. A new candidate epitope-based vaccine against PspA PhtD of Streptococcus pneumoniae: a computational experimental approach. Front Cell Infect Microbiol 2023; 13:1271143. [PMID: 38035337 PMCID: PMC10684780 DOI: 10.3389/fcimb.2023.1271143] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 10/26/2023] [Indexed: 12/02/2023] Open
Abstract
Introduction Pneumococcus is an important respiratory pathogen that is associated with high rates of death in newborn children and the elderly. Given the disadvantages of current polysaccharide-based vaccines, the most promising alternative for developing improved vaccines may be to use protein antigens with different roles in pneumococcus virulence. PspA and PhtD, highly immunogenic surface proteins expressed by almost all pneumococcal strains, are capable of eliciting protective immunity against lethal infections. Methods In this study using immunoinformatics approaches, we constructed one fusion construct (called PAD) by fusing the immunodominant regions of PspA from families 1 & 2 (PA) to the immunodominant regions of PhtD (PD). The objective of this project was to test the immunogenicity of the fusion protein PAD and to compare its protective activity against S. pneumoniae infection with PA or PD alone and a combination of PA and PD. The prediction of physicochemical properties, antigenicity, allergenicity, toxicity, and 3D-structure of the constructs, as well as molecular docking with HLA receptor and immune simulation were performed using computational tools. Finally, mice were immunized and the serum levels of antibodies/cytokines and functionality of antibodies in vitro were evaluated after immunization. The mice survival rates and decrease of bacterial loads in the blood/spleen were examined following the challenge. Results The computational analyses indicated the proposed constructs could be antigenic, non-allergenic, non-toxic, soluble and able to elicit robust immune responses. The results of actual animal experiments revealed the candidate vaccines could induce the mice to produce high levels of antibodies and cytokines. The complement-mediated bactericidal activity of antibodies was confirmed and the antibodies provided favorable survival in immunized mice after bacterial challenge. In general, the experimental results verified the immunoinformatics studies. Conclusion For the first time this report presents novel peptide-based vaccine candidates consisting of immunodominant regions of PspA and PhtD antigens. The obtained findings confirmed that the fusion formulation could be relatively more efficient than the individual and combination formulations. The results propose that the fusion protein alone could be used as a serotype-independent pneumococcal vaccine or as an effective partner protein for a conjugate polysaccharide vaccine.
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Affiliation(s)
- Mona Shafaghi
- Department of Medical Biotechnology, faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran
- Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
| | - Zohreh Bahadori
- Department of Medical Biotechnology, faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran
- Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
| | | | - Elnaz Afshari
- Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Hamid Madanchi
- Department of Medical Biotechnology, faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran
- Drug Design and Bioinformatics Unit, Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | | | - Ali Akbar Shabani
- Department of Medical Biotechnology, faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran
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4
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Shafaghi M, Bahadori Z, Madanchi H, Ranjbar MM, Shabani AA, Mousavi SF. Immunoinformatics-aided design of a new multi-epitope vaccine adjuvanted with domain 4 of pneumolysin against Streptococcus pneumoniae strains. BMC Bioinformatics 2023; 24:67. [PMID: 36829109 PMCID: PMC9951839 DOI: 10.1186/s12859-023-05175-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 02/06/2023] [Indexed: 02/26/2023] Open
Abstract
BACKGROUND Streptococcus pneumoniae (Pneumococcus) has remained a leading cause of fatal infections such as pneumonia, meningitis, and sepsis. Moreover, this pathogen plays a major role in bacterial co-infection in patients with life-threatening respiratory virus diseases such as influenza and COVID-19. High morbidity and mortality in over one million cases, especially in very young children and the elderly, are the main motivations for pneumococcal vaccine development. Due to the limitations of the currently marketed polysaccharide-based vaccines, non-serotype-specific protein-based vaccines have received wide research interest in recent years. One step further is to identify high antigenic regions within multiple highly-conserved proteins in order to develop peptide vaccines that can affect various stages of pneumococcal infection, providing broader serotype coverage and more effective protection. In this study, immunoinformatics tools were used to design an effective multi-epitope vaccine in order to elicit neutralizing antibodies against multiple strains of pneumococcus. RESULTS The B- and T-cell epitopes from highly protective antigens PspA (clades 1-5) and PhtD were predicted and immunodominant peptides were linked to each other with proper linkers. The domain 4 of Ply, as a potential TLR4 agonist adjuvant candidate, was attached to the end of the construct to enhance the immunogenicity of the epitope vaccine. The evaluation of the physicochemical and immunological properties showed that the final construct was stable, soluble, antigenic, and non-allergenic. Furthermore, the protein was found to be acidic and hydrophilic in nature. The protein 3D-structure was built and refined, and the Ramachandran plot, ProSA-web, ERRAT, and Verify3D validated the quality of the final model. Molecular docking analysis showed that the designed construct via Ply domain 4 had a strong interaction with TLR4. The structural stability of the docked complex was confirmed by molecular dynamics. Finally, codon optimization was performed for gene expression in E. coli, followed by in silico cloning in the pET28a(+) vector. CONCLUSION The computational analysis of the construct showed acceptable results, however, the suggested vaccine needs to be experimentally verified in laboratory to ensure its safety and immunogenicity.
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Affiliation(s)
- Mona Shafaghi
- grid.486769.20000 0004 0384 8779Department of Medical Biotechnology, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran ,grid.486769.20000 0004 0384 8779Research Center of Biotechnology, Semnan University of Medical Sciences, Semnan, Iran ,grid.420169.80000 0000 9562 2611Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
| | - Zohreh Bahadori
- grid.486769.20000 0004 0384 8779Department of Medical Biotechnology, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran ,grid.486769.20000 0004 0384 8779Research Center of Biotechnology, Semnan University of Medical Sciences, Semnan, Iran ,grid.420169.80000 0000 9562 2611Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
| | - Hamid Madanchi
- grid.486769.20000 0004 0384 8779Department of Medical Biotechnology, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran ,grid.486769.20000 0004 0384 8779Research Center of Biotechnology, Semnan University of Medical Sciences, Semnan, Iran ,grid.420169.80000 0000 9562 2611Drug Design and Bioinformatics Unit, Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Mohammad Mehdi Ranjbar
- grid.418970.3Agricultural Research, Education, and Extension Organization (AREEO), Razi Vaccine and Serum Research Institute, Karaj, Iran
| | - Ali Akbar Shabani
- Department of Medical Biotechnology, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran. .,Research Center of Biotechnology, Semnan University of Medical Sciences, Semnan, Iran.
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5
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Devarakonda Y, Reddy MVNJ, Neethu RS, Chandran A, Syal K. Multi epitope vaccine candidate design against Streptococcus pneumonia. J Biomol Struct Dyn 2023; 41:12654-12667. [PMID: 36636838 DOI: 10.1080/07391102.2023.2167123] [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: 06/29/2022] [Accepted: 01/05/2023] [Indexed: 01/14/2023]
Abstract
Streptococcus pneumonia, the causative agent of sepsis, meningitis and pneumonia, is held responsible for causing invasive diseases predominantly in children along with adults from both developing and developed countries. The available vaccines coverage in the context of different serotypes is limited and emergence of non-vaccine serotypes could further emerge as a threat in future. Advanced immunoinformatics tools have been used for developing a multi epitope subunit vaccine. In the current study we have subjected these four surface antigenic proteins Ply, PsaA, PspA and PspK to construct vaccine designs. We have predicted different B-cell and T-cell epitopes by using NetCTL 1.2, IEDB (Immune Epitope Databases) and ABCpred. An adjuvant (griselimycin) has been added to the vaccine construct sequence in order to improve its immunogenicity. The vaccine construct has been evaluated for its antigenicity, allergenicity, toxicity and different physio-chemical properties. The bioinformatic tools have been used for prediction, refinement and validation of the 3 D structure. Further, the vaccine structure has been docked with a toll-like receptor (TLR-4) by ClusPro 2.0. In conclusion, the proposed multi-epitope vaccine designs could potentially activate both humoral and cellular immune responses and has a potential to be a vaccine candidate against S.pneumoniae, and requires experimental validation for ensuring immunogenicity and safety profile.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Yogeshwar Devarakonda
- Department of Biological Sciences, Center for Genetics and Molecular Microbiology, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad, India
| | - M V N Janaradhan Reddy
- Department of Biological Sciences, Center for Genetics and Molecular Microbiology, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad, India
| | - R S Neethu
- Department of Biological Sciences, Center for Genetics and Molecular Microbiology, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad, India
| | - Aneesh Chandran
- Department of Biotechnology and Microbiology, Kannur University, Kannur, India
| | - Kirtimaan Syal
- Department of Biological Sciences, Center for Genetics and Molecular Microbiology, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad, India
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6
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Bahadori Z, Shafaghi M, Madanchi H, Ranjbar MM, Shabani AA, Mousavi SF. In silico designing of a novel epitope-based candidate vaccine against Streptococcus pneumoniae with introduction of a new domain of PepO as adjuvant. J Transl Med 2022; 20:389. [PMID: 36059030 PMCID: PMC9440865 DOI: 10.1186/s12967-022-03590-6] [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: 02/14/2022] [Accepted: 08/14/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Streptococcus pneumoniae is the leading reason for invasive diseases including pneumonia and meningitis, and also secondary infections following viral respiratory diseases such as flu and COVID-19. Currently, serotype-dependent vaccines, which have several insufficiency and limitations, are the only way to prevent pneumococcal infections. Hence, it is plain to need an alternative effective strategy for prevention of this organism. Protein-based vaccine involving conserved pneumococcal protein antigens with different roles in virulence could provide an eligible alternative to existing vaccines. METHODS In this study, PspC, PhtD and PsaA antigens from pneumococcus were taken to account to predict B-cell and helper T-cell epitopes, and epitope-rich regions were chosen to build the construct. To enhance the immunogenicity of the epitope-based vaccine, a truncated N-terminal fragment of pneumococcal endopeptidase O (PepO) was used as a potential TLR2/4 agonist which was identified by molecular docking studies. The ultimate construct was consisted of the chosen epitope-rich regions, along with the adjuvant role (truncated N-PepO) and suitable linkers. RESULTS The epitope-based vaccine was assessed as regards physicochemical properties, allergenicity, antigenicity, and toxicity. The 3D structure of the engineered construct was modeled, refined, and validated. Molecular docking and simulation of molecular dynamics (MD) indicated the proper and stable interactions between the vaccine and TLR2/4 throughout the simulation periods. CONCLUSIONS For the first time this work presents a novel vaccine consisting of epitopes of PspC, PhtD, and PsaA antigens which is adjuvanted with a new truncated domain of PepO. The computational outcomes revealed that the suggested vaccine could be deemed an efficient therapeutic vaccine for S. pneumoniae; nevertheless, in vitro and in vivo examinations should be performed to prove the potency of the candidate vaccine.
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Affiliation(s)
- Zohreh Bahadori
- Department of Medical Biotechnology, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran.,Research Center of Biotechnology, Semnan University of Medical Sciences, Semnan, Iran.,Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
| | - Mona Shafaghi
- Department of Medical Biotechnology, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran.,Research Center of Biotechnology, Semnan University of Medical Sciences, Semnan, Iran.,Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
| | - Hamid Madanchi
- Department of Medical Biotechnology, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran.,Research Center of Biotechnology, Semnan University of Medical Sciences, Semnan, Iran.,Drug Design and Bioinformatics Unit, Department of Medical Biotechnology, Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
| | - Mohammad Mehdi Ranjbar
- Agricultural Research, Education, and Extension Organization (AREEO), Razi Vaccine and Serum Research Institute, Karaj, Iran
| | - Ali Akbar Shabani
- Department of Medical Biotechnology, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran. .,Research Center of Biotechnology, Semnan University of Medical Sciences, Semnan, Iran.
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7
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Gingerich AD, Mousa JJ. Diverse Mechanisms of Protective Anti-Pneumococcal Antibodies. Front Cell Infect Microbiol 2022; 12:824788. [PMID: 35155281 PMCID: PMC8834882 DOI: 10.3389/fcimb.2022.824788] [Citation(s) in RCA: 6] [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: 11/29/2021] [Accepted: 01/11/2022] [Indexed: 02/05/2023] Open
Abstract
The gram-positive bacterium Streptococcus pneumoniae is a leading cause of pneumonia, otitis media, septicemia, and meningitis in children and adults. Current prevention and treatment efforts are primarily pneumococcal conjugate vaccines that target the bacterial capsule polysaccharide, as well as antibiotics for pathogen clearance. While these methods have been enormously effective at disease prevention and treatment, there has been an emergence of non-vaccine serotypes, termed serotype replacement, and increasing antibiotic resistance among these serotypes. To combat S. pneumoniae, the immune system must deploy an arsenal of antimicrobial functions. However, S. pneumoniae has evolved a repertoire of evasion techniques and is able to modulate the host immune system. Antibodies are a key component of pneumococcal immunity, targeting both the capsule polysaccharide and protein antigens on the surface of the bacterium. These antibodies have been shown to play a variety of roles including increasing opsonophagocytic activity, enzymatic and toxin neutralization, reducing bacterial adherence, and altering bacterial gene expression. In this review, we describe targets of anti-pneumococcal antibodies and describe antibody functions and effectiveness against S. pneumoniae.
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Affiliation(s)
- Aaron D. Gingerich
- Center for Vaccines and Immunology, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
| | - Jarrod J. Mousa
- Center for Vaccines and Immunology, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
- Department of Biochemistry and Molecular Biology, Franklin College of Arts and Sciences, University of Georgia, Athens, GA, United States
- *Correspondence: Jarrod J. Mousa,
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8
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André GO, Borges MT, Assoni L, Ferraz LFC, Sakshi P, Adamson P, Gordon DL, Ogunniyi AD, Venter H, Converso TR, Darrieux M. Protective role of PhtD and its amino and carboxyl fragments against pneumococcal sepsis. Vaccine 2021; 39:3626-3632. [PMID: 34045100 DOI: 10.1016/j.vaccine.2021.04.068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 04/27/2021] [Accepted: 04/30/2021] [Indexed: 11/28/2022]
Abstract
The implementation of polysaccharide-based vaccines has massively reduced the incidence of invasive pneumococcal diseases. However, there is great concern regarding serotype replacement and the increase in antibiotic resistant strains expressing non-vaccine capsular types. In addition, conjugate vaccines have high production costs, a limiting factor for their implementation in mass immunization programs in developing countries. These limitations have prompted the development of novel vaccine strategies for prevention of Streptococcus pneumoniae infections. The use of conserved pneumococcal antigens such as recombinant proteins or protein fragments presents an interesting serotype-independent alternative. Pht is a family of surface-exposed proteins which have been evaluated as potential vaccine candidates with encouraging results. The present work investigated the immune responses elicited by subcutaneous immunization of mice with the polyhistidine triad protein D (PhtD) and its amino and carboxyl terminal fragments. The proteins were immunogenic and protective against pneumococcal sepsis in mice. Antibodies raised against PhtD increased complement C3b deposition on the pneumococcal surface, mainly mediated by the alternative pathway. Sera from mice immunized with PhtD and PhtD_Cter promoted an increase in bacterial uptake by mouse phagocytes. The interaction of PhtD with the complement system regulator factor H was investigated in silico and in vitro by ELISA and western blot, confirming PhtD as a factor-H binding protein. Our results support the inclusion of PhtD and more specifically, its C-terminal fragment in a multicomponent serotype independent vaccine and suggests a role for the complement system in PhtD-mediated protection.
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Affiliation(s)
- Greiciely O André
- Laboratório de Microbiologia Molecular e Clínica, Universidade São Francisco, Bragança Paulista, Brazil
| | - Mayara T Borges
- Laboratório de Microbiologia Molecular e Clínica, Universidade São Francisco, Bragança Paulista, Brazil
| | - Lucas Assoni
- Laboratório de Microbiologia Molecular e Clínica, Universidade São Francisco, Bragança Paulista, Brazil
| | - Lucio F C Ferraz
- Laboratório de Microbiologia Molecular e Clínica, Universidade São Francisco, Bragança Paulista, Brazil
| | - Piplani Sakshi
- College of Medicine and Public Health. Flinders University, Adelaide, South Australia, Australia
| | - Penelope Adamson
- Department of Microbiology and Infectious Diseases, Flinders University, Adelaide, South Australia, Australia
| | - David L Gordon
- Department of Microbiology and Infectious Diseases, Flinders University, Adelaide, South Australia, Australia
| | - Abiodun D Ogunniyi
- Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia, Australia
| | - Henrietta Venter
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Thiago R Converso
- Laboratório de Microbiologia Molecular e Clínica, Universidade São Francisco, Bragança Paulista, Brazil
| | - Michelle Darrieux
- Laboratório de Microbiologia Molecular e Clínica, Universidade São Francisco, Bragança Paulista, Brazil.
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9
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Broadly Reactive Human Monoclonal Antibodies Targeting the Pneumococcal Histidine Triad Protein Protect against Fatal Pneumococcal Infection. Infect Immun 2021; 89:IAI.00747-20. [PMID: 33649050 PMCID: PMC8091081 DOI: 10.1128/iai.00747-20] [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: 11/30/2020] [Accepted: 02/21/2021] [Indexed: 02/07/2023] Open
Abstract
Streptococcus pneumoniae remains a leading cause of bacterial pneumonia despite the widespread use of vaccines. While vaccines are effective at reducing the incidence of most serotypes included in vaccines, a rise in infection due to nonvaccine serotypes and moderate efficacy against some vaccine serotypes have contributed to high disease incidence. Streptococcus pneumoniae remains a leading cause of bacterial pneumonia despite the widespread use of vaccines. While vaccines are effective at reducing the incidence of most serotypes included in vaccines, a rise in infection due to nonvaccine serotypes and moderate efficacy against some vaccine serotypes have contributed to high disease incidence. Additionally, numerous isolates of S. pneumoniae are antibiotic or multidrug resistant. Several conserved pneumococcal proteins prevalent in the majority of serotypes have been examined for their potential as vaccines in preclinical and clinical trials. An additional, yet-unexplored tool for disease prevention and treatment is the use of human monoclonal antibodies (MAbs) targeting conserved pneumococcal proteins. Here, we isolated the first human MAbs (PhtD3, PhtD6, PhtD7, PhtD8, and PspA16) against the pneumococcal histidine triad protein (PhtD) and the pneumococcal surface protein A (PspA), two conserved and protective antigens. MAbs to PhtD target diverse epitopes on PhtD, and MAb PspA16 targets the N-terminal segment of PspA. The PhtD-specific MAbs bind to multiple serotypes, while MAb PspA16 serotype breadth is limited. MAbs PhtD3 and PhtD8 prolong the survival of mice infected with pneumococcal serotype 3. Furthermore, MAb PhtD3 prolongs the survival of mice in intranasal and intravenous infection models with pneumococcal serotype 4 and in mice infected with pneumococcal serotype 3 when administered 24 h after pneumococcal infection. All PhtD and PspA MAbs demonstrate opsonophagocytic activity, suggesting a potential mechanism of protection. Our results identify new human MAbs for pneumococcal disease prevention and treatment and identify epitopes on PhtD and PspA recognized by human B cells.
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10
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Immunization with PhtD truncated fragments reduces nasopharyngeal colonization by Streptococcus pneumoniae. Vaccine 2020; 38:4146-4153. [PMID: 32362528 DOI: 10.1016/j.vaccine.2020.04.050] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 03/19/2020] [Accepted: 04/20/2020] [Indexed: 01/14/2023]
Abstract
Despite the undeniable success of polysaccharide vaccines against Streptococcus pneumoniae infections, there is a consensus on the scientific field that this approach should be revised in order to overpass the problems related with these formulations, such as serotype replacement and high production costs. The study of conserved pneumococcal proteins or its truncated fragments has emerged as a serotype independent alternative. In this work, we have characterized the immune response elicited by systemic immunization of mice with the Histidine triad protein D (PhtD) and its' amino and carboxyl terminal fragments. The proteins were shown to be immunogenic and protective against pneumococcal colonization, with increased IL-17 production, and induction of antibodies able to limit pneumococcal adhesion to human respiratory cells. Antiserum against PhtD_Nter, but not C_ter or PhtD, promoted an increase in bacterial phagocytosis in vitro. Interestingly, antibodies against the PhtD_Nter displayed cross-reactivity with two other pneumococcal proteins, PspA and PspC, due to sequence similarities in the proline rich region of the molecules. On a whole, our results support the inclusion of PhtD, and more specifically, its N-terminal fragment, in a multicomponent serotype independent vaccine.
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11
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Malekan M, Siadat SD, Aghasadeghi M, Shahrokhi N, Afrough P, Behrouzi A, Ahmadi K, Mousavi SF. Evaluation of protective immunity responses against pneumococcal PhtD and its C-terminal in combination with outer-membrane vesicles as adjuvants. J Med Microbiol 2020; 69:465-477. [DOI: 10.1099/jmm.0.001103] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Introduction.
Streptococcus pneumoniae
is a significant bacterial pathogen in humans. Currently, there are two types of pneumococcal vaccines, but there are concerns regarding their application.
Aim. Since many pneumococcal proteins are serotype-independent, polyhistidine triad protein D (PhtD) has been selected as a vaccine candidate.
Methodology. We prepared recombinant PhtD and its C-terminal fragment (PhtD-C) using alum and outer-membrane vesicles (OMVs) as adjuvants. The combinations were injected intraperitoneally into mice, and then total immunoglobulin G (IgG) and specific IgG, IgG1 and IgG2a were measured. A serum bactericidal assay and opsonophagocytosis were also performed as complementary tests. Meningococcal OMVs were used as an adjuvant.
Results. The levels of specific IgG and IgG1 against combinations of PhtD and its C-terminal with OMVs and alum as adjuvants increased at the time of the third mouse immunization on day 35. Forty per cent and 60% of
S. pneumoniae
ATCC 6303 (serotype 3) as a virulent pneumococcal strain, respectively, were killed in the opsonophagocytosis test and these results could also be observed in the serum bactericidal assay. Mice mmunized iwith PhtD and its C-terminal with OMVs and alum as adjuvants survived after 10 days of pneumococcal challenge.
Conclusion. The combination of PhtD and PhtD-C with alum produced optimal results, but the combination of PhtD and PhtD-C with OMVs produced minimal results by comparison. The survival rates were also measured, and these corresponded with the results of the immunological assessments. Our findings showed that mice receiving PhtD and PhtD-C plus OMV and alum had higher survival rates than the mice in the other groups.
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Affiliation(s)
| | - Seyed Davar Siadat
- Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran
| | | | - Nader Shahrokhi
- Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran
| | - Parviz Afrough
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran
| | - Ava Behrouzi
- Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran
| | - Khadijeh Ahmadi
- Department of Biotechnology, Pasteur Institute of Iran, Tehran, Iran
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12
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Potocki S, Delgado P, Dudek D, Janicka-Kłos A, Kozłowski H, Rowińska-Żyrek M. Pneumococcal HxxHxH triad – Copper(II) interactions – How important is the ‘x’? Inorganica Chim Acta 2019. [DOI: 10.1016/j.ica.2019.01.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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13
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Lagousi T, Basdeki P, Routsias J, Spoulou V. Novel Protein-Based Pneumococcal Vaccines: Assessing the Use of Distinct Protein Fragments Instead of Full-Length Proteins as Vaccine Antigens. Vaccines (Basel) 2019; 7:vaccines7010009. [PMID: 30669439 PMCID: PMC6466302 DOI: 10.3390/vaccines7010009] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 01/15/2019] [Accepted: 01/16/2019] [Indexed: 12/20/2022] Open
Abstract
Non-serotype-specific protein-based pneumococcal vaccines have received extensive research focus due to the limitations of polysaccharide-based vaccines. Pneumococcal proteins (PnPs), universally expressed among serotypes, may induce broader immune responses, stimulating humoral and cellular immunity, while being easier to manufacture and less expensive. Such an approach has raised issues mainly associated with sequence/level of expression variability, chemical instability, as well as possible undesirable reactogenicity and autoimmune properties. A step forward employs the identification of highly-conserved antigenic regions within PnPs with the potential to retain the benefits of protein antigens. Besides, their low-cost and stable construction facilitates the combination of several antigenic regions or peptides that may impair different stages of pneumococcal disease offering even wider serotype coverage and more efficient protection. This review discusses the up-to-date progress on PnPs that are currently under clinical evaluation and the challenges for their licensure. Focus is given on the progress on the identification of antigenic regions/peptides within PnPs and their evaluation as vaccine candidates, accessing their potential to overcome the issues associated with full-length protein antigens. Particular mention is given of the use of newer delivery system technologies including conjugation to Toll-like receptors (TLRs) and reformulation into nanoparticles to enhance the poor immunogenicity of such antigens.
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Affiliation(s)
- Theano Lagousi
- First Department of Paediatrics, "Aghia Sophia" Children's Hospital, Immunobiology Research Laboratory and Infectious Diseases Department "MAKKA," Athens Medical School, 11527 Athens, Greece.
| | - Paraskevi Basdeki
- First Department of Paediatrics, "Aghia Sophia" Children's Hospital, Immunobiology Research Laboratory and Infectious Diseases Department "MAKKA," Athens Medical School, 11527 Athens, Greece.
| | - John Routsias
- Department of Microbiology, Athens Medical School, 11527 Athens, Greece.
| | - Vana Spoulou
- First Department of Paediatrics, "Aghia Sophia" Children's Hospital, Immunobiology Research Laboratory and Infectious Diseases Department "MAKKA," Athens Medical School, 11527 Athens, Greece.
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14
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Luo Z, Pederick VG, Paton JC, McDevitt CA, Kobe B. Structural characterisation of the HT3 motif of the polyhistidine triad protein D from Streptococcus pneumoniae. FEBS Lett 2018; 592:2341-2350. [PMID: 29856892 DOI: 10.1002/1873-3468.13122] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 05/11/2018] [Accepted: 05/21/2018] [Indexed: 01/12/2023]
Abstract
The bacterium Streptococcus pneumoniae (the pneumococcus) is a major human pathogen that requires Zn2+ for its survival and virulence in the host environment. Polyhistidine triad protein D (PhtD) has a known role in pneumococcal Zn2+ homeostasis. However, the mechanistic basis of PhtD function remains unclear, partly due to a lack of structural information. Here, we determined the crystal structure of the fragment PhtD269-339 , containing the third Zn2+ -binding histidine triad (HT) motif of the protein. Analysis of the structure suggests that Zn2+ binding occurs at the surface of the protein and that all five HT motifs in the protein bind Zn2+ and share similar structures. These new structural insights aid in our understanding of how the Pht proteins facilitate pneumococcal Zn2+ acquisition.
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Affiliation(s)
- Zhenyao Luo
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia.,Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia.,Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland, Australia
| | - Victoria G Pederick
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, South Australia, Australia
| | - James C Paton
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, South Australia, Australia
| | - Christopher A McDevitt
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, South Australia, Australia
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia.,Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia.,Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland, Australia
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15
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Evaluation of Protective Efficacy of Selected Immunodominant B-Cell Epitopes within Virulent Surface Proteins of Streptococcus pneumoniae. Infect Immun 2018; 86:IAI.00673-17. [PMID: 29263108 DOI: 10.1128/iai.00673-17] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 12/17/2017] [Indexed: 02/07/2023] Open
Abstract
Four previously identified immunodominant B-cell epitopes, located within known virulent pneumococcal proteins CbpD, PhtD, PhtE, and ZmpB, had shown promising in vivo immunological characteristics, indicating their potential to be used as vaccine antigens. In this study, we further evaluated the opsonophagocytic activity of antibodies against these epitopes and their capacity to protect mice from pneumococcal sepsis. An opsonophagocytic killing assay (OPKA) revealed that OPKA titers of human anti-peptide antibodies against pneumococcal serotypes 1, 3, and 19A were significantly higher (P < 0.001) than those of the control sera, suggesting their functional potential against virulent clinical isolates. Data obtained from mice actively immunized with any of the selected epitope analogues or with a mixture of these (G_Mix group) showed, compared to controls, enhanced survival against the highly virulent pneumococcal serotype 3 (P < 0.001). Moreover, passive transfer of hyperimmune serum from G_Mix to naive mice also conferred protection to a lethal challenge with serotype 3, which demonstrates that the observed protection was antibody mediated. All immunized murine groups elicited gradually higher antibody titers and avidity, suggesting a maturation of immune response over time. Among the tested peptides, PhD_pep19 and PhtE_pep40 peptides, which reside within the zinc-binding domains of PhtD and PhtE proteins, exhibited superior immunological characteristics. Recently it has been shown that zinc uptake is of high importance for the virulence of Streptococcus pneumoniae; thus, our findings suggest that these epitopes deserve further evaluation as novel immunoreactive components for the development of a polysaccharide-independent pneumococcal vaccine.
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16
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Miller A, Dudek D, Potocki S, Czapor-Irzabek H, Kozłowski H, Rowińska-Żyrek M. Pneumococcal histidine triads – involved not only in Zn2+, but also Ni2+ binding? Metallomics 2018; 10:1631-1637. [DOI: 10.1039/c8mt00275d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Polyhistidine triad proteins (with multiple copies of the HxxHxH sequence), which participate in Zn2+ uptake in Streptococcus pneumoniae, are also efficient Ni2+ binders.
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Affiliation(s)
- Adriana Miller
- Faculty of Chemistry
- University of Wroclaw
- F. Joliot-Curie 14
- 50-383 Wroclaw
- Poland
| | - Dorota Dudek
- Faculty of Chemistry
- University of Wroclaw
- F. Joliot-Curie 14
- 50-383 Wroclaw
- Poland
| | - Sławomir Potocki
- Faculty of Chemistry
- University of Wroclaw
- F. Joliot-Curie 14
- 50-383 Wroclaw
- Poland
| | - Hanna Czapor-Irzabek
- Laboratory of Elemental Analysts and Structural Research
- Wroclaw Medical University
- Wroclaw 50-556
- Poland
| | - Henryk Kozłowski
- Faculty of Chemistry
- University of Wroclaw
- F. Joliot-Curie 14
- 50-383 Wroclaw
- Poland
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17
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Xu Q, Pryharski K, Pichichero ME. Trivalent pneumococcal protein vaccine protects against experimental acute otitis media caused by Streptococcus pneumoniae in an infant murine model. Vaccine 2016; 35:337-344. [PMID: 27919628 DOI: 10.1016/j.vaccine.2016.11.046] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 10/31/2016] [Accepted: 11/10/2016] [Indexed: 10/20/2022]
Abstract
BACKGROUND Currently licensed serotype-based pneumococcal vaccines are effective in preventing invasive pneumococcal diseases, but less effective in preventing non-bacteremic pneumonia and acute otitis media (AOM). We previously reported that a trivalent pneumococcal protein recombinant vaccine (PPrV) protected against pneumonia in a murine model. Here we evaluated PPrV protection against AOM in an infant murine model. METHODS C57BL/6J mice were intramuscularly vaccinated at 1-3weeks of age with monovalent pneumococcal histidine triad protein D (PhtD), or pneumococcal choline binding protein A (PcpA), or detoxified pneumolysin (PlyD1), or trivalent vaccine, and transtympanically challenged at 7-8weeks of age with 1×102CFU of pneumococcal strain BG7322 (6A) or 1×104CFU of pneumococcal nontypeable strain 0702064MEF. Serum IgG titers were determined by ELISA. At 24 and 48h post infection (hpi), animals were sacrificed and middle ear fluid (MEF) samples were collected to determine pneumococcal CFUs. RESULTS We found that vaccination of infant mice with monovalent and trivalent pneumococcal proteins elicited significant serum IgG antibody responses to corresponding component proteins. Vaccination with PhtD reduced BG7322 bacterial burdens in MEF at both 24 (p=0.05) and 48hpi (p=0.16). Vaccination with PcpA significantly reduced the bacterial burdens in MEF at both 24 (p=0.02) and 48hpi (p=0.004), and PlyD1 significantly reduced bacterial burden in MEF at 48hpi (p=0.02). Vaccination with trivalent PPrV (PhtD, PcpA and PlyD1) significantly reduced Spn burdens in MEF at both 24 (p=0.001) and 48hpi (p<0.0001). Similar reductions of bacterial burdens were found when the vaccinated animals were challenged with a non-typeable Spn strain. Vaccinated mice had significantly milder inflammatory cytokine levels (IL-1β, IL-6, TNF-α, MIP-2 and KC) in middle ears at 24hpi (all p values<0.05). CONCLUSION Trivalent PPrV confers protection against pneumococcal AOM in an infant murine model.
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Affiliation(s)
- Qingfu Xu
- Center for Infectious Diseases and Immunity, Rochester General Hospital Research Institute, Rochester, NY 14621, USA.
| | - Karin Pryharski
- Center for Infectious Diseases and Immunity, Rochester General Hospital Research Institute, Rochester, NY 14621, USA
| | - Michael E Pichichero
- Center for Infectious Diseases and Immunity, Rochester General Hospital Research Institute, Rochester, NY 14621, USA
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18
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Li M, Shao ZQ, Guo Y, Wang L, Hou T, Hu D, Zheng F, Tang J, Wang C, Feng Y, Gao J, Pan X. The type II histidine triad protein HtpsC is a novel adhesion with the involvement of Streptococcus suis virulence. Virulence 2016; 6:631-41. [PMID: 26151575 PMCID: PMC4720241 DOI: 10.1080/21505594.2015.1056971] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Streptococcal histidine triad proteins HTPs are widely distributed within the Streptococcus genus. Based on the phylogenetic relationship and domain composition, HTPs are classified into type I and type II subfamilies. Previous studies revealed that several pathogenic streptococci contain more than one htp gene. We found that the highly virulent strain of Streptococcus suis 2 (S. suis 2), 05ZYH33 encodes 3 HTPs, designated HtpsA (previously described as HtpS), HtpsB, and HtpsC. Among them, HtpsC is the only member that contains leucine-rich repeat (LRR) domains at the C-terminal. In this study, we demonstrated that the recombinant HtpsC could bind to 2 different components of human ECM complex laminin and fibronectin in vitro, suggesting that it is a novel adhesin of S. suis 2. Having constructed an htpsC mutant, we evaluated its role in the pathogenesis of the highly virulent S. suis 2 strain 05ZYH33. Our data showed that inactivation of htpsC significantly affected adherence of S. suis 2 to Hep-2 cells and shortened the survival of the bacteria in whole blood. Furthermore, deletion of htpsC significantly attenuated the virulence of S. suis 2 in mice. These results demonstrated that htpsC was involved in the pathogenesis of the highly virulent S. suis 2 strain 05ZYH33. In line with the observation, immunization with HtpsC significantly prolonged mice's survival after S. suis 05ZYH33 challenge, indicating its potential use in the vaccine development against S. suis.
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Affiliation(s)
- Min Li
- a School of Laboratory Medicine and Life Science ; Wenzhou Medical University ; Wenzhou , China.,b Department of Epidemiology ; Research Institute for Medicine of Nanjing Command ; Nanjing , China
| | - Zhu-Qing Shao
- b Department of Epidemiology ; Research Institute for Medicine of Nanjing Command ; Nanjing , China.,c State Key Laboratory of Pharmaceutical Biotechnology ; School of Life Sciences ; Nanjing University ; Nanjing , China
| | - Yuqing Guo
- a School of Laboratory Medicine and Life Science ; Wenzhou Medical University ; Wenzhou , China.,b Department of Epidemiology ; Research Institute for Medicine of Nanjing Command ; Nanjing , China
| | - Ling Wang
- b Department of Epidemiology ; Research Institute for Medicine of Nanjing Command ; Nanjing , China.,d School of Life Sciences ; Nanjing Normal University ; Nanjing , China
| | - Tianqing Hou
- b Department of Epidemiology ; Research Institute for Medicine of Nanjing Command ; Nanjing , China
| | - Dan Hu
- b Department of Epidemiology ; Research Institute for Medicine of Nanjing Command ; Nanjing , China
| | - Feng Zheng
- b Department of Epidemiology ; Research Institute for Medicine of Nanjing Command ; Nanjing , China
| | - Jiaqi Tang
- b Department of Epidemiology ; Research Institute for Medicine of Nanjing Command ; Nanjing , China.,e Institute of Laboratory Medicine ; Jinling Hospital ; Nanjing , China
| | - Changjun Wang
- b Department of Epidemiology ; Research Institute for Medicine of Nanjing Command ; Nanjing , China
| | - Youjun Feng
- f Center for Infection & Immunity ; Department of Medical Microbiology & Parasitology ; Zhejiang University School of Medicine ; Hangzhou, Zhejiang , China
| | - Jimin Gao
- a School of Laboratory Medicine and Life Science ; Wenzhou Medical University ; Wenzhou , China
| | - Xiuzhen Pan
- a School of Laboratory Medicine and Life Science ; Wenzhou Medical University ; Wenzhou , China.,b Department of Epidemiology ; Research Institute for Medicine of Nanjing Command ; Nanjing , China
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19
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The First Histidine Triad Motif of PhtD Is Critical for Zinc Homeostasis in Streptococcus pneumoniae. Infect Immun 2015; 84:407-15. [PMID: 26573735 DOI: 10.1128/iai.01082-15] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 11/08/2015] [Indexed: 12/20/2022] Open
Abstract
Streptococcus pneumoniae is the world's foremost human pathogen. Acquisition of the first row transition metal ion zinc is essential for pneumococcal colonization and disease. Zinc is acquired via the ATP-binding cassette transporter AdcCB and two zinc-binding proteins, AdcA and AdcAII. We have previously shown that AdcAII is reliant upon the polyhistidine triad (Pht) proteins to aid in zinc recruitment. Pht proteins generally contain five histidine (His) triad motifs that are believed to facilitate zinc binding and therefore play a significant role in pneumococcal metal ion homeostasis. However, the importance and potential redundancy of these motifs have not been addressed. We examined the effects of mutating each of the five His triad motifs of PhtD. The combination of in vitro growth assays, active zinc uptake, and PhtD expression studies show that the His triad closest to the protein's amino terminus is the most important for zinc acquisition. Intriguingly, in vivo competitive infection studies investigating the amino- and carboxyl-terminal His triad mutants indicate that the motifs have similar importance in colonization. Collectively, our new insights into the contributions of the individual His triad motifs of PhtD, and by extension the other Pht proteins, highlight the crucial role of the first His triad site in zinc acquisition. This study also suggests that the Pht proteins likely play a role beyond zinc acquisition in pneumococcal virulence.
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20
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Mahdi LK, Van der Hoek MB, Ebrahimie E, Paton JC, Ogunniyi AD. Characterization of Pneumococcal Genes Involved in Bloodstream Invasion in a Mouse Model. PLoS One 2015; 10:e0141816. [PMID: 26539717 PMCID: PMC4634996 DOI: 10.1371/journal.pone.0141816] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 10/13/2015] [Indexed: 01/15/2023] Open
Abstract
Streptococcus pneumoniae (the pneumococcus) continues to account for significant morbidity and mortality worldwide, causing life-threatening diseases such as pneumonia, bacteremia and meningitis, as well as less serious infections such as sinusitis, conjunctivitis and otitis media. Current polysaccharide vaccines are strictly serotype-specific and also drive the emergence of non-vaccine serotype strains. In this study, we used microarray analysis to compare gene expression patterns of either serotype 4 or serotype 6A pneumococci in the nasopharynx and blood of mice, as a model to identify genes involved in invasion of blood in the context of occult bacteremia in humans. In this manner, we identified 26 genes that were significantly up-regulated in the nasopharynx and 36 genes that were significantly up-regulated in the blood that were common to both strains. Gene Ontology classification revealed that transporter and DNA binding (transcription factor) activities constitute the significantly different molecular functional categories for genes up-regulated in the nasopharynx and blood. Targeted mutagenesis of selected genes from both niches and subsequent virulence and pathogenesis studies identified the manganese-dependent superoxide dismutase (SodA) as most likely to be essential for colonization, and the cell wall-associated serine protease (PrtA) as important for invasion of blood. This work extends our previous analyses and suggests that both PrtA and SodA warrant examination in future studies aimed at prevention and/or control of pneumococcal disease.
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Affiliation(s)
- Layla K. Mahdi
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Mark B. Van der Hoek
- Adelaide Microarray Centre, The University of Adelaide and SA Pathology, Adelaide, South Australia, Australia
| | - Esmaeil Ebrahimie
- Department of Genetics and Evolution, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - James C. Paton
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Abiodun D. Ogunniyi
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
- * E-mail:
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21
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Xu Q, Casey JR, Pichichero ME. Higher levels of mucosal antibody to pneumococcal vaccine candidate proteins are associated with reduced acute otitis media caused by Streptococcus pneumoniae in young children. Mucosal Immunol 2015; 8:1110-7. [PMID: 25648056 PMCID: PMC4524797 DOI: 10.1038/mi.2015.1] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 12/24/2014] [Indexed: 02/04/2023]
Abstract
Mucosal immunity has a crucial role in controlling human respiratory tract infections. This study characterizes the naturally acquired mucosal antibody levels to three Streptococcus pneumoniae (Spn) protein antigens, pneumococcal histidine triad protein D (PhtD), pneumococcal choline binding protein A (PcpA), and pneumolysin (Ply), and assesses the association of the mucosal antibody levels with occurrence of acute otitis media (AOM) caused by Spn. Both nasopharyngeal (NP) immunoglobulin G (IgG) and IgA levels to all three proteins slightly decreased in children from 6 to 9 months of age and then gradually increased through 24 months of age. Spn NP colonization was associated with higher mucosal antibody levels to all three proteins. However, children with Spn AOM had 5-8-fold lower IgG and 3-6-fold lower IgA levels to the three proteins than children without AOM but asymptomatically colonized with Spn. Antigen-specific antibody levels in the middle ear fluid (MEF) were correlated with antibody levels in the NP. Children with AOM caused by Spn had lower antibody levels in both the MEF and NP than children with AOM caused by other pathogens. These results indicate that higher naturally acquired mucosal antibody levels to PhtD, PcpA and Ply are associated with reduced AOM caused by Spn.
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Affiliation(s)
- Qingfu Xu
- Rochester General Hospital Research Institue, 1425 Portland Avenue, Rochester, NY 14621
| | - Janet R. Casey
- Legacy Pediatrics, 1815 S. Clinton Avenue Suite 360, Rochester, New York 14618
| | - Michael E. Pichichero
- Rochester General Hospital Research Institue, 1425 Portland Avenue, Rochester, NY 14621
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22
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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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23
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Kuipers K, Daleke-Schermerhorn MH, Jong WSP, ten Hagen-Jongman CM, van Opzeeland F, Simonetti E, Luirink J, de Jonge MI. Salmonella outer membrane vesicles displaying high densities of pneumococcal antigen at the surface offer protection against colonization. Vaccine 2015; 33:2022-9. [PMID: 25776921 DOI: 10.1016/j.vaccine.2015.03.010] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 02/24/2015] [Accepted: 03/04/2015] [Indexed: 11/17/2022]
Abstract
Bacterial outer membrane vesicles (OMVs) are attractive vaccine formulations because they have intrinsic immunostimulatory properties. In principle, heterologous antigens incorporated into OMVs will elicit specific immune responses, especially if presented at the vesicle surface and thus optimally exposed to the immune system. In this study, we explored the feasibility of our recently developed autotransporter Hbp platform, designed to efficiently and simultaneously display multiple antigens at the surface of bacterial OMVs, for vaccine development. Using two Streptococcus pneumoniae proteins as model antigens, we showed that intranasally administered Salmonella OMVs displaying high levels of antigens at the surface induced strong protection in a murine model of pneumococcal colonization, without the need for a mucosal adjuvant. Importantly, reduction in bacterial recovery from the nasal cavity was correlated with local production of antigen-specific IL-17A. Furthermore, the protective efficacy and the production of antigen-specific IL-17A, and local and systemic IgGs, were all improved at increased concentrations of the displayed antigen. This discovery highlights the importance of an adequate antigen expression system for development of recombinant OMV vaccines. In conclusion, our findings demonstrate the suitability of the Hbp platform for development of a new generation of OMV vaccines, and illustrate the potential of using this approach to develop a broadly protective mucosal pneumococcal vaccine.
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Affiliation(s)
- Kirsten Kuipers
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Maria H Daleke-Schermerhorn
- Section Molecular Microbiology, Department of Molecular Cell Biology, Faculty of Earth and Life Sciences, VU University, Amsterdam, The Netherlands; Abera Bioscience AB, Stockholm, Sweden
| | - Wouter S P Jong
- Section Molecular Microbiology, Department of Molecular Cell Biology, Faculty of Earth and Life Sciences, VU University, Amsterdam, The Netherlands; Abera Bioscience AB, Stockholm, Sweden
| | - Corinne M ten Hagen-Jongman
- Section Molecular Microbiology, Department of Molecular Cell Biology, Faculty of Earth and Life Sciences, VU University, Amsterdam, The Netherlands; Abera Bioscience AB, Stockholm, Sweden
| | - Fred van Opzeeland
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Elles Simonetti
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Joen Luirink
- Section Molecular Microbiology, Department of Molecular Cell Biology, Faculty of Earth and Life Sciences, VU University, Amsterdam, The Netherlands; Abera Bioscience AB, Stockholm, Sweden.
| | - Marien I de Jonge
- Laboratory of Pediatric Infectious Diseases, Department of Pediatrics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
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Saxena S, Khan N, Dehinwal R, Kumar A, Sehgal D. Conserved surface accessible nucleoside ABC transporter component SP0845 is essential for pneumococcal virulence and confers protection in vivo. PLoS One 2015; 10:e0118154. [PMID: 25689507 PMCID: PMC4331430 DOI: 10.1371/journal.pone.0118154] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 01/05/2015] [Indexed: 11/30/2022] Open
Abstract
Streptococcus pneumoniae is a leading cause of bacterial pneumonia, sepsis and meningitis. Surface accessible proteins of S. pneumoniae are being explored for the development of a protein-based vaccine in order to overcome the limitations of existing polysaccharide-based pneumococcal vaccines. To identify a potential vaccine candidate, we resolved surface-associated proteins of S. pneumoniae TIGR4 strain using two-dimensional gel electrophoresis followed by immunoblotting with antisera generated against whole heat-killed TIGR4. Ten immunoreactive spots were identified by mass spectrometric analysis that included a putative lipoprotein SP0845. Analysis of the inferred amino acid sequence of sp0845 homologues from 36 pneumococcal strains indicated that SP0845 was highly conserved (>98% identity) and showed less than 11% identity with any human protein. Our bioinformatic and functional analyses demonstrated that SP0845 is the substrate-binding protein of an ATP-binding cassette (ABC) transporter that is involved in nucleoside uptake with cytidine, uridine, guanosine and inosine as the preferred substrates. Deletion of the gene encoding SP0845 renders pneumococci avirulent suggesting that it is essential for virulence. Immunoblot analysis suggested that SP0845 is expressed in in vitro grown pneumococci and during mice infection. Immunofluorescence microscopy and flow cytometry data indicated that SP0845 is surface exposed in encapsulated strains and accessible to antibodies. Subcutaneous immunization with recombinant SP0845 induced high titer antibodies in mice. Hyperimmune sera raised against SP0845 promoted killing of encapsulated pneumococcal strains in a blood bactericidal assay. Immunization with SP0845 protected mice from intraperitoneal challenge with heterologous pneumococcal serotypes. Based on its surface accessibility, role in virulence and ability to elicit protective immunity, we propose that SP0845 may be a potential candidate for a protein-based pneumococcal vaccine.
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Affiliation(s)
- Sneha Saxena
- Molecular Immunology Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India
| | - Naeem Khan
- Molecular Immunology Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India
| | - Ruchika Dehinwal
- Molecular Immunology Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India
| | - Ajay Kumar
- Molecular Immunology Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India
| | - Devinder Sehgal
- Molecular Immunology Laboratory, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, India
- * E-mail:
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Trivalent pneumococcal protein recombinant vaccine protects against lethal Streptococcus pneumoniae pneumonia and correlates with phagocytosis by neutrophils during early pathogenesis. Vaccine 2015; 33:993-1000. [PMID: 25597944 DOI: 10.1016/j.vaccine.2015.01.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 12/04/2014] [Accepted: 01/06/2015] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Due to the fact that current polysaccharide-based pneumococcal vaccines have limited serotype coverage, protein-based vaccine candidates have been sought for over a decade to replace or complement current vaccines. We previously reported that a trivalent Pneumococcal Protein recombinant Vaccine (PPrV), showed protection against pneumonia and sepsis in an infant murine model. Here we investigated immunological correlates of protection of PPrV in the same model. METHODS C57BL/6J infant mice were intramuscularly vaccinated at age 1-3 weeks with 3 doses of PPrV, containing pneumococcal histidine triad protein D (PhtD), pneumococcal choline binding protein A (PcpA), and detoxified pneumolysin mutant PlyD1. 3-4 weeks after last vaccination, serum and lung antibody levels to PPrV components were measured, and mice were intranasally challenged with a lethal dose of Streptococcus pneumoniae (Spn) serotype 6A. Lung Spn bacterial burden, number of neutrophils and alveolar macrophages, phagocytosed Spn by granulocytes, and levels of cytokines and chemokines were determined at 6, 12, 24, and 48h after challenge. RESULTS PPrV vaccination conferred 83% protection against Spn challenge. Vaccinated mice had significantly elevated serum and lung antibody levels to three PPrV components. In the first stage of pathogenesis of Spn induced pneumonia (6-24h after challenge), vaccinated mice had lower Spn bacterial lung burdens and more phagocytosed Spn in the granulocytes. PPrV vaccination led to lower levels of pro-inflammatory cytokines IL-6, IL-1β, and TFN-α, and other cytokines and chemokines (IL-12, IL-17, IFN-γ, MIP-1b, MIP-2 and KC, and G-CSF), presumably due to a lower lung bacterial burden. CONCLUSION Trivalent PPrV vaccination results in increased serum and lung antibody levels to the vaccine components, a reduction in Spn induced lethality, enhanced early clearance of Spn in lungs due to more rapid and thorough phagocytosis of Spn by neutrophils, and correspondingly a reduction in lung inflammation and tissue damage.
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Feldman C, Anderson R. Review: Current and new generation pneumococcal vaccines. J Infect 2014; 69:309-25. [DOI: 10.1016/j.jinf.2014.06.006] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 06/16/2014] [Indexed: 12/22/2022]
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Overlapping functionality of the Pht proteins in zinc homeostasis of Streptococcus pneumoniae. Infect Immun 2014; 82:4315-24. [PMID: 25069983 DOI: 10.1128/iai.02155-14] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Streptococcus pneumoniae is a globally significant pathogen that causes a range of diseases, including pneumonia, sepsis, meningitis, and otitis media. Its ability to cause disease depends upon the acquisition of nutrients from its environment, including transition metal ions such as zinc. The pneumococcus employs a number of surface proteins to achieve this, among which are four highly similar polyhistidine triad (Pht) proteins. It has previously been established that these proteins collectively aid in the delivery of zinc to the ABC transporter substrate-binding protein AdcAII. Here we have investigated the contribution of each individual Pht protein to pneumococcal zinc homeostasis by analyzing mutant strains expressing only one of the four pht genes. Under conditions of low zinc availability, each of these mutants showed superior growth and zinc accumulation profiles relative to a mutant strain lacking all four genes, indicating that any of the four Pht proteins are able to facilitate delivery of zinc to AdcAII. However, optimal growth and zinc accumulation in vitro and pneumococcal survival and proliferation in vivo required production of all four Pht proteins, indicating that, despite their overlapping functionality, the proteins are not dispensable without incurring a fitness cost. We also show that surface-attached forms of the Pht proteins are required for zinc recruitment and that they do not contribute to defense against extracellular zinc stress.
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