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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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Afshari E, Ahangari Cohan R, Shams Nosrati MS, Mousavi SF. Development of a bivalent protein-based vaccine candidate against invasive pneumococcal diseases based on novel pneumococcal surface protein A in combination with pneumococcal histidine triad protein D. Front Immunol 2023; 14:1187773. [PMID: 37680628 PMCID: PMC10480505 DOI: 10.3389/fimmu.2023.1187773] [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: 03/16/2023] [Accepted: 08/01/2023] [Indexed: 09/09/2023] Open
Abstract
Extensive efforts have been made toward improving effective strategies for pneumococcal vaccination, focusing on evaluating the potential of multivalent protein-based vaccines and overcoming the limitations of pneumococcal polysaccharide-based vaccines. In this study, we investigated the protective potential of mice co-immunization with the pneumococcal PhtD and novel rPspA proteins against pneumococcal sepsis infection. The formulations of each antigen alone or in combination were administered intraperitoneally with alum adjuvant into BALB/c mice three times at 14-day intervals. The production of antigen-specific IgG, IgG1 and IgG2a subclasses, and IL-4 and IFN-γ cytokines, were analyzed. Two in vitro complement- and opsonophagocytic-mediated killing activities of raised antibodies on day 42 were also assessed. Finally, the protection against an intraperitoneal challenge with 106 CFU/mouse of multi-drug resistance of Streptococcus pneumoniae ATCC49619 was investigated. Our findings showed a significant increase in the anti-PhtD and anti-rPspA sera IgG levels in the immunized group with the PhtD+rPspA formulation compared to each alone. Moreover, the results demonstrated a synergistic effect with a 6.7- and 1.3- fold increase in anti-PhtD and anti-rPspA IgG1, as well as a 5.59- and 1.08- fold increase in anti-PhtD and anti-rPspA IgG2a, respectively. Co-administration of rPspA+PhtD elicited a mixture of Th-2 and Th-1 immune responses, more towards Th-2. In addition, the highest complement-mediated killing activity was observed in the sera of the immunized group with PhtD+rPspA at 1/16 dilution, and the opsonophagocytic activity was increased from 74% to 86.3%. Finally, the survival rates showed that mice receiving the rPspA+PhtD formulation survived significantly longer (100%) than those receiving protein alone or PBS and exhibited the strongest clearance with a 2 log10 decrease in bacterial load in the blood 24h after challenge compared to the control group. In conclusion, the rPspA+PhtD formulation can be considered a promising bivalent serotype-independent vaccine candidate for protection against invasive pneumococcal infection in the future.
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Affiliation(s)
- Elnaz Afshari
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
- Department of Microbiology, Pasteur Institute of Iran, Tehran, Iran
| | - Reza Ahangari Cohan
- Department of Nanobiotechnology, New Technologies Research Group, Pasteur Institute of Iran, Tehran, Iran
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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] [MESH Headings] [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
- 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
| | - 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
| | - 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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Afshari E, Cohan RA, Sotoodehnejadnematalahi F, Mousavi SF. In-silico design and evaluation of an epitope-based serotype-independent promising vaccine candidate for highly cross-reactive regions of pneumococcal surface protein A. J Transl Med 2023; 21:13. [PMID: 36627666 PMCID: PMC9830136 DOI: 10.1186/s12967-022-03864-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 12/29/2022] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND The pathogenicity of pneumococcus with high morbidity, mortality, and multi-drug resistance patterns has been increasing. The limited coverage of the licensed polysaccharide-based vaccines and the replacement of the non-vaccine serotypes are the main reasons for producing a successful serotype-independent vaccine. Pneumococcal surface protein A (PspA) is an extremely important virulence factor and an interesting candidate for conserved protein-based pneumococcal vaccine classified into two prominent families containing five clades. PspA family-elicited immunity is clade-dependent, and the level of the PspA cross-reactivity is restricted to the same family. METHODS To cover and overcome the clade-dependent immunity of the PspAs in this study, we designed and tested a PspA1-5c+p vaccine candidate composed of the highest immunodominant coverage of B- and T-cell epitope truncated domain of each clade focusing on two cross-reactive B and C regions of the PspAs. The antigenicity, toxicity, physicochemical properties, 3D structure prediction, stability and flexibility of the designed protein using molecular dynamic (MD) simulation, molecular docking of the construct withHLADRB1*(01:01) and human lactoferrin N-lop, and immune simulation were assessed using immunoinformatics tools. In the experimental section, after intraperitoneal immunization of the mice with Alum adjuvanted recombinant PspA1-5c+p, we evaluated the immune response, cross-reactivity, and functionality of the Anti-PspA1-5c+p antibody using ELISA, Opsonophagocytic killing activity, and serum bactericidal assay. RESULTS For the first time, this work suggested a novel PspA-based vaccine candidate using immunoinformatics tools. The designed PspA1-5c+p protein is predicted to be highly antigenic, non-toxic, soluble, stable with low flexibility in MD simulation, and able to stimulate both humoral and cellular immune responses. The designed protein also could interact strongly with HLADRB1*(01:01) and human lactoferrin N-lop in the docking study. Our immunoinformatics predictions were validated using experimental data. Results showed that the anti-PspA1-5c+p IgG not only had a high titer with strong and same cross-reactivity coverage against all pneumococcal serotypes used but also had high and effective bioactivity for pneumococcal clearance using complement system and phagocytic cells. CONCLUSION Our findings elucidated the potential application of the PspA1-5c+p vaccine candidate as a serotype-independent pneumococcal vaccine with a strong cross-reactivity feature. Further in-vitro and in-vivo investigations against other PspA clades should be performed to confirm the full protection of the PspA1-5c+p vaccine candidate.
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Affiliation(s)
- Elnaz Afshari
- grid.411463.50000 0001 0706 2472Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Reza Ahangari Cohan
- grid.420169.80000 0000 9562 2611Department of Nanobiotechnology, New Technologies Research Group, Pasteur Institute of Iran, Tehran, Iran
| | - Fattah Sotoodehnejadnematalahi
- grid.411463.50000 0001 0706 2472Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Seyed Fazlollah Mousavi
- grid.420169.80000 0000 9562 2611Department of Microbiology, Pasteur Institute of Iran, 69 Pasteur Ave., Tehran, 13164 Iran
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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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Lane JR, Tata M, Briles DE, Orihuela CJ. A Jack of All Trades: The Role of Pneumococcal Surface Protein A in the Pathogenesis of Streptococcus pneumoniae. Front Cell Infect Microbiol 2022; 12:826264. [PMID: 35186799 PMCID: PMC8847780 DOI: 10.3389/fcimb.2022.826264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/10/2022] [Indexed: 12/11/2022] Open
Abstract
Streptococcus pneumoniae (Spn), or the pneumococcus, is a Gram-positive bacterium that colonizes the upper airway. Spn is an opportunistic pathogen capable of life-threatening disease should it become established in the lungs, gain access to the bloodstream, or disseminate to vital organs including the central nervous system. Spn is encapsulated, allowing it to avoid phagocytosis, and current preventative measures against infection include polyvalent vaccines composed of capsular polysaccharide corresponding to its most prevalent serotypes. The pneumococcus also has a plethora of surface components that allow the bacteria to adhere to host cells, facilitate the evasion of the immune system, and obtain vital nutrients; one family of these are the choline-binding proteins (CBPs). Pneumococcal surface protein A (PspA) is one of the most abundant CBPs and confers protection against the host by inhibiting recognition by C-reactive protein and neutralizing the antimicrobial peptide lactoferricin. Recently our group has identified two new roles for PspA: binding to dying host cells via host-cell bound glyceraldehyde 3-phosphate dehydrogenase and co-opting of host lactate dehydrogenase to enhance lactate availability. These properties have been shown to influence Spn localization and enhance virulence in the lower airway, respectively. Herein, we review the impact of CBPs, and in particular PspA, on pneumococcal pathogenesis. We discuss the potential and limitations of using PspA as a conserved vaccine antigen in a conjugate vaccine formulation. PspA is a vital component of the pneumococcal virulence arsenal - therefore, understanding the molecular aspects of this protein is essential in understanding pneumococcal pathogenesis and utilizing PspA as a target for treating or preventing pneumococcal pneumonia.
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Affiliation(s)
| | | | | | - Carlos J. Orihuela
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, United States
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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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Kiyono H, Yuki Y, Nakahashi-Ouchida R, Fujihashi K. Mucosal vaccines: wisdom from now and then. Int Immunol 2021; 33:767-774. [PMID: 34436595 PMCID: PMC8633596 DOI: 10.1093/intimm/dxab056] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 08/25/2021] [Indexed: 12/29/2022] Open
Abstract
The oral and nasal cavities are covered by the mucosal epithelium that starts at the beginning of the aero-digestive tract. These mucosal surfaces are continuously exposed to environmental antigens including pathogens and allergens and are thus equipped with a mucosal immune system that mediates initial recognition of pathogenicity and initiates pathogen-specific immune responses. At the dawn of our scientific effort to explore the mucosal immune system, dental science was one of the major driving forces as it provided insights into the importance of mucosal immunity and its application for the control of oral infectious diseases. The development of mucosal vaccines for the prevention of dental caries was thus part of a novel approach that contributed to building the scientific foundations of the mucosal immune system. Since then, mucosal immunology and vaccines have gone on a scientific journey to become one of the major entities within the discipline of immunology. Here, we introduce our past and current efforts and future directions for the development of mucosal vaccines, specifically a rice-based oral vaccine (MucoRice) and a nanogel-based nasal vaccine, with the aim of preventing and controlling gastrointestinal and respiratory infectious diseases using the interdisciplinary fusion of mucosal immunology with agricultural science and biomaterial engineering, respectively.
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Affiliation(s)
- Hiroshi Kiyono
- Division of Mucosal Immunology, IMSUT Distinguished Professor Unit, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
- Department of Immunology, Graduate School of Medicine, Chiba University, Chiba, Japan
- Department of Medicine, School of Medicine and CU-UCSD Center for Mucosal Immunology, Allergy and Vaccines, University of California, San Diego, San Diego, CA, USA
| | - Yoshikazu Yuki
- Division of Mucosal Immunology, IMSUT Distinguished Professor Unit, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Rika Nakahashi-Ouchida
- Division of Mucosal Immunology, IMSUT Distinguished Professor Unit, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan
| | - Kohtaro Fujihashi
- Division of Clinical Vaccinology, International Research and Development Center for Mucosal Vaccines, Institute of Medical Science, University of Tokyo, Tokyo, Japan
- Department of Pediatric Dentistry, The University of Alabama at Birmingham, Birmingham, AL, USA
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Nakahashi-Ouchida R, Uchida Y, Yuki Y, Katakai Y, Yamanoue T, Ogawa H, Munesue Y, Nakano N, Hanari K, Miyazaki T, Saito Y, Umemoto S, Sawada SI, Mukerji R, Briles DE, Yasutomi Y, Akiyoshi K, Kiyono H. A nanogel-based trivalent PspA nasal vaccine protects macaques from intratracheal challenge with pneumococci. Vaccine 2021; 39:3353-3364. [PMID: 34016473 DOI: 10.1016/j.vaccine.2021.04.069] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/20/2021] [Accepted: 04/30/2021] [Indexed: 12/17/2022]
Abstract
Current polysaccharide-based pneumococcal vaccines are effective but not compatible with all serotypes of Streptococcus pneumoniae. We previously developed an adjuvant-free cationic nanogel nasal vaccine containing pneumococcal surface protein A (PspA), which is expressed on the surfaces of all pneumococcal serotypes. Here, to address the sequence diversity of PspA proteins, we formulated a cationic nanogel-based trivalent pneumococcal nasal vaccine and demonstrated the vaccine's immunogenicity and protective efficacy in macaques by using a newly developed nasal spray device applicable to humans. Nasal vaccination of macaques with cationic cholesteryl pullulan nanogel (cCHP)-trivalent PspA vaccine effectively induced PspA-specific IgGs that bound to pneumococcal surfaces and triggered complement C3 deposition. The immunized macaques were protected from pneumococcal intratracheal challenge through both inhibition of lung inflammation and a dramatic reduction in the numbers of bacteria in the lungs. These results demonstrated that the cCHP-trivalent PspA vaccine is an effective candidate vaccine against pneumococcal infections.
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Affiliation(s)
- Rika Nakahashi-Ouchida
- Division of Mucosal Vaccines, International Research and Development Center for Mucosal Vaccine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan; Department of Mucosal Immunology, IMSUT Distinguished Professor Unit, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Yohei Uchida
- Division of Mucosal Vaccines, International Research and Development Center for Mucosal Vaccine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Yoshikazu Yuki
- Division of Mucosal Vaccines, International Research and Development Center for Mucosal Vaccine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan; HanaVax Inc., Tokyo 103-0012, Japan
| | - Yuko Katakai
- Department of Medical Science Project Planning and Support, The Corporation for Production and Research of Laboratory Primates, Ibaraki, 305-0843, Japan
| | - Tomoyuki Yamanoue
- Division of Mucosal Vaccines, International Research and Development Center for Mucosal Vaccine, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Hiromi Ogawa
- Department of Medical Science Project Planning and Support, The Corporation for Production and Research of Laboratory Primates, Ibaraki, 305-0843, Japan
| | - Yoshiko Munesue
- Department of Medical Science Project Planning and Support, The Corporation for Production and Research of Laboratory Primates, Ibaraki, 305-0843, Japan
| | - Nozomi Nakano
- Department of Medical Science Project Planning and Support, The Corporation for Production and Research of Laboratory Primates, Ibaraki, 305-0843, Japan
| | - Kouji Hanari
- Department of Medical Science Project Planning and Support, The Corporation for Production and Research of Laboratory Primates, Ibaraki, 305-0843, Japan
| | | | - Yuki Saito
- Toko Yakuhin Kogyo Co., Ltd., 930-0211, Japan
| | - Shingo Umemoto
- Department of Mucosal Immunology, IMSUT Distinguished Professor Unit, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan; Faculty of Medicine, Department of Otorhinolaryngology and Head and Neck Surgery, Oita University, Oita 879-5593, Japan
| | - Shin-Ichi Sawada
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Reshmi Mukerji
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294-2170, United States
| | - David E Briles
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294-2170, United States
| | - Yasuhiro Yasutomi
- Laboratory of Immunoregulation and Vaccine Research, Tsukuba Primate Research Center, National Institutes of Biomedical Innovation, Health and Nutrition, Ibaraki, 305-0843, Japan
| | - Kazunari Akiyoshi
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Hiroshi Kiyono
- Department of Mucosal Immunology, IMSUT Distinguished Professor Unit, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan; HanaVax Inc., Tokyo 103-0012, Japan; Mucosal Immunology and Allergy Therapeutics, Institute for Global Prominent Research, Chiba University, Chiba 263-8522, Japan; CU-UCSD Center for Mucosal Immunology, Allergy and Vaccine (cMAV), Division of Gastroenterology, Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0063, United States.
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Park SS, Gonzalez-Juarbe N, Martínez E, Hale JY, Lin YH, Huffines JT, Kruckow KL, Briles DE, Orihuela CJ. Streptococcus pneumoniae Binds to Host Lactate Dehydrogenase via PspA and PspC To Enhance Virulence. mBio 2021; 12:e00673-21. [PMID: 33947761 PMCID: PMC8437407 DOI: 10.1128/mbio.00673-21] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 03/22/2021] [Indexed: 02/06/2023] Open
Abstract
Pneumococcal surface protein A (PspA) and pneumococcal surface protein C (PspC, also called CbpA) are major virulence factors of Streptococcus pneumoniae (Spn). These surface-exposed choline-binding proteins (CBPs) function independently to inhibit opsonization, neutralize antimicrobial factors, or serve as adhesins. PspA and PspC both carry a proline-rich domain (PRD) whose role, other than serving as a flexible connector between the N-terminal and C-terminal domains, was up to this point unknown. Herein, we demonstrate that PspA binds to lactate dehydrogenase (LDH) released from dying host cells during infection. Using recombinant versions of PspA and isogenic mutants lacking PspA or specific domains of PspA, this property was mapped to a conserved 22-amino-acid nonproline block (NPB) found within the PRD of most PspAs and PspCs. The NPB of PspA had specific affinity for LDH-A, which converts pyruvate to lactate. In a mouse model of pneumonia, preincubation of Spn carrying NPB-bearing PspA with LDH-A resulted in increased bacterial titers in the lungs. In contrast, incubation of Spn carrying a version of PspA lacking the NPB with LDH-A or incubation of wild-type Spn with enzymatically inactive LDH-A did not enhance virulence. Preincubation of NPB-bearing Spn with lactate alone enhanced virulence in a pneumonia model, indicating exogenous lactate production by Spn-bound LDH-A had an important role in pneumococcal pathogenesis. Our observations show that lung LDH, released during the infection, is an important binding target for Spn via PspA/PspC and that pneumococci utilize LDH-A derived lactate for their benefit in vivoIMPORTANCEStreptococcus pneumoniae (Spn) is the leading cause of community-acquired pneumonia. PspA and PspC are among its most important virulence factors, and these surface proteins carry the proline-rich domain (PRD), whose role was unknown until now. Herein, we show that a conserved 22-amino-acid nonproline block (NPB) found within most versions of the PRD binds to host-derived lactate dehydrogenase A (LDH-A), a metabolic enzyme which converts pyruvate to lactate. PspA-mediated binding of LDH-A increased Spn titers in the lungs and this required LDH-A enzymatic activity. Enhanced virulence was also observed when Spn was preincubated with lactate, suggesting LDH-A-derived lactate is a vital food source. Our findings define a role for the NPB of the PRD and show that Spn co-opts host enzymes for its benefit. They advance our understanding of pneumococcal pathogenesis and have key implications on the susceptibility of individuals with preexisting airway damage that results in LDH-A release.
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Affiliation(s)
- Sang-Sang Park
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Norberto Gonzalez-Juarbe
- Infectious Diseases and Genomic Medicine Group, J Craig Venter Institute, Rockville, Maryland, USA
| | - Eriel Martínez
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Joanetha Yvette Hale
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Yi-Han Lin
- Infectious Diseases and Genomic Medicine Group, J Craig Venter Institute, Rockville, Maryland, USA
| | - Joshua T Huffines
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Katherine L Kruckow
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - David E Briles
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Carlos J Orihuela
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
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11
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Du S, Vilhena C, King S, Sahagún-Ruiz A, Hammerschmidt S, Skerka C, Zipfel PF. Molecular analyses identifies new domains and structural differences among Streptococcus pneumoniae immune evasion proteins PspC and Hic. Sci Rep 2021; 11:1701. [PMID: 33462258 PMCID: PMC7814132 DOI: 10.1038/s41598-020-79362-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 12/07/2020] [Indexed: 12/13/2022] Open
Abstract
The PspC and Hic proteins of Streptococcuspneumoniae are some of the most variable microbial immune evasion proteins identified to date. Due to structural similarities and conserved binding profiles, it was assumed for a long time that these pneumococcal surface proteins represent a protein family comprised of eleven subgroups. Recently, however, the evaluation of more proteins revealed a greater diversity of individual proteins. In contrast to previous assumptions a pattern evaluation of six PspC and five Hic variants, each representing one of the previously defined subgroups, revealed distinct structural and likely functionally regions of the proteins, and identified nine new domains and new domain alternates. Several domains are unique to PspC and Hic variants, while other domains are also present in other virulence factors encoded by pneumococci and other bacterial pathogens. This knowledge improved pattern evaluation at the level of full-length proteins, allowed a sequence comparison at the domain level and identified domains with a modular composition. This novel strategy increased understanding of individual proteins variability and modular domain composition, enabled a structural and functional characterization at the domain level and furthermore revealed substantial structural differences between PspC and Hic proteins. Given the exceptional genomic diversity of the multifunctional PspC and Hic proteins a detailed structural and functional evaluation need to be performed at the strain level. Such knowledge will also be useful for molecular strain typing and characterizing PspC and Hic proteins from new clinical S. pneumoniae strains.
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Affiliation(s)
- Shanshan Du
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Cláudia Vilhena
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Samantha King
- Center for Microbial Pathogenesis, Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA.,Department of Pediatrics, The Ohio State University, Columbus, OH, USA
| | - Alfredo Sahagún-Ruiz
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany.,Molecular Immunology Laboratory, Department of Microbiology and Immunology, Faculty of Veterinary Medicine and Animal Husbandry, National Autonomous University of Mexico, Mexico City, Mexico
| | - Sven Hammerschmidt
- Department of Molecular Genetics and Infection Biology, Interfaculty Institute for Genetics and Functional Genomics, Center for Functional Genomics of Microbes, University of Greifswald, Greifswald, Germany
| | - Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Peter F Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany. .,Institute of Microbiology, Friedrich-Schiller-University, Jena, Germany.
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12
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Guo X, Sun Q, Xi H, Zhang Y, Guo M, Zhang C, Zhu S, Gu T, Kong W, Wu Y. Expression, purification, and characterization of pneumococcal PsaA-PspA fusion protein. Protein Expr Purif 2020; 178:105782. [PMID: 33122039 DOI: 10.1016/j.pep.2020.105782] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 07/01/2020] [Accepted: 10/14/2020] [Indexed: 11/30/2022]
Abstract
Streptococcus pneumoniae is a gram-positive bacterial pathogen causing invasive pneumonia, meningitis, otitis media, and bacteremia. Owing to the current pitfalls of polysaccharide and polysaccharide-conjugate vaccines, protein vaccines are considered promising candidates against pneumonia. Pneumococcal surface protein A (PspA) and pneumococcal surface adhesin A (PsaA) are virulence proteins showing good immunogenicity and protective effects against S. pneumoniae strains in mice. In this study, we expressed the fusion protein PsaA-PspA, which consists of PsaA and the N-terminal region of PspA family 1 and 2, in Escherichia coli. We describe a novel and effective method to purify PsaA-PspA using hydroxyapatite and two-step chromatography. After determining the optimal induction conditions and a series of purification steps, we obtained PsaA-PspA fusion protein with over 95% purity at a final yield of 22.44% from the starting cell lysate. The molecular weight of PsaA-PspA was approximately 83.6 kDa and its secondary structure was evaluated by circular dichroism. Immunization with the purified protein induced high levels of IgG antibodies in mice. Collectively, these results demonstrate that our purification method can effectively produce high-purity PsaA-PspA fusion protein with biological activity and chemical integrity, which can be widely applied to the purification of other PspA subclass proteins.
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Affiliation(s)
- Xiaonan Guo
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, China
| | - Qing Sun
- CSPC Biotechnology Company, Shijiazhuang, China
| | - Hualong Xi
- BCHT Biotechnology Company, Changchun, China
| | - Yue Zhang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, China
| | - Mengze Guo
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, China
| | - Chenxing Zhang
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, China
| | - Shidong Zhu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, China
| | - Tiejun Gu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, China
| | - Wei Kong
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, China
| | - Yongge Wu
- National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, China.
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13
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Chaguza C, Yang M, Cornick JE, du Plessis M, Gladstone RA, Kwambana-Adams BA, Lo SW, Ebruke C, Tonkin-Hill G, Peno C, Senghore M, Obaro SK, Ousmane S, Pluschke G, Collard JM, Sigaùque B, French N, Klugman KP, Heyderman RS, McGee L, Antonio M, Breiman RF, von Gottberg A, Everett DB, Kadioglu A, Bentley SD. Bacterial genome-wide association study of hyper-virulent pneumococcal serotype 1 identifies genetic variation associated with neurotropism. Commun Biol 2020; 3:559. [PMID: 33033372 PMCID: PMC7545184 DOI: 10.1038/s42003-020-01290-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 09/11/2020] [Indexed: 12/19/2022] Open
Abstract
Hyper-virulent Streptococcus pneumoniae serotype 1 strains are endemic in Sub-Saharan Africa and frequently cause lethal meningitis outbreaks. It remains unknown whether genetic variation in serotype 1 strains modulates tropism into cerebrospinal fluid to cause central nervous system (CNS) infections, particularly meningitis. Here, we address this question through a large-scale linear mixed model genome-wide association study of 909 African pneumococcal serotype 1 isolates collected from CNS and non-CNS human samples. By controlling for host age, geography, and strain population structure, we identify genome-wide statistically significant genotype-phenotype associations in surface-exposed choline-binding (P = 5.00 × 10-08) and helicase proteins (P = 1.32 × 10-06) important for invasion, immune evasion and pneumococcal tropism to CNS. The small effect sizes and negligible heritability indicated that causation of CNS infection requires multiple genetic and other factors reflecting a complex and polygenic aetiology. Our findings suggest that certain pathogen genetic variation modulate pneumococcal survival and tropism to CNS tissue, and therefore, virulence for meningitis.
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Affiliation(s)
- Chrispin Chaguza
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, UK.
- Darwin College, University of Cambridge, Silver Street, Cambridge, UK.
| | - Marie Yang
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Jennifer E Cornick
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Mignon du Plessis
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, Johannesburg, South Africa
- School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Rebecca A Gladstone
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, UK
| | - Brenda A Kwambana-Adams
- NIHR Global Health Research Unit on Mucosal Pathogens, Division of Infection and Immunity, University College London, London, UK
- Medical Research Council (MRC) Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Stephanie W Lo
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, UK
| | - Chinelo Ebruke
- Medical Research Council (MRC) Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
| | - Gerry Tonkin-Hill
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, UK
| | - Chikondi Peno
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- MRC Centre for Inflammation Research, Queens Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Madikay Senghore
- Medical Research Council (MRC) Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard TH Chan School of Public Health, Boston, MA, USA
| | - Stephen K Obaro
- Division of Pediatric Infectious Disease, University of Nebraska Medical Center Omaha, Omaha, NE, USA
- International Foundation against Infectious Diseases in Nigeria, Abuja, Nigeria
| | - Sani Ousmane
- Centre de Recherche Médicale et Sanitaire, Niamey, Niger
| | - Gerd Pluschke
- Swiss Tropical and Public Health Institute, Basel, Switzerland
| | | | - Betuel Sigaùque
- Centro de Investigação em Saúde da Manhiça, Maputo, Mozambique
| | - Neil French
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Keith P Klugman
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Robert S Heyderman
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- NIHR Global Health Research Unit on Mucosal Pathogens, Division of Infection and Immunity, University College London, London, UK
| | - Lesley McGee
- Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Martin Antonio
- Medical Research Council (MRC) Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
- Warwick Medical School, University of Warwick, Coventry, UK
| | - Robert F Breiman
- Emory Global Health Institute, Emory University, Atlanta, GA, USA
| | - Anne von Gottberg
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, Johannesburg, South Africa
- School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Dean B Everett
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- MRC Centre for Inflammation Research, Queens Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Aras Kadioglu
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Stephen D Bentley
- Parasites and Microbes Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, UK.
- Department of Pathology, University of Cambridge, Cambridge, UK.
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14
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Prevalence of PspA families and pilus islets among Streptococcus pneumoniae colonizing children before and after universal use of pneumococcal conjugate vaccines in Brazil. Braz J Microbiol 2020. [PMID: 31802411 DOI: 10.1007/s42770-019-00179-y10.1007/s42770-019-00179-y/published] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
In 2010, the 10-valent (PCV10) and 13-valent (PCV13) pneumococcal conjugate vaccines were introduced in Brazil to immunize children, resulting in serotype replacement. We analyzed 253 carriage isolates recovered from children aged <6 years in Brazil, including 124 and 129 isolates from the pre-PCV10/13 (December 2009-July 2010) and post-PCV10/13 (September-December 2014) periods, respectively, to investigate the prevalence of PspA families and pilus islets, potential vaccine candidates. Serotypes and resistance profiles were previously characterized. We used PCR to type PspA families (Fam1-3) and pilus islets (PI-1 and PI-2). We identified the PspA family of 130 (51.4%) isolates. PspA families 1, 2, and 3 were identified in 12.2%, 38.7%, and 0.4% of the isolates, respectively. Eighteen (58.1%) Fam1 isolates were serogroup 6. Nine (81.8%) of 11 serotype 14 isolates were Fam2. Fam1 isolates resistant to penicillin (50%), erythromycin (43.7%), clindamycin (31.2%), and chloramphenicol (6.2%) were only found after PCV10/13 introduction. Resistance among Fam2 isolates was higher in the post-PCV10/13 period to erythromycin (1.8% vs. 18.6%), clindamycin (0 vs. 13.9%), and tetracycline (10.9% vs. 16.3%). PI-I was detected in 42 (16.6%) isolates. Fourteen (56%) of 25 serotype 15B/C and nine (81.8%) of 11 serotype 14 isolates had PI-1 (p < 0.01). Eight (3.2%) isolates had PI-2, and six (75%) were serogroup 19. Five (2%) serogroup 19 isolates had both PI-1 and PI-2. We found associations between serogroups/serotypes, PspA families, and pilus islets, but distribution of PspA families and pilus islets was similar in both periods. After universal vaccination, we observed higher antimicrobial resistance frequencies, regardless PspA or pilus types.
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15
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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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16
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Development of Next Generation Streptococcus pneumoniae Vaccines Conferring Broad Protection. Vaccines (Basel) 2020; 8:vaccines8010132. [PMID: 32192117 PMCID: PMC7157650 DOI: 10.3390/vaccines8010132] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/22/2020] [Accepted: 02/29/2020] [Indexed: 02/06/2023] Open
Abstract
Streptococcus pneumoniae is a major pathogen causing pneumonia with over 2 million deaths annually, especially in young children and the elderly. To date, at least 98 different pneumococcal capsular serotypes have been identified. Currently, the vaccines for prevention of S. pneumoniae infections are the 23-valent pneumococcal polysaccharide-based vaccine (PPV23) and the pneumococcal conjugate vaccines (PCV10 and PCV13). These vaccines only cover some pneumococcal serotypes and are unable to protect against non-vaccine serotypes and unencapsulated S. pneumoniae. This has led to a rapid increase in antibiotic-resistant non-vaccine serotypes. Hence, there is an urgent need to develop new, effective, and affordable pneumococcal vaccines, which could cover a wide range of serotypes. This review discusses the new approaches to develop effective vaccines with broad serotype coverage as well as recent development of promising pneumococcal vaccines in clinical trials. New vaccine candidates are the inactivated whole-cell vaccine strain (Δpep27ΔcomD mutant) constructed by mutations of specific genes and several protein-based S. pneumoniae vaccines using conserved pneumococcal antigens, such as lipoprotein and surface-exposed protein (PspA). Among the vaccines in Phase 3 clinical trials are the pneumococcal conjugate vaccines, PCV-15 (V114) and 20vPnC. The inactivated whole-cell and several protein-based vaccines are either in Phase 1 or 2 trials. Furthermore, the recent progress of nanoparticles that play important roles as delivery systems and adjuvants to improve the performance, as well as the immunogenicity of the nanovaccines, are reviewed.
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17
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The Modified Surface Killing Assay Distinguishes between Protective and Nonprotective Antibodies to PspA. mSphere 2019; 4:4/6/e00589-19. [PMID: 31826968 PMCID: PMC6908419 DOI: 10.1128/msphere.00589-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The most important finding of this study is that the MSKA can be used as an in vitro functional assay. Such an assay will be critical for the development of PspA-containing vaccines. The other important findings relate to the locations and nature of the protection-eliciting epitopes of PspA. There are limited prior data on the locations of protection-eliciting PspA epitopes, but those data along with the data presented here make it clear that there is not a single epitope or domain of PspA that can elicit protective antibody and there exists at least one region of the αHD which seldom elicits protective antibody. Moreover, these data, in concert with prior data, strongly make the case that protective epitopes in the αHD are highly conformational (≥100-amino-acid fragments of the αHD are required), whereas at least some protection-eliciting epitopes in the proline-rich domain are encoded by ≤15-amino-acid sequences. Pneumococcal surface protein A (PspA) elicits antibody protective against lethal challenge by Streptococcus pneumoniae and is a candidate noncapsular antigen for inclusion in vaccines. Evaluation of immunity to PspA in human trials would be greatly facilitated by an in vitro functional assay able to distinguish protective from nonprotective antibodies to PspA. Mouse monoclonal antibodies (MAbs) to PspA can mediate killing by human granulocytes in the modified surface killing assay (MSKA). To determine if the MSKA can distinguish between protective and nonprotective MAbs, we examined seven MAbs to PspA. All bound recombinant PspA, as detected by enzyme-linked immunosorbent assay and Western blotting; four gave strong passive protection against fatal challenge, two were nonprotective, and the seventh one only delayed death. The four that were able to provide strong passive protection were also most able to enhance killing in the MSKA, the two that were not protective in mice were not effective in the MSKA, and the MAb that was only weakly protective in mice was weakly effective in the MSKA (P < 0.001). One of the four most protective MAbs tested reacted to the proline-rich domain of PspA. Two of the other most protective MAbs and the weakly protective MAb reacted with a fragment from PspA’s α-helical domain (αHD), containing amino acids (aa) 148 to 247 from the N terminus of PspA. The fourth highly protective MAb recognized none of the overlapping 81- or 100-aa fragments of PspA. The two nonprotective MAbs recognized a more N-terminal αHD fragment (aa 48 to 147). IMPORTANCE The most important finding of this study is that the MSKA can be used as an in vitro functional assay. Such an assay will be critical for the development of PspA-containing vaccines. The other important findings relate to the locations and nature of the protection-eliciting epitopes of PspA. There are limited prior data on the locations of protection-eliciting PspA epitopes, but those data along with the data presented here make it clear that there is not a single epitope or domain of PspA that can elicit protective antibody and there exists at least one region of the αHD which seldom elicits protective antibody. Moreover, these data, in concert with prior data, strongly make the case that protective epitopes in the αHD are highly conformational (≥100-amino-acid fragments of the αHD are required), whereas at least some protection-eliciting epitopes in the proline-rich domain are encoded by ≤15-amino-acid sequences.
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18
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Prevalence of PspA families and pilus islets among Streptococcus pneumoniae colonizing children before and after universal use of pneumococcal conjugate vaccines in Brazil. Braz J Microbiol 2019; 51:419-425. [PMID: 31802411 DOI: 10.1007/s42770-019-00179-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 10/15/2019] [Indexed: 12/17/2022] Open
Abstract
In 2010, the 10-valent (PCV10) and 13-valent (PCV13) pneumococcal conjugate vaccines were introduced in Brazil to immunize children, resulting in serotype replacement. We analyzed 253 carriage isolates recovered from children aged <6 years in Brazil, including 124 and 129 isolates from the pre-PCV10/13 (December 2009-July 2010) and post-PCV10/13 (September-December 2014) periods, respectively, to investigate the prevalence of PspA families and pilus islets, potential vaccine candidates. Serotypes and resistance profiles were previously characterized. We used PCR to type PspA families (Fam1-3) and pilus islets (PI-1 and PI-2). We identified the PspA family of 130 (51.4%) isolates. PspA families 1, 2, and 3 were identified in 12.2%, 38.7%, and 0.4% of the isolates, respectively. Eighteen (58.1%) Fam1 isolates were serogroup 6. Nine (81.8%) of 11 serotype 14 isolates were Fam2. Fam1 isolates resistant to penicillin (50%), erythromycin (43.7%), clindamycin (31.2%), and chloramphenicol (6.2%) were only found after PCV10/13 introduction. Resistance among Fam2 isolates was higher in the post-PCV10/13 period to erythromycin (1.8% vs. 18.6%), clindamycin (0 vs. 13.9%), and tetracycline (10.9% vs. 16.3%). PI-I was detected in 42 (16.6%) isolates. Fourteen (56%) of 25 serotype 15B/C and nine (81.8%) of 11 serotype 14 isolates had PI-1 (p < 0.01). Eight (3.2%) isolates had PI-2, and six (75%) were serogroup 19. Five (2%) serogroup 19 isolates had both PI-1 and PI-2. We found associations between serogroups/serotypes, PspA families, and pilus islets, but distribution of PspA families and pilus islets was similar in both periods. After universal vaccination, we observed higher antimicrobial resistance frequencies, regardless PspA or pilus types.
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19
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Combined prime-boost immunization with systemic and mucosal pneumococcal vaccines based on Pneumococcal surface protein A to enhance protection against lethal pneumococcal infections. Immunol Res 2019; 67:398-407. [PMID: 31773490 DOI: 10.1007/s12026-019-09107-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Limited protective effects of commercially available vaccines necessitate the development of novel pneumococcal vaccines. We recently reported a pneumococcal systemic vaccine containing two proteins, Pneumococcal surface protein A (PspA of family 1 and 2) and a bacterium-like particle-based pneumococcal mucosal vaccine containing PspA2 and PspA4 fragments, both eliciting broad protective immune responses. We had previously reported that subcutaneous (s.c.+s.c.+s.c.) immunization with the systemic vaccine induced more pronounced humoral serum IgG responses, while intranasal (i.n.+i.n.+i.n.) immunization with the mucosal vaccine elicited a more pronounced mucosal secretory IgA (sIgA) response. We hypothesized that a combinatorial administration of the two vaccines might elicit more pronounced and broader protective immune responses. Therefore, this study aimed to determine the efficacy of combinatorial prime-boost immunization using both systemic and mucosal vaccines for a pneumococcal infection. Combinatorial prime-boost immunization (s.c.+i.n. and i.n.+s.c.) induced not only IgG, but also mucosal sIgA production at high levels. Systemic priming and mucosal boosting immunization (s.c.+i.n.) provided markedly better protection than homologous prime-boost immunization (s.c.+s.c.+s.c. and i.n.+i.n.+i.n.). Moreover, it induced more robust Th1 and Th17 cell-mediated immune responses than mucosal priming and systemic boosting immunization (i.n.+s.c.). These results indicate that combinatorial prime-boost immunization potentially induces a robust systemic and mucosal immune response, making it an optimal alternative for maximum protection against lethal pneumococcal infections.
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20
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Briles DE, Paton JC, Mukerji R, Swiatlo E, Crain MJ. Pneumococcal Vaccines. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0028-2018. [PMID: 31858954 PMCID: PMC10921951 DOI: 10.1128/microbiolspec.gpp3-0028-2018] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Indexed: 01/14/2023] Open
Abstract
Streptococcus pneumoniae is a Gram-Positive pathogen that is a major causative agent of pneumonia, otitis media, sepsis and meningitis across the world. The World Health Organization estimates that globally over 500,000 children are killed each year by this pathogen. Vaccines offer the best protection against S. pneumoniae infections. The current polysaccharide conjugate vaccines have been very effective in reducing rates of invasive pneumococcal disease caused by vaccine type strains. However, the effectiveness of these vaccines have been somewhat diminished by the increasing numbers of cases of invasive disease caused by non-vaccine type strains, a phenomenon known as serotype replacement. Since, there are currently at least 98 known serotypes of S. pneumoniae, it may become cumbersome and expensive to add many additional serotypes to the current 13-valent vaccine, to circumvent the effect of serotype replacement. Hence, alternative serotype independent strategies, such as vaccination with highly cross-reactive pneumococcal protein antigens, should continue to be investigated to address this problem. This chapter provides a comprehensive discussion of pneumococcal vaccines past and present, protein antigens that are currently under investigation as vaccine candidates, and other alternatives, such as the pneumococcal whole cell vaccine, that may be successful in reducing current rates of disease caused by S. pneumoniae.
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Affiliation(s)
- D E Briles
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - J C Paton
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, 5005, Australia
| | - R Mukerji
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - E Swiatlo
- Section of Infectious Diseases, Southeast Louisiana Veterans Health Care System, New Orleans, LA
| | - M J Crain
- Department of Pediatrics and Microbiology, University of Alabama at Birmingham
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21
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PspA facilitates evasion of pneumococci from bactericidal activity of neutrophil extracellular traps (NETs). Microb Pathog 2019; 136:103653. [PMID: 31398527 DOI: 10.1016/j.micpath.2019.103653] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 07/09/2019] [Accepted: 08/05/2019] [Indexed: 02/02/2023]
Abstract
Pneumococcal strains are variably resistant to killing by neutrophil extracellular traps (NETs). We hypothesize that this variability in resistance is due to heterogeneity in pneumococcal surface protein A (PspA), a structurally diverse virulence factor of Streptococcus pneumoniae. Pneumococcal strains showed variability in induction of NETs and in susceptibility to killing by NETs. The variability in susceptibility to NETs-mediated killing of pneumococcal strains is attributed to PspA, as strains lacking the surface expression of PspA were significantly more sensitive to NETs-mediated killing compared to the wild-type strains. Using pspA switch mutants we were further able to demonstrate that NETs induction and killing by NETs is a function of PspA as mutants with switch PspA demonstrated donor phenotype. Antibody to PspA alone showed an increase in induction of NETs, and NETs thus generated were able to trap and kill pneumococci. Pneumococci opsonized with antibody to PspA showed increase adherence to NETs but a decrease susceptibility to killing by NETs. In conclusion we demonstrate a novel role for pneumococcal PspA in resisting NETs mediated killing and allowing the bacteria to escape containment by blocking binding of pneumococci to NETs.
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22
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Akbari E, Negahdari B, Faraji F, Behdani M, Kazemi-Lomedasht F, Habibi-Anbouhi M. Protective responses of an engineered PspA recombinant antigen against Streptococcus pneumoniae. ACTA ACUST UNITED AC 2019; 24:e00385. [PMID: 31763198 PMCID: PMC6864353 DOI: 10.1016/j.btre.2019.e00385] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 09/20/2019] [Accepted: 10/08/2019] [Indexed: 11/24/2022]
Abstract
In this study, two immunogenic antigens based on recombinant PspA proteins were immunized mice. The protective effects of developed anti-PspA antibodies in mice in intranasal and intraperitoneal challenges were proved. Based on the obtained results, immunization with the B-regions of PspA antigens are crucial in protection of challenged mice with S. pneumoniae strains.
Streptococcus pneumoniae is a major pathogen in human respiratory tract which causes significant morbidity and mortality across from the world. Currently available vaccines are not completely effective and cannot cover all pathogenic strains so there is an important need to develop an alternative cost-effective vaccine, based on conserved protein antigens. Pneumococcal surface protein A (PspA) is one of interesting candidates for development of a serotype-independent vaccine against pneumococcal infections. PspA is grouped into two major families with five clades, and broad-reacting PspA-based vaccines should contain at least one functional fragment from each of the two families. In this study, we developed two immunogenic antigens based on recombinant PspA proteins that including the different antigenic regions of PspA from both two families. The cross-reactivity of antibodies elicited against two PspA proteins PspAB1-5 and PspA4ABC and their role in complement deposition with three strains of pneumococci were tested. The protective effects of developed anti-PspA antibodies in mice in intranasal and intraperitoneal challenges were evaluated using a strain from clade 2. Sera from immunized mice with PspAB1-5 in comparison with PspA4ABC was able to deposit more C3 complement component on surface of pneumococci bearing diverse PspA from both families 1 and 2, and immunized mice with the PspAB1-5 showed a higher protection than PspA4ABC in pneumococcal challenges. The obtained results from this study indicate that a PspA-based antigen composed of B region from all clades in addition to conserved domains, can provide a significant protection against multiple strains of S. pneumoniae and may overcome the limitation of polysaccharide vaccines.
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Affiliation(s)
- Elaheh Akbari
- National Cell Bank of Iran, Pasteur Institute of Iran, Tehran, Iran.,Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Babak Negahdari
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Faraji
- National Cell Bank of Iran, Pasteur Institute of Iran, Tehran, Iran
| | - Mahdi Behdani
- Biotechnology Research Center, Pasteur Institute of Iran, Tehran, Iran
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23
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Immunization with proline rich region of pneumococcal surface protein A has no role in protection against Streptococcus pneumoniae serotype 19F. Microb Pathog 2019; 138:103761. [PMID: 31560974 DOI: 10.1016/j.micpath.2019.103761] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 09/21/2019] [Accepted: 09/24/2019] [Indexed: 11/20/2022]
Abstract
Pneumococcal surface protein A (PspA) is one of the major virulence factors expressed by almost all pneumococcal serotypes and was suggested to be a promising universal vaccine candidate for all pneumococcal sero-groups. Here, we expressed and purified the proline-rich region (PR) of PspA and tested it as a recombinant vaccine against infection caused by a clinical isolate (SP19) of Streptococcus pneumoniae serotype 19F. Our results showed that BALB/c mice immunized with recombinant proline-rich (rPR) region showed a significant higher antibody titre against rPR region compared to control non-immunized group. However, immunized mice or mice recived polyclonal antibodies against rPR region challenged via the intra-peritoneal route with a lethal dose of SP19 isolate showed no significant difference in survival compared to control non-immunized group. These results suggested that, immunization of BALB/c mice with rPR region of PspA is not protective against infection caused by serotype 19F in a mouse model.
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24
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David SC, Laan Z, Minhas V, Chen AY, Davies J, Hirst TR, McColl SR, Alsharifi M, Paton JC. Enhanced safety and immunogenicity of a pneumococcal surface antigen A mutant whole-cell inactivated pneumococcal vaccine. Immunol Cell Biol 2019; 97:726-739. [PMID: 31050022 DOI: 10.1111/imcb.12257] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 03/21/2019] [Accepted: 04/29/2019] [Indexed: 01/14/2023]
Abstract
Existing capsular polysaccharide-based vaccines against pneumococcal disease are highly effective against vaccine-included serotypes, but they are unable to combat serotype replacement. We have developed a novel pneumococcal vaccine that confers serotype-independent protection, and could therefore constitute a "universal" vaccine formulation. This preparation is comprised of whole un-encapsulated pneumococci inactivated with gamma irradiation (γ-PN), and we have previously reported induction of cross-reactive immunity after nonadjuvanted intranasal vaccination. To further enhance vaccine immunogenicity and safety, we modified the pneumococcal vaccine strain to induce a stressed state during growth. Specifically, the substrate binding component of the psaBCA operon for manganese import was mutated to create a pneumococcal surface antigen A (psaA) defective vaccine strain. psaA mutation severely attenuated the growth of the vaccine strain in vitro without negatively affecting pneumococcal morphology, thereby enhancing vaccine safety. In addition, antibodies raised against vaccine preparations based on the modified strain [γ-PN(ΔPsaA)] showed more diversified reactivity to wild-type pneumococcal challenge strains compared to those induced by the original formulation. The modified vaccine also induced comparable protective TH 17 responses in the lung, and conferred greater protection against lethal heterologous pneumococcal challenge. Overall, the current study demonstrates successful refinement of a serotype-independent pneumococcal vaccine candidate to enhance safety and immunogenicity.
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Affiliation(s)
- Shannon C David
- Research Centre for Infectious Diseases, and Department of Molecular and Biomedical Science, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Zoe Laan
- Research Centre for Infectious Diseases, and Department of Molecular and Biomedical Science, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Vikrant Minhas
- Research Centre for Infectious Diseases, and Department of Molecular and Biomedical Science, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Austen Y Chen
- Research Centre for Infectious Diseases, and Department of Molecular and Biomedical Science, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Justin Davies
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, Australia
| | - Timothy R Hirst
- Research Centre for Infectious Diseases, and Department of Molecular and Biomedical Science, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia.,GPN Vaccines Pty Ltd, Yarralumla, ACT, Australia.,Gamma Vaccines Pty Ltd, Yarralumla, ACT, Australia
| | - Shaun R McColl
- Research Centre for Infectious Diseases, and Department of Molecular and Biomedical Science, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Mohammed Alsharifi
- Research Centre for Infectious Diseases, and Department of Molecular and Biomedical Science, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia.,GPN Vaccines Pty Ltd, Yarralumla, ACT, Australia.,Gamma Vaccines Pty Ltd, Yarralumla, ACT, Australia
| | - James C Paton
- Research Centre for Infectious Diseases, and Department of Molecular and Biomedical Science, School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia.,GPN Vaccines Pty Ltd, Yarralumla, ACT, Australia
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25
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Kye YC, Park SM, Shim BS, Firdous J, Kim G, Kim HW, Ju YJ, Kim CG, Cho CS, Kim DW, Cho JH, Song MK, Han SH, Yun CH. Intranasal immunization with pneumococcal surface protein A in the presence of nanoparticle forming polysorbitol transporter adjuvant induces protective immunity against the Streptococcus pneumoniae infection. Acta Biomater 2019; 90:362-372. [PMID: 30922953 DOI: 10.1016/j.actbio.2019.03.049] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 03/06/2019] [Accepted: 03/24/2019] [Indexed: 02/03/2023]
Abstract
Developing effective mucosal subunit vaccine for the Streptococcus pneumoniae has been unsuccessful mainly because of their poor immunogenicity with insufficient memory T and B cell responses. We thus address whether such limitation can be overcome by introducing effective adjuvants that can enhance immunity and show here that polysorbitol transporter (PST) serves as a mucosal adjuvant for a subunit vaccine against the Streptococcus pneumoniae. Pneumococcal surface protein A (PspA) with PST adjuvant induced protective immunity against S. pneumoniae challenge, especially long-term T and B cell immune responses. Moreover, we found that the PST preferentially induced T helper (Th) responses toward Th2 or T follicular helper (Tfh) cells and, importantly, that the responses were mediated through antigen-presenting cells via activating a peroxisome proliferator-activated receptor gamma (PPAR-γ) pathway. Thus, these data indicate that PST can be used as an effective and safe mucosal vaccine adjuvant against S. pneumoniae infection. STATE OF SIGNIFICANCE: In this study, we suggested the nanoparticle forming adjuvant, PST works as an effective adjuvant for the pneumococcal vaccine, PspA. The PspA subunit vaccine together with PST adjuvant efficiently induced protective immunity, even in the long-term memory responses, against Streptococcus pneumoniae lethal challenge. We found that PspA with PST adjuvant induced dendritic cell activation followed by follicular helper T cell responses through PPAR-γ pathway resulting long-term memory antibody-producing cells. Consequently, in this paper, we suggest the mechanism for safe nanoparticle forming subunit vaccine adjuvant against pneumococcal infection.
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26
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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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27
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Shah HB, Smith K, Wren JD, Webb CF, Ballard JD, Bourn RL, James JA, Lang ML. Insights From Analysis of Human Antigen-Specific Memory B Cell Repertoires. Front Immunol 2019; 9:3064. [PMID: 30697210 PMCID: PMC6340933 DOI: 10.3389/fimmu.2018.03064] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 12/11/2018] [Indexed: 12/17/2022] Open
Abstract
Memory B cells that are generated during an infection or following vaccination act as sentinels to guard against future infections. Upon repeat antigen exposure memory B cells differentiate into new antibody-secreting plasma cells to provide rapid and sustained protection. Some pathogens evade or suppress the humoral immune system, or induce memory B cells with a diminished ability to differentiate into new plasma cells. This leaves the host vulnerable to chronic or recurrent infections. Single cell approaches coupled with next generation antibody gene sequencing facilitate a detailed analysis of the pathogen-specific memory B cell repertoire. Monoclonal antibodies that are generated from antibody gene sequences allow a functional analysis of the repertoire. This review discusses what has been learned thus far from analysis of diverse pathogen-specific memory B cell compartments and describes major differences in their repertoires. Such information may illuminate ways to advance the goal of improving vaccine and therapeutic antibody design.
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Affiliation(s)
- Hemangi B Shah
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Kenneth Smith
- Arthritis and Clinical Immunology, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States
| | - Jonathan D Wren
- Arthritis and Clinical Immunology, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States.,Department of Biochemistry and Molecular Biology and Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Carol F Webb
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States.,Division of Rheumatology, Immunology and Allergy, Department of Cell Biology and Internal Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Jimmy D Ballard
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Rebecka L Bourn
- Arthritis and Clinical Immunology, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States
| | - Judith A James
- Arthritis and Clinical Immunology, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States.,Department of Medicine and Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Mark L Lang
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
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28
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Nagai K, Domon H, Maekawa T, Hiyoshi T, Tamura H, Yonezawa D, Habuka R, Saitoh A, Terao Y. Immunization with pneumococcal elongation factor Tu enhances serotype-independent protection against Streptococcus pneumoniae infection. Vaccine 2018; 37:160-168. [PMID: 30442480 DOI: 10.1016/j.vaccine.2018.11.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 11/01/2018] [Accepted: 11/07/2018] [Indexed: 11/25/2022]
Abstract
Vaccination is an effective strategy to prevent pneumococcal diseases. Currently, licensed vaccines include the pneumococcal polysaccharide vaccine (PPSV) and the pneumococcal conjugate vaccine (PCV), which target some of the most common of the 94 serotypes of S. pneumoniae based on their capsular composition. However, it has been reported that PPSV is not effective in children aged less than 2 years old and PCV induces serotype replacement, which means that the pneumococcal population has changed following widespread introduction of these vaccines, and the non-vaccine serotypes have increased in being the cause of invasive pneumococcal disease. Therefore, it is important that there is development of novel pneumococcal vaccines to either replace or complement current polysaccharide-based vaccines. Our previous study suggested that S. pneumoniae releases elongation factor Tu (EF-Tu) through autolysis followed by the induction of proinflammatory cytokines in macrophages via toll-like receptor 4, that may contribute to the development of pneumococcal diseases. In this study, we investigated the expression of EF-Tu in various S. pneumoniae strains and whether EF-Tu could be an antigen candidate for serotype-independent vaccine against pneumococcal infection. Western blotting and flow cytometry analysis revealed that EF-Tu is a common factor expressed on the surface of all pneumococcal strains tested, as well as intracellularly. In addition, we demonstrate that immunization with recombinant (r) EF-Tu induced the production of inflammatory cytokines and the IgG1 and IgG2a antibodies in mice, and increased the CD4+ T-cells proportion in splenocytes. We also reveal that anti-EF-Tu serum increased the phagocytic activity of mouse peritoneal macrophages against S. pneumoniae infection, independent of their serotypes. Finally, our results indicate that mice immunized with rEF-Tu were significantly and non-specifically protected against lethal challenges with S. pneumoniae serotypes (2 and 15A). Therefore, pneumococcal EF-Tu could be an antigen candidate for the serotype-independent vaccine against pneumococcal infection.
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Affiliation(s)
- Kosuke Nagai
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Hisanori Domon
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; Research Centre for Advanced Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Tomoki Maekawa
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; Research Centre for Advanced Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; Division of Periodontology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Takumi Hiyoshi
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; Division of Periodontology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Hikaru Tamura
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; Research Centre for Advanced Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; Division of Periodontology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Daisuke Yonezawa
- Research Centre for Advanced Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; Division of Oral Science for Health Promotion, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Rie Habuka
- Department of Pediatrics, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Akihiko Saitoh
- Department of Pediatrics, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Yutaka Terao
- Division of Microbiology and Infectious Diseases, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; Research Centre for Advanced Oral Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
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29
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Mukerji R, Hendrickson C, Genschmer KR, Park SS, Bouchet V, Goldstein R, Lefkowitz EJ, Briles DE. The diversity of the proline-rich domain of pneumococcal surface protein A (PspA): Potential relevance to a broad-spectrum vaccine. Vaccine 2018; 36:6834-6843. [PMID: 30293761 DOI: 10.1016/j.vaccine.2018.08.045] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 07/18/2018] [Accepted: 08/19/2018] [Indexed: 01/28/2023]
Abstract
Pneumococcal surface protein A (PspA) is a surface exposed, highly immunogenic protein of Streptococcus pneumoniae. Its N-terminal α-helical domain (αHD) elicits protective antibody in humans and animals that can protect mice from fatal infections with pneumococci and can be detected in vitro with opsonophagocytosis assays. The proline-rich domain (PRD) in the center of the PspA sequence can also elicit protection. This study revealed that although the sequence of PRD was diverse, PRD from different pneumococcal isolates contained many shared elements. The inferred amino acid sequences of 123 such PRDs, which were analyzed by assembly and alignment-free (AAF) approaches, formed three PRD groups. Of these sequences, 45 were classified as Group 1, 19 were classified as Group 2, and 59 were classified as Group 3. All Group 3 sequences contained a highly conserved 22-amino acid non-proline block (NPB). A significant polymorphism was observed, however, at a single amino acid position within NPB. Each of the three PRD groups had characteristic patterns of short amino acid repeats, with most of the repeats being found in more than one PRD group. One of these repeats, PKPEQP as well as the NPB were previously shown to elicit protective antibodies in mice. In this study, we found that sera from 12 healthy human adult volunteers contained antibodies to all three PRD groups. This suggested that a PspA-containing vaccine containing carefully selected PRDs and αHDs could redundantly cover the known diversity of PspA. Such an approach might reduce the chances of PspA variants escaping a PspA vaccine's immunity.
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Affiliation(s)
- Reshmi Mukerji
- Department of Microbiology, University of Alabama at Birmingham, United States
| | - Curtis Hendrickson
- Center for Clinical and Translational Sciences, University of Alabama at Birmingham, United States
| | - Kristopher R Genschmer
- Department of Microbiology, University of Alabama at Birmingham, United States; Department of Medicine, Division of Pulmonary, Allergy and Critical Care, United States
| | - Sang-Sang Park
- Department of Microbiology, University of Alabama at Birmingham, United States
| | - Valérie Bouchet
- Section of Molecular Genetics, Maxwell Finland Laboratory for Infectious Diseases, Division of Pediatric Infectious Diseases, Boston University Medical Center, Boston, MA 02118, United States
| | - Richard Goldstein
- Section of Molecular Genetics, Maxwell Finland Laboratory for Infectious Diseases, Division of Pediatric Infectious Diseases, Boston University Medical Center, Boston, MA 02118, United States
| | - Elliot J Lefkowitz
- Department of Microbiology, University of Alabama at Birmingham, United States; Center for Clinical and Translational Sciences, University of Alabama at Birmingham, United States
| | - David E Briles
- Department of Microbiology, University of Alabama at Birmingham, United States.
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30
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Wagner-Muñiz DA, Haughney SL, Kelly SM, Wannemuehler MJ, Narasimhan B. Room Temperature Stable PspA-Based Nanovaccine Induces Protective Immunity. Front Immunol 2018; 9:325. [PMID: 29599766 PMCID: PMC5863507 DOI: 10.3389/fimmu.2018.00325] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 02/06/2018] [Indexed: 01/05/2023] Open
Abstract
Streptococcus pneumoniae is a major causative agent of pneumonia, a debilitating disease particularly in young and elderly populations, and is the leading worldwide cause of death in children under the age of five. While there are existing vaccines against S. pneumoniae, none are protective across all serotypes. Pneumococcal surface protein A (PspA), a key virulence factor of S. pneumoniae, is an antigen that may be incorporated into future vaccines to address the immunological challenges presented by the diversity of capsular antigens. PspA has been shown to be immunogenic and capable of initiating a humoral immune response that is reactive across approximately 94% of pneumococcal strains. Biodegradable polyanhydrides have been studied as a nanoparticle-based vaccine (i.e., nanovaccine) platform to stabilize labile proteins, to provide adjuvanticity, and enhance patient compliance by providing protective immunity in a single dose. In this study, we designed a room temperature stable PspA-based polyanhydride nanovaccine that eliminated the need for a free protein component (i.e., 100% encapsulated within the nanoparticles). Mice were immunized once with the lead nanovaccine and upon challenge, presented significantly higher survival rates than animals immunized with soluble protein alone, even with a 25-fold reduction in protein dose. This lead nanovaccine formulation performed similarly to protein adjuvanted with Alum, however, with much less tissue reactogenicity at the site of immunization. By eliminating the free PspA from the nanovaccine formulation, the lead nanovaccine was efficacious after being stored dry for 60 days at room temperature, breaking the need for maintaining the cold chain. Altogether, this study demonstrated that a single dose PspA-based nanovaccine against S. pneumoniae induced protective immunity and provided thermal stability when stored at room temperature for at least 60 days.
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Affiliation(s)
- Danielle A. Wagner-Muñiz
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, United States
| | - Shannon L. Haughney
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, United States
| | - Sean M. Kelly
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, United States
| | - Michael J. Wannemuehler
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, Ames, IA, United States
- Nanovaccine Institute, Iowa State University, Ames, IA, United States
| | - Balaji Narasimhan
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA, United States
- Nanovaccine Institute, Iowa State University, Ames, IA, United States
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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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A protein chimera including PspA in fusion with PotD is protective against invasive pneumococcal infection and reduces nasopharyngeal colonization in mice. Vaccine 2017; 35:5140-5147. [DOI: 10.1016/j.vaccine.2017.08.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 06/27/2017] [Accepted: 08/04/2017] [Indexed: 11/18/2022]
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Kim GL, Seon SH, Rhee DK. Pneumonia and Streptococcus pneumoniae vaccine. Arch Pharm Res 2017; 40:885-893. [PMID: 28735461 PMCID: PMC7090487 DOI: 10.1007/s12272-017-0933-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 07/17/2017] [Indexed: 12/19/2022]
Abstract
Pneumonia is an inflammatory disease of the lung, responsible for high morbidity and mortality worldwide. It is caused by bacteria, viruses, fungi, or other microorganisms. Streptococcus pneumoniae, a gram-positive bacterium with over 90 serotypes, is the most common causative agent. Moreover, comorbid factors including heart failure, renal disease, and pulmonary disease could increase the risk of pneumococcal pneumonia. Since the advent of the pneumococcal vaccine in the 1980s, the incidence of pneumonia has decreased significantly. However, current vaccines confer only limited protection against serotypes included in the vaccine. Thus, to overcome this limitation, new types of pneumococcal vaccines have been sought and under clinical trials. In this review, we discuss pneumonia and summarize the various types of pneumococcal vaccines in progress.
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Affiliation(s)
- Gyu-Lee Kim
- School of Pharmacy, Sungkyunkwan University, Suwon, 440-746, South Korea
| | - Seung-Han Seon
- School of Pharmacy, Sungkyunkwan University, Suwon, 440-746, South Korea
| | - Dong-Kwon Rhee
- School of Pharmacy, Sungkyunkwan University, Suwon, 440-746, South Korea.
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Khan N, Jan AT. Towards Identifying Protective B-Cell Epitopes: The PspA Story. Front Microbiol 2017; 8:742. [PMID: 28512452 PMCID: PMC5411445 DOI: 10.3389/fmicb.2017.00742] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 04/10/2017] [Indexed: 01/15/2023] Open
Abstract
Pneumococcal surface protein A (PspA) is one of the most abundant cell surface protein of Streptococcus pneumoniae (S. pneumoniae). PspA variants are structurally and serologically diverse and help evade complement-mediated phagocytosis of S. pneumoniae, which is essential for its survival in the host. PspA is currently been screened for employment in the generation of more effective (serotype independent) vaccine to overcome the limitations of polysaccharide based vaccines, providing serotype specific immune responses. The cross-protection eliciting regions of PspA localize to the α-helical and proline rich regions. Recent data indicate significant variation in the ability of antibodies induced against the recombinant PspA variants to recognize distinct S. pneumoniae strains. Hence, screening for the identification of the topographical repertoire of B-cell epitopes that elicit cross-protective immune response seems essential in the engineering of a superior PspA-based vaccine. Herein, we revisit epitope identification in PspA and the utility of hybridoma technology in directing the identification of protective epitope regions of PspA that can be used in vaccine research.
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Affiliation(s)
- Naeem Khan
- Glycobiology Group, Max Planck Institute of Colloids and Interfaces (MPG)Potsdam, Germany
| | - Arif T Jan
- Department of Medical Biotechnology, Yeungnam UniversityGyeongsan, South Korea
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Recombinant BCG expressing a PspA-PdT fusion protein protects mice against pneumococcal lethal challenge in a prime-boost strategy. Vaccine 2017; 35:1683-1691. [PMID: 28242071 DOI: 10.1016/j.vaccine.2017.02.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 01/13/2017] [Accepted: 02/14/2017] [Indexed: 11/24/2022]
Abstract
Pneumococcal proteins have been evaluated as genetically-conserved potential vaccine candidates. We have previously demonstrated that a fragment of PspA in fusion with PdT (rPspA-PdT) induced protective immune responses in mice. However, purified proteins have shown poor immunogenicity and often require the combination with strong adjuvants and booster doses. Here, we investigated the use of a Bacillus Calmette-Guérin (BCG) strain, a well-established prophylactic vaccine for tuberculosis with known adjuvant properties, for delivery of the PspA-PdT fusion protein. Immunization of mice in a prime-boost strategy, using rPspA-PdT as a boost, demonstrated that rBCG PspA-PdT/rPspA-PdT was able to induce an antibody response against both proteins, promoting an IgG1 to IgG2 antibody isotype shift. Sera from rBCG PspA-PdT/rPspA-PdT immunized mice showed antibodies able to bind to the pneumococcal surface and promoted higher complement deposition when compared with WT-BCG/rPspA-PdT or a single dose of rPspA-PdT. In addition, these antisera inhibited the cytolytic activity of Ply. Production of interleukin-6 (IL-6), gamma interferon (IFN-γ), and tumor necrosis factor alpha (TNF-α) was increased in splenocytes culture. Furthermore, a higher expression of CD69 early activation molecule was observed on splenic CD4+ T cells from mice immunized with rBCG PspA-PdT before and after the protein booster dose. Finally, immunization with rBCG PspA-PdT/rPspA-PdT protected mice against pneumococcal lethal challenge. These results support the further investigation of recombinant BCG strains to express pneumococcal proteins, which could be administered in early stages of life and lead to protective pneumococcal immunity in infants and children.
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Cornick JE, Tastan Bishop Ö, Yalcin F, Kiran AM, Kumwenda B, Chaguza C, Govindpershad S, Ousmane S, Senghore M, du Plessis M, Pluschke G, Ebruke C, McGee L, Sigaùque B, Collard JM, Bentley SD, Kadioglu A, Antonio M, von Gottberg A, French N, Klugman KP, Heyderman RS, Alderson M, Everett DB. The global distribution and diversity of protein vaccine candidate antigens in the highly virulent Streptococcus pnuemoniae serotype 1. Vaccine 2017; 35:972-980. [PMID: 28081968 PMCID: PMC5287219 DOI: 10.1016/j.vaccine.2016.12.037] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 11/29/2016] [Accepted: 12/15/2016] [Indexed: 11/28/2022]
Abstract
Serotype 1 is one of the most common causes of pneumococcal disease worldwide. Pneumococcal protein vaccines are currently being developed as an alternate intervention strategy to pneumococcal conjugate vaccines. Pre-requisites for an efficacious pneumococcal protein vaccine are universal presence and minimal variation of the target antigen in the pneumococcal population, and the capability to induce a robust human immune response. We used in silico analysis to assess the prevalence of seven protein vaccine candidates (CbpA, PcpA, PhtD, PspA, SP0148, SP1912, SP2108) among 445 serotype 1 pneumococci from 26 different countries, across four continents. CbpA (76%), PspA (68%), PhtD (28%), PcpA (11%) were not universally encoded in the study population, and would not provide full coverage against serotype 1. PcpA was widely present in the European (82%), but not in the African (2%) population. A multi-valent vaccine incorporating CbpA, PcpA, PhtD and PspA was predicted to provide coverage against 86% of the global population. SP0148, SP1912 and SP2108 were universally encoded and we further assessed their predicted amino acid, antigenic and structural variation. Multiple allelic variants of these proteins were identified, different allelic variants dominated in different continents; the observed variation was predicted to impact the antigenicity and structure of two SP0148 variants, one SP1912 variant and four SP2108 variants, however these variants were each only present in a small fraction of the global population (<2%). The vast majority of the observed variation was predicted to have no impact on the efficaciousness of a protein vaccine incorporating a single variant of SP0148, SP1912 and/or SP2108 from S. pneumoniae TIGR4. Our findings emphasise the importance of taking geographic differences into account when designing global vaccine interventions and support the continued development of SP0148, SP1912 and SP2108 as protein vaccine candidates against this important pneumococcal serotype.
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Affiliation(s)
- Jennifer E Cornick
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Queen Elizabeth Central Hospital, Blantyre, Malawi; Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool L69 7BE, UK.
| | - Özlem Tastan Bishop
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, South Africa
| | - Feyruz Yalcin
- Pathogen Genomics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
| | - Anmol M Kiran
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Queen Elizabeth Central Hospital, Blantyre, Malawi; Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool L69 7BE, UK
| | - Benjamin Kumwenda
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Queen Elizabeth Central Hospital, Blantyre, Malawi
| | - Chrispin Chaguza
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Queen Elizabeth Central Hospital, Blantyre, Malawi; Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool L69 7BE, UK
| | - Shanil Govindpershad
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, A Division of the National Health Laboratory Service, Johannesburg, South Africa; School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Sani Ousmane
- Centre de Recherche Médicale et Sanitaire, Niamey, Niger
| | - Madikay Senghore
- Medical Research Council, Banjul, Gambia; Division of Translational and Systems Medicine, Microbiology and Infection Unit, The University of Warwick, UK
| | - Mignon du Plessis
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, A Division of the National Health Laboratory Service, Johannesburg, South Africa; School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Gerd Pluschke
- Swiss Tropical and Public Health Institute, Basel, Switzerland
| | | | - Lesley McGee
- Centers for Disease Control and Prevention, Atlanta, USA
| | - Beutel Sigaùque
- Centro de Investigação em Saúde da Manhiça, Maputo, Mozambique
| | | | - Stephen D Bentley
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, South Africa
| | - Aras Kadioglu
- Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool L69 7BE, UK
| | - Martin Antonio
- Medical Research Council, Banjul, Gambia; Division of Translational and Systems Medicine, Microbiology and Infection Unit, The University of Warwick, UK; Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Anne von Gottberg
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, A Division of the National Health Laboratory Service, Johannesburg, South Africa; School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Neil French
- Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool L69 7BE, UK
| | - Keith P Klugman
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, USA
| | - Robert S Heyderman
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Queen Elizabeth Central Hospital, Blantyre, Malawi
| | | | - Dean B Everett
- Malawi-Liverpool Wellcome Trust Clinical Research Programme, Queen Elizabeth Central Hospital, Blantyre, Malawi; Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool L69 7BE, UK
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Abstract
INTRODUCTION The success of the vaccines available on the market has significantly increased interest in vaccine development. Areas covered: The main aim of this paper is to discuss the most important vaccines of pediatric interest that are currently being developed. New pneumococcal vaccines and vaccines against group B Streptococcus, Staphylococcus aureus and respiratory syncytial virus are analyzed in detail. Expert commentary: Advances in understanding human immunology, including human monoclonal antibody identification, sequencing technology, and the ability to solve atomic level structures of vaccine targets have provided tools to guide the rational design of future vaccines. It is likely that some of these vaccines will reach the market in the future and will thus partially contribute to the prevention of very severe diseases that significantly affect the morbidity and mortality of children. However, further studies in animals and several clinical trials in children must be performed before new vaccines become licensed.
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Affiliation(s)
- Susanna Esposito
- a Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation , Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico , Milan , Italy
| | - Nicola Principi
- a Pediatric Highly Intensive Care Unit, Department of Pathophysiology and Transplantation , Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico , Milan , Italy
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Free Sialic Acid Acts as a Signal That Promotes Streptococcus pneumoniae Invasion of Nasal Tissue and Nonhematogenous Invasion of the Central Nervous System. Infect Immun 2016; 84:2607-15. [PMID: 27354445 DOI: 10.1128/iai.01514-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 06/18/2016] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pneumoniae (pneumococcus) is a leading cause of bacterial meningitis and neurological sequelae in children worldwide. Acute bacterial meningitis is widely considered to result from bacteremia that leads to blood-brain barrier breakdown and bacterial dissemination throughout the central nervous system (CNS). Previously, we showed that pneumococci can gain access to the CNS through a nonhematogenous route without peripheral blood infection. This access is thought to occur when the pneumococci in the upper sinus follow the olfactory nerves and enter the CNS through the olfactory bulbs. In this study, we determined whether the addition of exogenous sialic acid postcolonization promotes nonhematogenous invasion of the CNS. Previously, others showed that treatment with exogenous sialic acid post-pneumococcal infection increased the numbers of CFU recovered from an intranasal mouse model of infection. Using a pneumococcal colonization model, an in vivo imaging system, and a multiplex assay for cytokine expression, we demonstrated that sialic acid can increase the number of pneumococci recovered from the olfactory bulbs and brains of infected animals. We also show that pneumococci primarily localize to the olfactory bulb, leading to increased expression levels of proinflammatory cytokines and chemokines. These findings provide evidence that sialic acid can enhance the ability of pneumococci to disseminate into the CNS and provide details about the environment needed to establish nonhematogenous pneumococcal meningitis.
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Kristian SA, Ota T, Bubeck SS, Cho R, Groff BC, Kubota T, Destito G, Laudenslager J, Koriazova L, Tahara T, Kanda Y. Generation and Improvement of Effector Function of a Novel Broadly Reactive and Protective Monoclonal Antibody against Pneumococcal Surface Protein A of Streptococcus pneumoniae. PLoS One 2016; 11:e0154616. [PMID: 27171010 PMCID: PMC4865217 DOI: 10.1371/journal.pone.0154616] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 04/17/2016] [Indexed: 01/21/2023] Open
Abstract
A proof-of-concept study evaluating the potential of Streptococcus pneumoniae Pneumococcal Surface Protein A (PspA) as a passive immunization target was conducted. We describe the generation and isolation of several broadly reactive mouse anti-PspA monoclonal antibodies (mAbs). MAb 140H1 displayed (i) 98% strain coverage, (ii) activity in complement deposition and opsonophagocytic killing (OPK) assays, which are thought to predict the in vivo efficacy of anti-pneumococcal mAbs, (iii) efficacy in mouse sepsis models both alone and in combination with standard-of-care antibiotics, and (iv) therapeutic activity in a mouse pneumonia model. Moreover, we demonstrate that antibody engineering can significantly enhance anti-PspA mAb effector function. We believe that PspA has promising potential as a target for the therapy of invasive pneumococcal disease by mAbs, which could be used alone or in conjunction with standard-of-care antibiotics.
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Affiliation(s)
- Sascha A. Kristian
- Kyowa Kirin Pharmaceutical Research, Inc., 9420 Athena Circle, La Jolla, CA 92037, United States of America
| | - Takayuki Ota
- Kyowa Hakko Kirin Co., Ltd., R&D Division, 1-6-1, Ōtemachi, Chiyoda-ku, Tokyo 100–8185, Japan
| | - Sarah S. Bubeck
- Kyowa Kirin Pharmaceutical Research, Inc., 9420 Athena Circle, La Jolla, CA 92037, United States of America
- * E-mail:
| | - Rebecca Cho
- Kyowa Kirin Pharmaceutical Research, Inc., 9420 Athena Circle, La Jolla, CA 92037, United States of America
| | - Brian C. Groff
- Kyowa Kirin Pharmaceutical Research, Inc., 9420 Athena Circle, La Jolla, CA 92037, United States of America
| | - Tsuguo Kubota
- Kyowa Hakko Kirin Co., Ltd., R&D Division, 1-6-1, Ōtemachi, Chiyoda-ku, Tokyo 100–8185, Japan
| | - Giuseppe Destito
- Kyowa Kirin Pharmaceutical Research, Inc., 9420 Athena Circle, La Jolla, CA 92037, United States of America
| | - John Laudenslager
- Kyowa Kirin Pharmaceutical Research, Inc., 9420 Athena Circle, La Jolla, CA 92037, United States of America
| | - Lilia Koriazova
- Kyowa Kirin Pharmaceutical Research, Inc., 9420 Athena Circle, La Jolla, CA 92037, United States of America
| | - Tomoyuki Tahara
- Kyowa Hakko Kirin Co., Ltd., R&D Division, 1-6-1, Ōtemachi, Chiyoda-ku, Tokyo 100–8185, Japan
| | - Yutaka Kanda
- Kyowa Hakko Kirin Co., Ltd., R&D Division, 1-6-1, Ōtemachi, Chiyoda-ku, Tokyo 100–8185, Japan
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Daniels CC, Rogers PD, Shelton CM. A Review of Pneumococcal Vaccines: Current Polysaccharide Vaccine Recommendations and Future Protein Antigens. J Pediatr Pharmacol Ther 2016; 21:27-35. [PMID: 26997927 PMCID: PMC4778694 DOI: 10.5863/1551-6776-21.1.27] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
This review describes development of currently available pneumococcal vaccines, provides summary tables of current pneumococcal vaccine recommendations in children and adults, and describes new potential vaccine antigens in the pipeline. Streptococcus pneumoniae, the bacteria responsible for pneumonia, otitis media, meningitis and bacteremia, remains a cause of morbidity and mortality in both children and adults. Introductions of unconjugated and conjugated pneumococcal polysaccharide vaccines have each reduced the rate of pneumococcal infections caused by the organism S. pneumoniae. The first vaccine developed, the 23-valent pneumococcal polysaccharide vaccine (PPSV23), protected adults and children older than 2 years of age against invasive disease caused by the 23 capsular serotypes contained in the vaccine. Because PPSV23 did not elicit a protective immune response in children younger than 2 years of age, the 7-valent pneumococcal conjugate vaccine (PCV7) containing seven of the most common serotypes from PPSV23 in pediatric invasive disease was developed for use in children younger than 2 years of age. The last vaccine to be developed, the 13-valent pneumococcal conjugate vaccine (PCV13), contains the seven serotypes in PCV7, five additional serotypes from PPSV23, and a new serotype not contained in PPSV23 or PCV7. Serotype replacement with virulent strains that are not contained in the polysaccharide vaccines has been observed after vaccine implementation and stresses the need for continued research into novel vaccine antigens. We describe eight potential protein antigens that are in the pipeline for new pneumococcal vaccines.
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Affiliation(s)
- Calvin C. Daniels
- College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee
| | - P. David Rogers
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee
- Center for Pediatric Pharmacokinetics and Therapeutics, Memphis, Tennessee
| | - Chasity M. Shelton
- Department of Clinical Pharmacy, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee
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Tamborrini M, Geib N, Marrero-Nodarse A, Jud M, Hauser J, Aho C, Lamelas A, Zuniga A, Pluschke G, Ghasparian A, Robinson JA. A Synthetic Virus-Like Particle Streptococcal Vaccine Candidate Using B-Cell Epitopes from the Proline-Rich Region of Pneumococcal Surface Protein A. Vaccines (Basel) 2015; 3:850-74. [PMID: 26501327 PMCID: PMC4693222 DOI: 10.3390/vaccines3040850] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 10/09/2015] [Indexed: 02/01/2023] Open
Abstract
Alternatives to the well-established capsular polysaccharide-based vaccines against Streptococcus pneumoniae that circumvent limitations arising from limited serotype coverage and the emergence of resistance due to capsule switching (serotype replacement) are being widely pursued. Much attention is now focused on the development of recombinant subunit vaccines based on highly conserved pneumococcal surface proteins and virulence factors. A further step might involve focusing the host humoral immune response onto protective protein epitopes using as immunogens structurally optimized epitope mimetics. One approach to deliver such epitope mimetics to the immune system is through the use of synthetic virus-like particles (SVLPs). SVLPs are made from synthetic coiled-coil lipopeptides that are designed to spontaneously self-assemble into 20–30 nm diameter nanoparticles in aqueous buffer. Multivalent display of epitope mimetics on the surface of SVLPs generates highly immunogenic nanoparticles that elicit strong epitope-specific humoral immune responses without the need for external adjuvants. Here, we set out to demonstrate that this approach can yield vaccine candidates able to elicit a protective immune response, using epitopes derived from the proline-rich region of pneumococcal surface protein A (PspA). These streptococcal SVLP-based vaccine candidates are shown to elicit strong humoral immune responses in mice. Following active immunization and challenge with lethal doses of streptococcus, SVLP-based immunogens are able to elicit significant protection in mice. Furthermore, a mimetic-specific monoclonal antibody is shown to mediate partial protection upon passive immunization. The results show that SVLPs combined with synthetic epitope mimetics may have potential for the development of an effective vaccine against Streptococcus pneumoniae.
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Affiliation(s)
- Marco Tamborrini
- Swiss Tropical and Public Health Institute, Socinstrasse 57, Basel 4051, Switzerland; E-Mails: (M.T.); (M.J.); (J.H.); (C.A.); (A.L.); (G.P.)
- University of Basel, Petersplatz 1, Basel 4003, Switzerland
| | - Nina Geib
- Virometix AG, Wagistrasse 14, Schlieren 8952, Switzerland; E-Mails: (N.G.); (A.M.-N.); (A.Z.)
| | | | - Maja Jud
- Swiss Tropical and Public Health Institute, Socinstrasse 57, Basel 4051, Switzerland; E-Mails: (M.T.); (M.J.); (J.H.); (C.A.); (A.L.); (G.P.)
- University of Basel, Petersplatz 1, Basel 4003, Switzerland
| | - Julia Hauser
- Swiss Tropical and Public Health Institute, Socinstrasse 57, Basel 4051, Switzerland; E-Mails: (M.T.); (M.J.); (J.H.); (C.A.); (A.L.); (G.P.)
- University of Basel, Petersplatz 1, Basel 4003, Switzerland
| | - Celestine Aho
- Swiss Tropical and Public Health Institute, Socinstrasse 57, Basel 4051, Switzerland; E-Mails: (M.T.); (M.J.); (J.H.); (C.A.); (A.L.); (G.P.)
- University of Basel, Petersplatz 1, Basel 4003, Switzerland
| | - Araceli Lamelas
- Swiss Tropical and Public Health Institute, Socinstrasse 57, Basel 4051, Switzerland; E-Mails: (M.T.); (M.J.); (J.H.); (C.A.); (A.L.); (G.P.)
- University of Basel, Petersplatz 1, Basel 4003, Switzerland
| | - Armando Zuniga
- Virometix AG, Wagistrasse 14, Schlieren 8952, Switzerland; E-Mails: (N.G.); (A.M.-N.); (A.Z.)
| | - Gerd Pluschke
- Swiss Tropical and Public Health Institute, Socinstrasse 57, Basel 4051, Switzerland; E-Mails: (M.T.); (M.J.); (J.H.); (C.A.); (A.L.); (G.P.)
- University of Basel, Petersplatz 1, Basel 4003, Switzerland
| | - Arin Ghasparian
- Virometix AG, Wagistrasse 14, Schlieren 8952, Switzerland; E-Mails: (N.G.); (A.M.-N.); (A.Z.)
- Authors to whom correspondence should be addressed; E-Mails: (A.G.); (J.A.R.); Tel.: +41-43-433-8685 (A.G.); +41-44-635-4242 (J.A.R.)
| | - John A. Robinson
- Department of Chemistry, University of Zürich, Winterthurerstrasse 190, Zürich 8057, Switzerland
- Authors to whom correspondence should be addressed; E-Mails: (A.G.); (J.A.R.); Tel.: +41-43-433-8685 (A.G.); +41-44-635-4242 (J.A.R.)
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Lagousi T, Routsias J, Piperi C, Tsakris A, Chrousos G, Theodoridou M, Spoulou V. Discovery of Immunodominant B Cell Epitopes within Surface Pneumococcal Virulence Proteins in Pediatric Patients with Invasive Pneumococcal Disease. J Biol Chem 2015; 290:27500-10. [PMID: 26396191 DOI: 10.1074/jbc.m115.666818] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Indexed: 01/17/2023] Open
Abstract
The identification of immunodominant B cell epitopes within surface pneumococcal virulence proteins in pediatric patients with invasive pneumococcal disease (IPD) is a valuable approach to define novel vaccine candidates. To this aim, we evaluated sera from children with IPD and age-matched controls against 141 20-mer synthetic peptides covering the entire sequence of major antigenic fragments within pneumococcal virulence proteins; namely, choline-binding protein D (CbpD), pneumococcal histidine triad proteins (PhtD and PhtE), pneumococcal surface protein A (PspA), plasminogen and fibronectin binding protein B (PfbB), and zinc metalloproteinase B (ZmpB). Ten immunodominant B cell epitopes were identified: CbpD-pep4 (amino acids (aa) 291-310), PhtD-pep11 (aa 88-107), PhtD-pep17 (aa 172-191), PhtD-pep19 (aa 200-219), PhtE-pep32 (aa 300-319), PhtE-pep40 (aa 79-98), PfbB-pep76 (aa 180-199), PfbB-pep79 (aa 222-241), PfbB-pep90 (aa 484-503), and ZmpB-pep125 (aa 431-450). All epitopes were highly conserved among different pneumococcal serotypes, and four of them were located within the functional zinc-binding domain of the histidine triad proteins PhtD and PhtE. Peptides CbpD-pep4, PhtD-pep19, and PhtE-pep40 were broadly recognized by IPD patient sera with prevalences of 96.4%, 92.9%, and 71.4%, respectively, whereas control sera exhibited only minor reactivities (<10.7%). Their specificities for IPD were 93.3%, 95%, and 96.7%; their sensitivities were 96.4%, 92.9%, and 71.4% and their positivity likelihood ratios for IPD were 14.5, 18.6, and 21.4, respectively. Furthermore, purified antibodies against CbpD-pep4, PhtD-pep19, and PhtE-pep40 readily bound on the surfaces of different pneumococcal serotypes, as assessed by FACS and immunofluorescence analysis. The identified immunodominant B cell epitopes provide a better understanding of immune response in IPD and are worth evaluation in additional studies as potential vaccine candidates.
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Affiliation(s)
- Theano Lagousi
- From the First Department of Paediatrics, "Aghia Sophia" Children's Hospital, Immunobiology Research Laboratory and Infectious Diseases Department "MAKKA," and Departments of Microbiology and
| | | | | | | | - George Chrousos
- From the First Department of Paediatrics, "Aghia Sophia" Children's Hospital, Immunobiology Research Laboratory and Infectious Diseases Department "MAKKA," and
| | - Maria Theodoridou
- From the First Department of Paediatrics, "Aghia Sophia" Children's Hospital, Immunobiology Research Laboratory and Infectious Diseases Department "MAKKA," and
| | - Vana Spoulou
- From the First Department of Paediatrics, "Aghia Sophia" Children's Hospital, Immunobiology Research Laboratory and Infectious Diseases Department "MAKKA," and
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Multivalent Pneumococcal Protein Vaccines Comprising Pneumolysoid with Epitopes/Fragments of CbpA and/or PspA Elicit Strong and Broad Protection. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2015; 22:1079-89. [PMID: 26245351 DOI: 10.1128/cvi.00293-15] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 07/28/2015] [Indexed: 12/11/2022]
Abstract
Immunization with the pneumococcal proteins pneumolysin (Ply), choline binding protein A (CbpA), or pneumococcal surface protein A (PspA) elicits protective responses against invasive pneumococcal disease in animal models. In this study, we used different mouse models to test the efficacy of a variety of multivalent protein-based vaccines that comprised various combinations of full-length or peptide regions of the immunogens Ply, CbpA, or PspA: Ply toxoid with the L460D substitution (referred to herein as L460D); L460D fused with protective peptide epitopes from CbpA (YPT-L460D-NEEK [YLN]); L460D fused with the CD2 peptide containing the proline-rich region (PRR) of PspA (CD2-L460D); a combination of L460D and H70 (L460D+H70), a slightly larger PspA-derived peptide containing the PRR and the SM1 region; H70+YLN; and other combinations. Each mouse was immunized either intraperitoneally (i.p.) or subcutaneously (s.c.) with three doses (at 2-week intervals) of the various antigen combinations in alum adjuvant and then challenged in mouse models featuring different infection routes with multiple Streptococcus pneumoniae strains. In the i.p. infection sepsis model, H70+YLN consistently provided significant protection against three different challenge strains (serotypes 1, 2, and 6A); the CD2+YLN and H70+L460D combinations also elicited significant protection. Protection against intravenous (i.v.) sepsis (type 3 and 6A challenge strains) was largely dependent on PspA-derived antigen components, and the most protection was elicited by H70 with or without L460D or YLN. In a type 4 intratracheal (i.t.) challenge model that results in progression to meningitis, antigen combinations that contained YLN elicited the strongest protection. Thus, the trivalent antigen combination of H70+YLN elicited the strongest and broadest protection in diverse pneumococcal challenge models.
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Vashishta M, Khan N, Mehto S, Sehgal D, Natarajan K. Pneumococal Surface Protein A (PspA) Regulates Programmed Death Ligand 1 Expression on Dendritic Cells in a Toll-Like Receptor 2 and Calcium Dependent Manner. PLoS One 2015. [PMID: 26214513 PMCID: PMC4516265 DOI: 10.1371/journal.pone.0133601] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Pneumonia leads to high mortality in children under the age of five years worldwide, resulting in close to 20 percent of all deaths in this age group. Therefore, investigations into host-pathogen interactions during Streptococcus pneumoniae infection are key in devising strategies towards the development of better vaccines and drugs. To that end, in this study we investigated the role of S. pneumoniae and its surface antigen Pneumococcal surface protein A (PspA) in modulating the expression of co-stimulatory molecule Programmed Death Ligand 1 (PD-L1) expression on dendritic cells (DCs) and the subsequent effects of increased PD-L1 on key defence responses. Our data indicate that stimulation of DCs with PspA increases the surface expression of PD-L1 in a time and dose dependent manner. Characterization of mechanisms involved in PspA induced expression of PD-L1 indicate the involvement of Toll-Like Receptor 2 (TLR2) and calcium homeostasis. While calcium release from intracellular stores positively regulated PD-L1 expression, calcium influx from external milieu negatively regulated PD-L1 expression. Increase in PD-L1 expression, when costimulated with PspA and through TLR2 was higher than when stimulated with PspA or through TLR2. Further, knockdown of TLR2 and the intermediates in the TLR signaling machinery pointed towards the involvement of a MyD88 dependent pathway in PspA induced PD-L1 expression. Incubation of DCs with S. pneumoniae resulted in the up-regulation of PD-L1 expression, while infection with a strain lacking surface PspA failed to do so. Our data also suggests the role of PspA in ROS generation. These results suggest a novel and specific role for PspA in modulating immune responses against S. pneumoniae by regulating PD-L1 expression.
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Affiliation(s)
- Mohit Vashishta
- Infectious Disease Immunology Laboratory, Dr. B. R. Ambedkar Centre for Biomedical Research, University of Delhi, Delhi, India
- * E-mail: (MV); (KN); (DS)
| | - Naeem Khan
- Molecular Immunology Laboratory, National Institute of Immunology, New Delhi, India
| | - Subhash Mehto
- Infectious Disease Immunology Laboratory, Dr. B. R. Ambedkar Centre for Biomedical Research, University of Delhi, Delhi, India
| | - Devinder Sehgal
- Molecular Immunology Laboratory, National Institute of Immunology, New Delhi, India
- * E-mail: (MV); (KN); (DS)
| | - Krishnamurthy Natarajan
- Infectious Disease Immunology Laboratory, Dr. B. R. Ambedkar Centre for Biomedical Research, University of Delhi, Delhi, India
- * E-mail: (MV); (KN); (DS)
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Evaluation of a vaccine formulation against Streptococcus pneumoniae based on choline-binding proteins. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2014; 22:213-20. [PMID: 25520146 DOI: 10.1128/cvi.00692-14] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Streptococcus pneumoniae has proteins that are attached to its surface by binding to phosphorylcholine of teichoic and lipoteichoic acids. These proteins are known as choline-binding proteins (CBPs). CBPs are an interesting alternative for the development of a cost-effective vaccine, and PspA (pneumococcal surface protein A) is believed to be the most important protective component among the different CBPs. We sought to use CBPs eluted from pneumococci as an experimental vaccine. Since PspA shows variability between isolates, we constructed strains producing different PspAs. We used the nonencapsulated Rx1 strain, which produces PspA from clade 2 (PspA2), to generate a pspA-knockout strain (Rx1 ΔpspA) and strains expressing PspA from clade 1 (Rx1 pspA1) and clade 4 (Rx1 pspA4). We grew Rx1, Rx1 ΔpspA, Rx1 pspA1, and Rx1 pspA4 in Todd-Hewitt medium containing 0.5% yeast extract and washed cells in 2% choline chloride (CC). SDS-PAGE analysis of the proteins recovered by a CC wash showed few bands, and the CBPs PspA and PspC (pneumococcal surface protein C) were identified by mass spectrometry analysis. Subcutaneous immunization of mice with these full-length native proteins without adjuvant led to significantly higher rates of survival than immunization with diluent after an intranasal lethal challenge with two pneumococcal strains and also after a colonization challenge with one strain. Importantly, immunization with recombinant PspA4 (rPspA4) without adjuvant did not elicit significant protection.
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Correlation between in vitro complement deposition and passive mouse protection of anti-pneumococcal surface protein A monoclonal antibodies. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2014; 22:99-107. [PMID: 25410204 DOI: 10.1128/cvi.00001-14] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The shortcomings of the licensed polysaccharide-based pneumococcal vaccine are driving efforts toward development of a protein-based vaccine that is serotype independent and effective in all age groups. An opsonophagocytic killing assay (OPKA) is used to evaluate the antibody response against polysaccharide-based pneumococcal vaccines. However, the OPKA is not reliable for noncapsular antigens. Thus, there is a need to develop an in vitro surrogate for protection for protein vaccine candidates like pneumococcal surface antigen A (PspA). PspA is a serologically variable cell surface virulence factor. Based on its sequence, PspA has been classified into families 1 (clade 1 and 2), 2 (clades 3, 4 and 5), and 3 (clade 6). Here, we report the characterization of 18 IgG anti-PspA monoclonal antibodies (anti-PspA(hkR36A) MAbs) generated from mice immunized with heat-killed strain R36A (clade 2). An enzyme-linked immunosorbent assay (ELISA)-based analysis of the reactivity of the MAbs with recombinant PspAs from the 6 clades indicated that they were family 1 specific. This was confirmed by flow cytometry using a hyperimmune serum generated against PspA from R36A. Eight MAbs that bind at least one clade 1- and clade 2-expressing strain were evaluated for complement deposition, bactericidal activity, and passive protection. The anti-PspA(hkR36A) MAb-dependent deposition of complement on pneumococci showed a positive correlation with passive protection against strain WU2 (r = 0.8783, P = 0.0041). All of our protective MAbs showed bactericidal activity; however, not all MAbs that exhibited bactericidal activity conferred protection in vivo. The protective MAbs described here can be used to identify conserved protection eliciting B cell epitopes for engineering a superior PspA-based vaccine.
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Schachern PA, Tsuprun V, Ferrieri P, Briles DE, Goetz S, Cureoglu S, Paparella MM, Juhn S. Pneumococcal PspA and PspC proteins: potential vaccine candidates for experimental otitis media. Int J Pediatr Otorhinolaryngol 2014; 78:1517-21. [PMID: 25015773 PMCID: PMC4129636 DOI: 10.1016/j.ijporl.2014.06.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 05/27/2014] [Accepted: 06/16/2014] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Otitis media is the most commonly diagnosed disease in ambulatory care and Streptococcuspneumoniae continues to be the most common bacterial agent. Bacterial resistance to antibiotics underscores the need for better vaccines. Current pneumococcal conjugate vaccines are modestly protective against otitis media; however, limited serotype coverage and serotype replacement have led to the investigation of pneumococcal proteins as potential vaccine candidates. Two proteins, pneumococcal surface proteins A (PspA) and C (PspC) are important virulence factors, expressed by virtually all strains. Although a number of pneumococcal proteins have been investigated in other infection sites, these proteins can have diverse organ-specific effects. In this study, we investigated the viability and virulence of single (PspA(-) and PspC(-)) and double (PspA(-)/PspC(-)) mutants of pneumococcal PspA and PspC proteins in the chinchilla middle ear. METHODS Bullae of 24 chinchillas were inoculated with 0.5 ml of 10(6) colony forming units (CFUs)/ml bacteria: 6 with wild-type D39 strain; 6 with PspA(-); 6 with PspC(-); and 6 with PspA(-)/PspC(-) isogenic mutant strains. Bacterial CFU levels in middle ear effusions and light microscopic analysis of the number of inflammatory cells in the round window membrane (RWM) were compared 48 h after inoculation. RESULTS At 48 h, CFUs in middle ears were increased for wild-type and PspC(-) strains compared to inoculum levels; however, they were significantly less for the group inoculated with the PspC(-) strain compared to wild-type strain. No bacteria were detected in the PspA(-) and PspA(-)/PspC(-) groups. The number of inflammatory cells in the RWM was significantly higher in wild-type compared to the PspA(-), PspC(-), and PspA(-)/PspC(-) groups. No significant difference in number of inflammatory cells was observed between any pairs of groups inoculated with mutant strains. CONCLUSION Viability and virulence of the PspC(-) strain were similar to the wild-type strain. The single PspA(-) and double PspA(-)/PspC(-) mutants were highly attenuated in the ear. Bacterial clearance of the PspA(-)/PspC(-) double mutant was indistinguishable from that of the PspA mutant. These studies provide no reason to exclude PspC from a multi-component protein vaccine containing PspA.
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Affiliation(s)
| | - Vladimir Tsuprun
- Departments of Otolaryngology, University of Minnesota, Minneapolis, MN, United States.
| | - Patricia Ferrieri
- Department of Pediatrics, University of Minnesota, Minneapolis, MN,Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN
| | - David E Briles
- Department of Microbiology, University of Alabama at Birmingham, AL
| | - Sarah Goetz
- Department of Pediatrics, University of Minnesota, Minneapolis, MN
| | | | | | - Steven Juhn
- Department of Otolaryngology, University of Minnesota, Minneapolis, MN
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Tarahomjoo S. Recent Approaches in Vaccine Development against Streptococcus pneumoniae. J Mol Microbiol Biotechnol 2014; 24:215-27. [DOI: 10.1159/000365052] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Kohler S, Hallström T, Singh B, Riesbeck K, Spartà G, Zipfel PF, Hammerschmidt S. Binding of vitronectin and Factor H to Hic contributes to immune evasion of Streptococcus pneumoniae serotype 3. Thromb Haemost 2014; 113:125-42. [PMID: 25181963 DOI: 10.1160/th14-06-0561] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Accepted: 07/24/2014] [Indexed: 11/05/2022]
Abstract
Streptococcus pneumoniae serotype 3 strains are highly resistant to opsonophagocytosis due to recruitment of the complement inhibitor Factor H via Hic, a member of the pneumococcal surface protein C (PspC) family. In this study, we demonstrated that Hic also interacts with vitronectin, a fluid-phase regulator involved in haemostasis, angiogenesis, and the terminal complement cascade as well as a component of the extracellular matrix. Blocking of Hic by specific antiserum or genetic deletion significantly reduced pneumococcal binding to soluble and immobilised vitronectin and to Factor H, respectively. In parallel, ectopic expression of Hic on the surface of Lactococcus lactis conferred binding to soluble and immobilised vitronectin as well as Factor H. Molecular analyses with truncated Hic fragments narrowed down the vitronectin-binding site to the central core of Hic (aa 151-201). This vitronectin-binding region is separate from that of Factor H, which binds to the N-terminus of Hic (aa 38-92). Binding of pneumococcal Hic was localised to the C-terminal heparin-binding domain (HBD3) of vitronectin. However, an N-terminal region to HBD3 was further involved in Hic-binding to immobilised vitronectin. Finally, vitronectin bound to Hic was functionally active and inhibited formation of the terminal complement complex. In conclusion, Hic interacts with vitronectin and simultaneously with Factor H, and both human proteins may contribute to colonisation and invasive disease caused by serotype 3 pneumococci.
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Affiliation(s)
| | | | | | | | | | | | - Sven Hammerschmidt
- Prof. Dr. Sven Hammerschmidt, Department Genetics of Microorganisms, Interfaculty Institute for Genetics and Functional Genomics, Ernst Moritz Arndt University Greifswald, Friedrich-Ludwig-Jahn-Strasse 15A, 17487 Greifswald, Germany, Tel.: +49 3834 864161, Fax: +49 3834 864172, E-mail:
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Piao Z, Akeda Y, Takeuchi D, Ishii KJ, Ubukata K, Briles DE, Tomono K, Oishi K. Protective properties of a fusion pneumococcal surface protein A (PspA) vaccine against pneumococcal challenge by five different PspA clades in mice. Vaccine 2014; 32:5607-13. [PMID: 25132335 DOI: 10.1016/j.vaccine.2014.07.108] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 07/21/2014] [Accepted: 07/31/2014] [Indexed: 12/17/2022]
Abstract
An increase in the appearance of nonvaccine serotypes in both children and adults with invasive pneumococcal disease (IPD) after introduction of pneumococcal conjugate vaccine represents a limitation of this vaccine. In this study, we generated three recombinant pneumococcal surface protein A (PspA) proteins comprising PspA families 1 and 2, and we examined the reactivity of antisera raised in mice immunized with a PspA fusion protein in combination with CpG oligonucleotides plus aluminum hydroxide gel. The protective effects of immunization with PspA fusion proteins against pneumococcal challenge by strains with five different PspA clades were also examined in mice. Flow cytometry demonstrated that PspA3+2-induced antiserum showed the greatest binding of PspA-specific IgG to all five challenge strains with different clades. PspA2+4- or PspA2+5-induced antiserum showed the lowest binding of PspA-specific IgG to clade 3. Immunization with PspA3+2 afforded significant protection against pneumococcal challenge by five strains with different clades in mice, but immunization with PspA2+4 or PspA2+5 failed to protect mice from pneumococcal challenge by strains with clades 1 and 3. The binding of PspA-specific IgG in antisera raised by three PspA fusion proteins was examined in 68 clinical isolates from adult patients with IPD. Immunization of mice with PspA3+2-induced antiserum with a high binding capacity for clinical isolates expressing clades 1-4, but not clade 5. Our results suggest that the PspA3+2 vaccine has an advantage over the PspA2+4 or PspA2+5 vaccine in terms of a broad range of cross-reactivity with clinical isolates and cross-protection against pneumococcal challenge in mice.
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Affiliation(s)
- Zhenyu Piao
- Laboratory for Clinical Research on Infectious Disease, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Japan; Division of Infection Control and Prevention, Osaka University Graduate School of Medicine, Japan
| | - Yukihiro Akeda
- Laboratory for Clinical Research on Infectious Disease, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Japan
| | - Dan Takeuchi
- Laboratory for Clinical Research on Infectious Disease, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Japan
| | - Ken J Ishii
- National Institute of Biomedical Innovation, Japan; Laboratory of Vaccine Science, WPI Immunology Frontier Research Center, Osaka University, Japan
| | - Kimiko Ubukata
- Department of Infectious Diseases, Keio University School of Medicine, Japan
| | - David E Briles
- Department of Microbiology, University of Alabama at Birmingham, USA
| | - Kazunori Tomono
- Division of Infection Control and Prevention, Osaka University Graduate School of Medicine, Japan
| | - Kazunori Oishi
- Infectious Disease Surveillance Center, National Institute of Infectious Diseases, Japan.
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