1
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Da Costa RM, Rooke JL, Wells TJ, Cunningham AF, Henderson IR. Type 5 secretion system antigens as vaccines against Gram-negative bacterial infections. NPJ Vaccines 2024; 9:159. [PMID: 39218947 PMCID: PMC11366766 DOI: 10.1038/s41541-024-00953-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 08/14/2024] [Indexed: 09/04/2024] Open
Abstract
Infections caused by Gram-negative bacteria are leading causes of mortality worldwide. Due to the rise in antibiotic resistant strains, there is a desperate need for alternative strategies to control infections caused by these organisms. One such approach is the prevention of infection through vaccination. While live attenuated and heat-killed bacterial vaccines are effective, they can lead to adverse reactions. Newer vaccine technologies focus on utilizing polysaccharide or protein subunits for safer and more targeted vaccination approaches. One promising avenue in this regard is the use of proteins released by the Type 5 secretion system (T5SS). This system is the most prevalent secretion system in Gram-negative bacteria. These proteins are compelling vaccine candidates due to their demonstrated protective role in current licensed vaccines. Notably, Pertactin, FHA, and NadA are integral components of licensed vaccines designed to prevent infections caused by Bordetella pertussis or Neisseria meningitidis. In this review, we delve into the significance of incorporating T5SS proteins into licensed vaccines, their contributions to virulence, conserved structural motifs, and the protective immune responses elicited by these proteins.
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Affiliation(s)
- Rochelle M Da Costa
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Jessica L Rooke
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Timothy J Wells
- Frazer Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Adam F Cunningham
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Ian R Henderson
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia.
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2
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Lei EK, Azmat A, Henry KA, Hussack G. Outer membrane vesicles as a platform for the discovery of antibodies to bacterial pathogens. Appl Microbiol Biotechnol 2024; 108:232. [PMID: 38396192 PMCID: PMC10891261 DOI: 10.1007/s00253-024-13033-5] [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: 11/03/2023] [Revised: 01/24/2024] [Accepted: 01/26/2024] [Indexed: 02/25/2024]
Abstract
Bacterial outer membrane vesicles (OMVs) are nanosized spheroidal particles shed by gram-negative bacteria that contain biomolecules derived from the periplasmic space, the bacterial outer membrane, and possibly other compartments. OMVs can be purified from bacterial culture supernatants, and by genetically manipulating the bacterial cells that produce them, they can be engineered to harbor cargoes and/or display molecules of interest on their surfaces including antigens that are immunogenic in mammals. Since OMV bilayer-embedded components presumably maintain their native structures, OMVs may represent highly useful tools for generating antibodies to bacterial outer membrane targets. OMVs have historically been utilized as vaccines or vaccine constituents. Antibodies that target bacterial surfaces are increasingly being explored as antimicrobial agents either in unmodified form or as targeting moieties for bactericidal compounds. Here, we review the properties of OMVs, their use as immunogens, and their ability to elicit antibody responses against bacterial antigens. We highlight antigens from bacterial pathogens that have been successfully targeted using antibodies derived from OMV-based immunization and describe opportunities and limitations for OMVs as a platform for antimicrobial antibody development. KEY POINTS: • Outer membrane vesicles (OMVs) of gram-negative bacteria bear cell-surface molecules • OMV immunization allows rapid antibody (Ab) isolation to bacterial membrane targets • Review and analysis of OMV-based immunogens for antimicrobial Ab development.
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Affiliation(s)
- Eric K Lei
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, ON, Canada
| | - Aruba Azmat
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, ON, Canada
| | - Kevin A Henry
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, ON, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON, Canada
| | - Greg Hussack
- Human Health Therapeutics Research Centre, National Research Council Canada, Ottawa, ON, Canada.
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3
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Girgis MM, Christodoulides M. Vertebrate and Invertebrate Animal and New In Vitro Models for Studying Neisseria Biology. Pathogens 2023; 12:782. [PMID: 37375472 DOI: 10.3390/pathogens12060782] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/03/2023] [Accepted: 05/18/2023] [Indexed: 06/29/2023] Open
Abstract
The history of Neisseria research has involved the use of a wide variety of vertebrate and invertebrate animal models, from insects to humans. In this review, we itemise these models and describe how they have made significant contributions to understanding the pathophysiology of Neisseria infections and to the development and testing of vaccines and antimicrobials. We also look ahead, briefly, to their potential replacement by complex in vitro cellular models.
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Affiliation(s)
- Michael M Girgis
- Neisseria Research Group, Molecular Microbiology, School of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
- Department of Microbiology and Immunology, Faculty of Pharmacy, Mansoura University, Mansoura 35516, Egypt
| | - Myron Christodoulides
- Neisseria Research Group, Molecular Microbiology, School of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK
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4
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Greening DW, Xu R, Ale A, Hagemeyer CE, Chen W. Extracellular vesicles as next generation immunotherapeutics. Semin Cancer Biol 2023; 90:73-100. [PMID: 36773820 DOI: 10.1016/j.semcancer.2023.02.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/01/2023] [Accepted: 02/02/2023] [Indexed: 02/11/2023]
Abstract
Extracellular vesicles (EVs) function as a mode of intercellular communication and molecular transfer to elicit diverse biological/functional response. Accumulating evidence has highlighted that EVs from immune, tumour, stromal cells and even bacteria and parasites mediate the communication of various immune cell types to dynamically regulate host immune response. EVs have an innate capacity to evade recognition, transport and transfer functional components to target cells, with subsequent removal by the immune system, where the immunological activities of EVs impact immunoregulation including modulation of antigen presentation and cross-dressing, immune activation, immune suppression, and immune surveillance, impacting the tumour immune microenvironment. In this review, we outline the recent progress of EVs in immunorecognition and therapeutic intervention in cancer, including vaccine and targeted drug delivery and summarise their utility towards clinical translation. We highlight the strategies where EVs (natural and engineered) are being employed as a therapeutic approach for immunogenicity, tumoricidal function, and vaccine development, termed immuno-EVs. With seminal studies providing significant progress in the sequential development of engineered EVs as therapeutic anti-tumour platforms, we now require direct assessment to tune and improve the efficacy of resulting immune responses - essential in their translation into the clinic. We believe such a review could strengthen our understanding of the progress in EV immunobiology and facilitate advances in engineering EVs for the development of novel EV-based immunotherapeutics as a platform for cancer treatment.
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Affiliation(s)
- David W Greening
- Molecular Proteomics, Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia; Baker Department of Cardiovascular Research, Translation and Implementation, Australia; Department of Biochemistry and Chemistry, School of Agriculture, Biomedicine and Environment, La Trobe University, Victoria, Australia; Central Clinical School, Monash University, Victoria, Australia; Baker Department of Cardiometabolic Health, University of Melbourne, Victoria, Australia.
| | - Rong Xu
- Central Clinical School, Monash University, Victoria, Australia; Australian Centre for Blood Diseases, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Anukreity Ale
- Central Clinical School, Monash University, Victoria, Australia; Australian Centre for Blood Diseases, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Christoph E Hagemeyer
- Central Clinical School, Monash University, Victoria, Australia; Australian Centre for Blood Diseases, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Weisan Chen
- Department of Biochemistry and Chemistry, School of Agriculture, Biomedicine and Environment, La Trobe University, Victoria, Australia
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5
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Tian CM, Yang MF, Xu HM, Zhu MZ, Zhang Y, Yao J, Wang LS, Liang YJ, Li DF. Emerging role of bacterial outer membrane vesicle in gastrointestinal tract. Gut Pathog 2023; 15:20. [PMID: 37106359 PMCID: PMC10133921 DOI: 10.1186/s13099-023-00543-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/30/2023] [Indexed: 04/29/2023] Open
Abstract
Bacteria form a highly complex ecosystem in the gastrointestinal (GI) tract. In recent years, mounting evidence has shown that bacteria can release nanoscale phospholipid bilayer particles that encapsulate nucleic acids, proteins, lipids, and other molecules. Extracellular vesicles (EVs) are secreted by microorganisms and can transport a variety of important factors, such as virulence factors, antibiotics, HGT, and defensive factors produced by host eukaryotic cells. In addition, these EVs are vital in facilitating communication between microbiota and the host. Therefore, bacterial EVs play a crucial role in maintaining the GI tract's health and proper functioning. In this review, we outlined the structure and composition of bacterial EVs. Additionally, we highlighted the critical role that bacterial EVs play in immune regulation and in maintaining the balance of the gut microbiota. To further elucidate progress in the field of intestinal research and to provide a reference for future EV studies, we also discussed the clinical and pharmacological potential of bacterial EVs, as well as the necessary efforts required to understand the mechanisms of interaction between bacterial EVs and gut pathogenesis.
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Affiliation(s)
- Cheng-Mei Tian
- Department of Emergency, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; the First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, 518020, Guangdong, China
| | - Mei-Feng Yang
- Department of Hematology, Yantian District People's Hospital, Shenzhen, Guangdong, China
| | - Hao-Ming Xu
- Department of Gastroenterology and Hepatology, Guangzhou Digestive Disease Center, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, China
| | - Min-Zheng Zhu
- Department of Gastroenterology and Hepatology, Guangzhou Digestive Disease Center, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, China
| | - Yuan Zhang
- Department of Medical Administration, Huizhou Institute of Occupational Diseases Control and Prevention, Huizhou, Guangdong, China
| | - Jun Yao
- Department of Gastroenterology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; the First Affiliated Hospital, Southern University of Science and Technology), No.1017, Dongmen North Road, Luohu District, Shenzhen, 518020, People's Republic of China.
| | - Li-Sheng Wang
- Department of Gastroenterology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; the First Affiliated Hospital, Southern University of Science and Technology), No.1017, Dongmen North Road, Luohu District, Shenzhen, 518020, People's Republic of China.
| | - Yu-Jie Liang
- Department of Child and Adolescent Psychiatry, Shenzhen Kangning Hospital, No.1080, Cuizu Road, Luohu District, Shenzhen, 518020, People's Republic of China.
| | - De-Feng Li
- Department of Gastroenterology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; the First Affiliated Hospital, Southern University of Science and Technology), No.1017, Dongmen North Road, Luohu District, Shenzhen, 518020, People's Republic of China.
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6
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Cappelli L, Cinelli P, Giusti F, Ferlenghi I, Utrio-Lanfaloni S, Wahome N, Bottomley MJ, Maione D, Cozzi R. Self-assembling protein nanoparticles and virus like particles correctly display β-barrel from meningococcal factor H-binding protein through genetic fusion. PLoS One 2022; 17:e0273322. [PMID: 36112575 PMCID: PMC9480994 DOI: 10.1371/journal.pone.0273322] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 08/06/2022] [Indexed: 12/04/2022] Open
Abstract
Recombinant protein-based vaccines are a valid and safer alternative to traditional vaccines based on live-attenuated or killed pathogens. However, the immune response of subunit vaccines is generally lower compared to that elicited by traditional vaccines and usually requires the use of adjuvants. The use of self-assembling protein nanoparticles, as a platform for vaccine antigen presentation, is emerging as a promising approach to enhance the production of protective and functional antibodies. In this work we demonstrated the successful repetitive antigen display of the C-terminal β-barrel domain of factor H binding protein, derived from serogroup B Meningococcus on the surface of different self-assembling nanoparticles using genetic fusion. Six nanoparticle scaffolds were tested, including virus-like particles with different sizes, geometries, and physicochemical properties. Combining computational and structure-based rational design we were able generate antigen-fused scaffolds that closely aligned with three-dimensional structure predictions. The chimeric nanoparticles were produced as recombinant proteins in Escherichia coli and evaluated for solubility, stability, self-assembly, and antigen accessibility using a variety of biophysical methods. Several scaffolds were identified as being suitable for genetic fusion with the β-barrel from fHbp, including ferritin, a de novo designed aldolase from Thermotoga maritima, encapsulin, CP3 phage coat protein, and the Hepatitis B core antigen. In conclusion, a systematic screening of self-assembling nanoparticles has been applied for the repetitive surface display of a vaccine antigen. This work demonstrates the capacity of rational structure-based design to develop new chimeric nanoparticles and describes a strategy that can be utilized to discover new nanoparticle-based approaches in the search for vaccines against bacterial pathogens.
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Affiliation(s)
| | - Paolo Cinelli
- University of Bologna, Bologna, Italy
- GSK, Siena, Italy
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7
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Barbosa MMF, Kanno AI, Barazzone GC, Rodriguez D, Pancakova V, Trentini M, Faquim-Mauro EL, Freitas AP, Khouri MI, Lobo-Silva J, Goncalves VM, Schenkman RPF, Tanizaki MM, Boraschi D, Malley R, Farias LP, Leite LCC. Robust Immune Response Induced by Schistosoma mansoni TSP-2 Antigen Coupled to Bacterial Outer Membrane Vesicles. Int J Nanomedicine 2021; 16:7153-7168. [PMID: 34712047 PMCID: PMC8548026 DOI: 10.2147/ijn.s315786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 09/22/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose The use of adjuvants can significantly strengthen a vaccine’s efficacy. We sought to explore the immunization efficacy of bacterial outer membrane vesicles (OMVs) displaying the Schistosoma mansoni antigen, SmTSP-2, through a biotin-rhizavidin coupling approach. The rationale is to exploit the nanoparticulate structure and the adjuvant properties of OMVs to induce a robust antigen-specific immune response, in light of developing new vaccines against S. mansoni. Materials and Methods OMVs were obtained from Neisseria lactamica and conjugated with biotin. The recombinant SmTSP-2 in fusion with the biotin-binding protein rhizavidin (rRzvSmTSP-2) was produced in E. coli and coupled to biotinylated OMVs to generate an OMV complex displaying SmTSP-2 on the membrane surface (OMV:rSmTSP-2). Transmission electron microscopy (TEM) and dynamic light scattering analysis were used to determine particle charge and size. The immunogenicity of the vaccine complex was evaluated in C57BL/6 mice. Results The rRzvSmTSP-2 protein was successfully coupled to biotinylated OMVs and purified by size-exclusion chromatography. The OMV:rSmTSP-2 nanoparticles showed an average size of 200 nm, with zeta potential around – 28 mV. Mouse Bone Marrow Dendritic Cells were activated by the nanoparticles as determined by increased expression of the co-stimulatory molecules CD40 and CD86, and the proinflammatory cytokines (TNF-α, IL-6 and IL-12) or IL-10. Splenocytes of mice immunized with OMV:rSmTSP-2 nanoparticles reacted to an in vitro challenge with SmTSP-2 with an increased production of IL-6, IL-10 and IL-17 and displayed a higher number of CD4+ and CD8+ T lymphocytes expressing IFN-γ, IL-4 and IL-2, compared to mice immunized with the antigen alone. Immunization of mice with OMV:rSmTSP-2 induced a 100-fold increase in specific anti-SmTSP-2 IgG antibody titers, as compared to the group receiving the recombinant rSmTSP-2 protein alone or even co-administered with unconjugated OMV. Conclusion Our results demonstrate that the SmTSP-2 antigen coupled with OMVs is highly immunogenic in mice, supporting the potential effectiveness of this platform for improved antigen delivery in novel vaccine strategies.
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Affiliation(s)
- Mayra M F Barbosa
- Laboratório de Desenvolvimento de Vacinas, Instituto Butantan, São Paulo, Brazil.,Programa de Pós-Graduação Interunidades em Biotecnologia, Universidade de São Paulo, São Paulo, Brazil
| | - Alex I Kanno
- Laboratório de Desenvolvimento de Vacinas, Instituto Butantan, São Paulo, Brazil
| | - Giovana C Barazzone
- Laboratório de Desenvolvimento de Vacinas, Instituto Butantan, São Paulo, Brazil
| | - Dunia Rodriguez
- Laboratório de Desenvolvimento de Vacinas, Instituto Butantan, São Paulo, Brazil
| | - Violeta Pancakova
- Laboratório de Desenvolvimento de Vacinas, Instituto Butantan, São Paulo, Brazil.,Université Claude Bernard Lyon 1 (UCBL1), Villeurbanne, 69100, France
| | - Monalisa Trentini
- Laboratório de Desenvolvimento de Vacinas, Instituto Butantan, São Paulo, Brazil
| | | | - Amanda P Freitas
- Laboratório de Imunopatologia, Instituto Butantan, São Paulo, Brazil
| | - Mariana I Khouri
- Laboratório de Biomarcadores e Inflamação, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil
| | - Jessica Lobo-Silva
- Laboratório de Biomarcadores e Inflamação, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil
| | - Viviane M Goncalves
- Laboratório de Desenvolvimento de Vacinas, Instituto Butantan, São Paulo, Brazil
| | | | - Martha M Tanizaki
- Laboratório de Desenvolvimento de Vacinas, Instituto Butantan, São Paulo, Brazil
| | - Diana Boraschi
- Istituto di Biochimica e Biologia Cellulare, Consiglio Nazionale delle Ricerche, Napoli, Italy.,Stazione Zoologica Anton Dohrn, Napoli, Italy.,Shenzhen Institute of Advanced Technologies (SIAT), Chinese Academy of Sciences (CAS), Shenzhen, China Division of Infectious Diseases, Boston Children's Hospital, Boston, MA, USA
| | - Richard Malley
- Division of Infectious Diseases, Boston Children's Hospital, Boston, MA, USA
| | - Leonardo P Farias
- Laboratório de Biomarcadores e Inflamação, Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Brazil
| | - Luciana C C Leite
- Laboratório de Desenvolvimento de Vacinas, Instituto Butantan, São Paulo, Brazil
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8
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Matthias KA, Connolly KL, Begum AA, Jerse AE, Macintyre AN, Sempowski GD, Bash MC. Meningococcal Detoxified Outer Membrane Vesicle Vaccines Enhance Gonococcal Clearance in a Murine Infection Model. J Infect Dis 2021; 225:650-660. [PMID: 34498079 DOI: 10.1093/infdis/jiab450] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 09/08/2021] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Despite decades of research efforts, development of a gonorrhea vaccine has remained elusive. Epidemiological studies suggest that detoxified outer membrane vesicle (dOMV) vaccines from Neisseria meningitidis (Nm) may protect against infection with Neisseria gonorrhoeae (Ng). We recently reported that Nm dOMVs lacking the major outer membrane proteins (OMPs) PorA, PorB, and RmpM induced greater antibody cross-reactivity against heterologous Nm strains than wild-type (WT) dOMVs and may represent an improved vaccine against gonorrhea. METHODS We prepared dOMV vaccines from meningococcal strains that were sufficient or deleted for PorA, PorB, and RmpM. Vaccines were tested in a murine genital tract infection model and antisera were used to identify vaccine targets. RESULTS Immunization with Nm dOMVs significantly and reproducibly enhanced gonococcal clearance for mice immunized with OMP-deficient dOMVs; significant clearance for WT dOMV-immunized mice was observed in one of two experiments. Clearance was associated with serum and vaginal anti-Nm dOMV IgG antibodies that cross-reacted with Ng. Serum IgG was used to identify putative Ng vaccine targets, including PilQ, MtrE, NlpD, and GuaB. CONCLUSIONS Meningococcal dOMVs elicited a protective effect against experimental gonococcal infection. Recognition and identification of Ng vaccine targets by Nm dOMV-induced antibodies supports the development of a cross-protective Neisseria vaccine.
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Affiliation(s)
- Kathryn A Matthias
- Laboratory of Bacterial Polysaccharides, Division of Bacterial, Parasitic, and Allergenic Products, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, USA
| | - Kristie L Connolly
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Afrin A Begum
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Ann E Jerse
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA
| | - Andrew N Macintyre
- Duke Human Vaccine Institute and Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Gregory D Sempowski
- Duke Human Vaccine Institute and Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Margaret C Bash
- Laboratory of Bacterial Polysaccharides, Division of Bacterial, Parasitic, and Allergenic Products, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, USA
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9
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Campylobacter fetus releases S-layered and immunoreactive outer membrane vesicles. Rev Argent Microbiol 2021; 54:74-80. [PMID: 34412928 DOI: 10.1016/j.ram.2021.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 02/23/2021] [Accepted: 06/07/2021] [Indexed: 11/23/2022] Open
Abstract
The study of outer membrane vesicles (OMVs) became relevant because of their probable important role in the transfer of virulence factors to host cells. Campylobacter fetus is mainly a mammal pathogen whose virulence characterization is still limited. The aim of this study was to evaluate and to characterize the secretion of OMVs in this bacterium. By transmission electron microscopy, we confirmed the production of OMVs in all the strains assayed. Purified OMVs showed a spherical shape and variable size, although comparable to those of other gram-negative bacteria. We also confirmed the presence of the S-layer on the surface of the OMVs of all the strains assayed with the exception of those derived from the NTCC reference strain. In addition, we demonstrated their immunoreactivity by the dot-blot assay. Hence, C. fetus OMVs could contribute to the modulation of the host response and constitute a candidate to be evaluated as an adjuvant of current vaccines used in the veterinary field. This work represents a platform to drive future studies towards the role of these subcellular structures in C. fetus-host interaction.
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10
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Exploring the Ability of Meningococcal Vaccines to Elicit Mucosal Immunity: Insights from Humans and Mice. Pathogens 2021; 10:pathogens10070906. [PMID: 34358056 PMCID: PMC8308890 DOI: 10.3390/pathogens10070906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/01/2021] [Accepted: 07/09/2021] [Indexed: 12/16/2022] Open
Abstract
Neisseria meningitidis causes a devastating invasive disease but is also a normal colonizer of the human nasopharynx. Due to the rapid progression of disease, the best tool to protect individuals against meningococcal infections is immunization. Clinical experience with polysaccharide conjugate vaccines has revealed that an ideal meningococcal vaccine must prevent both invasive disease and nasal colonization, which confers herd immunity. However, not all meningococcal vaccines are equal in their ability to prevent nasal colonization, for unknown reasons. Herein, we describe recent efforts to utilize humanized mouse models to understand the impact of different meningococcal vaccines on nasal colonization. These mice are susceptible to nasal colonization, and they become immune following live nasal infection or immunization with matched capsule-conjugate or protein-based vaccines, replicating findings from human work. We bring together insights regarding meningococcal colonization and immunity from clinical work with findings using humanized mouse models, providing new perspective into the different determinants of mucosal versus systemic immunity. Then, we use this as a framework to help focus future studies toward understanding key mechanistic aspects left unresolved, including the bacterial factors required for colonization and immune evasion, determinants of nasal mucosal protection, and characteristics of an ideal meningococcal vaccine.
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11
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Sands NA, Beernink PT. Two human antibodies to a meningococcal serogroup B vaccine antigen enhance binding of complement Factor H by stabilizing the Factor H binding site. PLoS Pathog 2021; 17:e1009655. [PMID: 34125873 PMCID: PMC8224966 DOI: 10.1371/journal.ppat.1009655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 06/24/2021] [Accepted: 05/20/2021] [Indexed: 11/19/2022] Open
Abstract
Microbial pathogens bind host complement regulatory proteins to evade the immune system. The bacterial pathogen Neisseria meningitidis, or meningococcus, binds several complement regulators, including human Factor H (FH). FH binding protein (FHbp) is a component of two licensed meningococcal vaccines and in mice FHbp elicits antibodies that inhibit binding of FH to FHbp, which defeat the bacterial evasion mechanism. However, humans vaccinated with FHbp develop antibodies that enhance binding of FH to the bacteria, which could limit the effectiveness of the vaccines. In the present study, we show that two vaccine-elicited antibody fragments (Fabs) isolated from different human subjects increase binding of complement FH to meningococcal FHbp by ELISA. The two Fabs have different effects on the kinetics of FH binding to immobilized FHbp as measured by surface plasmon resonance. The 1.7- and 2.0-Å resolution X-ray crystal structures of the Fabs in complexes with FHbp illustrate that the two Fabs bind to similar epitopes on the amino-terminal domain of FHbp, adjacent to the FH binding site. Superposition models of ternary complexes of each Fab with FHbp and FH show that there is likely minimal contact between the Fabs and FH. Collectively, the structures reveal that the Fabs enhance binding of FH to FHbp by altering the conformations and mobilities of two loops adjacent to the FH binding site of FHbp. In addition, the 1.5 Å-resolution structure of one of the isolated Fabs defines the structural rearrangements associated with binding to FHbp. The FH-enhancing human Fabs, which are mirrored in the human polyclonal antibody responses, have important implications for tuning the effectiveness of FHbp-based vaccines.
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Affiliation(s)
- Nathaniel A. Sands
- Division of Infectious Diseases and Global Health, Department of Pediatrics, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Peter T. Beernink
- Division of Infectious Diseases and Global Health, Department of Pediatrics, School of Medicine, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
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12
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Moore SR, Menon SS, Cortes C, Ferreira VP. Hijacking Factor H for Complement Immune Evasion. Front Immunol 2021; 12:602277. [PMID: 33717083 PMCID: PMC7947212 DOI: 10.3389/fimmu.2021.602277] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 01/15/2021] [Indexed: 12/15/2022] Open
Abstract
The complement system is an essential player in innate and adaptive immunity. It consists of three pathways (alternative, classical, and lectin) that initiate either spontaneously (alternative) or in response to danger (all pathways). Complement leads to numerous outcomes detrimental to invaders, including direct killing by formation of the pore-forming membrane attack complex, recruitment of immune cells to sites of invasion, facilitation of phagocytosis, and enhancement of cellular immune responses. Pathogens must overcome the complement system to survive in the host. A common strategy used by pathogens to evade complement is hijacking host complement regulators. Complement regulators prevent attack of host cells and include a collection of membrane-bound and fluid phase proteins. Factor H (FH), a fluid phase complement regulatory protein, controls the alternative pathway (AP) both in the fluid phase of the human body and on cell surfaces. In order to prevent complement activation and amplification on host cells and tissues, FH recognizes host cell-specific polyanionic markers in combination with complement C3 fragments. FH suppresses AP complement-mediated attack by accelerating decay of convertases and by helping to inactivate C3 fragments on host cells. Pathogens, most of which do not have polyanionic markers, are not recognized by FH. Numerous pathogens, including certain bacteria, viruses, protozoa, helminths, and fungi, can recruit FH to protect themselves against host-mediated complement attack, using either specific receptors and/or molecular mimicry to appear more like a host cell. This review will explore pathogen complement evasion mechanisms involving FH recruitment with an emphasis on: (a) characterizing the structural properties and expression patterns of pathogen FH binding proteins, as well as other strategies used by pathogens to capture FH; (b) classifying domains of FH important in pathogen interaction; and (c) discussing existing and potential treatment strategies that target FH interactions with pathogens. Overall, many pathogens use FH to avoid complement attack and appreciating the commonalities across these diverse microorganisms deepens the understanding of complement in microbiology.
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Affiliation(s)
- Sara R Moore
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
| | - Smrithi S Menon
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
| | - Claudio Cortes
- Department of Foundational Medical Sciences, Oakland University William Beaumont School of Medicine, Rochester, MI, United States
| | - Viviana P Ferreira
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, OH, United States
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13
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O'Bier NS, Patel DT, Oliver LD, Miller DP, Marconi RT. Development of an FhbB based chimeric vaccinogen that elicits antibodies that block Factor H binding and cleavage by the periopathogen Treponema denticola. Mol Oral Microbiol 2020; 36:50-57. [PMID: 33219611 DOI: 10.1111/omi.12325] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 11/13/2020] [Accepted: 11/17/2020] [Indexed: 12/17/2022]
Abstract
Treponema denticola is a proteolytic anaerobic spirochete and key contributor to periodontal disease of microbial etiology. As periodontal disease develops and progresses, T. denticola thrives in the hostile environment of the subgingival crevice by exploiting the negative regulatory activity of the complement protein, factor H (FH). FH bound to the cell surface receptor, FhbB (FH binding protein B), is competent to serve as a cofactor for the Factor I mediated-cleavage of the opsonin C3b. However, bound FH is ultimately cleaved by the T. denticola protease, dentilisin. As the T. denticola population expands, the rate of FH cleavage may exceed its rate of replenishment leading to local FH depletion and immune dysregulation culminating in tissue and ligament destruction and tooth loss. The goal of this study was to develop a T. denticola FhbB based-vaccine antigen that can block FH binding and cleavage and kill cells via antibody-mediated bactericidal activity. Tetra (FhbB-ch4) and pentavalent fhbB (FhbB-ch5) chimerics were engineered to have attenuated FH binding ability. The chimerics were immunogenic and elicited high-titer bactericidal and agglutinating antibody. Anti-Fhb-ch4 antisera blocked FH binding and cleavage by the T. denticola protease, dentilisin, in a dose dependent manner. Precedent for the use of FH binding proteins comes from the successful development of two FDA approved vaccines for type B Neiserria meningitidis. This study is the first to extend this approach to the development of a preventive or therapeutic vaccine (or monoclonal Ab) for periodontal disease.
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Affiliation(s)
- Nathaniel S O'Bier
- Department Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA, USA
| | - Dhara T Patel
- Department Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA, USA
| | - Lee D Oliver
- Department Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA, USA
| | - Daniel P Miller
- Department Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA, USA
| | - Richard T Marconi
- Department Microbiology and Immunology, Virginia Commonwealth University Medical Center, Richmond, VA, USA
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14
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The serogroup B meningococcal outer membrane vesicle-based vaccine 4CMenB induces cross-species protection against Neisseria gonorrhoeae. PLoS Pathog 2020; 16:e1008602. [PMID: 33290434 PMCID: PMC7748408 DOI: 10.1371/journal.ppat.1008602] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 12/18/2020] [Accepted: 10/08/2020] [Indexed: 12/15/2022] Open
Abstract
There is a pressing need for a gonorrhea vaccine due to the high disease burden associated with gonococcal infections globally and the rapid evolution of antibiotic resistance in Neisseria gonorrhoeae (Ng). Current gonorrhea vaccine research is in the stages of antigen discovery and the identification of protective immune responses, and no vaccine has been tested in clinical trials in over 30 years. Recently, however, it was reported in a retrospective case-control study that vaccination of humans with a serogroup B Neisseria meningitidis (Nm) outer membrane vesicle (OMV) vaccine (MeNZB) was associated with reduced rates of gonorrhea. Here we directly tested the hypothesis that Nm OMVs induce cross-protection against gonorrhea in a well-characterized female mouse model of Ng genital tract infection. We found that immunization with the licensed Nm OMV-based vaccine 4CMenB (Bexsero) significantly accelerated clearance and reduced the Ng bacterial burden compared to administration of alum or PBS. Serum IgG and vaginal IgA and IgG that cross-reacted with Ng OMVs were induced by 4CMenB vaccination by either the subcutaneous or intraperitoneal routes. Antibodies from vaccinated mice recognized several Ng surface proteins, including PilQ, BamA, MtrE, NHBA (known to be recognized by humans), PorB, and Opa. Immune sera from both mice and humans recognized Ng PilQ and several proteins of similar apparent molecular weight, but MtrE was only recognized by mouse serum. Pooled sera from 4CMenB-immunized mice showed a 4-fold increase in serum bactericidal50 titers against the challenge strain; in contrast, no significant difference in bactericidal activity was detected when sera from 4CMenB-immunized and unimmunized subjects were compared. Our findings directly support epidemiological evidence that Nm OMVs confer cross-species protection against gonorrhea, and implicate several Ng surface antigens as potentially protective targets. Additionally, this study further defines the usefulness of murine infection model as a relevant experimental system for gonorrhea vaccine development.
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15
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Findlow J, Bayliss CD, Beernink PT, Borrow R, Liberator P, Balmer P. Broad vaccine protection against Neisseria meningitidis using factor H binding protein. Vaccine 2020; 38:7716-7727. [PMID: 32878710 PMCID: PMC8082720 DOI: 10.1016/j.vaccine.2020.08.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 07/27/2020] [Accepted: 08/12/2020] [Indexed: 11/29/2022]
Abstract
Neisseria meningitidis, the causative agent of invasive meningococcal disease (IMD), is classified into different serogroups defined by their polysaccharide capsules. Meningococcal serogroups A, B, C, W, and Y are responsible for most IMD cases, with serogroup B (MenB) causing a substantial percentage of IMD cases in many regions. Vaccines using capsular polysaccharides conjugated to carrier proteins have been successfully developed for serogroups A, C, W, and Y. However, because the MenB capsular polysaccharide is poorly immunogenic, MenB vaccine development has focused on alternative antigens. The 2 currently available MenB vaccines (MenB-4C and MenB-FHbp) both include factor H binding protein (FHbp), a surface-exposed protein harboured by nearly all meningococcal isolates that is important for survival of the bacteria in human blood. MenB-4C contains a nonlipidated FHbp from subfamily B in addition to other antigens, including Neisserial Heparin Binding Antigen, Neisserial adhesin A, and outer membrane vesicles, whereas MenB-FHbp contains a lipidated FHbp from each subfamily (A and B). FHbp is highly immunogenic and a main target of bactericidal activity of antibodies elicited by both licensed MenB vaccines. FHbp is also an important vaccine component, in contrast to some other meningococcal antigens that may have limited cross-protection across strains, as FHbp-specific antibodies can provide broad cross-protection within each subfamily. Limited cross-protection between subfamilies necessitates the inclusion of FHbp variants from both subfamilies to achieve broad FHbp-based vaccine coverage. Additionally, immune responses to the lipidated form of FHbp have a superior cross-reactive profile to those elicited by the nonlipidated form. Taken together, the inclusion of lipidated FHbp variants from both FHbp subfamilies is expected to provide broad protection against the diverse disease-causing meningococcal strains expressing a wide range of FHbp sequence variants. This review describes the development of vaccines for MenB disease prevention, with a focus on the FHbp antigen.
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Affiliation(s)
- Jamie Findlow
- Vaccine Medical Development, Scientific and Clinical Affairs, Pfizer Ltd, Tadworth, UK.
| | | | - Peter T Beernink
- Department of Pediatrics, School of Medicine, University of California, San Francisco, San Francisco, CA, USA.
| | - Ray Borrow
- Public Health England, Manchester Royal Infirmary, Manchester, UK.
| | - Paul Liberator
- Vaccine Research and Development, Pfizer Inc, Pearl River, NY, USA.
| | - Paul Balmer
- Vaccine Medical Development, Scientific and Clinical Affairs, Pfizer Inc, Collegeville, PA, USA.
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16
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Neisseria meningitidis Urethritis Outbreak Isolates Express a Novel Factor H Binding Protein Variant That Is a Potential Target of Group B-Directed Meningococcal (MenB) Vaccines. Infect Immun 2020; 88:IAI.00462-20. [PMID: 32958529 DOI: 10.1128/iai.00462-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 09/17/2020] [Indexed: 12/12/2022] Open
Abstract
Factor H binding protein (FHbp) is an important Neisseria meningitidis virulence factor that binds a negative regulator of the alternative complement pathway, human factor H (FH). Binding of FH increases meningococcal resistance to complement-mediated killing. FHbp also is reported to prevent interaction of the antimicrobial peptide (AMP) LL-37 with the meningococcal surface and meningococcal killing. FHbp is a target of two licensed group B-directed meningococcal (MenB) vaccines. We found a new FHbp variant, peptide allele identification no. 896 (ID 896), was highly expressed by an emerging meningococcal pathotype, the nonencapsulated urethritis clade (US_NmUC). This clade has been responsible for outbreaks of urethritis in multiple U.S. cities since 2015, other mucosal infections, and cases of invasive meningococcal disease. FHbp ID 896 is a member of the variant group 1 (subfamily B), bound protective anti-FHbp monoclonal antibodies, bound high levels of human FH, and enhanced the resistance of the clade to complement-mediated killing in low levels of human complement likely present at human mucosal surfaces. Interestingly, expression of FHbp ID 896 resulted in augmented killing of the clade by LL-37. FHbp ID 896 of the clade was recognized by antibodies elicited by FHbp in MenB vaccines.
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17
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Isitt C, Cosgrove CA, Ramsay ME, Ladhani SN. Success of 4CMenB in preventing meningococcal disease: evidence from real-world experience. Arch Dis Child 2020; 105:784-790. [PMID: 32029437 DOI: 10.1136/archdischild-2019-318047] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 01/14/2020] [Accepted: 01/15/2020] [Indexed: 11/03/2022]
Abstract
Meningococcal disease remains one of the most feared infectious diseases worldwide because of its sudden onset, rapid progression and high case fatality rates, while survivors are often left with severe long-term sequelae. Young children have the highest incidence of invasive meningococcal disease (IMD), and nearly all cases in the UK, as in most of Europe and many other industrialised countries, are due to group B meningococci (MenB). The licensure of a broad-coverage, recombinant protein-based MenB vaccine (4CMenB) in 2013 was, therefore, heralded a major breakthrough in the fight against IMD. This vaccine was, however, licensed on immunogenicity and reactogenicity studies only, raising uncertainties about field effectiveness, long-term safety and antibody persistence. In 2015, the UK became the first country to implement 4CMenB into the national infant immunisation schedule and, since then, several countries have followed suit. Seven years after licensure, a wealth of real-world data has emerged to confirm 4CMenB effectiveness, along with large-scale safety data, duration of protection in different age groups, successful strategies to reduce vaccine reactogenicity, impact on carriage in adolescents and the potential for 4CMenB to protect against other meningococcal serogroups and against gonorrhoea. A number of questions, however, remain unanswered, including the investigation and management of vaccine-associated fever in infants, as well as disease severity and assessment of breakthrough cases in immunised children. Increasing use of 4CMenB will provide answers in due course. We now have vaccines against all the major serogroups causing IMD worldwide. Next-generation and combination vaccines against multiple serogroups look very promising.
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Affiliation(s)
- Catherine Isitt
- Paediatric Infectious Diseases Research Group, St. George's University of London, London, UK
| | | | | | - Shamez N Ladhani
- Paediatric Infectious Diseases Research Group, St. George's University of London, London, UK .,Immunisation and Countermeasures Division, Public Health England, London, UK
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18
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Piccini G, Montomoli E. Pathogenic signature of invasive non-typhoidal Salmonella in Africa: implications for vaccine development. Hum Vaccin Immunother 2020; 16:2056-2071. [PMID: 32692622 PMCID: PMC7553687 DOI: 10.1080/21645515.2020.1785791] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Invasive non-typhoidal Salmonella (iNTS) infections are a leading cause of bacteremia in Sub-Saharan Africa (sSA), thereby representing a major public health threat. Salmonella Typhimurium clade ST313 and Salmonella Enteriditis lineages associated with Western and Central/Eastern Africa are among the iNTS serovars which are of the greatest concern due to their case-fatality rate, especially in children and in the immunocompromised population. Identification of pathogen-associated features and host susceptibility factors that increase the risk for invasive non-typhoidal salmonellosis would be instrumental for the design of targeted prevention strategies, which are urgently needed given the increasing spread of multidrug-resistant iNTS in Africa. This review summarizes current knowledge of bacterial traits and host immune responses associated with iNTS infections in sSA, then discusses how this knowledge can guide vaccine development while providing a summary of vaccine candidates in preclinical and early clinical development.
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Affiliation(s)
| | - Emanuele Montomoli
- VisMederi srl , Siena, Italy.,Department of Molecular and Developmental Medicine, University of Siena , Siena, Italy
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19
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Song Z, Li B, Zhang Y, Li R, Ruan H, Wu J, Liu Q. Outer Membrane Vesicles of Helicobacter pylori 7.13 as Adjuvants Promote Protective Efficacy Against Helicobacter pylori Infection. Front Microbiol 2020; 11:1340. [PMID: 32733396 PMCID: PMC7358646 DOI: 10.3389/fmicb.2020.01340] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/25/2020] [Indexed: 12/14/2022] Open
Abstract
Helicobacter pylori(H. pylori), a gram-negative bacterium in the human stomach with global prevalence, is relevant to chronic gastrointestinal diseases. Due to its increasing drug resistance and the low protective efficacy of some anti-H. pylori vaccines, it is necessary to find a suitable adjuvant to improve antigen efficiency. In our previous study, we determined that outer membrane vesicles (OMVs), a multicomponent secretion generated by gram-negative bacteria, of H. pylori were safe and could induce long-term and robust immune responses against H. pylori in mice. In this study, we employed two common vaccines, outer membrane proteins (OMPs) and whole cell vaccine (WCV) to assess the adjuvanticity of OMVs in mice. A standard adjuvant, cholera toxin (CT), was used as a control. Purified H. pylori OMVs used as adjuvants generated lasting anti-H. pylori resistance for 12 weeks. Additionally, both systematic and gastric mucosal immunity, as well as humoral immunity, of mice immunized with vaccine and OMVs combinations were significantly enhanced. Moreover, OMVs efficiently promoted Th1 immune response, but the response was skewed toward Th2 and Th17 immunity when compared with that induced by the CT adjuvant. Most importantly, OMVs as adjuvants enhanced the eradication of H. pylori. Thus, OMVs have potential applications as adjuvants in the development of a new generation of vaccines to treat H. pylori infection.
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Affiliation(s)
- Zifan Song
- Department of Medical Microbiology, School of Medicine, Nanchang University, Nanchang, China.,The First Clinical Medical College, Nanchang University, Nanchang, China
| | - Biaoxian Li
- Department of Medical Microbiology, School of Medicine, Nanchang University, Nanchang, China
| | - Yingxuan Zhang
- Department of Medical Microbiology, School of Medicine, Nanchang University, Nanchang, China.,The First Clinical Medical College, Nanchang University, Nanchang, China
| | - Ruizhen Li
- Department of Medical Microbiology, School of Medicine, Nanchang University, Nanchang, China.,The First Clinical Medical College, Nanchang University, Nanchang, China
| | - Huan Ruan
- Department of Medical Microbiology, School of Medicine, Nanchang University, Nanchang, China
| | - Jing Wu
- Department of Medical Microbiology, School of Medicine, Nanchang University, Nanchang, China
| | - Qiong Liu
- Department of Medical Microbiology, School of Medicine, Nanchang University, Nanchang, China.,Key Laboratory of Tumor Pathogenesis and Molecular Pathology, School of Medicine, Nanchang University, Nanchang, China
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20
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Principato S, Pizza M, Rappuoli R. Meningococcal factor H binding protein as immune evasion factor and vaccine antigen. FEBS Lett 2020; 594:2657-2669. [PMID: 32298465 DOI: 10.1002/1873-3468.13793] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 03/25/2020] [Accepted: 03/30/2020] [Indexed: 01/15/2023]
Abstract
Factor H binding protein (fHbp) is a key virulence factor of Neisseria meningitidis and a main component of the two licensed vaccines against serogroup B meningococcus (Bexsero and Trumenba). fHbp is a surface-exposed lipoprotein that enables the bacterium to survive in human blood by binding the human complement regulator factor H (fH). When used as vaccine, the protein induces antibodies with potent bactericidal activity. While the fHbp gene is present in the majority of N. meningitidis serogroup B isolates, the expression level varies up to 15 times between different strains and more than 700 different sequence variants have been described. Antigenically, the protein has been divided into three variants or two subfamilies. The 3D structure of fHbp alone, in combination with fH or in complex with bactericidal antibodies, has been key to understanding the molecular details of the protein. In this article, we will review the biochemical and immunological properties of fHbp, and its key role in meningococcal pathogenesis, complement regulation, and immune evasion.
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21
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Beernink PT. Effect of complement Factor H on antibody repertoire and protection elicited by meningococcal capsular group B vaccines containing Factor H binding protein. Hum Vaccin Immunother 2020; 16:703-712. [PMID: 31526219 DOI: 10.1080/21645515.2019.1664241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Bacteria produce surface ligands for host complement regulators including Factor H (FH), which allows the bacteria to evade immunity. Meningococcal Factor H binding protein (FHbp) is both a virulence factor and a vaccine antigen. Antibodies to FHbp can neutralize its function by inhibiting binding of FH to the bacteria and confer robust complement-mediated protection. However, in the presence of human or primate FH, antibodies to FHbp do not inhibit FH binding and the protective antibody responses are decreased. This immune suppression can be overcome by modification of the FHbp antigen to decrease FH binding, which modulates the antibody repertoire to inhibit FH binding and increase protection. When FHbp is present at sufficient density on the bacterial surface, two or more antibodies can synergize to activate the complement system. Thus, modification of FHbp antigens to decrease FH binding expands the anti-FHbp antibody repertoire and increases the potential for synergistic activity.
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Affiliation(s)
- Peter T Beernink
- Center for Immunobiology and Vaccine Development, UCSF Benioff Children's Hospital Oakland, Oakland, CA, USA.,Department of Pediatrics, School of Medicine, University of California, San Francisco, San Francisco, CA, USA
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22
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Lewis LA, Ram S. Complement interactions with the pathogenic Neisseriae: clinical features, deficiency states, and evasion mechanisms. FEBS Lett 2020; 594:2670-2694. [PMID: 32058583 DOI: 10.1002/1873-3468.13760] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 02/04/2020] [Accepted: 02/09/2020] [Indexed: 02/06/2023]
Abstract
Neisseria gonorrhoeae causes the sexually transmitted infection gonorrhea, while Neisseria meningitidis is an important cause of bacterial meningitis and sepsis. Complement is a central arm of innate immune defenses and plays an important role in combating Neisserial infections. Persons with congenital and acquired defects in complement are at a significantly higher risk for invasive Neisserial infections such as invasive meningococcal disease and disseminated gonococcal infection compared to the general population. Of note, Neisseria gonorrhoeae and Neisseria meningitidis can only infect humans, which in part may be related to their ability to evade only human complement. This review summarizes the epidemiologic and clinical aspects of Neisserial infections in persons with defects in the complement system. Mechanisms used by these pathogens to subvert killing by complement and preclinical studies showing how these complement evasion strategies may be used to counteract the global threat of meningococcal and gonococcal infections are discussed.
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Affiliation(s)
- Lisa A Lewis
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Sanjay Ram
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, MA, USA
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23
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Sharkey K, Beernink PT, Langley JM, Gantt S, Quach C, Dold C, Liu Q, Galvan M, Granoff DM. Anti-Factor H Antibody Reactivity in Young Adults Vaccinated with a Meningococcal Serogroup B Vaccine Containing Factor H Binding Protein. mSphere 2019; 4:e00393-19. [PMID: 31270173 PMCID: PMC6609231 DOI: 10.1128/msphere.00393-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 06/18/2019] [Indexed: 12/29/2022] Open
Abstract
Meningococcal serogroup B (MenB) vaccines contain recombinant factor H binding protein (FHbp), which can complex with complement factor H (CFH) and thereby risk eliciting anti-FH autoantibodies. While anti-FH antibodies can be present in sera of healthy persons, the antibodies are implicated in autoimmune atypical hemolytic uremic syndrome and C3 glomerulopathies. We immunized 120 students with a MenB vaccine (Bexsero). By enzyme-linked immunosorbent assay (ELISA), there were small increases in serum anti-FH levels at 3 weeks postvaccination (geometric mean optical density at 405 nm [OD405], 0.54 versus 0.51 preimmunization, P ≤ 0.003 for each schedule tested). There was a similar small increase in anti-FH antibody levels in a second historical MenB study of 20 adults with stored paired preimmunization and postimmunization sera (P = 0.007) but not in three other studies of 57 adults immunized with other meningococcal vaccines that did not contain recombinant FHbp (P = 0.17, 0.84, and 0.60, respectively). Thus, humans vaccinated with MenB-4C develop small increases in serum anti-FH antibody reactivity. Although not likely to be clinically important, the data indicate a host response to FH. In the prospective MenB study, three subjects (2.5%) developed higher anti-FH titers postimmunization. The elevated titers returned to baseline within 3 to 4 months, and none of the subjects reported adverse events during the follow-up. Although anti-FH antibodies can decrease FH function, the postimmunization sera with high anti-FH antibody levels did not impair serum FH function as measured using a hemolytic assay. Thus, while additional studies are warranted, there is no evidence that the anti-FH antibodies elicited by MenB-4C are likely to cause anti-FH-mediated autoimmune disorders. (This study has been registered at ClinicalTrials.gov under registration no. NCT02583412.)IMPORTANCE Meningococci are bacteria that cause sepsis and meningitis. Meningococcal species are subdivided into serogroups on the basis of different sugar capsules. Vaccines that target serogroup A, C, Y, and W capsules are safe and highly effective. New serogroup B (MenB) vaccines target a bacterial protein that can bind to a blood protein called complement factor H (FH). While serogroup B vaccines appear to be safe and effective, there is a theoretical risk that immunization with a bacterial protein that binds host FH might elicit anti-FH autoantibodies. Autoantibodies to FH have been detected in healthy persons but in rare cases can cause certain autoimmune diseases. We found small and/or transient increases in serum antibody to FH after MenB immunization. While no serious adverse events were reported in the subjects with elevated anti-FH titers, since onset of autoimmune disease is a rare event and may occur months or years after vaccination, additional, larger studies are warranted.
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Affiliation(s)
- Kelsey Sharkey
- Center for Immunobiology and Vaccine Development, University of California San Francisco Benioff Children's Hospital Oakland, Oakland, California, USA
| | - Peter T Beernink
- Center for Immunobiology and Vaccine Development, University of California San Francisco Benioff Children's Hospital Oakland, Oakland, California, USA
| | - Joanne M Langley
- IWK Health Centre and the Nova Scotia Health Authority, Canadian Center for Vaccinology at Dalhousie University, Halifax, Nova Scotia, Canada
| | - Soren Gantt
- BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Caroline Quach
- McGill University Health Centre Research Institute and CHU Sainte Justine, Montreal, Quebec, Canada
| | | | - Qin Liu
- Wistar Institute, Philadelphia, Pennsylvania, USA
| | - Manuel Galvan
- National Jewish Health Complement Laboratory, Denver, Colorado, USA
| | - Dan M Granoff
- Center for Immunobiology and Vaccine Development, University of California San Francisco Benioff Children's Hospital Oakland, Oakland, California, USA
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