1
|
Viviani V, Biolchi A, Pizza M. Synergistic activity of antibodies in the multicomponent 4CMenB vaccine. Expert Rev Vaccines 2022; 21:645-658. [PMID: 35257644 DOI: 10.1080/14760584.2022.2050697] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION : Vaccines based on multiple antigens often induce an immune response which is higher than that triggered by each single component, with antibodies acting cooperatively and synergistically in tackling the infection. AREAS COVERED An interesting example is the antibody response induced by the 4CMenB vaccine, currently licensed for the prevention of Neisseria meningitidis serogroup B (MenB). It contains four antigenic components: Factor H binding protein (fHbp), Neisseria adhesin A (NadA), Neisserial Heparin Binding Antigen (NHBA) and Outer Membrane Vesicles (OMV). Monoclonal and polyclonal antibodies raised by vaccination with 4CMenB show synergistic activity in complement-dependent bacterial killing. This review summarizes published and unpublished data and provides evidence of the added value of multicomponent vaccines. EXPERT OPINION : The ability of 4CMenB vaccine to elicit antibodies targeting multiple surface-exposed antigens is corroborated by the recent data on real world evidences. Bactericidal activity is generally mediated by antibodies that bind to antigens highly expressed on the bacterial surface and immunologically related. However, simultaneous binding of antibodies to various surface-exposed antigens can overcome the threshold density of antigen-antibody complexes needed for complement activation. The data discussed in this review highlight the interplay between antibodies targeting major and minor antigens and their effect on functionality. Clinical trial registration: www.clinicaltrials.gov identifiers of studies with original data mentioned in the article: NCT00937521, NCT00433914, NCT02140762 and NCT02285777.
Collapse
Affiliation(s)
| | | | - Mariagrazia Pizza
- Bacterial Vaccines, GSK, Siena, Italy.,GVGH, GSK Vaccine Institute for Global Health, Siena, Italy
| |
Collapse
|
2
|
Hou Y, Yan T, Cao H, Liu P, Zheng K, Li Z, Deng Q, Hu S. Chimeric hepatitis B virus core particles displaying Neisserial surface protein A confer protection against virulent Neisseria meningitidis serogroup B in BALB/c mice. Int J Nanomedicine 2019; 14:6601-6613. [PMID: 31496701 PMCID: PMC6702424 DOI: 10.2147/ijn.s206210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 08/01/2019] [Indexed: 12/22/2022] Open
Abstract
Purpose The primary goal of the present study was to explore and evaluate the highly conserved Neisserial surface protein A (NspA) molecule, fused with truncated HBV virus-like particles (VLPs), as a candidate vaccine against the virulent Neisseria meningitidis serogroup B (NMB). Methods NspA was inserted into the major immunodominant region of the truncated hepatitis B virus core protein (HBc; amino acids 1–144). The chimeric protein, HBc-N144-NspA, was expressed from a prokaryotic vector and generated HBc-like particles, as determined by transmission electron microscopy. Further, the chimeric protein and control proteins were used to immunize mice and the resulting immune responses evaluated by flow cytometry, enzyme-linked immunosorbent assay, and analysis of serum bactericidal activity (SBA) titer. Results Evaluation of the immunogenicity of the recombinant HBc-N144-NspA protein showed that it elicited the production of high levels of NspA-specific total IgG. The SBA titer of HBc-N144-NspA/F reached 1:16 2 weeks after the last immunization in BALB/c mice, when human serum complement was included in the vaccine. Immunization of HBc-N144-NspA, even without adjuvant, induced high levels of IL-4 and a high IgG1 to IgG2a ratio, confirming induction of an intense Th2 immune response. Levels of IL-17A increased rapidly in mice after the first immunization with HBc-N144-NspA, indicating the potential for this vaccine to induce a mucosal immune response. Meanwhile, the immunization of HBc-N144-NspA without adjuvant induced only mild inflammatory infiltration into the mouse muscle tissue. Conclusion This study demonstrates that modification using HBc renders NspA a candidate vaccine, which can trigger protective immunity against NMB.
Collapse
Affiliation(s)
- YongLi Hou
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Institution of Pathogenic Biology, Hengyang Medical College, University of South China, Hengyang 421001, People's Republic of China
| | - Ting Yan
- Department of Health Services, Air Force Medical University, Xi'an, Shaanxi 710032, People's Republic of China
| | - Hui Cao
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Institution of Pathogenic Biology, Hengyang Medical College, University of South China, Hengyang 421001, People's Republic of China
| | - Peng Liu
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Institution of Pathogenic Biology, Hengyang Medical College, University of South China, Hengyang 421001, People's Republic of China
| | - Kang Zheng
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Institution of Pathogenic Biology, Hengyang Medical College, University of South China, Hengyang 421001, People's Republic of China
| | - Zhenyu Li
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Institution of Pathogenic Biology, Hengyang Medical College, University of South China, Hengyang 421001, People's Republic of China
| | - Qing Deng
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Institution of Pathogenic Biology, Hengyang Medical College, University of South China, Hengyang 421001, People's Republic of China
| | - SiHai Hu
- Hunan Provincial Key Laboratory for Special Pathogens Prevention and Control, Institution of Pathogenic Biology, Hengyang Medical College, University of South China, Hengyang 421001, People's Republic of China
| |
Collapse
|
3
|
Piccini G, Torelli A, Gianchecchi E, Piccirella S, Montomoli E. FightingNeisseria meningitidis: past and current vaccination strategies. Expert Rev Vaccines 2016; 15:1393-1407. [DOI: 10.1080/14760584.2016.1187068] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
4
|
Impaired Immunogenicity of Meningococcal Neisserial Surface Protein A in Human Complement Factor H Transgenic Mice. Infect Immun 2015; 84:452-8. [PMID: 26597984 DOI: 10.1128/iai.01267-15] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 11/14/2015] [Indexed: 01/20/2023] Open
Abstract
Neisserial surface protein A (NspA) is a highly conserved outer membrane protein previously investigated as a meningococcal vaccine candidate. Despite eliciting serum bactericidal activity in mice, a recombinant NspA vaccine failed to elicit serum bactericidal antibodies in a phase 1 clinical trial in humans. The discordant results may be explained by the recent discovery that NspA is a human-specific ligand of the complement inhibitor factor H (FH). Therefore, in humans but not mice, NspA would be expected to form a complex with FH, which could impair human anti-NspA protective antibody responses. To investigate this question, we immunized human FH transgenic BALB/c mice with three doses of recombinant NspA expressed in Escherichia coli microvesicles, with each dose being separated by 3 weeks. Three of 12 (25%) transgenic mice and 13 of 14 wild-type mice responded with bactericidal titers of ≥1:10 in postimmunization sera (P = 0.0008, Fisher's exact test). In contrast, human FH transgenic and wild-type mice immunized with a control meningococcal native outer membrane vesicle vaccine had similar serum bactericidal antibody responses directed at PorA, which is not known to bind human FH, and a mutant factor H binding protein (FHbp) antigen with a >50-fold lower level of FH binding than wild-type FHbp antigen binding.Thus, human FH can impair anti-NspA serum bactericidal antibody responses, which may explain the poor immunogenicity of the NspA vaccine previously tested in humans. A mutant NspA vaccine engineered to have decreased binding to human FH may increase protective antibody responses in humans.
Collapse
|
5
|
Meningococcal Antigen Typing System Development and Application to the Evaluation of Effectiveness of Meningococcal B Vaccine and Possible Use for Other Purposes. J Immunol Res 2015; 2015:353461. [PMID: 26351645 PMCID: PMC4553328 DOI: 10.1155/2015/353461] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 01/16/2015] [Accepted: 02/17/2015] [Indexed: 01/22/2023] Open
Abstract
Development of the 4-component meningococcal serogroup B vaccine (4CMenB) has required new assays for the reliable evaluation of the expression and cross-reactivity of those specific antigen variants that are predicted to be targeted by bactericidal antibodies elicited by the vaccine in different isolates. Existing laboratory techniques, such as multilocus sequence typing, are poorly suited to this purpose, since they do not provide information on the contribution of single vaccine components and therefore cannot be applied to estimate the potential coverage of the multicomponent vaccine. The hSBA, the only correlate of protection against invasive meningococcal disease accepted thus far, cannot conveniently be used to test large number of strains. To overcome these issues, the meningococcal antigen typing system (MATS) has been specifically developed in order to predict 4CMenB coverage of individual meningococcus serogroup B strains. To date, MATS has proved advantageous for several reasons, including its ability to assess both qualitative and quantitative aspects of surface antigens of single strains in a highly reproducible, rapid, and resource-saving manner, while its shortcomings include a possible underestimation of 4CMenB coverage and the use of pooled sera to calculate the positive bactericidal threshold. This paper provides an overview of MATS development and its field application.
Collapse
|
6
|
Ying S, He J, Yu M, Zhang Y, Deng S, Zhang L, Xie M, Hu S. Recombinant Neisseria surface protein A is a potential vaccine candidate against Neisseria meningitides serogroup B. Mol Med Rep 2014; 10:1619-25. [PMID: 24926810 DOI: 10.3892/mmr.2014.2325] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 04/14/2014] [Indexed: 11/06/2022] Open
Abstract
Neisseria meningitidis is the pathogen of epidemic encephalomyelitis and is responsible for permanent damage to the brain and nervous system. In the present study, the prokaryotic expression vector pGEX-6p-1/neisseria surface protein A (NspA) was constructed and the immune protective effect was investigated with the purified recombinant rNspA. Female BALB/c mice were immunized by intraperitoneal inoculation of rNspA, glutathione S-transferase (GST) or phosphate-buffered saline (PBS). The protection experiment in mice demonstrated that the protection rate of the rNspA group was 85% against the N. meningitidis strain MC58, and a serum bactericidal assay in vitro revealed that the serum bactericidal titer of the rNspA group reached 1:64 following three immunizations. The levels of specific immunoglobulin (Ig) A (SIgA), IgG, IgG1, IgG2a, IgG2b and IgG3 of mice in the rNspA group peaked at week six and were higher than those in the mice in the GST and PBS groups. The levels of stimulation index, interleukin-4 and interferon-γ in the culture supernatant of the spleen lymphocytes of the rNspA group increased in a time-dependent manner and were higher than those of the mice in the GST and PBS groups over the same period. The results suggested that rNspA may induce increased specific humoral and cellular immune responses, and that it is effectively protective against N. meningitidis serogroup B in mice. The present study offered novel evidence that may lead to the development of a novel effective N. meningitidis serogroup B vaccine.
Collapse
Affiliation(s)
- Shangyun Ying
- Pathogenic Biology Institute, College of Basic Medicine, University of South China, Hengyang, Hunan 421001, P.R. China
| | - Jun He
- Pathogenic Biology Institute, College of Basic Medicine, University of South China, Hengyang, Hunan 421001, P.R. China
| | - Minjun Yu
- Pathogenic Biology Institute, College of Basic Medicine, University of South China, Hengyang, Hunan 421001, P.R. China
| | - Yukuai Zhang
- Pathogenic Biology Institute, College of Basic Medicine, University of South China, Hengyang, Hunan 421001, P.R. China
| | - Suhong Deng
- Pathogenic Biology Institute, College of Basic Medicine, University of South China, Hengyang, Hunan 421001, P.R. China
| | - Lusi Zhang
- Pathogenic Biology Institute, College of Basic Medicine, University of South China, Hengyang, Hunan 421001, P.R. China
| | - Meihua Xie
- Pathogenic Biology Institute, College of Basic Medicine, University of South China, Hengyang, Hunan 421001, P.R. China
| | - Sihai Hu
- Pathogenic Biology Institute, College of Basic Medicine, University of South China, Hengyang, Hunan 421001, P.R. China
| |
Collapse
|
7
|
Gasparini R, Amicizia D, Domnich A, Lai PL, Panatto D. Neisseria meningitidis B vaccines: recent advances and possible immunization policies. Expert Rev Vaccines 2014; 13:345-64. [PMID: 24476428 DOI: 10.1586/14760584.2014.880341] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Since the development of the first-generation vaccines based on outer membrane vesicles (OMV), which were able to contain strain-specific epidemics, but were not suitable for universal use, enormous steps forward in the prevention of Neisseria meningitidis B have been made. The first multicomponent vaccine, Bexsero(®), has recently been authorized for use; other vaccines, bivalent rLP2086 and next-generation OMV vaccines, are under development. The new vaccines may substantially contribute to reducing invasive bacterial infections as they could cover most Neisseria meningitidis B strains. Moreover, other potentially effective serogroup B vaccine candidates are being studied in preclinical settings. It is therefore appropriate to review what has recently been achieved in the prevention of disease caused by serogroup B.
Collapse
|
8
|
Abstract
A recent report by the Weekly Epidemiological Record of an outbreak of Neisseria meningitidis serogroup A in the Great Lakes region shows that meningococcal epidemics are an unsolved problem in resource-poor countries, particularly in Africa [1]. During the last epidemic wave in the 1990s, about 350,000 people developed meningitis and 1000 people died [101]. An effective polysaccharide vaccine has been available since the early 1970s. Unfortunately, attempts to contain the epidemics by timely detection of cases through active surveillance and prompt mass vaccination campaigns have failed to prevent the deaths of thousands of people in several African countries in the 1980s and 1990s. This article describes the epidemiology of N. meningitidis serogroup A, the available polysaccharide vaccines, their advantages and limitations. The current vaccination policies and their economic implications are discussed, to clarify why the use of an effective vaccine has, to date, been disappointing. The recent exciting developments with respect to conjugate vaccines are described.
Collapse
Affiliation(s)
- Stefania Vergnano
- International Perinatal Unit, Institute of Child Health, 30 Guildford Street, London WC1N IE4, UK.
| | | |
Collapse
|
9
|
Panatto D, Amicizia D, Lai PL, Cristina ML, Domnich A, Gasparini R. New versus old meningococcal group B vaccines: how the new ones may benefit infants & toddlers. Indian J Med Res 2013; 138:835-46. [PMID: 24521624 PMCID: PMC3978970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Invasive disease caused by Neisseria meningitidis is associated with high mortality and high disability rates and mainly affects children under one year of age. Vaccination is the best way to prevent meningococcal disease, especially in infants and toddlers. The introduction of massive meningococcal serogroup C vaccination has drastically reduced the incidence of disease caused by this serogroup, and serogroup B has now become the main causative agent in several industrialized countries. The first serogroup B vaccines, which were used for more than two decades, were based on outer membrane vesicles and proved to be protective only against specific epidemic strains in Cuba, Norway, Brazil and New Zealand. Moreover, these often elicited a scant immune response in young children. Innovative genomics-based reverse vaccinology subsequently enabled researchers to identify genes encoding for surface proteins that are able to elicit a strong immune response against several B strains. This important discovery led to the development and recent approval in Europe of the four-component meningococcal serogroup B (4CMenB) vaccine. Large clinical trials have shown high immunogenicity and tolerability and acceptable safety levels of 4CMenB in infants and toddlers. This vaccine is expected to cover a large number of circulating invasive strains and may also be efficacious against other serogroups. Young children are particularly vulnerable to the devastating consequences of meningococcal disease. Given the high performance of 4CMenB and its non-interference with routine vaccinations, this age-group will be the first to benefit from the introduction of this vaccine.
Collapse
Affiliation(s)
- D. Panatto
- Department of Health Sciences, University of Genoa, Genoa, Italy,Reprint requests: Dr D. Panatto, Department of Health Sciences, University of Genoa, via Pastore 1-16132, Genoa, Italy e-mail:
| | - D. Amicizia
- Department of Health Sciences, University of Genoa, Genoa, Italy
| | - PL. Lai
- Department of Health Sciences, University of Genoa, Genoa, Italy
| | - ML. Cristina
- Department of Health Sciences, University of Genoa, Genoa, Italy
| | - A. Domnich
- Department of Health Sciences, University of Genoa, Genoa, Italy
| | - R. Gasparini
- Department of Health Sciences, University of Genoa, Genoa, Italy
| |
Collapse
|
10
|
Neisseria gonorrhoeae NspA induces specific bactericidal and opsonic antibodies in mice. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2011; 18:1817-22. [PMID: 21918113 DOI: 10.1128/cvi.05245-11] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Neisseria gonorrhoeae surface protein A (NspA) is a highly conserved gonococcal antigen. To explore the potential of NspA in vaccine development against gonorrhea, BALB/c mice were immunized with pcNspA containing the NspA gene from N. gonorrhoeae strain WHO-A via intramuscular (i.m.) injection, intranasal (i.n.) immunization, or intravaginal (i.vag.) immunization. Following the last DNA immunization, mice were boosted with recombinant NspA (rNspA). Enzyme-linked immunosorbent assays (ELISAs) indicated that all immunized mice generated measurable NspA-specific IgG and IgA in serum and secretory IgA (sIgA) in vaginal wash fluids. The antisera had bactericidal and opsonic activities. These data demonstrated that NspA induced antibodies with antigonococcal activity.
Collapse
|
11
|
Lewis LA, Ngampasutadol J, Wallace R, Reid JEA, Vogel U, Ram S. The meningococcal vaccine candidate neisserial surface protein A (NspA) binds to factor H and enhances meningococcal resistance to complement. PLoS Pathog 2010; 6:e1001027. [PMID: 20686663 PMCID: PMC2912398 DOI: 10.1371/journal.ppat.1001027] [Citation(s) in RCA: 134] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2010] [Accepted: 06/30/2010] [Indexed: 12/13/2022] Open
Abstract
Complement forms an important arm of innate immunity against invasive meningococcal infections. Binding of the alternative complement pathway inhibitor factor H (fH) to fH-binding protein (fHbp) is one mechanism meningococci employ to limit complement activation on the bacterial surface. fHbp is a leading vaccine candidate against group B Neisseria meningitidis. Novel mechanisms that meningococci employ to bind fH could undermine the efficacy of fHbp-based vaccines. We observed that fHbp deletion mutants of some meningococcal strains showed residual fH binding suggesting the presence of a second receptor for fH. Ligand overlay immunoblotting using membrane fractions from one such strain showed that fH bound to a ∼17 kD protein, identified by MALDI-TOF analysis as Neisserial surface protein A (NspA), a meningococcal vaccine candidate whose function has not been defined. Deleting nspA, in the background of fHbp deletion mutants, abrogated fH binding and mAbs against NspA blocked fH binding, confirming NspA as a fH binding molecule on intact bacteria. NspA expression levels vary among strains and expression correlated with the level of fH binding; over-expressing NspA enhanced fH binding to bacteria. Progressive truncation of the heptose (Hep) I chain of lipooligosaccharide (LOS), or sialylation of lacto-N-neotetraose LOS both increased fH binding to NspA-expressing meningococci, while expression of capsule reduced fH binding to the strains tested. Similar to fHbp, binding of NspA to fH was human-specific and occurred through fH domains 6–7. Consistent with its ability to bind fH, deleting NspA increased C3 deposition and resulted in increased complement-dependent killing. Collectively, these data identify a key complement evasion mechanism with important implications for ongoing efforts to develop meningococcal vaccines that employ fHbp as one of its components. Neisseria meningitidis is an important cause of bacterial meningitis and sepsis worldwide. The complement system is a family of proteins that is critical for innate immune defenses against this pathogen. In order to successfully colonize humans and cause disease, the meningococcus must escape killing by the complement system. In this study we show that meningococci can use one of its surface proteins called Neisserial surface protein A (NspA) to bind to a host complement inhibitory protein called factor H (fH). NspA is a protein vaccine candidate against group B meningococcal disease. Binding of fH limits complement activation on the bacterial surface and enhances the ability of the meningococcus to resist complement-dependent killing. Capsular polysaccharide expression decreases fH binding to NspA, while truncation of the core glycan chain of lipooligosaccharide increases fH binding to meningococcal NspA. Loss of NspA results in enhanced complement activation on the bacterial surface and increased complement-dependent killing of meningococci. Our findings have disclosed a novel function for NspA and sheds further light on how this pathogen evades killing by the complement system.
Collapse
Affiliation(s)
- Lisa A Lewis
- Division of Infectious Diseases and Immunology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
| | | | | | | | | | | |
Collapse
|
12
|
Lewis S, Sadarangani M, Hoe JC, Pollard AJ. Challenges and progress in the development of a serogroup B meningococcal vaccine. Expert Rev Vaccines 2009; 8:729-45. [PMID: 19485754 DOI: 10.1586/erv.09.30] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Serogroup B meningococci cause the majority of the meningococcal disease burden in developed countries. Production of an effective and safe vaccine for serogroup B organisms has been hampered by the poor immunogenicity of the capsular polysaccharide that defines this group of bacteria. Previous efforts have focused on outer membrane vesicle vaccines, which have been implemented successfully during clonal outbreaks. However, the search for a universal vaccine against endemic polyclonal serogroup B meningococcal disease continues. In this review, we have highlighted recent development of outer membrane vesicle vaccines and progress in the evaluation of recombinant outer membrane protein vaccines.
Collapse
Affiliation(s)
- Susan Lewis
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Centre for Clinical Vaccinology and Tropical Medicine, Churchill Hospital, Headington, Oxford, OX3 7LJ, UK.
| | | | | | | |
Collapse
|
13
|
Specificity of subcapsular antibody responses in Ethiopian patients following disease caused by serogroup A meningococci. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2008; 15:863-71. [PMID: 18337382 DOI: 10.1128/cvi.00252-07] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Dissecting the specificities of human antibody responses following disease caused by serogroup A meningococci may be important for the development of improved vaccines. We performed a study of Ethiopian patients during outbreaks in 2002 and 2003. Sera were obtained from 71 patients with meningitis caused by bacteria of sequence type 7, as confirmed by PCR or culture, and from 113 Ethiopian controls. Antibody specificities were analyzed by immunoblotting (IB) against outer membrane antigen extracts of a reference strain and of the patients' own isolates and by enzyme-linked immunosorbent assay for immunoglobulin G (IgG) levels against lipooligosaccharide (LOS) L11 and the proteins NadA and NspA. IB revealed that the main antigens targeted were the proteins PorA, PorB, RmpM, and Opa/OpcA, as well as LOS. MenA disease induced significant increases in IgG against LOS L11 and NadA. The IgG levels against LOS remained elevated following disease, whereas the IgG anti-NadA levels returned to acute-phase levels in the late convalescent phase. Among adults, the anti-LOS IgG levels were similar in acute-phase patient sera as in control sera, whereas anti-NadA IgG levels were significantly higher in acute-phase sera than in controls. The IgG antibody levels against LOS and NadA correlated moderately but significantly with serum bactericidal activity against MenA strains. Future studies on immune response during MenA disease should take into account the high levels of anti-MenA polysaccharide IgG commonly found in the population and seek to clarify the role of antibodies against subcapsular antigens in protection against MenA disease.
Collapse
|
14
|
Shaik YB, Grogan S, Davey M, Sebastian S, Goswami S, Szmigielski B, Genco CA. Expression of the iron-activated nspA and secY genes in Neisseria meningitidis group B by Fur-dependent and -independent mechanisms. J Bacteriol 2006; 189:663-9. [PMID: 17085550 PMCID: PMC1797404 DOI: 10.1128/jb.01638-06] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Our whole-genome microarray studies of Neisseria meningitidis MC58 previously identified a set of 153 genes whose transcription was activated during growth in iron. In this study, Fur-mediated regulation of the iron-activated nspA gene was confirmed, whereas iron-activated regulation of the secY gene was demonstrated to be Fur independent. Analysis of the Fur binding sequences in the nspA gene and an additional iron-activated and Fur-regulated gene identified a hexameric (G/T)ATAAT unit in the operator regions of these genes similar to that observed in Fur- and iron-repressed genes. These studies indicate that the expression of the iron-activated nspA and secY genes in N. meningitidis occur by Fur-dependent and -independent mechanisms, respectively.
Collapse
Affiliation(s)
- Yazdani B Shaik
- Department of Medicine, Section of Molecular Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | | | | | | | | | | | | |
Collapse
|
15
|
Halperin SA, Langley JM, Smith B, Wunderli P, Kaufman L, Kimura A, Martin D. Phase 1 first-in-human studies of the reactogenicity and immunogenicity of a recombinant meningococcal NspA vaccine in healthy adults. Vaccine 2006; 25:450-7. [PMID: 17052819 DOI: 10.1016/j.vaccine.2006.08.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Revised: 07/31/2006] [Accepted: 08/02/2006] [Indexed: 11/26/2022]
Abstract
BACKGROUND Neisserial surface protein A (NspA) is a highly conserved, surface-exposed outer membrane protein of Neisseria meningitidis that has been shown to induce a bactericidal immune response in animals against all pathogenic Neisserial serogroups. METHODS Healthy 18-50-year-old adults were assigned to receive, in a dose escalating manner, 3 doses of 1 of 5 formulations of an experimental, unfolded, recombinant NspA (rNspA) vaccine or placebo, or 1 dose of commercially available quadravalent (A, C, Y, W-135) meningococcal polysaccharide vaccine (Menomune((R))). Adverse events were collected during the first week post-immunization, prior to the next dose and 1 month after the last dose. Serum for measurement of hematological and biochemical parameters and antibodies by enzyme immunoassay and bactericidal assay were measured before the first dose, prior to the second dose and 1 month after the last dose of vaccine. RESULTS The rNspA vaccine was well tolerated by recipients. Injection-site pain was reported more frequently by recipients of the three highest doses of rNspA compared to placebo but at similar rates to the licensed meningococcal polysaccharide vaccine. Adverse events were reported less frequently after subsequent doses in the three-dose series. An antibody rise measured by enzyme immunoassay was elicited with a dose-related increase that reached a maximum with the 125mug dose. Prolongation of the dosing interval between the second and third dose appeared to be associated with increased antibody levels. No bactericidal antibodies were detected after any of the rNspA formulations. CONCLUSIONS The unfolded rNspA meningococcal vaccine was well tolerated and immunogenic in healthy adult volunteers but did not elicit bactericidal antibodies.
Collapse
Affiliation(s)
- Scott A Halperin
- Clinical Trials Research Center, Dalhousie University, The IWK Health Centre, Halifax, NS, Canada.
| | | | | | | | | | | | | |
Collapse
|
16
|
Abstract
Neisseria meningitidis is the leading cause of bacterial meningitis in the United States and worldwide. A serogroup A/C/W-135/Y polysaccharide meningococcal vaccine has been licensed in the United States since 1981 but has not been used universally outside of the military. On 14 January 2005, a polysaccharide conjugate vaccine that covers meningococcal serogroups A, C, W-135, and Y was licensed in the United States for 11- to 55-year-olds and is now recommended for the routine immunization of adolescents and other high-risk groups. This review covers the changing epidemiology of meningococcal disease in the United States, issues related to vaccine prevention, and recommendations on the use of the new vaccine.
Collapse
Affiliation(s)
- Lee H Harrison
- Infectious Diseases Epidemiology Research Unit, 521 Parran Hall, 130 Desoto St., University of Pittsburgh, Pittsburgh, PA 15261, USA.
| |
Collapse
|
17
|
Abstract
Meningococcal disease, presenting primarily as septicaemia and meningitis, continues to be a devastating problem around the world. Over the last century, vaccine development has been undertaken in earnest for the prevention of this disease. Polysaccharide vaccines have been available for almost 40 years, yet they are poorly immunogenic in young children who are at the highest risk. Since their introduction into some routine immunisation schedules in 1999, polysaccharide-protein conjugate vaccines for the prevention of serogroup C meningococcal infection have proven efficacious. A quadrivalent polysaccharide-protein conjugate vaccine against serogroups A, C, W135 and Y, which is being introduced in the US this year, is hoped to control disease caused by these serogroups. To date, however, the development of a universally safe, immunogenic and effective serogroup B Neisseria meningitidis vaccine has remained a challenge. This review details the many conventional vaccine strategies and the more recent genome-derived technological approaches being used in serogroup B vaccine development. The future prevention of serogroup B disease will rely on both outer membrane vesicle vaccines being used for serosubtype-specific outbreaks and new vaccines containing multiple other antigens. Investment by the pharmaceutical industry in preclinical research and development provides hope that an efficacious serogroup B meningococcal vaccine can be developed.
Collapse
Affiliation(s)
- Kirsten P Perrett
- Oxford Vaccine Group, Centre for Clinical Vaccinology and Tropical Medicine, Churchill Hospital, Headington, Oxford, OX3 7LJ, UK.
| | | |
Collapse
|
18
|
Kotelnikova OV, Chibiskova OV, Nesmeyanov VA, Alliluev AP, Volpina OV, Koroev DO, Zhmak MN, Titova MA, Ivanov VT. Protective Properties of Synthetic Peptides of Outer Meningococcal Membrane. Bull Exp Biol Med 2005; 139:593-5. [PMID: 16224557 DOI: 10.1007/s10517-005-0353-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Peptide fragments of conservative sites of PorA, OpaB, and NspA proteins of the outer membrane of serogroup B meningococci were synthesized. These peptides caused a pronounced protective effect in immunized mice infected with virulent homologous and heterologous strains of serogroups B and A meningococci. The protective effect appreciably increased, if the studied peptides were associated in a polycomponent preparation, which can be used in the construction of meningococcal bivalent B+A vaccine.
Collapse
Affiliation(s)
- O V Kotelnikova
- MM Shemyakin and Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow.
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
de Filippis I, do Nascimento CRS, Clementino MBM, Sereno AB, Rebelo C, Souza NNF, Riley LW. Rapid detection of Neisseria meningitidis in cerebrospinal fluid by one-step polymerase chain reaction of the nspA gene. Diagn Microbiol Infect Dis 2005; 51:85-90. [PMID: 15698712 DOI: 10.1016/j.diagmicrobio.2004.10.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2004] [Accepted: 10/06/2004] [Indexed: 11/19/2022]
Abstract
A polymerase chain reaction (PCR) protocol for the rapid detection of meningococcal DNA in cerebrospinal fluid (CSF) was developed and optimized. A set of primers based on Neisseria surface protein A (nspA) gene sequence was designed to amplify a 481-bp product specific for N. meningitidis. We tested 85 N. meningitidis strains obtained from patients with meningococcal meningitis and 112 CSF samples from patients with suspected meningococcal meningitis. No amplification of the nspA gene was observed from other Neisseriaceae species (except from N. gonorrhoeae) and from other bacteria frequently associated with meningitis. N. meningitidis belonging to different serogroups yielded the same product after PCR amplification. The sensitivity and specificity of our protocol was determined by comparing the results of specific amplification of nspA gene by PCR reaction (nspA-PCR) with those obtained by conventional methods. All positive samples by conventional methods were confirmed by nspA-PCR, whereas 48% of negative samples after culture and latex agglutination tested positive by nspA-PCR. The use of nspA-PCR proved to be a rapid diagnostic method, in which sensitivity and specificity may not be affected by prior antibiotic treatment.
Collapse
Affiliation(s)
- Ivano de Filippis
- Instituto Nacional de Controle de Qualidade em Saúde, Depto. de Microbiologia/Fundação Oswaldo Cruz, Rio de Janeiro 21045-900, Brazil.
| | | | | | | | | | | | | |
Collapse
|
20
|
O'dwyer CA, Reddin K, Martin D, Taylor SC, Gorringe AR, Hudson MJ, Brodeur BR, Langford PR, Kroll JS. Expression of heterologous antigens in commensal Neisseria spp.: preservation of conformational epitopes with vaccine potential. Infect Immun 2004; 72:6511-8. [PMID: 15501782 PMCID: PMC523026 DOI: 10.1128/iai.72.11.6511-6518.2004] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Commensal neisseriae share with Neisseria meningitidis (meningococcus) a tendency towards overproduction of the bacterial outer envelope, leading to the formation and release during growth of outer membrane vesicles (OMVs). OMVs from both meningococci and commensal neisseriae have shown promise as vaccines to protect against meningococcal disease. We report here the successful expression at high levels of heterologous proteins in commensal neisseriae and the display, in its native conformation, of one meningococcal outer membrane protein vaccine candidate, NspA, in OMVs prepared from such a recombinant Neisseria flavescens strain. These NspA-containing OMVs conferred protection against otherwise lethal intraperitoneal challenge of mice with N. meningitidis serogroup B, and sera raised against them mediated opsonophagocytosis of meningococcal strains expressing this antigen. This development promises to facilitate the design of novel vaccines containing membrane protein antigens that are otherwise difficult to present in native conformation that provide cross-protective efficacy in the prevention of meningococcal disease.
Collapse
MESH Headings
- Animals
- Antibodies, Bacterial/blood
- Antibodies, Bacterial/immunology
- Antibodies, Bacterial/metabolism
- Antigens, Bacterial/chemistry
- Antigens, Bacterial/genetics
- Antigens, Bacterial/immunology
- Antigens, Bacterial/metabolism
- Bacterial Outer Membrane Proteins/genetics
- Bacterial Outer Membrane Proteins/immunology
- Bacterial Outer Membrane Proteins/metabolism
- Cell Line
- Conjugation, Genetic
- Cytoplasmic Vesicles
- Epitopes/chemistry
- Epitopes/immunology
- Flow Cytometry
- Humans
- Immunization, Passive
- Meningococcal Infections/immunology
- Meningococcal Infections/prevention & control
- Meningococcal Vaccines/administration & dosage
- Meningococcal Vaccines/genetics
- Meningococcal Vaccines/immunology
- Mice
- Neisseria/genetics
- Neisseria/immunology
- Neisseria/metabolism
- Neisseria meningitidis, Serogroup B/immunology
- Opsonin Proteins
- Phagocytosis
- Protein Conformation
- Recombinant Proteins/chemistry
- Recombinant Proteins/immunology
- Recombinant Proteins/metabolism
Collapse
Affiliation(s)
- Clíona A O'dwyer
- Molecular Infectious Diseases Group, Department of Paediatrics, Faculty of Medicine, Imperial College London, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Hou VC, Moe GR, Raad Z, Wuorimaa T, Granoff DM. Conformational epitopes recognized by protective anti-neisserial surface protein A antibodies. Infect Immun 2004; 71:6844-9. [PMID: 14638771 PMCID: PMC308938 DOI: 10.1128/iai.71.12.6844-6849.2003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
NspA is a conserved membrane protein that elicits protective antibody responses in mice against Neisseria meningitidis. A recent crystallographic study showed that NspA adopts an eight-stranded beta-barrel structure when reconstituted in detergent. In order to define the segments of NspA-containing epitopes recognized by protective murine anti-NspA antibodies, we studied the binding of two bactericidal and protective anti-NspA monoclonal antibodies (MAbs), AL12 and 14C7. Neither MAb binds to overlapping synthetic peptides (10-mers, 12-mers, and cyclic 12-mers) corresponding to the entire mature sequence of NspA, or to denatured recombinant NspA (rNspA), although binding to the protein can be restored by refolding in liposomes. Based on the ability of the two MAbs to bind to Escherichia coli microvesicles prepared from a set of rNspA variants created by site-specific mutagenesis, the most important contacts between the MAbs and NspA appear to be located within the LGG segment of loop 3. The conformation of loop 2 also appears to be an important determinant, as particular combinations of residues in this segment resulted in loss of antibody binding. Thus, the two anti-NspA MAbs recognize discontinuous conformational epitopes that result from the close proximity of loops 2 and 3 in the three-dimensional structure of NspA. The data suggest that optimally immunogenic vaccines using rNspA will require formulations that permit proper folding of the protein.
Collapse
Affiliation(s)
- Victor C Hou
- Children's Hospital Oakland Research Institute, Oakland, California, USA
| | | | | | | | | |
Collapse
|
22
|
Segal S, Pollard AJ. The Last of the Meningococcus? ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2004; 549:201-9. [PMID: 15250534 DOI: 10.1007/978-1-4419-8993-2_27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shelley Segal
- Department of Pediatrics, University of Oxford, United Kingdom
| | | |
Collapse
|
23
|
Abstract
Meningitis remains an important cause of morbidity and mortality among children >5 years of age and is especially prevalent in developing countries. Effective routine immunization against Hib, pneumococcus and serogroupC meningococcus has had a significant impact on both invasive disease and carriage caused by these encapsulated bacteria. The major challenge in prevention of meningitis remains the delivery of vaccines worldwide, especially to resource-poor regions with the greatest disease burden.
Collapse
Affiliation(s)
- S Segal
- Department of Paediatrics, University of Oxford, Level 4, John Radcliffe Hospital, Oxford OX3 9DU, UK.
| | | |
Collapse
|
24
|
Vandeputte-Rutten L, Bos MP, Tommassen J, Gros P. Crystal structure of Neisserial surface protein A (NspA), a conserved outer membrane protein with vaccine potential. J Biol Chem 2003; 278:24825-30. [PMID: 12716881 DOI: 10.1074/jbc.m302803200] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The neisserial surface protein A (NspA) from Neisseria meningitidis is a promising vaccine candidate because it is highly conserved among meningococcal strains and induces bactericidal antibodies. NspA is a homolog of the Opa proteins, which mediate adhesion to host cells. Here, we present the crystal structure of NspA, determined to 2.55-A resolution. NspA forms an eight-stranded antiparallel beta-barrel. The four loops at the extracellular side of the NspA molecule form a long cleft, which contains mainly hydrophobic residues and harbors a detergent molecule, suggesting that the protein might function in the binding of hydrophobic ligands, such as lipids. In addition, the structure provides a starting point for structure-based vaccine design.
Collapse
Affiliation(s)
- Lucy Vandeputte-Rutten
- Department of Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Utrecht, The Netherlands
| | | | | | | |
Collapse
|
25
|
Segal S, Pollard AJ. The future of meningitis vaccines. HOSPITAL MEDICINE (LONDON, ENGLAND : 1998) 2003; 64:161-7. [PMID: 12669483 DOI: 10.12968/hosp.2003.64.3.1799] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Without effective vaccines meningitis remains a substantial worldwide threat with major health-care implications. A number of advances have been made in vaccine design and implementation over the last decade, with new vaccine initiatives providing substantial promise for the future reduction of global disease burden.
Collapse
Affiliation(s)
- S Segal
- Department of Paediatrics, John Radcliffe Hospital, Oxford OX3 9DU
| | | |
Collapse
|
26
|
Navarro-Alonso JA. La inmunización activa frente a Neisseria meningitidis serogrupo B. Enferm Infecc Microbiol Clin 2003; 21:513-9. [PMID: 14572386 DOI: 10.1016/s0213-005x(03)72998-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Serogroup B Neisseria meningitidis causes high morbidity and mortality rates over the world. This article reviews the current vaccination strategies against this microorganism, including vaccines already tested on a large scale, particularly those based on class 1 outer membrane proteins, and vaccines in different stages of development. The latter involve several approaches, such as modification of the polysaccharide capsule composition or conjugation with proteins, and the use of recombinant DNA techniques to obtain vaccines that express the prevalent sero-subtypes in a particular geographical area. The challenges that have emerged with the sequencing of the meningococcus B genome are also addressed.
Collapse
MESH Headings
- Antibodies, Bacterial/biosynthesis
- Antibodies, Bacterial/immunology
- Antigens, Bacterial/immunology
- Bacterial Capsules
- Bacterial Outer Membrane Proteins/immunology
- Clinical Trials as Topic
- Cross Reactions
- Humans
- Immunoglobulin M/biosynthesis
- Meningitis, Meningococcal/immunology
- Meningitis, Meningococcal/microbiology
- Meningitis, Meningococcal/prevention & control
- Meningococcal Vaccines/immunology
- Neisseria meningitidis, Serogroup B/immunology
- Polysaccharides, Bacterial/immunology
- Species Specificity
- Vaccination
- Vaccines, Conjugate/immunology
- Vaccines, Synthetic/immunology
Collapse
|
27
|
Abstract
Serogroup B Neisseria meningitidis is a frequent cause of invasive meningococcal disease, yet there are no effective vaccines suitable for routine immunisation. Limited efficacy has been shown with meningococcal outer membrane vacccines in children 4 years and older. Here we review the status of current research and consider new approaches to development of meningococcal serogroup B vaccines.
Collapse
Affiliation(s)
- A J Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK.
| | | |
Collapse
|
28
|
Abstract
Neisseria meningitidis is a major cause of bacterial meningitis and sepsis. Polysaccharide-protein conjugate vaccines for prevention of group C disease have been licensed in Europe. Such vaccines for prevention of disease caused by groups A (which is associated with the greatest disease burden worldwide), Y, and W135 are being developed. However, conventional approaches to develop a vaccine for group B strains, which are responsible for most cases in Europe and the USA, have been largely unsuccessful. Capsular polysaccharide-based vaccines can elicit autoantibodies to host polysialic acid, whereas the ability of most non-capsular antigens to elicit broad-based immunity is limited by their antigenic diversity. Many new membrane proteins have been discovered during analyses of genomic sequencing data. These antigens are highly conserved and, in mice, elicit serum bactericidal antibodies, which are the serological hallmark of protective immunity in man. Therefore, there are many promising new vaccine candidates, and improved prospects for development of a broadly protective vaccine for group B disease, and for control of all meningococcal disease.
Collapse
Affiliation(s)
- Luis Jódar
- Vaccine Development and Quality and Safety of Biologicals, World Health Organization, Geneva, Switzerland.
| | | | | | | |
Collapse
|
29
|
Abstract
The past century has seen the use of a number of vaccines for prevention and control of meningococcal disease with varied success. The use of polysaccharide vaccines for the control of outbreaks of serogroup C infections in teenagers and young adults and epidemic serogroup A disease has been established for 30 years and an effective protein-polysaccharide conjugate vaccine against serogroup C was introduced into the UK infant immunisation schedule in 2000. The next generation of these glycoconjugate vaccines will be on the shelf soon, eventually offering the prospect of eradication of serogroups A, C, Y and W135 through routine infant immunisation. Despite these exciting prospects, serogroup B meningococci still account for a majority of infections in industrialised nations but development of safe, immunogenic and effective serogroup B meningococcal vaccines has been an elusive goal. Outer membrane vesicle vaccines for B disease are already used in some countries, and will likely be used more widely in the next few years, but efficacy for endemic disease in children has so far been disappointing. However, the innovations arising from the availability of the meningococcal genome sequence, public and scientific interest in the disease and recent pharmaceutical company investment in development of serogroup B vaccines may have started the countdown to the end of meningococcal infection in children.
Collapse
Affiliation(s)
- S L Morley
- Department of Paediatrics, Imperial College School of Medicine, St Mary's Campus, Norfolk Place, London W2 1PG, UK.
| | | |
Collapse
|
30
|
Moe GR, Zuno-Mitchell P, Lee SS, Lucas AH, Granoff DM. Functional activity of anti-Neisserial surface protein A monoclonal antibodies against strains of Neisseria meningitidis serogroup B. Infect Immun 2001; 69:3762-71. [PMID: 11349041 PMCID: PMC98387 DOI: 10.1128/iai.69.6.3762-3771.2001] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Neisserial surface protein A (NspA) is currently being investigated with humans as a candidate vaccine for the prevention of meningococcal disease. Although NspA is highly conserved, the ability of anti-NspA antibodies to bind to or elicit complement-mediated bactericidal activity against diverse Neisseria meningitidis serogroup B strains is controversial. To evaluate strain differences in NspA surface accessibility and susceptibility to bactericidal activity, we prepared murine immunoglobulin G2a anti-NspA monoclonal antibodies (MAbs) and evaluated their functional activity against 10 genetically diverse N. meningitidis serogroup B strains. By colony Western blot, all 10 strains expressed NspA as detected by one or more MAbs. By flow cytometry, two MAbs were found to bind to the bacterial surface of 6 of the 10 strains. In addition, two strains showed variable NspA surface accessibility for the MAbs despite being uniformly positive for NspA expression by colony Western blotting. Only 4 of the 10 strains were susceptible to anti-NspA complement-mediated bacteriolysis. Passively administered MAb protected infant rats from developing bacteremia after challenge with N. meningitidis serogroup B strain 8047 (surface binding positive, susceptible to anti-NspA bacteriolysis), was poorly protective against strain BZ232 (surface binding variable, resistant to bacteriolysis), and did not protect against strain M986 (surface binding negative, resistant to bacteriolysis). Finally, NspA does not appear to be critical for causing bacteremia, as an NspA knockout from strain 8047 was highly virulent in infant rats. Taken together, these findings suggest that an NspA-based vaccine will need to incorporate additional antigens to elicit broad protection against N. meningitidis serogroup B.
Collapse
Affiliation(s)
- G R Moe
- Children's Hospital Oakland Research Institute, California 94609, USA
| | | | | | | | | |
Collapse
|
31
|
Abstract
Global control and prevention of meningococcal disease depends on the further development of vaccines that overcome the limitations of the current polysaccharide vaccines. Protein-polysaccharide conjugate vaccines likely will address the marginal protective antibody responses and short duration of immunity in young children derived from the A, C, Y, and W-135 capsular polysaccharides, but they will be expensive to produce and purchase, and may not offer a practical solution to the countries with greatest need. In addition, OMP vaccines have been tested extensively in humans and hold some promise in the development of a serogroup B vaccine, but are limited by the antigenic variability of these subcapsular antigens and the resulting strain-specific protection. Elimination of meningococcal disease likely will require a novel approach to vaccine development, ideally incorporating a safe and effective antigen or antigens common to all meningoccocal serogroups. As a solely human pathogen, however, N. meningitidis has developed many tools with which to evade the human immune system, and likely will pose a formidable challenge for years to come.
Collapse
Affiliation(s)
- N E Rosenstein
- Meningitis and Special Pathogens Branch, Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.
| | | | | |
Collapse
|
32
|
West D, Reddin K, Matheson M, Heath R, Funnell S, Hudson M, Robinson A, Gorringe A. Recombinant Neisseria meningitidis transferrin binding protein A protects against experimental meningococcal infection. Infect Immun 2001; 69:1561-7. [PMID: 11179327 PMCID: PMC98056 DOI: 10.1128/iai.69.3.1561-1567.2001] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To better characterize the vaccine potential of Neisseria meningitidis transferrin binding proteins (Tbps), we have overexpressed TbpA and TbpB from Neisseria meningitidis isolate K454 in Escherichia coli. The ability to bind human transferrin was retained by both recombinant proteins, enabling purification by affinity chromotography. The recombinant Tbps were evaluated individually and in combination in a mouse intraperitoneal-infection model to determine their ability to protect against meningococcal infection and to induce cross-reactive and bactericidal antibodies. For the first time, TbpA was found to afford protection against meningococcal challenge when administered as the sole immunogen. In contrast to the protection conferred by TbpB, this protection extended to a serogroup C isolate and strain B16B6, a serogroup B isolate with a lower-molecular-weight TbpB than that from strain K454. However, serum from a TbpB-immunized rabbit was found to be significantly more bactericidal than that from a TbpA-immunized animal. Our evidence demonstrates that TbpA used as a vaccine antigen may provide protection against a wider range of meningococcal strains than does TbpB alone. This protection appears not to be due to complement-mediated lysis and indicates that serum bactericidal activity may not always be the most appropriate predictor of efficacy for protein-based meningococcal vaccines.
Collapse
Affiliation(s)
- D West
- Centre for Applied Microbiology and Research, Salisbury SP4 0JG, United Kingdom
| | | | | | | | | | | | | | | |
Collapse
|
33
|
De Gaspari EN. Production and characterization of a new monoclonal antibody against Neisseria meningitidis: study of the cross-reactivity with different bacterial genera. Hybridoma (Larchmt) 2000; 19:445-53. [PMID: 11152396 DOI: 10.1089/027245700750053931] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We have generated a hybridoma cell line which produces an 8C7Br1 clone of the IgM antibody isotype. It recognizes the 50-, 65-, and 60-kDa antigens and is reactive with strains of N. meningitidis in the 98% of local Neisseria genera by Dot-ELISA assays. Two percent of the strains of N. meningitidis B do not present reactivity with the 8C7Br1 monoclonal antibody (MAb). The antibody reacted against N. meningitidis of serogroups A, B, C, X, Y, Z, and different serotypes and subtypes of N. meningitidis B and C by means of Dot-ELISA and Immunoblot. It cross-reacted with Neisseria gonorrhoeae, Neisseria lactamica, Haemophilus influenzae type b, Escherichia coli, Salmonella typhimurium, Salmonella typhi, Shigella flexneri, Bordetella pertussis, and Bacillus subtilis. The 8C7Br1 MAb reacted with the 65-kDa protein present in the prototype meningococcal strains B:16:B6(B2a:P1.5.2) and 2996 (B2b:P1.5.2). In H. influenzae type b, E. coli and B. subtilis, the MAb recognized the protein of 60, 65, and 70 kDa, respectively. FACS analysis showed that 8C7Brl MAb could recognize the 50-kDa protein on the surface of N. meningitidis homologous (B:4:P1.9) strain. These results, together with the bactericidal activity of 8C7Br1, and an experiment of passive protection in mice, demonstrated the potential importance of the cross-reactive protein as a candidate antigen for N. meningitidis B vaccine composition.
Collapse
Affiliation(s)
- E N De Gaspari
- Immunology Section, Adolfo Lutz Institute, São Paulo, SP, Brazil.
| |
Collapse
|
34
|
Martin D, Brodeur BR, Hamel J, Couture F, de Alwis U, Lian Z, Martin S, Andrews D, Ellis RW. Candidate Neisseria meningitidis NspA vaccine. J Biotechnol 2000; 83:27-31. [PMID: 11000456 DOI: 10.1016/s0168-1656(00)00294-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The highly conserved NspA protein has been found in the outer membrane of every Neisseria meningitidis strain tested so far. Two monoclonal antibodies (MAbs) directed against this protein were used to demonstrate that biologically important epitopes of the NspA protein are exposed at the surface of serologically distinct meningococcal strains. Analysis of sera collected from mice that survived a deadly meningococcal challenge following immunization with recombinant NspA protein (rNspA) revealed the presence of cross-reactive antibodies which efficiently attached to and killed the four serogroup B strains tested. These data are additional proof that the NspA protein is exposed at the surface of intact meningococcal cells, which is an important characteristic for a vaccine candidate.
Collapse
Affiliation(s)
- D Martin
- Unite de Recherche en Vaccinologie, Centre Hospitalier Universitaire de Québec, Pavillon CHUL et Université Laval, Sainte-Foy, G1V 4G2, Québec, Canada.
| | | | | | | | | | | | | | | | | |
Collapse
|