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Sándor N, Schneider AE, Matola AT, Barbai VH, Bencze D, Hammad HH, Papp A, Kövesdi D, Uzonyi B, Józsi M. The human factor H protein family - an update. Front Immunol 2024; 15:1135490. [PMID: 38410512 PMCID: PMC10894998 DOI: 10.3389/fimmu.2024.1135490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 01/08/2024] [Indexed: 02/28/2024] Open
Abstract
Complement is an ancient and complex network of the immune system and, as such, it plays vital physiological roles, but it is also involved in numerous pathological processes. The proper regulation of the complement system is important to allow its sufficient and targeted activity without deleterious side-effects. Factor H is a major complement regulator, and together with its splice variant factor H-like protein 1 and the five human factor H-related (FHR) proteins, they have been linked to various diseases. The role of factor H in inhibiting complement activation is well studied, but the function of the FHRs is less characterized. Current evidence supports the main role of the FHRs as enhancers of complement activation and opsonization, i.e., counter-balancing the inhibitory effect of factor H. FHRs emerge as soluble pattern recognition molecules and positive regulators of the complement system. In addition, factor H and some of the FHR proteins were shown to modulate the activity of immune cells, a non-canonical function outside the complement cascade. Recent efforts have intensified to study factor H and the FHRs and develop new tools for the distinction, quantification and functional characterization of members of this protein family. Here, we provide an update and overview on the versatile roles of factor H family proteins, what we know about their biological functions in healthy conditions and in diseases.
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Affiliation(s)
- Noémi Sándor
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
- HUN-REN-ELTE Complement Research Group, Hungarian Research Network, Budapest, Hungary
| | | | | | - Veronika H. Barbai
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Dániel Bencze
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Hani Hashim Hammad
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Alexandra Papp
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Dorottya Kövesdi
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
- HUN-REN-ELTE Complement Research Group, Hungarian Research Network, Budapest, Hungary
| | - Barbara Uzonyi
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
- HUN-REN-ELTE Complement Research Group, Hungarian Research Network, Budapest, Hungary
| | - Mihály Józsi
- Department of Immunology, ELTE Eötvös Loránd University, Budapest, Hungary
- HUN-REN-ELTE Complement Research Group, Hungarian Research Network, Budapest, Hungary
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2
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Heggi MT, Nour El-Din HT, Morsy DI, Abdelaziz NI, Attia AS. Microbial evasion of the complement system: a continuous and evolving story. Front Immunol 2024; 14:1281096. [PMID: 38239357 PMCID: PMC10794618 DOI: 10.3389/fimmu.2023.1281096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 11/30/2023] [Indexed: 01/22/2024] Open
Abstract
The complement system is a fundamental part of the innate immune system that plays a key role in the battle of the human body against invading pathogens. Through its three pathways, represented by the classical, alternative, and lectin pathways, the complement system forms a tightly regulated network of soluble proteins, membrane-expressed receptors, and regulators with versatile protective and killing mechanisms. However, ingenious pathogens have developed strategies over the years to protect themselves from this complex part of the immune system. This review briefly discusses the sequence of the complement activation pathways. Then, we present a comprehensive updated overview of how the major four pathogenic groups, namely, bacteria, viruses, fungi, and parasites, control, modulate, and block the complement attacks at different steps of the complement cascade. We shed more light on the ability of those pathogens to deploy more than one mechanism to tackle the complement system in their path to establish infection within the human host.
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Affiliation(s)
- Mariam T. Heggi
- Clinical Pharmacy Undergraduate Program, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Hanzada T. Nour El-Din
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | | | | | - Ahmed S. Attia
- Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
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3
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Yee WX, Barnes G, Lavender H, Tang CM. Meningococcal factor H-binding protein: implications for disease susceptibility, virulence, and vaccines. Trends Microbiol 2023; 31:805-815. [PMID: 36941192 PMCID: PMC10914675 DOI: 10.1016/j.tim.2023.02.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 03/23/2023]
Abstract
Neisseria meningitidis is a human-adapted pathogen that causes meningitis and sepsis worldwide. N. meningitidis factor H-binding protein (fHbp) provides a mechanism for immune evasion by binding human complement factor H (CFH) to protect it from complement-mediated killing. Here, we discuss features of fHbp which enable it to engage human CFH (hCFH), and the regulation of fHbp expression. Studies of host susceptibility and bacterial genome-wide association studies (GWAS) highlight the importance of the interaction between fHbp and CFH and other complement factors, such as CFHR3, on the development of invasive meningococcal disease (IMD). Understanding the basis of fHbp:CFH interactions has also informed the design of next-generation vaccines as fHbp is a protective antigen. Structure-informed refinement of fHbp vaccines will help to combat the threat posed by the meningococcus, and accelerate the elimination of IMD.
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Affiliation(s)
- Wearn-Xin Yee
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Grace Barnes
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Hayley Lavender
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
| | - Christoph M Tang
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
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Ispasanie E, Muri L, Schmid M, Schubart A, Thorburn C, Zamurovic N, Holbro T, Kammüller M, Pluschke G. In vaccinated individuals serum bactericidal activity against B meningococci is abrogated by C5 inhibition but not by inhibition of the alternative complement pathway. Front Immunol 2023; 14:1180833. [PMID: 37457736 PMCID: PMC10349132 DOI: 10.3389/fimmu.2023.1180833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 06/05/2023] [Indexed: 07/18/2023] Open
Abstract
Introduction Several diseases caused by the dysregulation of complement activation can be treated with inhibitors of the complement components C5 and/or C3. However, complement is required for serum bactericidal activity (SBA) against encapsulated Gram-negative bacteria. Therefore, C3 and C5 inhibition increases the risk of invasive disease, in particular by Neisseria meningitidis. As inhibitors against complement components other than C3 and C5 may carry a reduced risk of infection, we compared the effect of inhibitors targeting the terminal pathway (C5), the central complement component C3, the alternative pathway (FB and FD), and the lectin pathway (MASP-2) on SBA against serogroup B meningococci. Methods Serum from adults was collected before and after vaccination with the meningococcal serogroup B vaccine 4CMenB and tested for meningococcal killing. Since the B capsular polysaccharide is structurally similar to certain human polysaccharides, 4CMenB was designed to elicit antibodies against meningococcal outer membrane proteins. Results While only a few pre-vaccination sera showed SBA against the tested B meningococcal isolates, 4CMenB vaccination induced potent complement-activating IgG titers against isolates expressing a matching allele of the bacterial cell surface-exposed factor H-binding protein (fHbp). SBA triggered by these cell surface protein-specific antibodies was blocked by C5 and reduced by C3 inhibition, whereas alternative (factor B and D) and lectin (MASP-2) pathway inhibitors had no effect on the SBA of post-4CMenB vaccination sera. Discussion Compared to the SBA triggered by A,C,W,Y capsule polysaccharide conjugate vaccination, SBA against B meningococci expressing a matching fHbp allele was remarkably resilient against the alternative pathway inhibition.
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Affiliation(s)
- Emma Ispasanie
- Swiss Tropical and Public Health Institute, Molecular Immunology Unit, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Lukas Muri
- Swiss Tropical and Public Health Institute, Molecular Immunology Unit, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Marc Schmid
- Swiss Tropical and Public Health Institute, Molecular Immunology Unit, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Anna Schubart
- Novartis Institutes for Biomedical Research, Department Autoimmunity, Transplantation and Inflammation, Basel, Switzerland
| | | | - Natasa Zamurovic
- Novartis Institutes for Biomedical Research, Translational Medicine-Preclinical Safety, Basel, Switzerland
| | - Thomas Holbro
- Global Drug Development, Novartis Pharma AG, Basel, Switzerland
| | - Michael Kammüller
- Novartis Institutes for Biomedical Research, Translational Medicine-Preclinical Safety, Basel, Switzerland
| | - Gerd Pluschke
- Swiss Tropical and Public Health Institute, Molecular Immunology Unit, Basel, Switzerland
- University of Basel, Basel, Switzerland
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5
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Dold C, Marsay L, Wang N, Silva-Reyes L, Clutterbuck E, Paterson GK, Sharkey K, Wyllie D, Beernink PT, Hill AV, Pollard AJ, Rollier CS. An adenoviral-vectored vaccine confers seroprotection against capsular group B meningococcal disease. Sci Transl Med 2023; 15:eade3901. [PMID: 37343082 DOI: 10.1126/scitranslmed.ade3901] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 05/30/2023] [Indexed: 06/23/2023]
Abstract
Adenoviral-vectored vaccines are licensed for prevention of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Ebola virus, but, for bacterial proteins, expression in a eukaryotic cell may affect the antigen's localization and conformation or lead to unwanted glycosylation. Here, we investigated the potential use of an adenoviral-vectored vaccine platform for capsular group B meningococcus (MenB). Vector-based candidate vaccines expressing MenB antigen factor H binding protein (fHbp) were generated, and immunogenicity was assessed in mouse models, including the functional antibody response by serum bactericidal assay (SBA) using human complement. All adenovirus-based vaccine candidates induced high antigen-specific antibody and T cell responses. A single dose induced functional serum bactericidal responses with titers superior or equal to those induced by two doses of protein-based comparators, as well as longer persistence and a similar breadth. The fHbp transgene was further optimized for human use by incorporating a mutation abrogating binding to the human complement inhibitor factor H. The resulting vaccine candidate induced high and persistent SBA responses in transgenic mice expressing human factor H. The optimized transgene was inserted into the clinically relevant ChAdOx1 backbone, and this vaccine has now progressed to clinical development. The results of this preclinical vaccine development study underline the potential of vaccines based on genetic material to induce functional antibody responses against bacterial outer membrane proteins.
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Affiliation(s)
- Christina Dold
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, CCVTM, Churchill Lane, Oxford OX3 7LE, UK
| | - Leanne Marsay
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, CCVTM, Churchill Lane, Oxford OX3 7LE, UK
| | - Nelson Wang
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, CCVTM, Churchill Lane, Oxford OX3 7LE, UK
| | - Laura Silva-Reyes
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, CCVTM, Churchill Lane, Oxford OX3 7LE, UK
| | - Elizabeth Clutterbuck
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, CCVTM, Churchill Lane, Oxford OX3 7LE, UK
| | - Gavin K Paterson
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK
| | - Kelsey Sharkey
- Division of Infectious Diseases and Global Health, Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - David Wyllie
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK
| | - Peter T Beernink
- Division of Infectious Diseases and Global Health, Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Adrian V Hill
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK
| | - Andrew J Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, CCVTM, Churchill Lane, Oxford OX3 7LE, UK
| | - Christine S Rollier
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, CCVTM, Churchill Lane, Oxford OX3 7LE, UK
- School of Biosciences and Medicine, University of Surrey, Guildford GU2 7XH, UK
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6
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Zografaki I, Detsis M, Del Amo M, Iantomasi R, Maia A, Montuori EA, Mendez C. Invasive Meningococcal Disease epidemiology and vaccination strategies in four Southern European countries: a review of the available data. Expert Rev Vaccines 2023. [PMID: 37316234 DOI: 10.1080/14760584.2023.2225596] [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: 11/16/2022] [Accepted: 06/12/2023] [Indexed: 06/16/2023]
Abstract
INTRODUCTION Invasive meningococcal disease (IMD) is a major health concern which can be prevented through vaccination. Conjugate vaccines against serogroups A, C, W and Y and two protein-based vaccines against serogroup B are currently available in the European Union. AREAS COVERED We present epidemiologic data for Italy, Portugal, Greece and Spain using publicly available reports from national reference laboratories and national or regional immunization programs (1999-2019), aiming to confirm risk groups, and describe time trends in overall incidence and serogroup distribution, as well as impact of immunization. Analysis of circulating MenB isolates in terms of the surface factor H binding protein (fHbp) using PubMLST is discussed as fHbp represents an important MenB vaccine antigen. Predictions of potential reactivity of the two available MenB vaccines (MenB-fHbp and 4CMenB) with circulating MenB isolates are also provided as assessed using the recently developed MenDeVAR tool. EXPERT OPINION Understanding dynamics of IMD and continued genomic surveillance are essential for evaluating vaccine effectiveness, but also prompting proactive immunization programs to prevent future outbreaks. Importantly, the successful design of further effective meningococcal vaccines to fight IMD relies on considering the unpredictable epidemiology of the disease and combining lessons learnt from capsule polysaccharide vaccines and protein-based vaccines.
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Affiliation(s)
| | | | | | | | - Ana Maia
- Vaccines Department, Pfizer Portugal, Lisbon, Portugal
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7
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Rodríguez de Córdoba S. Genetic variability shapes the alternative pathway complement activity and predisposition to complement-related diseases. Immunol Rev 2023; 313:71-90. [PMID: 36089777 PMCID: PMC10086816 DOI: 10.1111/imr.13131] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The implementation of next-generation sequencing technologies has provided a sharp picture of the genetic variability in the components and regulators of the alternative pathway (AP) of the complement system and has revealed the association of many AP variants with different rare and common diseases. An important finding that has emerged from these analyses is that each of these complement-related diseases associate with genetic variants altering specific aspects of the activation and regulation of the AP. These genotype-phenotype correlations have provided valuable insights into their pathogenic mechanisms with important diagnostic and therapeutic implications. While genetic variants in coding regions and structural variants are reasonably well characterized and occasionally have been instrumental to uncover unknown features of the complement proteins, data about complement expressed quantitative trait loci are still very limited. A crucial task for future studies will be to identify these quantitative variations and to determine their impact in the overall activity of the AP. This is fundamental as it is now clear that the consequences of genetic variants in the AP are additive and that susceptibility or resistance to disease is the result of specific combinations of genetic variants in different complement components and regulators ("complotypes").
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8
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Pathogenic Neisseria Bind the Complement Protein CFHR5 via Outer Membrane Porins. Infect Immun 2022; 90:e0037722. [PMID: 36194022 PMCID: PMC9584296 DOI: 10.1128/iai.00377-22] [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] [Indexed: 11/20/2022] Open
Abstract
Neisseria meningitidis and Neisseria gonorrhoeae are important human pathogens that have evolved to bind the major negative regulator of the complement system, complement factor H (CFH). However, little is known about the interaction of pathogens with CFH-related proteins (CFHRs) which are structurally similar to CFH but lack the main complement regulatory domains found in CFH. Insights into the role of CFHRs have been hampered by a lack of specific reagents. We generated a panel of CFHR-specific monoclonal antibodies and demonstrated that CFHR5 was bound by both pathogenic Neisseria spp. We showed that CFHR5 bound to PorB expressed by both pathogens in the presence of sialylated lipopolysaccharide and enhanced complement activation on the surface of N. gonorrhoeae. Our study furthered our understanding of the interactions of CFHRs with bacterial pathogens and revealed that CFHR5 bound the meningococcus and gonococcus via similar mechanisms.
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9
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Evaluating the clinical utility of measuring levels of factor H and the related proteins. Mol Immunol 2022; 151:166-182. [PMID: 36162225 DOI: 10.1016/j.molimm.2022.08.010] [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: 05/09/2022] [Revised: 08/04/2022] [Accepted: 08/15/2022] [Indexed: 11/21/2022]
Abstract
After years of disappointing clinical results, the tide has finally changed and complement targeted-therapies have become a validated and accepted treatment option for several diseases. These accomplishments have revitalized the field and brought renewed attention to the prospects that complement therapeutics can offer. Streamlining diagnostics and therapeutics is imperative in this new era of clinical use of complement therapeutics. However, the incredible success in therapeutics has not been accompanied by the development of novel standardized tools for complement testing. Complement biomarkers can assist in the risk assessment and diagnosis of diseases as well as the prediction of disease progression and treatment response. Recently, a group of complement proteins has been suggested to be highly relevant in various complement-associated disorders, namely the human factor H (FH) protein family. This family of closely related proteins consists of FH, FH-like protein 1, and five factor H-related proteins, and they have been linked to eye, kidney, infectious, vascular, and autoimmune diseases as well as cancer. The goal of this review is to provide a comprehensive overview of the available data on circulating levels of FH and its related proteins in different pathologies. In addition, we examined the current literature to determine the clinical utility of measuring levels of the FH protein family in health and disease. Finally, we discuss future steps that are needed to make their clinical translation a reality.
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10
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Alfini R, Brunelli B, Bartolini E, Carducci M, Luzzi E, Ferlicca F, Buccato S, Galli B, Lo Surdo P, Scarselli M, Romagnoli G, Cartocci E, Maione D, Savino S, Necchi F, Delany I, Micoli F. Investigating the Role of Antigen Orientation on the Immune Response Elicited by Neisseria meningitidis Factor H Binding Protein on GMMA. Vaccines (Basel) 2022; 10:vaccines10081182. [PMID: 35893831 PMCID: PMC9331691 DOI: 10.3390/vaccines10081182] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/15/2022] [Accepted: 07/16/2022] [Indexed: 11/16/2022] Open
Abstract
GMMA are outer membrane vesicles (OMVs) released from Gram-negative bacteria genetically modified to enhance OMVs formation that have been shown to be optimal systems to enhance immunogenicity of protein antigens. Here, we selected Neisseria meningitidis factor H binding protein (fHbp) and used the conjugation chemistry as a tool to alter antigen orientation on GMMA. Indeed, fHbp was randomly linked to GMMA or selectively attached via the N-terminus to mimic native presentation of the protein on the bacterial surface. Interestingly, protein and peptide array analyses confirmed that antibodies induced by the selective and the random conjugates showed a pattern very similar to fHbp natively expressed on bacterial surfaces or to the recombinant protein mixed with GMMA, respectively. However, the two conjugates elicited antibodies with similar serum bactericidal activity against meningococcal strains, superior to the protein alone or physically mixed with GMMA. Presentation of fHbp on GMMA strongly enhances the functional immune response elicited by the protein but its orientation on the bacterial surface does not have an impact. This study demonstrates the flexibility of the GMMA platform as a display and delivery system for enhancing antigen immunogenicity and further supports the use of such promising technology for the development of effective vaccines.
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Affiliation(s)
- Renzo Alfini
- GSK Vaccines Institute for Global Health (GVGH), 53100 Siena, Italy; (R.A.); (M.C.); (F.N.)
| | - Brunella Brunelli
- GSK, 53100 Siena, Italy; (B.B.); (E.B.); (E.L.); (F.F.); (S.B.); (B.G.); (P.L.S.); (M.S.); (G.R.); (E.C.); (D.M.); (S.S.); (I.D.)
| | - Erika Bartolini
- GSK, 53100 Siena, Italy; (B.B.); (E.B.); (E.L.); (F.F.); (S.B.); (B.G.); (P.L.S.); (M.S.); (G.R.); (E.C.); (D.M.); (S.S.); (I.D.)
| | - Martina Carducci
- GSK Vaccines Institute for Global Health (GVGH), 53100 Siena, Italy; (R.A.); (M.C.); (F.N.)
| | - Enrico Luzzi
- GSK, 53100 Siena, Italy; (B.B.); (E.B.); (E.L.); (F.F.); (S.B.); (B.G.); (P.L.S.); (M.S.); (G.R.); (E.C.); (D.M.); (S.S.); (I.D.)
| | - Francesca Ferlicca
- GSK, 53100 Siena, Italy; (B.B.); (E.B.); (E.L.); (F.F.); (S.B.); (B.G.); (P.L.S.); (M.S.); (G.R.); (E.C.); (D.M.); (S.S.); (I.D.)
| | - Scilla Buccato
- GSK, 53100 Siena, Italy; (B.B.); (E.B.); (E.L.); (F.F.); (S.B.); (B.G.); (P.L.S.); (M.S.); (G.R.); (E.C.); (D.M.); (S.S.); (I.D.)
| | - Barbara Galli
- GSK, 53100 Siena, Italy; (B.B.); (E.B.); (E.L.); (F.F.); (S.B.); (B.G.); (P.L.S.); (M.S.); (G.R.); (E.C.); (D.M.); (S.S.); (I.D.)
| | - Paola Lo Surdo
- GSK, 53100 Siena, Italy; (B.B.); (E.B.); (E.L.); (F.F.); (S.B.); (B.G.); (P.L.S.); (M.S.); (G.R.); (E.C.); (D.M.); (S.S.); (I.D.)
| | - Maria Scarselli
- GSK, 53100 Siena, Italy; (B.B.); (E.B.); (E.L.); (F.F.); (S.B.); (B.G.); (P.L.S.); (M.S.); (G.R.); (E.C.); (D.M.); (S.S.); (I.D.)
| | - Giacomo Romagnoli
- GSK, 53100 Siena, Italy; (B.B.); (E.B.); (E.L.); (F.F.); (S.B.); (B.G.); (P.L.S.); (M.S.); (G.R.); (E.C.); (D.M.); (S.S.); (I.D.)
| | - Elena Cartocci
- GSK, 53100 Siena, Italy; (B.B.); (E.B.); (E.L.); (F.F.); (S.B.); (B.G.); (P.L.S.); (M.S.); (G.R.); (E.C.); (D.M.); (S.S.); (I.D.)
| | - Domenico Maione
- GSK, 53100 Siena, Italy; (B.B.); (E.B.); (E.L.); (F.F.); (S.B.); (B.G.); (P.L.S.); (M.S.); (G.R.); (E.C.); (D.M.); (S.S.); (I.D.)
| | - Silvana Savino
- GSK, 53100 Siena, Italy; (B.B.); (E.B.); (E.L.); (F.F.); (S.B.); (B.G.); (P.L.S.); (M.S.); (G.R.); (E.C.); (D.M.); (S.S.); (I.D.)
| | - Francesca Necchi
- GSK Vaccines Institute for Global Health (GVGH), 53100 Siena, Italy; (R.A.); (M.C.); (F.N.)
| | - Isabel Delany
- GSK, 53100 Siena, Italy; (B.B.); (E.B.); (E.L.); (F.F.); (S.B.); (B.G.); (P.L.S.); (M.S.); (G.R.); (E.C.); (D.M.); (S.S.); (I.D.)
| | - Francesca Micoli
- GSK Vaccines Institute for Global Health (GVGH), 53100 Siena, Italy; (R.A.); (M.C.); (F.N.)
- Correspondence:
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11
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Edwardsiella tarda TraT is an anti-complement factor and a cellular infection promoter. Commun Biol 2022; 5:637. [PMID: 35768577 PMCID: PMC9243006 DOI: 10.1038/s42003-022-03587-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 06/15/2022] [Indexed: 12/04/2022] Open
Abstract
Edwardsiella tarda is a well-known bacterial pathogen with a broad range of host, including fish, amphibians, and mammals. One eminent virulence feature of E. tarda is its strong ability to resist the killing of host serum complement, but the involving mechanism is unclear. In this report, we identified E. tarda TraT as a key player in both complement resistance and cellular invasion. TraT, a surface-localized protein, bound and recruited complement factor H onto E. tarda, whereby inhibiting complement activation via the alternative pathway. TraT also interacted with host CD46 in a specific complement control protein domain-dependent manner, whereby facilitating the cellular infection and tissue dissemination of E. tarda. Thus, by acting as an anti-complement factor and a cellular infection promoter, TraT makes an important contribution to the complement evasion and systemic infection of E. tarda. These results add insights into the pathogen-host interaction mechanism during E. tarda infection. Edwardsiella tarda TraT promotes cellular infection and serves as an anti-complement factor, shedding light on the mechanisms of E. tarda’s strong evasion of killing by the host.
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12
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van Beek AE, Pouw RB, Wright VJ, Sallah N, Inwald D, Hoggart C, Brouwer MC, Galassini R, Thomas J, Calvo-Bado L, Fink CG, Jongerius I, Hibberd M, Wouters D, Levin M, Kuijpers TW. Low Levels of Factor H Family Proteins During Meningococcal Disease Indicate Systemic Processes Rather Than Specific Depletion by Neisseria meningitidis. Front Immunol 2022; 13:876776. [PMID: 35720329 PMCID: PMC9204383 DOI: 10.3389/fimmu.2022.876776] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 04/29/2022] [Indexed: 11/13/2022] Open
Abstract
Neisseria meningitidis, the causative agent of meningococcal disease (MD), evades complement-mediated clearance upon infection by ‘hijacking’ the human complement regulator factor H (FH). The FH protein family also comprises the homologous FH-related (FHR) proteins, hypothesized to act as antagonists of FH, and FHR-3 has recently been implicated to play a major role in MD susceptibility. Here, we show that the circulating levels of all FH family proteins, not only FH and FHR-3, are equally decreased during the acute illness. We did neither observe specific consumption of FH or FHR-3 by N. meningitidis, nor of any of the other FH family proteins, suggesting that the globally reduced levels are due to systemic processes including dilution by fluid administration upon admission and vascular leakage. MD severity associated predominantly with a loss of FH rather than FHRs. Additionally, low FH levels associated with renal failure, suggesting insufficient protection of host tissue by the active protection by the FH protein family, which is reminiscent of reduced FH activity in hemolytic uremic syndrome. Retaining higher levels of FH may thus limit tissue injury during MD.
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Affiliation(s)
- Anna E van Beek
- Sanquin Research, Department of Immunopathology, and Landsteiner Laboratory, Amsterdam University Medical Centre, Amsterdam Infection and Immunity Institute, Amsterdam, Netherlands.,Department of Pediatric Immunology, Rheumatology, and Infectious Diseases, Emma Children's Hospital, Amsterdam University Medical Centre, Amsterdam, Netherlands
| | - Richard B Pouw
- Sanquin Research, Department of Immunopathology, and Landsteiner Laboratory, Amsterdam University Medical Centre, Amsterdam Infection and Immunity Institute, Amsterdam, Netherlands.,Department of Pediatric Immunology, Rheumatology, and Infectious Diseases, Emma Children's Hospital, Amsterdam University Medical Centre, Amsterdam, Netherlands
| | - Victoria J Wright
- Section for Paediatric Infectious Disease, Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Neneh Sallah
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - David Inwald
- Section for Paediatric Infectious Disease, Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Clive Hoggart
- Section for Paediatric Infectious Disease, Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Mieke C Brouwer
- Sanquin Research, Department of Immunopathology, and Landsteiner Laboratory, Amsterdam University Medical Centre, Amsterdam Infection and Immunity Institute, Amsterdam, Netherlands
| | - Rachel Galassini
- Section for Paediatric Infectious Disease, Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - John Thomas
- Micropathology Ltd., University of Warwick, Warwick, United Kingdom
| | - Leo Calvo-Bado
- Micropathology Ltd., University of Warwick, Warwick, United Kingdom
| | - Colin G Fink
- Micropathology Ltd., University of Warwick, Warwick, United Kingdom
| | - Ilse Jongerius
- Sanquin Research, Department of Immunopathology, and Landsteiner Laboratory, Amsterdam University Medical Centre, Amsterdam Infection and Immunity Institute, Amsterdam, Netherlands.,Department of Pediatric Immunology, Rheumatology, and Infectious Diseases, Emma Children's Hospital, Amsterdam University Medical Centre, Amsterdam, Netherlands
| | - Martin Hibberd
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Diana Wouters
- Sanquin Research, Department of Immunopathology, and Landsteiner Laboratory, Amsterdam University Medical Centre, Amsterdam Infection and Immunity Institute, Amsterdam, Netherlands
| | - Michael Levin
- Section for Paediatric Infectious Disease, Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Taco W Kuijpers
- Department of Pediatric Immunology, Rheumatology, and Infectious Diseases, Emma Children's Hospital, Amsterdam University Medical Centre, Amsterdam, Netherlands.,Sanquin Research, Department of Blood Cell Research, and Landsteiner Laboratory, Amsterdam University Medical Centre, Amsterdam, Netherlands
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13
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Grossman AS, Escobar CA, Mans EJ, Mucci NC, Mauer TJ, Jones KA, Moore CC, Abraham PE, Hettich RL, Schneider L, Campagna SR, Forest KT, Goodrich-Blair H. A Surface Exposed, Two-Domain Lipoprotein Cargo of a Type XI Secretion System Promotes Colonization of Host Intestinal Epithelia Expressing Glycans. Front Microbiol 2022; 13:800366. [PMID: 35572647 PMCID: PMC9100927 DOI: 10.3389/fmicb.2022.800366] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 03/07/2022] [Indexed: 11/17/2022] Open
Abstract
The only known required component of the newly described Type XI secretion system (TXISS) is an outer membrane protein (OMP) of the DUF560 family. TXISSOMPs are broadly distributed across proteobacteria, but properties of the cargo proteins they secrete are largely unexplored. We report biophysical, histochemical, and phenotypic evidence that Xenorhabdus nematophila NilC is surface exposed. Biophysical data and structure predictions indicate that NilC is a two-domain protein with a C-terminal, 8-stranded β-barrel. This structure has been noted as a common feature of TXISS effectors and may be important for interactions with the TXISSOMP. The NilC N-terminal domain is more enigmatic, but our results indicate it is ordered and forms a β-sheet structure, and bioinformatics suggest structural similarities to carbohydrate-binding proteins. X. nematophila NilC and its presumptive TXISSOMP partner NilB are required for colonizing the anterior intestine of Steinernema carpocapsae nematodes: the receptacle of free-living, infective juveniles and the anterior intestinal cecum (AIC) in juveniles and adults. We show that, in adult nematodes, the AIC expresses a Wheat Germ Agglutinin (WGA)-reactive material, indicating the presence of N-acetylglucosamine or N-acetylneuraminic acid sugars on the AIC surface. A role for this material in colonization is supported by the fact that exogenous addition of WGA can inhibit AIC colonization by X. nematophila. Conversely, the addition of exogenous purified NilC increases the frequency with which X. nematophila is observed at the AIC, demonstrating that abundant extracellular NilC can enhance colonization. NilC may facilitate X. nematophila adherence to the nematode intestinal surface by binding to host glycans, it might support X. nematophila nutrition by cleaving sugars from the host surface, or it might help protect X. nematophila from nematode host immunity. Proteomic and metabolomic analyses of wild type X. nematophila compared to those lacking nilB and nilC revealed differences in cell wall and secreted polysaccharide metabolic pathways. Additionally, purified NilC is capable of binding peptidoglycan, suggesting that periplasmic NilC may interact with the bacterial cell wall. Overall, these findings support a model that NilB-regulated surface exposure of NilC mediates interactions between X. nematophila and host surface glycans during colonization. This is a previously unknown function for a TXISS.
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Affiliation(s)
- Alex S. Grossman
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Cristian A. Escobar
- Department of Bacteriology, The University of Wisconsin–Madison, Madison, WI, United States
| | - Erin J. Mans
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Nicholas C. Mucci
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Terra J. Mauer
- Department of Bacteriology, The University of Wisconsin–Madison, Madison, WI, United States
| | - Katarina A. Jones
- Department of Chemistry, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Cameron C. Moore
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Paul E. Abraham
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Robert L. Hettich
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Liesel Schneider
- Department of Animal Sciences, The University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Shawn R. Campagna
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Biological and Small Molecule Mass Spectrometry Core, The University of Tennessee, Knoxville, Knoxville, TN, United States
- The University of Tennessee Oak Ridge Innovation Institute, Knoxville, TN, United States
| | - Katrina T. Forest
- Department of Bacteriology, The University of Wisconsin–Madison, Madison, WI, United States
- Katrina T. Forest,
| | - Heidi Goodrich-Blair
- Department of Microbiology, The University of Tennessee, Knoxville, Knoxville, TN, United States
- Department of Bacteriology, The University of Wisconsin–Madison, Madison, WI, United States
- *Correspondence: Heidi Goodrich-Blair,
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14
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Mikucki A, McCluskey NR, Kahler CM. The Host-Pathogen Interactions and Epicellular Lifestyle of Neisseria meningitidis. Front Cell Infect Microbiol 2022; 12:862935. [PMID: 35531336 PMCID: PMC9072670 DOI: 10.3389/fcimb.2022.862935] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 02/28/2022] [Indexed: 01/17/2023] Open
Abstract
Neisseria meningitidis is a gram-negative diplococcus and a transient commensal of the human nasopharynx. It shares and competes for this niche with a number of other Neisseria species including N. lactamica, N. cinerea and N. mucosa. Unlike these other members of the genus, N. meningitidis may become invasive, crossing the epithelium of the nasopharynx and entering the bloodstream, where it rapidly proliferates causing a syndrome known as Invasive Meningococcal Disease (IMD). IMD progresses rapidly to cause septic shock and meningitis and is often fatal despite aggressive antibiotic therapy. While many of the ways in which meningococci survive in the host environment have been well studied, recent insights into the interactions between N. meningitidis and the epithelial, serum, and endothelial environments have expanded our understanding of how IMD develops. This review seeks to incorporate recent work into the established model of pathogenesis. In particular, we focus on the competition that N. meningitidis faces in the nasopharynx from other Neisseria species, and how the genetic diversity of the meningococcus contributes to the wide range of inflammatory and pathogenic potentials observed among different lineages.
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Affiliation(s)
- August Mikucki
- Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
| | - Nicolie R. McCluskey
- Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
- College of Science, Health, Engineering and Education, Telethon Kids Institute, Murdoch University, Perth, WA, Australia
| | - Charlene M. Kahler
- Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
- *Correspondence: Charlene M. Kahler,
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15
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Product review on the IMD serogroup B vaccine Bexsero®. Hum Vaccin Immunother 2022; 18:2020043. [PMID: 35192786 PMCID: PMC8986181 DOI: 10.1080/21645515.2021.2020043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Bexsero® is a multicomponent vaccine composed of four major proteins of Neisseria meningitidis: the fHbp, NHBA, NadA and PorA. This vaccine was licensed against invasive meningococcal disease (IMD) due to serogroup B isolates. When administered alone, Bexsero® showed a safety profile similar to other childhood vaccines. It provides an excellent immunogenicity but that requires booster doses in infants and young children. Although the vaccine does not seem to impact on acquisition of carriage of serogroup B isolates, it confers protection against isolates of serogroup B harboring distinct but cross-reactive variants of fHbp, NadA and NHBA. Primary vaccination schemes in infancy underwent a rapid increase after a toddler booster suggesting an anamnestic response and the establishment of a memory response. As Bexsero® targets sub-capsular proteins that can be conserved regardless the capsule, the vaccine can be effective against non-B isolates such as isolates of serogroups W and X.
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16
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Facchetti A, Wheeler JX, Vipond C, Whiting G, Lavender H, Feavers IM, Maiden MCJ, Maharjan S. Factor H binding protein (fHbp)-mediated differential complement resistance of a serogroup C Neisseria meningitidis isolate from cerebrospinal fluid of a patient with invasive meningococcal disease. Access Microbiol 2021; 3:000255. [PMID: 34712903 PMCID: PMC8549389 DOI: 10.1099/acmi.0.000255] [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: 01/07/2021] [Accepted: 07/03/2021] [Indexed: 11/01/2022] Open
Abstract
During an outbreak of invasive meningococcal disease (IMD) at the University of Southampton, UK, in 1997, two Neisseria meningitidis serogroup C isolates were retrieved from a student ('Case'), who died of IMD, and a close contact ('Carrier') who, after mouth-to-mouth resuscitation on the deceased, did not contract the disease. Genomic comparison of the isolates demonstrated extensive nucleotide sequence identity, with differences identified in eight genes. Here, comparative proteomics was used to measure differential protein expression between the isolates and investigate whether the differences contributed to the clinical outcomes. A total of six proteins were differentially expressed: four proteins (methylcitrate synthase, PrpC; hypothetical integral membrane protein, Imp; fructose-1,6-bisphosphate aldolase, Fba; aldehyde dehydrogenase A, AldA) were upregulated in the Case isolate, while one protein (Type IV pilus-associated protein, PilC2) was downregulated. Peptides for factor H binding protein (fHbp), a major virulence factor and antigenic protein, were only detected in the Case, with a single base deletion (ΔT366) in the Carrier fHbp causing lack of its expression. Expression of fHbp resulted in an increased resistance of the Case isolate to complement-mediated killing in serum. Complementation of fHbp expression in the Carrier increased its serum resistance by approximately 8-fold. Moreover, a higher serum bactericidal antibody titre was seen for the Case isolate when using sera from mice immunized with Bexsero (GlaxoSmithKline), a vaccine containing fHbp as an antigenic component. This study highlights the role of fHbp in the differential complement resistance of the Case and the Carrier isolates. Expression of fHbp in the Case resulted in its increased survival in serum, possibly leading to active proliferation of the bacteria in blood and death of the student through IMD. Moreover, enhanced killing of the Case isolate by sera raised against an fHbp-containing vaccine, Bexsero, underlines the role and importance of fHbp in infection and immunity.
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Affiliation(s)
- Alessandra Facchetti
- Division of Bacteriology, National Institute for Biological Standards and Control (NIBSC), Blanche Lane, South Mimms, Potters Bar, Hertfordshire, EN6 3QG, UK
| | - Jun X Wheeler
- Division of Analytical Biological Sciences, National Institute for Biological Standards and Control (NIBSC), Blanche Lane, South Mimms, Potters Bar, Hertfordshire, EN6 3QG, UK
| | - Caroline Vipond
- Division of Bacteriology, National Institute for Biological Standards and Control (NIBSC), Blanche Lane, South Mimms, Potters Bar, Hertfordshire, EN6 3QG, UK
| | - Gail Whiting
- Division of Analytical Biological Sciences, National Institute for Biological Standards and Control (NIBSC), Blanche Lane, South Mimms, Potters Bar, Hertfordshire, EN6 3QG, UK
| | - Hayley Lavender
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK
| | - Ian M Feavers
- Division of Bacteriology, National Institute for Biological Standards and Control (NIBSC), Blanche Lane, South Mimms, Potters Bar, Hertfordshire, EN6 3QG, UK
| | - Martin C J Maiden
- Department of Zoology, Peter Medawar Building, University of Oxford, South Parks Road, Oxford, OX1 3SY, UK
| | - Sunil Maharjan
- Division of Bacteriology, National Institute for Biological Standards and Control (NIBSC), Blanche Lane, South Mimms, Potters Bar, Hertfordshire, EN6 3QG, UK
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17
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Earle SG, Lobanovska M, Lavender H, Tang C, Exley RM, Ramos-Sevillano E, Browning DF, Kostiou V, Harrison OB, Bratcher HB, Varani G, Tang CM, Wilson DJ, Maiden MCJ. Genome-wide association studies reveal the role of polymorphisms affecting factor H binding protein expression in host invasion by Neisseria meningitidis. PLoS Pathog 2021; 17:e1009992. [PMID: 34662348 PMCID: PMC8553145 DOI: 10.1371/journal.ppat.1009992] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 10/28/2021] [Accepted: 09/29/2021] [Indexed: 11/18/2022] Open
Abstract
Many invasive bacterial diseases are caused by organisms that are ordinarily harmless components of the human microbiome. Effective interventions against these microbes require an understanding of the processes whereby symbiotic or commensal relationships transition into pathology. Here, we describe bacterial genome-wide association studies (GWAS) of Neisseria meningitidis, a common commensal of the human respiratory tract that is nevertheless a leading cause of meningitis and sepsis. An initial GWAS discovered bacterial genetic variants, including single nucleotide polymorphisms (SNPs), associated with invasive meningococcal disease (IMD) versus carriage in several loci across the meningococcal genome, encoding antigens and other extracellular components, confirming the polygenic nature of the invasive phenotype. In particular, there was a significant peak of association around the fHbp locus, encoding factor H binding protein (fHbp), which promotes bacterial immune evasion of human complement by recruiting complement factor H (CFH) to the meningococcal surface. The association around fHbp with IMD was confirmed by a validation GWAS, and we found that the SNPs identified in the validation affected the 5' region of fHbp mRNA, altering secondary RNA structures, thereby increasing fHbp expression and enhancing bacterial escape from complement-mediated killing. This finding is consistent with the known link between complement deficiencies and CFH variation with human susceptibility to IMD. These observations demonstrate the importance of human and bacterial genetic variation across the fHbp:CFH interface in determining IMD susceptibility, the transition from carriage to disease.
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Affiliation(s)
- Sarah G. Earle
- Big Data Institute, Nuffield Department of Population Health, University of Oxford, Li Ka Shing Centre for Health Information and Discovery, Oxford, United Kingdom
| | - Mariya Lobanovska
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Hayley Lavender
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Changyan Tang
- Department of Chemistry, University of Washington, Seattle, Washington United States of America
| | - Rachel M. Exley
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | | | - Douglas F. Browning
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Vasiliki Kostiou
- Nuffield Department of Clinical Medicine, Experimental Medicine Division, John Radcliffe Hospital, Oxford, United Kingdom
| | | | | | - Gabriele Varani
- Department of Chemistry, University of Washington, Seattle, Washington United States of America
- * E-mail: (GV); (CMT); (DJW); (MCJM)
| | - Christoph M. Tang
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
- * E-mail: (GV); (CMT); (DJW); (MCJM)
| | - Daniel J. Wilson
- Big Data Institute, Nuffield Department of Population Health, University of Oxford, Li Ka Shing Centre for Health Information and Discovery, Oxford, United Kingdom
- Department for Continuing Education, University of Oxford, Oxford, United Kingdom
- * E-mail: (GV); (CMT); (DJW); (MCJM)
| | - Martin C. J. Maiden
- Department of Zoology, University of Oxford, Oxford, United Kingdom
- * E-mail: (GV); (CMT); (DJW); (MCJM)
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18
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Muhuri M, Maeda Y, Ma H, Ram S, Fitzgerald KA, Tai PW, Gao G. Overcoming innate immune barriers that impede AAV gene therapy vectors. J Clin Invest 2021; 131:143780. [PMID: 33393506 DOI: 10.1172/jci143780] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The field of gene therapy has made considerable progress over the past several years. Adeno-associated virus (AAV) vectors have emerged as promising and attractive tools for in vivo gene therapy. Despite the recent clinical successes achieved with recombinant AAVs (rAAVs) for therapeutics, host immune responses against the vector and transgene product have been observed in numerous preclinical and clinical studies. These outcomes have hampered the advancement of AAV gene therapies, preventing them from becoming fully viable and safe medicines. The human immune system is multidimensional and complex. Both the innate and adaptive arms of the immune system seem to play a concerted role in the response against rAAVs. While most efforts have been focused on the role of adaptive immunity and developing ways to overcome it, the innate immune system has also been found to have a critical function. Innate immunity not only mediates the initial response to the vector, but also primes the adaptive immune system to launch a more deleterious attack against the foreign vector. This Review highlights what is known about innate immune responses against rAAVs and discusses potential strategies to circumvent these pathways.
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Affiliation(s)
- Manish Muhuri
- Horae Gene Therapy Center.,Department of Microbiology and Physiological Systems.,VIDE Program
| | - Yukiko Maeda
- Horae Gene Therapy Center.,VIDE Program.,Department of Medicine
| | | | - Sanjay Ram
- Division of Infectious Diseases and Immunology
| | | | - Phillip Wl Tai
- Horae Gene Therapy Center.,Department of Microbiology and Physiological Systems.,VIDE Program
| | - Guangping Gao
- Horae Gene Therapy Center.,Department of Microbiology and Physiological Systems.,Li Weibo Institute for Rare Diseases Research, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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19
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Safadi MAP, Martinón-Torres F, Serra L, Burman C, Presa J. Translating meningococcal serogroup B vaccines for healthcare professionals. Expert Rev Vaccines 2021; 20:401-414. [PMID: 34151699 DOI: 10.1080/14760584.2021.1899820] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Vaccination is an effective strategy to combat invasive meningococcal disease (IMD). Vaccines against the major disease-causing meningococcal serogroups are available; however, development of vaccines against serogroup B faced particular challenges, including the inability to target traditional meningococcal antigens (i.e. polysaccharide capsule) and limited alternative antigens due to serogroup B strain diversity. Two different recombinant, protein-based, serogroup B (MenB) vaccines that may address these challenges are currently available. These vaccines have been extensively evaluated in pre-licensure safety and immunogenicity trials, and recently in real-world studies on effectiveness, safety, and impact on disease burden. AREAS COVERED This review provides healthcare professionals, particularly pediatricians, an overview of currently available MenB vaccines, including development strategies and evaluation of coverage. EXPERT OPINION Overall, recombinant MenB vaccines are valuable tools for healthcare professionals to protect patients against IMD. Their development required innovative design approaches that overcame challenging hurdles and identified novel protein antigen targets; however, important distinctions in the approaches used in their development, evaluation, and administration exist and many unanswered questions remain. Healthcare providers frequently prescribing MenB vaccines are challenged to keep abreast of these differences to ensure patient protection against this serious disease.
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Affiliation(s)
- Marco Aurelio P Safadi
- Department of Pediatrics, Santa Casa De São Paulo School of Medical Sciences, São Paulo, Brazil
| | - Federico Martinón-Torres
- Translational Pediatrics and Infectious Diseases, Pediatrics Department, Hospital Clínico Universitario De Santiago De Compostela, Santiago De Compostela, Spain.,Genetics, Vaccines and Pediatrics Research Group, Universitario De Santiago De Compostela, Instituto De Investigación Sanitaria De Santiago De Compostela, Santiago De Compostela, Spain
| | - Lidia Serra
- Pfizer Vaccine Medical Development, Scientific and Clinical Affairs, Collegeville, PA, USA
| | - Cynthia Burman
- Pfizer Vaccine Medical Development, Scientific and Clinical Affairs, Collegeville, PA, USA
| | - Jessica Presa
- Pfizer Vaccines, Medical and Scientific Affairs, Collegeville, PA, USA
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20
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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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21
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Zewde NT, Hsu RV, Morikis D, Palermo G. Systems Biology Modeling of the Complement System Under Immune Susceptible Pathogens. FRONTIERS IN PHYSICS 2021; 9:603704. [PMID: 35145963 PMCID: PMC8827490 DOI: 10.3389/fphy.2021.603704] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The complement system is assembled from a network of proteins that function to bring about the first line of defense of the body against invading pathogens. However, complement deficiencies or invasive pathogens can hijack complement to subsequently increase susceptibility of the body to infections. Moreover, invasive pathogens are increasingly becoming resistant to the currently available therapies. Hence, it is important to gain insights into the highly dynamic interaction between complement and invading microbes in the frontlines of immunity. Here, we developed a mathematical model of the complement system composed of 670 ordinary differential equations with 328 kinetic parameters, which describes all three complement pathways (alternative, classical, and lectin) and includes description of mannose-binding lectin, collectins, ficolins, factor H-related proteins, immunoglobulin M, and pentraxins. Additionally, we incorporate two pathogens: (type 1) complement susceptible pathogen and (type 2) Neisseria meningitidis located in either nasopharynx or bloodstream. In both cases, we generate time profiles of the pathogen surface occupied by complement components and the membrane attack complex (MAC). Our model shows both pathogen types in bloodstream are saturated by complement proteins, whereas MACs occupy <<1.0% of the pathogen surface. Conversely, the MAC production in nasopharynx occupies about 1.5-10% of the total N. meningitidis surface, thus making nasal MAC levels at least about eight orders of magnitude higher. Altogether, we predict complement-imbalance, favoring overactivation, is associated with nasopharynx homeostasis. Conversely, orientating toward complement-balance may cause disruption to the nasopharynx homeostasis. Thus, for sporadic meningococcal disease, our model predicts rising nasal levels of complement regulators as early infection biomarkers.
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Affiliation(s)
- Nehemiah T. Zewde
- Department of Bioengineering, University of California, Riverside, Riverside, CA, United States
| | - Rohaine V. Hsu
- Department of Bioengineering, University of California, Riverside, Riverside, CA, United States
| | - Dimitrios Morikis
- Department of Bioengineering, University of California, Riverside, Riverside, CA, United States
- Correspondence: Giulia Palermo, , Dimitrios Morikis,
| | - Giulia Palermo
- Department of Bioengineering, University of California, Riverside, Riverside, CA, United States
- Department of Chemistry, University of California, Riverside, Riverside, CA, United States
- Correspondence: Giulia Palermo, , Dimitrios Morikis,
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22
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Eichner H, Karlsson J, Spelmink L, Pathak A, Sham LT, Henriques-Normark B, Loh E. RNA thermosensors facilitate Streptococcus pneumoniae and Haemophilus influenzae immune evasion. PLoS Pathog 2021; 17:e1009513. [PMID: 33914847 PMCID: PMC8084184 DOI: 10.1371/journal.ppat.1009513] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 03/29/2021] [Indexed: 11/18/2022] Open
Abstract
Bacterial meningitis is a major cause of death and disability in children worldwide. Two human restricted respiratory pathogens, Streptococcus pneumoniae and Haemophilus influenzae, are the major causative agents of bacterial meningitis, attributing to 200,000 deaths annually. These pathogens are often part of the nasopharyngeal microflora of healthy carriers. However, what factors elicit them to disseminate and cause invasive diseases, remain unknown. Elevated temperature and fever are hallmarks of inflammation triggered by infections and can act as warning signals to pathogens. Here, we investigate whether these respiratory pathogens can sense environmental temperature to evade host complement-mediated killing. We show that productions of two vital virulence factors and vaccine components, the polysaccharide capsules and factor H binding proteins, are temperature dependent, thus influencing serum/opsonophagocytic killing of the bacteria. We identify and characterise four novel RNA thermosensors in S. pneumoniae and H. influenzae, responsible for capsular biosynthesis and production of factor H binding proteins. Our data suggest that these bacteria might have independently co-evolved thermosensing abilities with different RNA sequences but distinct secondary structures to evade the immune system.
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Affiliation(s)
- Hannes Eichner
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
| | - Jens Karlsson
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
| | - Laura Spelmink
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
| | - Anuj Pathak
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
| | - Lok-To Sham
- Infectious Disease Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Birgitta Henriques-Normark
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
- Clinical Microbiology, Bioclinicum, Karolinska University Hospital, Solna, Sweden
- Lee Kong Chian School of Medicine and Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Edmund Loh
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna, Sweden
- Clinical Microbiology, Bioclinicum, Karolinska University Hospital, Solna, Sweden
- Lee Kong Chian School of Medicine and Singapore Centre on Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
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Spinsanti M, Brignoli T, Bodini M, Fontana LE, De Chiara M, Biolchi A, Muzzi A, Scarlato V, Delany I. Deconvolution of intergenic polymorphisms determining high expression of Factor H binding protein in meningococcus and their association with invasive disease. PLoS Pathog 2021; 17:e1009461. [PMID: 33770146 PMCID: PMC8026042 DOI: 10.1371/journal.ppat.1009461] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 04/07/2021] [Accepted: 03/09/2021] [Indexed: 12/11/2022] Open
Abstract
Neisseria meningitidis is a strictly human pathogen and is the major cause of septicemia and meningitis worldwide. Factor H binding protein (fHbp) is a meningococcal surface-exposed lipoprotein that binds the human Complement factor H allowing the bacterium to evade the host innate immune response. FHbp is also a key antigen in two vaccines against N. meningitidis serogroup B. Although the fHbp gene is present in most circulating meningococcal strains, level of fHbp expression varies among isolates and has been correlated to differences in promoter sequences upstream of the gene. Here we elucidated the sequence determinants that control fHbp expression in globally circulating strains. We analyzed the upstream fHbpintergenic region (fIR) of more than 5800 strains representative of the UK circulating isolates and we identified eleven fIR sequence alleles which represent 88% of meningococcal strains. By engineering isogenic recombinant strains where fHbp expression was under the control of each of the eleven fIR alleles, we confirmed that the fIR sequence determines a specific and distinct level of expression. Moreover, we identified the molecular basis for variation in expression through polymorphisms within key regulatory regions that are known to affect fHbp expression. We experimentally established three expression groups, high–medium–low, that correlated directly with the susceptibility to killing mediated by anti-fHbp antibodies and the ability of the meningococcal strain to survive within human serum. By using this sequence classification and information about the variant, we predicted fHbp expression in the panel of UK strains and we observed that strains with higher expressing fIR alleles are more likely associated with invasive disease. Overall, our findings can contribute to understand and predict vaccine coverage mediated by fHbp as well as to shed light on the role of this virulence factor in determining an invasive phenotype. Complement plays a key role in the immunity against Neisseria meningitidis. The meningococcus uses the Factor H binding protein (fHbp), to bind a negative regulator of the alternative complement pathway, factor H, to its surface thus preventing complement deposition and lysis. The use of fHbp as an antigen in two licensed vaccines highlights its public health relevance. Therefore the levels of this antigen produced by the bacterium are pivotal on the one hand for the survival of N. meningitidis in blood and on the other hand for the susceptibility to vaccine-induced killing antibodies. Here, we identify the predominant nucleotide sequences that drive distinct levels of the fHbp antigen in circulating meningococcal strains. We cluster them into distinct groups with increasing levels and observe that strains expressing higher fHbp amounts are associated with invasive disease. Our findings show that the nucleotide sequence of the fHbp promoter can be used for the prediction of antigen levels of any given strain and consequently for both the assessment of its sensitivity to killing by fHbp antibodies and its likelihood to cause invasive disease.
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Affiliation(s)
| | - Tarcisio Brignoli
- GSK, Siena, Italy
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Bologna, Italy
| | | | | | | | | | | | - Vincenzo Scarlato
- Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Bologna, Italy
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24
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Innate Immune Pattern Recognition Receptors of Mycobacterium tuberculosis: Nature and Consequences for Pathogenesis of Tuberculosis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1313:179-215. [PMID: 34661896 DOI: 10.1007/978-3-030-67452-6_9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Innate immunity against Mycobacterium tuberculosis is a critical early response to prevent the establishment of the infection. Despite recent advances in understanding the host-pathogen dialogue in the early stages of tuberculosis (TB), much has yet to be learnt. The nature and consequences of this dialogue ultimately determine the path of infection: namely, either early clearance of M. tuberculosis, or establishment of M. tuberculosis infection leading to active TB disease and/or latent TB infection. On the frontline in innate immunity are pattern recognition receptors (PRRs), with soluble factors (e.g. collectins and complement) and cell surface factors (e.g. Toll-like receptors and other C-type lectin receptors (Dectin 1/2, Nod-like receptors, DC-SIGN, Mincle, mannose receptor, and MCL) that play a central role in recognising M. tuberculosis and facilitating its clearance. However, in a 'double-edged sword' scenario, these factors can also be involved in enhancement of pathogenesis as well. Furthermore, innate immunity is also a critical bridge in establishing the subsequent adaptive immune response, which is also responsible for granuloma formation that cordons off M. tuberculosis infection, establishing latency and acting as a reservoir for bacterial persistence and dissemination of future disease. This chapter discusses the current understanding of pattern recognition of M. tuberculosis by innate immunity and the role this plays in the pathogenesis and protection against TB.
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25
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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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26
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Luo W, Arkwright PD, Borrow R. Antibody persistence following meningococcal ACWY conjugate vaccine licensed in the European Union by age group and vaccine. Expert Rev Vaccines 2020; 19:745-754. [PMID: 32897762 DOI: 10.1080/14760584.2020.1800460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Meningococcal disease caused by Neisseria meningitidis is a major cause of meningitis and septicemia with high rates of morbidity and mortality worldwide. MenACWY-TT and MenACWY-CRM197 are meningococcal conjugate vaccines approved for use in children and adults in the UK. The aim of this review was to evaluate and compare antibody responses and persistence in different age groups after MenACWY-TT and MenACWY-CRM197. AREAS COVERED Randomized trials showed that MenACWY-TT is immunogenic at all ages. MenACWY-CRM197 is immunogenic for infants and adults, but there is a lack of data for children aged 1 to 2 years. Studies on MenACWY-TT indicated that serum bactericidal antibody (SBA) utilizing baby rabbit complement (rSBA) titers were significantly higher and more stable than SBA using human complement (hSBA) titers, compared with hSBA titers, which were lower and declined more rapidly by 1 year following post-primary MenACWY-TT and MenACWY-CRM197 vaccination, especially for MenA. EXPERT OPINION MenACWY-TT and MenACWY-CRM197 are both well tolerated and induce similar antibody persistence and immunogenicity against all four serogroups for individuals more than one year old. rSBA assay is a more robust assay than the hSBA assay when vaccinating with MenACWY-TT, while rSBA and hSBA assays had similar antibody persistence when vaccinating with MenACWY-CRM197.
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Affiliation(s)
- Weichang Luo
- Royal Manchester Children's Hospital, University of Manchester , Manchester, UK
| | - Peter D Arkwright
- Royal Manchester Children's Hospital, Lydia Becker Institute of Immunology and Inflammation, University of Manchester , Manchester, UK
| | - Ray Borrow
- Vaccine Evaluation Unit, Public Health England, Manchester Royal Infirmary , Manchester, UK
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27
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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: 8] [Impact Index Per Article: 2.0] [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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28
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Martinón-Torres F, Serra L, Safadi MAP. Protecting the most vulnerable age group: a review of MenACWY-TT immunogenicity and safety in infants. Expert Rev Vaccines 2020; 19:313-325. [PMID: 32250710 DOI: 10.1080/14760584.2020.1745070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
INTRODUCTION Neisseria meningitidis causes invasive meningococcal disease (IMD), with the highest incidence observed in infants and young children. Meningococcal serogroups A, B, C, W, X, and Y account for almost all IMD cases worldwide. Available meningococcal vaccines targeting serogroups A, C, W, and Y (MenACWY) include those conjugated to diphtheria toxoid (MenACWY-D), diphtheria protein cross-reactive material 197 (MenACWY-CRM197), and tetanus toxoid (MenACWY-TT). MenACWY-TT is indicated for use starting at 6 weeks of age. AREAS COVERED This review discusses data from the four primary studies assessing MenACWY-TT safety and immunogenicity in infants, which evaluated a variety of dosing schedules, short-term and long-term outcomes, and impact of coadministration on the immunogenicity of routine childhood vaccines. Remaining gaps in the field are addressed. EXPERT OPINION Robust data support the use of MenACWY-TT in infants starting as early as 6 weeks of age. MenACWY-TT was safe and well tolerated in infants, was immunogenic after priming and booster, and demonstrated persistent immunogenicity. Lower persistence for serogroup A relative to other serogroups based on serum bactericidal assays (SBAs) using human complement appears to be a class effect of MenACWY conjugate vaccines. Correlates of protection other than SBA are being explored, including immunologic responses associated with different carrier proteins.
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Affiliation(s)
- Federico Martinón-Torres
- Translational Pediatrics and Infectious Diseases, Pediatrics Department, Hospital Clínico Universitario de Santiago de Compostela , Santiago de Compostela, Spain.,Genetics, Vaccines and Pediatrics Research Group, University of Santiago de Compostela, Instituto de Investigación Sanitaria de Santiago de Compostela , Santiago de Compostela, Spain
| | - Lidia Serra
- Pfizer Vaccine Medical Development, Scientific & Clinical Affairs , Collegeville, PA, USA
| | - Marco Aurelio P Safadi
- Department of Pediatrics, Santa Casa de São Paulo School of Medical Sciences , São Paulo, Brazil
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29
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Balmer P, Beeslaar J, Findlow J, Srivastava A. Understanding immunogenicity assessments for meningococcal serogroup B vaccines. Postgrad Med 2020; 132:184-191. [PMID: 32124678 DOI: 10.1080/00325481.2019.1696582] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Invasive meningococcal disease (IMD) is a potentially devastating infection associated with high mortality and long-term sequelae; however, vaccines are available to protect against the five common disease-causing serogroups (A, B, C, W, and Y). Because traditional field efficacy clinical trials were not feasible due to low IMD incidence that necessitates a very large number of participants, serum bactericidal antibody (SBA) assays using rabbit (rSBA) or human (hSBA) complement were established as in vitro surrogates of meningococcal vaccine efficacy and are now routinely used to support vaccine licensure. Specifically, rSBA assays have been used to evaluate responses to meningococcal capsular polysaccharide-protein conjugate vaccines against serogroups A, C, W, and Y; the accepted correlate of protection for rSBA assays is a titer ≥1:8. Importantly, because the bacterial capsular polysaccharide antigen is conserved across strains, only one test strain that expresses an invariant polysaccharide capsule for each serogroup is required to assess coverage. rSBA assays are unsuitable for subcapsular protein-based serogroup B (MenB) vaccines, and therefore, hSBA assays have been used for licensure; titers ≥1:4 are considered the correlate of protection against IMD for hSBA. In contrast to MenACWY vaccines, because bacterial surface proteins are antigenically variable, MenB vaccines must be tested with hSBA assays using multiple test strains that represent the antigenic diversity of disease-causing isolates. As this complexity regarding SBA assessment methods can make data interpretation difficult, herein we describe the use of hSBA assays to evaluate MenB vaccine efficacy and to support licensure. In addition, we highlight how the two recently approved MenB vaccines differ in their use of hSBA assays in clinical studies to demonstrate broad protection against MenB IMD.
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Affiliation(s)
- Paul Balmer
- Vaccine Medical Development, Scientific & Clinical Affairs, Pfizer Inc, Collegeville, PA, USA
| | | | - Jamie Findlow
- Vaccine Medical & Scientific Affairs, Pfizer Ltd, Tadworth, UK
| | - Amit Srivastava
- Vaccine Medical Development, Scientific & Clinical Affairs, Pfizer Inc, Collegeville, PA, USA
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30
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Ferreira VM, Ferreira ÍE, Chang HY, Nunes AMPB, Topaz N, Pimentel ER, Moura ARSS, Ribeiro GS, Feitosa CA, Reis MG, Wang X, Campos LC. Meningococcal carriage in young adults six years after meningococcal C conjugate (MCC) vaccine catch-up campaign in Salvador, Brazil. Vaccine 2020; 38:2995-3002. [PMID: 32115294 DOI: 10.1016/j.vaccine.2020.02.050] [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: 10/11/2019] [Revised: 02/16/2020] [Accepted: 02/17/2020] [Indexed: 11/29/2022]
Abstract
Meningococcal carriage studies are important to improve the knowledge of disease epidemiology as well as to support appropriate vaccination strategies. We conducted a cross-sectional study to determine the prevalence and genotypic characteristics of meningococci collected from young adults in Salvador, Brazil six years after a meningococcal C conjugate vaccine catch-up campaign. From August through November 2016, oropharyngeal swabs were collected from 407 students aged 1824 years attending a private college in Salvador, Brazil. Neisseria meningitidis was identified by standard microbiology methods and real time PCR. Genetic characteristics of meningococci were assessed by rt-PCR and/or whole genome sequencing. We also investigated potential factors associated with carriage. N. meningitidis was detectable in 50 students, 39 by both culture and rt-PCR, 7 by culture alone and 4 by rt-PCR alone, resulting in an overall meningococcal carriage prevalence of 12.3% (50/407). Carriage was independently associated with male sex (adjusted PR: 1.97; 95% CI: 1.12-3.46; p = 0.018) and attending bars or parties at least once per month (aPR: 3.31; 95% CI: 1.49-7.38; p = 0.003). Molecular tests identified 92% (46/50) N. meningitidis as non-groupable, of which 63% (29/46) had the capsule null genotype; 14 NG isolates contained disrupted capsule backbones and belonged to the following genogroups: 7 B, 3 Z, 3 E and 1 W. One isolate belonged to genogroup C tested only by PCR; 3 isolates contained a complete B capsule backbones, 2 of which were determined to be NG by slide agglutination serogrouping. While most meningococcal carriage isolates were non-groupable, there was a high degree of genetic diversity present in the collection, as evidenced by 25 unique STs being detected. The carriage prevalence of meningococcal serogroup C was low among young adults. Continuous vaccination is important to maintain reduced meningococcal carriage and transmission, inducing herd protection.
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Affiliation(s)
- Viviane Matos Ferreira
- Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Bahia, Brazil; Escola Bahiana de Medicina e Saúde Pública, Salvador, Bahia, Brazil
| | | | - How-Yi Chang
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - Nadav Topaz
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | | | - Guilherme Sousa Ribeiro
- Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Bahia, Brazil; Faculdade de Medicina, Universidade Federal da Bahia, Salvador, Bahia, Brazil
| | | | - Mitermayer Galvão Reis
- Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Bahia, Brazil; Faculdade de Medicina, Universidade Federal da Bahia, Salvador, Bahia, Brazil; Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut, United States
| | - Xin Wang
- Centers for Disease Control and Prevention, Atlanta, GA, USA
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31
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da Silva RAG, Karlyshev AV, Oldfield NJ, Wooldridge KG, Bayliss CD, Ryan A, Griffin R. Variant Signal Peptides of Vaccine Antigen, FHbp, Impair Processing Affecting Surface Localization and Antibody-Mediated Killing in Most Meningococcal Isolates. Front Microbiol 2019; 10:2847. [PMID: 31921030 PMCID: PMC6930937 DOI: 10.3389/fmicb.2019.02847] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 11/25/2019] [Indexed: 11/24/2022] Open
Abstract
Meningococcal lipoprotein, Factor H binding protein (FHbp), is the sole antigen of the Trumenba vaccine (Pfizer) and one of four antigens of the Bexsero vaccine (GSK) targeting Neisseria meningitidis serogroup B isolates. Lipidation of FHbp is assumed to occur for all isolates. We show in the majority of a collection of United Kingdom isolates (1742/1895) non-synonymous single nucleotide polymorphisms (SNPs) in the signal peptide (SP) of FHbp. A single SNP, common to all, alters a polar amino acid that abolishes processing: lipidation and SP cleavage. Whilst some of the FHbp precursor is retained in the cytoplasm due to reduced binding to SecA, remarkably some is translocated and further surface-localized by Slam. Thus we show Slam is not lipoprotein-specific. In a panel of isolates tested, the overall reduced surface localization of the precursor FHbp, compared to isolates with an intact SP, corresponded with decreased susceptibility to antibody-mediated killing. Our findings shed new light on the canonical pathway for lipoprotein processing and translocation of important relevance for lipoprotein-based vaccines in development and in particular for Trumenba.
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Affiliation(s)
- Ronni A G da Silva
- Centre for Biomolecular Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Andrey V Karlyshev
- School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames, United Kingdom
| | - Neil J Oldfield
- Centre for Biomolecular Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Karl G Wooldridge
- Centre for Biomolecular Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Christopher D Bayliss
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom
| | - Ali Ryan
- School of Life Sciences, Pharmacy and Chemistry, Kingston University, Kingston upon Thames, United Kingdom
| | - Ruth Griffin
- Centre for Biomolecular Sciences, University of Nottingham, Nottingham, United Kingdom
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32
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Boccalini S, Bechini A, Sartor G, Paolini D, Innocenti M, Bonanni P, Panatto D, Lai PL, Zangrillo F, Marchini F, Lecini E, Iovine M, Amicizia D, Landa P. [Health Technology Assessment of meningococcal B vaccine (Trumenba ®) in adolescent in Italy]. JOURNAL OF PREVENTIVE MEDICINE AND HYGIENE 2019; 60:E1-E94. [PMID: 32047867 PMCID: PMC7007189 DOI: 10.15167/2421-4248/jpmh2019.60.3s2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- S Boccalini
- Dipartimento di Scienze della Salute, Università degli Studi di Firenze
| | - A Bechini
- Dipartimento di Scienze della Salute, Università degli Studi di Firenze
| | - G Sartor
- Dipartimento di Scienze della Salute, Università degli Studi di Firenze
| | - D Paolini
- Dipartimento di Scienze della Salute, Università degli Studi di Firenze
| | - M Innocenti
- Dipartimento di Scienze della Salute, Università degli Studi di Firenze
| | - P Bonanni
- Dipartimento di Scienze della Salute, Università degli Studi di Firenze
| | - D Panatto
- Dipartimento di Scienze della Salute, Università degli Studi di Genova
| | - P L Lai
- Dipartimento di Scienze della Salute, Università degli Studi di Genova
| | - F Zangrillo
- Dipartimento di Scienze della Salute, Università degli Studi di Genova
| | - F Marchini
- Dipartimento di Scienze della Salute, Università degli Studi di Genova
| | - E Lecini
- Dipartimento di Scienze della Salute, Università degli Studi di Genova
| | - M Iovine
- Dipartimento di Scienze della Salute, Università degli Studi di Genova
| | - D Amicizia
- Dipartimento di Scienze della Salute, Università degli Studi di Genova
| | - P Landa
- Dipartimento di Economia, Università degli Studi di Genova
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33
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Regulation of regulators: Role of the complement factor H-related proteins. Semin Immunol 2019; 45:101341. [PMID: 31757608 DOI: 10.1016/j.smim.2019.101341] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/07/2019] [Accepted: 10/24/2019] [Indexed: 01/15/2023]
Abstract
The complement system, while being an essential and very efficient effector component of innate immunity, may cause damage to the host and result in various inflammatory, autoimmune and infectious diseases or cancer, when it is improperly activated or regulated. Factor H is a serum glycoprotein and the main regulator of the activity of the alternative complement pathway. Factor H, together with its splice variant factor H-like protein 1 (FHL-1), inhibits complement activation at the level of the central complement component C3 and beyond. In humans, there are also five factor H-related (FHR) proteins, whose function is poorly characterized. While data indicate complement inhibiting activity for some of the FHRs, there is increasing evidence that FHRs have an opposite role compared with factor H and FHL-1, namely, they enhance complement activation directly and also by competing with the regulators FH and FHL-1. This review summarizes the current stand and recent data on the roles of factor H family proteins in health and disease, with focus on the function of FHR proteins.
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Virulence Factors of Meningitis-Causing Bacteria: Enabling Brain Entry across the Blood-Brain Barrier. Int J Mol Sci 2019; 20:ijms20215393. [PMID: 31671896 PMCID: PMC6862235 DOI: 10.3390/ijms20215393] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 10/24/2019] [Accepted: 10/25/2019] [Indexed: 12/16/2022] Open
Abstract
Infections of the central nervous system (CNS) are still a major cause of morbidity and mortality worldwide. Traversal of the barriers protecting the brain by pathogens is a prerequisite for the development of meningitis. Bacteria have developed a variety of different strategies to cross these barriers and reach the CNS. To this end, they use a variety of different virulence factors that enable them to attach to and traverse these barriers. These virulence factors mediate adhesion to and invasion into host cells, intracellular survival, induction of host cell signaling and inflammatory response, and affect barrier function. While some of these mechanisms differ, others are shared by multiple pathogens. Further understanding of these processes, with special emphasis on the difference between the blood-brain barrier and the blood-cerebrospinal fluid barrier, as well as virulence factors used by the pathogens, is still needed.
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Bianchi F, Veggi D, Santini L, Buricchi F, Bartolini E, Lo Surdo P, Martinelli M, Finco O, Masignani V, Bottomley MJ, Maione D, Cozzi R. Cocrystal structure of meningococcal factor H binding protein variant 3 reveals a new crossprotective epitope recognized by human mAb 1E6. FASEB J 2019; 33:12099-12111. [PMID: 31442074 PMCID: PMC6902690 DOI: 10.1096/fj.201900374r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The 4 component meningococcus B vaccine (4CMenB) vaccine is the first vaccine containing recombinant proteins licensed for the prevention of invasive meningococcal disease caused by meningococcal serogroup B strains. 4CMenB contains 3 main recombinant proteins, including the Neisseria meningitidis factor H binding protein (fHbp), a lipoprotein able to bind the human factor H. To date, over 1000 aa sequences of fHbp have been identified, and they can be divided into variant groups 1, 2, and 3, which are usually not crossprotective. Nevertheless, previous characterizations of a small set (n = 10) of mAbs generated in humans after 4CMenB immunization revealed 2 human Fabs (huFabs) (1A12, 1G3) with some crossreactivity for variants 1, 2, and 3. This unexpected result prompted us to examine a much larger set of human mAbs (n = 110), with the aim of better understanding the extent and nature of crossreactive anti-fHbp antibodies. In this study, we report an analysis of the human antibody response to fHbp, by the characterization of 110 huFabs collected from 3 adult vaccinees during a 6-mo study. Although the 4CMenB vaccine contains fHbp variant 1, 13 huFabs were also found to be crossreactive with variants 2 and 3. The crystal structure of the crossreactive huFab 1E6 in complex with fHbp variant 3 was determined, revealing a novel, highly conserved epitope distinct from the epitopes recognized by 1A12 or 1G3. Further, functional characterization shows that human mAb 1E6 is able to elicit rabbit, but not human, complement-mediated bactericidal activity against meningococci displaying fHbp from any of the 3 different variant groups. This functional and structural information about the human antibody response upon 4CMenB immunization contributes to further unraveling the immunogenic properties of fHbp. Knowledge gained about the epitope profile recognized by the human antibody repertoire could guide future vaccine design.-Bianchi, F., Veggi, D., Santini, L., Buricchi, F., Bartolini, E., Lo Surdo, P., Martinelli, M., Finco, O., Masignani, V., Bottomley, M. J., Maione, D., Cozzi, R. Cocrystal structure of meningococcal factor H binding protein variant 3 reveals a new crossprotective epitope recognized by human mAb 1E6.
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Affiliation(s)
- Federica Bianchi
- GlaxoSmithKline, Siena, Italy.,University of Florence, Firenze, Italy
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Kurtovic L, Boyle MJ, Opi DH, Kennedy AT, Tham WH, Reiling L, Chan JA, Beeson JG. Complement in malaria immunity and vaccines. Immunol Rev 2019; 293:38-56. [PMID: 31556468 PMCID: PMC6972673 DOI: 10.1111/imr.12802] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 09/03/2019] [Indexed: 12/20/2022]
Abstract
Developing efficacious vaccines for human malaria caused by Plasmodium falciparum is a major global health priority, although this has proven to be immensely challenging over the decades. One major hindrance is the incomplete understanding of specific immune responses that confer protection against disease and/or infection. While antibodies to play a crucial role in malaria immunity, the functional mechanisms of these antibodies remain unclear as most research has primarily focused on the direct inhibitory or neutralizing activity of antibodies. Recently, there is a growing body of evidence that antibodies can also mediate effector functions through activating the complement system against multiple developmental stages of the parasite life cycle. These antibody‐complement interactions can have detrimental consequences to parasite function and viability, and have been significantly associated with protection against clinical malaria in naturally acquired immunity, and emerging findings suggest these mechanisms could contribute to vaccine‐induced immunity. In order to develop highly efficacious vaccines, strategies are needed that prioritize the induction of antibodies with enhanced functional activity, including the ability to activate complement. Here we review the role of complement in acquired immunity to malaria, and provide insights into how this knowledge could be used to harness complement in malaria vaccine development.
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Affiliation(s)
- Liriye Kurtovic
- Burnet Institute, Melbourne, Vic., Australia.,Central Clinical School, Monash University, Melbourne, Vic., Australia
| | | | | | - Alexander T Kennedy
- Walter and Eliza Hall Institute, Melbourne, Vic., Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Vic., Australia
| | - Wai-Hong Tham
- Walter and Eliza Hall Institute, Melbourne, Vic., Australia
| | | | - Jo-Anne Chan
- Burnet Institute, Melbourne, Vic., Australia.,Central Clinical School, Monash University, Melbourne, Vic., Australia
| | - James G Beeson
- Burnet Institute, Melbourne, Vic., Australia.,Central Clinical School, Monash University, Melbourne, Vic., Australia.,Department of Microbiology, Monash University, Clayton, Vic., Australia.,Department of Medicine, The University of Melbourne, Parkville, Vic., Australia
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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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Findlow J, Balmer P, Borrow R. A review of complement sources used in serum bactericidal assays for evaluating immune responses to meningococcal ACWY conjugate vaccines. Hum Vaccin Immunother 2019; 15:2491-2500. [PMID: 30883271 PMCID: PMC6816443 DOI: 10.1080/21645515.2019.1593082] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Invasive meningococcal disease is rare and potentially devastating but often vaccine-preventable. Evaluation of meningococcal vaccine effectiveness is impractical owing to relatively low disease incidence; protection is therefore estimated using serum bactericidal antibody (SBA) assays. Original experiments on natural immunity established a titer of ≥4 as the correlate of protection for SBA assays using human complement (hSBA), but human complement is relatively difficult to obtain and standardize. Use of baby rabbit complement (rSBA assays), per standard guidelines for serogroups A and C, generally results in comparatively higher titers. Postlicensure effectiveness data for serogroup C conjugate vaccines support acceptance of rSBA titers ≥8 as the correlate of protection for this serogroup, but no thresholds have been formally established for serogroups A, W, and Y. Studies evaluating MenACWY-TT (Nimenrix®; Pfizer Inc, Sandwich, UK) immunogenicity have used both hSBA and rSBA assays, and ultimately suggest that rSBA may be more appropriate for these measurements.
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Affiliation(s)
- Jamie Findlow
- Vaccines, Medical and Scientific Affairs, International Developed Markets, Pfizer Ltd , Surrey , UK
| | - Paul Balmer
- Vaccine Medical and Scientific Affairs, Pfizer Inc , Collegeville , PA , USA
| | - Ray Borrow
- Public Health England, Manchester Royal Infirmary , Manchester , UK
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A homopolymeric adenosine tract in the promoter region of nspA influences factor H-mediated serum resistance in Neisseria meningitidis. Sci Rep 2019; 9:2736. [PMID: 30804422 PMCID: PMC6389960 DOI: 10.1038/s41598-019-39231-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 01/18/2019] [Indexed: 01/18/2023] Open
Abstract
Although usually asymptomatically colonizing the human nasopharynx, the Gram-negative bacterium Neisseria meningitidis (meningococcus) can spread to the blood stream and cause invasive disease. For survival in blood, N. meningitidis evades the complement system by expression of a polysaccharide capsule and surface proteins sequestering the complement regulator factor H (fH). Meningococcal strains belonging to the sequence type (ST-) 41/44 clonal complex (cc41/44) cause a major proportion of serogroup B meningococcal disease worldwide, but they are also common in asymptomatic carriers. Proteome analysis comparing cc41/44 isolates from invasive disease versus carriage revealed differential expression levels of the outer membrane protein NspA, which binds fH. Deletion of nspA reduced serum resistance and NspA expression correlated with fH sequestration. Expression levels of NspA depended on the length of a homopolymeric tract in the nspA promoter: A 5-adenosine tract dictated low NspA expression, whereas a 6-adenosine motif guided high NspA expression. Screening German cc41/44 strain collections revealed the 6-adenosine motif in 39% of disease isolates, but only in 3.4% of carriage isolates. Thus, high NspA expression is associated with disease, but not strictly required. The 6-adenosine nspA promoter is most common to the cc41/44, but is also found in other hypervirulent clonal complexes.
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40
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Role of Gonococcal Neisserial Surface Protein A (NspA) in Serum Resistance and Comparison of Its Factor H Binding Properties with Those of Its Meningococcal Counterpart. Infect Immun 2019; 87:IAI.00658-18. [PMID: 30510105 DOI: 10.1128/iai.00658-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 11/25/2018] [Indexed: 01/15/2023] Open
Abstract
Neisseria gonorrhoeae, the causative agent of gonorrhea, has evolved several mechanisms to subvert complement, including binding of the complement inhibitor factor H (FH). We previously reported FH binding to N. gonorrhoeae independently of lipooligosaccharide (LOS) sialylation. Here we report that factor H-like protein 1 (FHL-1), which contains FH domains 1 through 7 and possesses complement-inhibitory activity, also binds to N. gonorrhoeae The ligand for both FH and FHL-1 was identified as neisserial surface protein A (NspA), which has previously been identified as a ligand for these molecules on Neisseria meningitidis As with N. meningitidis NspA (Nm-NspA), N. gonorrhoeae NspA (Ng-NspA) bound FH/FHL-1 through FH domains 6 and 7. Binding of FH/FHL-1 to NspA was human specific; the histidine (H) at position 337 of domain 6 contributed to human-specific FH binding to both Ng- and Nm-NspA. FH/FHL-1 bound Nm-NspA better than Ng-NspA; introducing Q at position 73 (loop 2, present in Ng-NspA) or replacing V and D at positions 112 and 113 in Nm-NspA loop 3 with A and H (Ng-NspA), respectively, reduced FH/FHL-1 binding. The converse Ng-NspA to Nm-NspA mutations increased FH/FHL-1 binding. Binding of FH/FHL-1 through domains 6 and 7 to N. gonorrhoeae increased with truncation of the heptose I (HepI) chain of LOS and decreased with LOS sialylation. Loss of NspA significantly decreased serum resistance of N. gonorrhoeae with either wild-type or truncated LOS. This report highlights the role for NspA in enabling N. gonorrhoeae to subvert complement despite LOS phase variation. Knowledge of FH-NspA interactions will inform the design of vaccines and immunotherapies against the global threat of multidrug-resistant gonorrhea.
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41
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Abstract
Temperature variation is one of the multiple parameters a microbial pathogen encounters when it invades a warm-blooded host. To survive and thrive at host body temperature, human pathogens have developed various strategies to sense and respond to their ambient temperature. An instantaneous response is mounted by RNA thermometers (RNATs), which are integral sensory structures in mRNAs that modulate translation efficiency. At low temperatures outside the host, the folded RNA blocks access of the ribosome to the translation initiation region. The temperature shift upon entering the host destabilizes the RNA structure and thus permits ribosome binding. This reversible zipper-like mechanism of RNATs is ideally suited to fine-tune virulence gene expression when the pathogen enters or exits the body of its host. This review summarizes our present knowledge on virulence-related RNATs and discusses recent developments in the field.
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42
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McDonald ND, DeMeester KE, Lewis AL, Grimes CL, Boyd EF. Structural and functional characterization of a modified legionaminic acid involved in glycosylation of a bacterial lipopolysaccharide. J Biol Chem 2018; 293:19113-19126. [PMID: 30315110 PMCID: PMC6295735 DOI: 10.1074/jbc.ra118.004966] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 10/07/2018] [Indexed: 12/23/2022] Open
Abstract
Nonulosonic acids (NulOs) are a diverse family of α-keto acid carbohydrates present across all branches of life. Bacteria biosynthesize NulOs among which are several related prokaryotic-specific isomers and one of which, N-acetylneuraminic acid (sialic acid), is common among all vertebrates. Bacteria display various NulO carbohydrates on lipopolysaccharide (LPS), and the identities of these molecules tune host-pathogen recognition mechanisms. The opportunistic bacterial pathogen Vibrio vulnificus possesses the genes for NulO biosynthesis; however, the structures and functions of the V. vulnificus NulO glycan are unknown. Using genetic and chemical approaches, we show here that the major NulO produced by a clinical V. vulnificus strain CMCP6 is 5-N-acetyl-7-N-acetyl-d-alanyl-legionaminic acid (Leg5Ac7AcAla). The CMCP6 strain could catabolize modified legionaminic acid, whereas V. vulnificus strain YJ016 produced but did not catabolize a NulO without the N-acetyl-d-alanyl modification. In silico analysis suggested that Leg5Ac7AcAla biosynthesis follows a noncanonical pathway but appears to be present in several bacterial species. Leg5Ac7AcAla contributed to bacterial outer-membrane integrity, as mutant strains unable to produce or incorporate Leg5Ac7AcAla into the LPS have increased membrane permeability, sensitivity to bile salts and antimicrobial peptides, and defects in biofilm formation. Using the crustacean model, Artemia franciscana, we demonstrate that Leg5Ac7AcAla-deficient bacteria have decreased virulence potential compared with WT. Our data indicate that different V. vulnificus strains produce multiple NulOs and that the modified legionaminic acid Leg5Ac7AcAla plays a critical role in the physiology, survivability, and pathogenicity of V. vulnificus CMCP6.
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Affiliation(s)
| | - Kristen E DeMeester
- Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716 and
| | - Amanda L Lewis
- the Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Catherine Leimkuhler Grimes
- From the Departments of Biological Sciences and
- Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716 and
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Pastor Y, Camacho AI, Zúñiga-Ripa A, Merchán A, Rosas P, Irache JM, Gamazo C. Towards a subunit vaccine from a Shigella flexneri ΔtolR mutant. Vaccine 2018; 36:7509-7519. [PMID: 30420041 DOI: 10.1016/j.vaccine.2018.10.066] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 09/12/2018] [Accepted: 10/17/2018] [Indexed: 11/24/2022]
Abstract
Disruption of one or more components of the Tol-Pal system, involved in maintaining the integrity of the outer membrane of Gram-negative bacteria, has been proposed as a method to increase the yield obtained from natural production of outer membrane vesicles (OMV). We present a new OMV-based product, obtained from genetically modified Shigella flexneri 2a with a non-polar deletion in tolR and heat-inactivated (HT-ΔtolR). The S. flexneri ΔtolR strain lead to a higher release of vesicles, more than 8-times when compared to the yield obtained from chemically inactivated wild type strain. S. flexneri mutant strain appeared to be more sensitive to different chemical compounds, including antibiotics, bile salts or human complement and it was also less virulent in both in vitro and in vivo assays. The mutation produced some changes in the LPS O-chain and protein expression. S. flexneri ΔtolR was enriched in long and very long LPS O-chain and expressed a different pattern of surface proteins or lipoproteins. In vitro toxicity and activation properties were determined in Raw 267.4 macrophage cell line. HT-ΔtolR antigenic complex was non-cytotoxic and activation markers, such as MHC-II or CD40, were highly expressed during incubation with this product. Finally, preliminary studies on the antibody response elicited by HT-ΔtolR demonstrated a robust and diverse response in mice. Considering these promising results, HT-ΔtolR antigenic extract appears as a new potential vaccine candidate to face shigellosis.
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Affiliation(s)
- Yadira Pastor
- Department of Microbiology, Institute of Tropical Health - University of Navarra, 31008 Pamplona, Spain
| | - Ana Isabel Camacho
- Department of Microbiology, Institute of Tropical Health - University of Navarra, 31008 Pamplona, Spain
| | - Amaia Zúñiga-Ripa
- Department of Microbiology, Institute of Tropical Health - University of Navarra, 31008 Pamplona, Spain
| | - Aritz Merchán
- Department of Microbiology, Institute of Tropical Health - University of Navarra, 31008 Pamplona, Spain
| | - Pablo Rosas
- Department of Microbiology, Institute of Tropical Health - University of Navarra, 31008 Pamplona, Spain
| | - Juan M Irache
- Department of Pharmaceutical Technology, Institute of Tropical Health - University of Navarra, 31008 Pamplona, Spain
| | - Carlos Gamazo
- Department of Microbiology, Institute of Tropical Health - University of Navarra, 31008 Pamplona, Spain.
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Cantini F, Banci L. Structural Knowledge for Molecular Optimization: The Cases of Metal-Mediated Protein-Protein Interactions and Structural Vaccinology. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800699] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Francesca Cantini
- Magnetic Resonance Center (CERM); University of Florence; Via L. Sacconi 6 50019 Sesto Fiorentino Italy
- Department of Chemistry; University of Florence; Via della Lastruccia 3 50019 Sesto Fiorentino Italy
| | - Lucia Banci
- Magnetic Resonance Center (CERM); University of Florence; Via L. Sacconi 6 50019 Sesto Fiorentino Italy
- Department of Chemistry; University of Florence; Via della Lastruccia 3 50019 Sesto Fiorentino Italy
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45
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Goicoechea de Jorge E, López Lera A, Bayarri-Olmos R, Yebenes H, Lopez-Trascasa M, Rodríguez de Córdoba S. Common and rare genetic variants of complement components in human disease. Mol Immunol 2018; 102:42-57. [PMID: 29914697 DOI: 10.1016/j.molimm.2018.06.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 06/06/2018] [Accepted: 06/08/2018] [Indexed: 12/21/2022]
Abstract
Genetic variability in the complement system and its association with disease has been known for more than 50 years, but only during the last decade have we begun to understand how this complement genetic variability contributes to the development of diseases. A number of reports have described important genotype-phenotype correlations that associate particular diseases with genetic variants altering specific aspects of the activation and regulation of the complement system. The detailed functional characterization of some of these genetic variants provided key insights into the pathogenic mechanisms underlying these pathologies, which is facilitating the design of specific anti-complement therapies. Importantly, these analyses have sometimes revealed unknown features of the complement proteins. As a whole, these advances have delineated the functional implications of genetic variability in the complement system, which supports the implementation of a precision medicine approach based on the complement genetic makeup of the patients. Here we provide an overview of rare complement variants and common polymorphisms associated with disease and discuss what we have learned from them.
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Affiliation(s)
- Elena Goicoechea de Jorge
- Department of Immunology, Complutense University, Madrid, Spain; Research Institute Hospital 12 de Octubre (imas12), Madrid, Spain
| | - Alberto López Lera
- Research Institute Hospital Universitario La Paz (IdiPaz), Madrid, Spain; Ciber de Enfermedades Raras, Madrid, Spain
| | - Rafael Bayarri-Olmos
- Department of Clinical Immunology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Hugo Yebenes
- Ciber de Enfermedades Raras, Madrid, Spain; Molecular Pathology and Complement Genetics Unit. Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | | | - Santiago Rodríguez de Córdoba
- Ciber de Enfermedades Raras, Madrid, Spain; Molecular Pathology and Complement Genetics Unit. Centro de Investigaciones Biológicas, CSIC, Madrid, Spain.
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46
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Lo Passo C, Zippilli L, Angiolillo A, Costa I, Pernice I, Galbo R, Felici F, Beernink PT. Molecular characterization of two sub-family specific monoclonal antibodies to meningococcal Factor H binding protein. Heliyon 2018; 4:e00591. [PMID: 29644339 PMCID: PMC5889710 DOI: 10.1016/j.heliyon.2018.e00591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/07/2018] [Accepted: 03/27/2018] [Indexed: 11/29/2022] Open
Abstract
Factor H binding protein (FHbp) is a component of two licensed vaccines for prevention of sepsis and meningitis caused by serogroup B meningococci. FHbp binds human Factor H (FH), which contributes to evasion of host immunity and FHbp sequence variants can be classified into two sub-families. Antibodies against FHbp elicit complement-mediated killing and can inhibit recruitment of FH to the bacterial surface. We report epitope mapping studies of two murine IgG mAbs, designated JAR 31 and JAR 36, isolated from a mouse immunized with FHbp in sub-family A, which is present in ∼30-40% of invasive isolates. In the present study, we tested the reactivity of mAbs JAR 31 and JAR 36 with seven natural FHbp sequence variants from different phylogenic groups. We screened bacteriophage-displayed peptide libraries to identify amino acid residues contributing to the JAR 36 epitope. Based on the reactivities of mAbs JAR 31 and JAR 36 with the seven FHbp variants, and the frequent occurrences of aspartate (D) and lysine (K) residues in the JAR 36-bound phage peptides, we selected six residues in the carboxyl-terminal region of FHbp for replacement with alanine (A). The D201A and K203A substitutions respectively eliminated and decreased binding of mAbs JAR 31 and JAR 36 to FHbp. These substitutions did not affect binding of the control mAb JAR 33 or of human FH. JAR 31 or JAR 36 mediated cooperative complement-mediated bactericidal activity with other anti-FHbp mAbs. The identification of two amino acid residues involved in the epitopes recognized by these anti-FHbp mAbs may contribute to a more complete understanding of the spatial requirements for cooperative anti-FHbp mAb bactericidal activity.
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Affiliation(s)
- C Lo Passo
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Italy
| | - L Zippilli
- Department of Biosciences and Territory, University of Molise, Pesche (CB), Italy
| | - A Angiolillo
- Department of Medicine and Health Sciences, University of Molise, Campobasso, Italy
| | - I Costa
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Italy
| | - I Pernice
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Italy
| | - R Galbo
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Italy
| | - F Felici
- Department of Biosciences and Territory, University of Molise, Pesche (CB), Italy
| | - P 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, USA
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Predicting the Susceptibility of Meningococcal Serogroup B Isolates to Bactericidal Antibodies Elicited by Bivalent rLP2086, a Novel Prophylactic Vaccine. mBio 2018. [PMID: 29535195 PMCID: PMC5850321 DOI: 10.1128/mbio.00036-18] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Bivalent rLP2086 (Trumenba), a vaccine for prevention of Neisseria meningitidis serogroup B (NmB) disease, was licensed for use in adolescents and young adults after it was demonstrated that it elicits antibodies that initiate complement-mediated killing of invasive NmB isolates in a serum bactericidal assay with human complement (hSBA). The vaccine consists of two factor H binding proteins (fHBPs) representing divergent subfamilies to ensure broad coverage. Although it is the surrogate of efficacy, an hSBA is not suitable for testing large numbers of strains in local laboratories. Previously, an association between the in vitro fHBP surface expression level and the susceptibility of NmB isolates to killing was observed. Therefore, a flow cytometric meningococcal antigen surface expression (MEASURE) assay was developed and validated by using an antibody that binds to all fHBP variants from both fHBP subfamilies and accurately quantitates the level of fHBP expressed on the cell surface of NmB isolates with mean fluorescence intensity as the readout. Two collections of invasive NmB isolates (n = 1,814, n = 109) were evaluated in the assay, with the smaller set also tested in hSBAs using individual and pooled human serum samples from young adults vaccinated with bivalent rLP2086. From these data, an analysis based on fHBP variant prevalence in the larger 1,814-isolate set showed that >91% of all meningococcal serogroup B isolates expressed sufficient levels of fHBP to be susceptible to bactericidal killing by vaccine-induced antibodies.IMPORTANCE Bivalent rLP2086 (Trumenba) vaccine, composed of two factor H binding proteins (fHBPs), was recently licensed for the prevention of N. meningitidis serogroup B (NmB) disease in individuals 10 to 25 years old in the United States. This study evaluated a large collection of NmB isolates from the United States and Europe by using a flow cytometric MEASURE assay to quantitate the surface expression of the vaccine antigen fHBP. We find that expression levels and the proportion of strains above the level associated with susceptibility in an hSBA are generally consistent across these geographic regions. Thus, the assay can be used to predict which NmB isolates are susceptible to killing in the hSBA and therefore is able to demonstrate an fHBP vaccine-induced bactericidal response. This work significantly advances our understanding of the potential for bivalent rLP2086 to provide broad coverage against diverse invasive-disease-causing NmB isolates.
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Abstract
There is an urgent need to develop vaccines against pathogenic bacteria. However, this is often hindered by antigenic diversity and difficulties encountered manufacturing membrane proteins. Here we show how to use structure-based design to develop chimeric antigens (ChAs) for subunit vaccines. ChAs are generated against serogroup B Neisseria meningitidis (MenB), the predominant cause of meningococcal disease in wealthy countries. MenB ChAs exploit factor H binding protein (fHbp) as a molecular scaffold to display the immunogenic VR2 epitope from the integral membrane protein PorA. Structural analyses demonstrate fHbp is correctly folded and the PorA VR2 epitope adopts an immunogenic conformation. In mice, immunisation with ChAs generates fHbp and PorA antibodies that recognise the antigens expressed by clinical MenB isolates; these antibody responses correlate with protection against meningococcal disease. Application of ChAs is therefore a potentially powerful approach to develop multivalent subunit vaccines, which can be tailored to circumvent pathogen diversity. Factor H binding protein (fHbp) and PorA are components of experimental serogroup B N. meningitidis vaccines. Here the authors graft the VR2 loop of PorA onto an fHBp-based scaffold to demonstrate proof-of-principle of a chimeric antigen strategy and vaccination against meningococcal disease.
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Price GA, Bash MC. Development of an FHbp-CTB holotoxin-like chimera and the elicitation of bactericidal antibodies against serogroup B Neisseria meningitidis. Vaccine 2018; 36:644-652. [PMID: 29287682 DOI: 10.1016/j.vaccine.2017.12.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 12/01/2017] [Accepted: 12/17/2017] [Indexed: 11/18/2022]
Abstract
The Neisseria meningitidis factor H binding protein (FHbp) is an important virulence factor and vaccine antigen contained in both USA licensed serogroup B meningococcal vaccines. Recent studies in human factor H (hFH) transgenic mice suggest that hFH-FHbp interactions lower FHbp-elicited immunogenicity. To provide tools with which to characterize and potentially improve FHbp immunogenicity, we developed an FHbp-cholera holotoxin-like chimera vaccine expression system in Escherichia coli that utilizes cholera toxin B (CTB) as both a scaffold and adjuvant for FHbp. We developed FHbp-CTB chimeras using a wild-type (WT) FHbp and a low hFH-binding FHbp mutant R41S. Both chimeras bound to GM1 ganglioside and were recognized by the FHbp-specific monoclonal antibody JAR4. The R41S mutant had greatly reduced hFH binding compared to the WT FHbp-CTB chimera. WT and R41S FHbp-CTB chimeric antigens were compared to equimolar amounts of FHbp admixed with CTB or FHbp alone in mouse immunogenicity studies. The chimeras were significantly more immunogenic than FHbp alone or mixed with CTB, and elicited bactericidal antibodies against a panel of MenB isolates. This study demonstrates a unique and simple method for studying FHbp immunogenicity. The chimeric approach may facilitate studies of other protein-based antigens targeting pathogenic Neisseria and lay groundwork for the development of new protein based vaccines against meningococcal and gonococcal disease.
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Affiliation(s)
- Gregory A Price
- Laboratory of Bacterial Polysaccharides, Division of Bacterial, Parasitic, and Allergenic Products, Center for Biologics Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993, USA.
| | - Margaret C Bash
- Laboratory of Bacterial Polysaccharides, Division of Bacterial, Parasitic, and Allergenic Products, Center for Biologics Evaluation and Research, Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993, USA
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Neisseria cinerea Expresses a Functional Factor H Binding Protein Which Is Recognized by Immune Responses Elicited by Meningococcal Vaccines. Infect Immun 2017; 85:IAI.00305-17. [PMID: 28739825 PMCID: PMC5607398 DOI: 10.1128/iai.00305-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 07/07/2017] [Indexed: 12/12/2022] Open
Abstract
Neisseria meningitidis is a major cause of bacterial meningitis and sepsis worldwide. Capsular polysaccharide vaccines are available against meningococcal serogroups A, C, W, and Y. More recently two protein-based vaccines, Bexsero and Trumenba, against meningococcal serogroup B strains have been licensed; both vaccines contain meningococcal factor H binding protein (fHbp). fHbp is a surface-exposed lipoprotein that binds the negative complement regulator complement factor H (CFH), thereby inhibiting the alternative pathway of complement activation. Recent analysis of available genomes has indicated that some commensal Neisseria species also contain genes that potentially encode fHbp, although the functions of these genes and how immunization with fHbp-containing vaccines could affect the commensal flora have yet to be established. Here, we show that the commensal species Neisseria cinerea expresses functional fHbp on its surface and that it is responsible for recruitment of CFH by the bacterium. N. cinerea fHbp binds CFH with affinity similar to that of meningococcal fHbp and promotes survival of N. cinerea in human serum. We examined the potential impact of fHbp-containing vaccines on N. cinerea We found that immunization with Bexsero elicits serum bactericidal activity against N. cinerea, which is primarily directed against fHbp. The shared function of fHbp in N. cinerea and N. meningitidis and cross-reactive responses elicited by Bexsero suggest that the introduction of fHbp-containing vaccines has the potential to affect carriage of N. cinerea and other commensal species.
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