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Chan H, Beresford N, Rudd TR, Rigsby P, Vipond C, Gao F, Matejtschuk P, Malik K, Duru C, Atkinson E, Burkin K, De Benedetto G, Lockyer K, Bolgiano B. Evaluation of candidate International Standards for meningococcal capsular polysaccharide groups W and Y. Biologicals 2024; 87:101780. [PMID: 38970883 DOI: 10.1016/j.biologicals.2024.101780] [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: 04/12/2024] [Revised: 06/11/2024] [Accepted: 06/19/2024] [Indexed: 07/08/2024] Open
Abstract
Two candidate International Standards for meningococcal capsular group W and Y (MenW and MenY, respectively) polysaccharides were assessed for their suitability as quantitative standards in various physicochemical assays. The study was designed to evaluate the intended purpose of these standards, namely, to standardize the quantification of the respective polysaccharide content in meningococcal polysaccharide and conjugate vaccines and their intermediate components. Twelve laboratories from eleven different countries participated in the collaborative study of candidate preparations for International Standards for MenW and MenY polysaccharide (coded 16/152 and 16/206, respectively). Unitage was assigned using the Resorcinol assay. Our proposals, on the basis of data from the Resorcinol assay were: 1) candidate standard for MenW polysaccharide (16/152) to be assigned a content of 1.015 ± 0.071 mg MenW polysaccharide per ampoule (expanded uncertainty with coverage factor k = 2.13, corresponding to a 95 % level of confidence) and 2) candidate standard for MenY polysaccharide (16/206) be assigned a content of 0.958 ± 0.076 mg MenY polysaccharide per ampoule (expanded uncertainty with coverage factor k = 2.26, corresponding to a 95 % level of confidence). The amount of polysaccharide per ampoule remained consistent under all stability conditions over a 36-month period.
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Affiliation(s)
- Hannah Chan
- Division of Bacteriology, National Institute for Biological Standards and Control, Blanche Lane, Potters Bar, Hertfordshire, EN6 3QG, UK.
| | - Nicola Beresford
- Division of Bacteriology, National Institute for Biological Standards and Control, Blanche Lane, Potters Bar, Hertfordshire, EN6 3QG, UK
| | - Timothy R Rudd
- Analytical and Biological Sciences Division, National Institute for Biological Standards and Control, Blanche Lane, Potters Bar, Hertfordshire, EN6 3QG, UK
| | - Peter Rigsby
- Analytical and Biological Sciences Division, National Institute for Biological Standards and Control, Blanche Lane, Potters Bar, Hertfordshire, EN6 3QG, UK
| | - Caroline Vipond
- Division of Bacteriology, National Institute for Biological Standards and Control, Blanche Lane, Potters Bar, Hertfordshire, EN6 3QG, UK
| | - Fang Gao
- Division of Bacteriology, National Institute for Biological Standards and Control, Blanche Lane, Potters Bar, Hertfordshire, EN6 3QG, UK
| | - Paul Matejtschuk
- Analytical and Biological Sciences Division, National Institute for Biological Standards and Control, Blanche Lane, Potters Bar, Hertfordshire, EN6 3QG, UK
| | - Kiran Malik
- Analytical and Biological Sciences Division, National Institute for Biological Standards and Control, Blanche Lane, Potters Bar, Hertfordshire, EN6 3QG, UK
| | - Chinwe Duru
- Analytical and Biological Sciences Division, National Institute for Biological Standards and Control, Blanche Lane, Potters Bar, Hertfordshire, EN6 3QG, UK
| | - Eleanor Atkinson
- Analytical and Biological Sciences Division, National Institute for Biological Standards and Control, Blanche Lane, Potters Bar, Hertfordshire, EN6 3QG, UK
| | - Karena Burkin
- Division of Bacteriology, National Institute for Biological Standards and Control, Blanche Lane, Potters Bar, Hertfordshire, EN6 3QG, UK
| | - Gianluigi De Benedetto
- Division of Bacteriology, National Institute for Biological Standards and Control, Blanche Lane, Potters Bar, Hertfordshire, EN6 3QG, UK
| | - Kay Lockyer
- Division of Bacteriology, National Institute for Biological Standards and Control, Blanche Lane, Potters Bar, Hertfordshire, EN6 3QG, UK
| | - Barbara Bolgiano
- Division of Bacteriology, National Institute for Biological Standards and Control, Blanche Lane, Potters Bar, Hertfordshire, EN6 3QG, UK
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2
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Tian G, Qin C, Hu J, Zou X, Yin J. Effect of Side-Chain Functional Groups in the Immunogenicity of Bacterial Surface Glycans. Molecules 2023; 28:7112. [PMID: 37894591 PMCID: PMC10609480 DOI: 10.3390/molecules28207112] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 10/13/2023] [Accepted: 10/13/2023] [Indexed: 10/29/2023] Open
Abstract
Glycans on the surface of bacteria have diverse and essential biological functions and have widely been employed for treating various bacterial infectious diseases. Furthermore, these glycans comprise various functional groups, such as O-, N-, and carboxyl-modified, which significantly increase the diversity of glycan structures. These functional groups are not only crucial for glycans' structural identity but are also essential for their biological functions. Therefore, a clear understanding of the biological functions of these modified groups in corresponding bacterial glycans is crucial for their medical applications. Thus far, the activities of functional groups in some biomedical active carbohydrates have been elucidated. It has been shown that some functional groups are key constituents of biologically active bacterial glycans, while others are actually not essential and may even mask the functions of the glycans. This paper reviews the structures of naturally occurring side-chain functional groups in glycans located on the bacterial surface and their roles in immunological responses.
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Affiliation(s)
- Guangzong Tian
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; (G.T.); (C.Q.); (X.Z.)
| | - Chunjun Qin
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; (G.T.); (C.Q.); (X.Z.)
| | - Jing Hu
- Wuxi School of Medicine, Jiangnan University, Wuxi 214122, China;
| | - Xiaopeng Zou
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; (G.T.); (C.Q.); (X.Z.)
| | - Jian Yin
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; (G.T.); (C.Q.); (X.Z.)
- School of Life Sciences and Health Engineering, Jiangnan University, Wuxi 214122, China
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3
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Schipper K, Preusting LC, van Sorge NM, Pannekoek Y, van der Ende A. Meningococcal virulence in zebrafish embryos depends on capsule polysaccharide structure. Front Cell Infect Microbiol 2022; 12:1020201. [PMID: 36211969 PMCID: PMC9538531 DOI: 10.3389/fcimb.2022.1020201] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 09/06/2022] [Indexed: 11/13/2022] Open
Abstract
Neisseria meningitidis or the meningococcus, can cause devasting diseases such as sepsis and meningitis. Its polysaccharide capsule, on which serogrouping is based, is the most important virulence factor. Non-encapsulated meningococci only rarely cause disease, due to their sensitivity to the host complement system. How the capsular polysaccharide structure of N. meningitidis relates to virulence is largely unknown. Meningococcal virulence can be modeled in zebrafish embryos as the innate immune system of the zebrafish embryo resembles that of mammals and is fully functional two days post-fertilization. In contrast, the adaptive immune system does not develop before 4 weeks post-fertilization. We generated isogenic meningococcal serogroup variants to study how the chemical composition of the polysaccharide capsule affects N. meningitidis virulence in the zebrafish embryo model. H44/76 serogroup B killed zebrafish embryos in a dose-dependent manner, whereas the non-encapsulated variant was completely avirulent. Neutrophil depletion was observed after infection with encapsulated H44/76, but not with its non-encapsulated variant HB-1. The survival of embryos infected with isogenic capsule variants of H44/76 was capsule specific. The amount of neutrophil depletion differed accordingly. Both embryo killing capacity and neutrophil depletion after infection correlated with the number of carbons used per repeat unit of the capsule polysaccharide during its biosynthesis (indicative of metabolic cost).ConclusionMeningococcal virulence in the zebrafish embryo largely depends on the presence of the polysaccharide capsule but the extent of the contribution is determined by its structure. The observed differences between the meningococcal isogenic capsule variants in zebrafish embryo virulence may depend on differences in metabolic cost.
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Sato K, Chiba A, Shiraishi T, Ogawa Y, Hara RI, Wada T. Solid-phase synthesis of N-trichloroacetyl mannosamine 1-phosphate repeating units Mimicking capsular polysaccharide derived from Neisseria meningitidis serotype A. Carbohydr Res 2022; 518:108585. [DOI: 10.1016/j.carres.2022.108585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 05/06/2022] [Accepted: 05/09/2022] [Indexed: 11/02/2022]
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Comparative study on the structure characterization and immune activity of Lactarius vellereus Fr. polysaccharide (LV-1) and Cordyceps militaris (L. ex Fr.) Link. polysaccharide (CM-S). JOURNAL OF FOOD MEASUREMENT AND CHARACTERIZATION 2021. [DOI: 10.1007/s11694-021-01215-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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6
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Ji Y, Sasmal A, Li W, Oh L, Srivastava S, Hargett AA, Wasik BR, Yu H, Diaz S, Choudhury B, Parrish CR, Freedberg DI, Wang LP, Varki A, Chen X. Reversible O-Acetyl Migration within the Sialic Acid Side Chain and Its Influence on Protein Recognition. ACS Chem Biol 2021; 16:1951-1960. [PMID: 33769035 DOI: 10.1021/acschembio.0c00998] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
O-Acetylation is a common naturally occurring modification of carbohydrates and is especially widespread in sialic acids, a family of nine-carbon acidic monosaccharides. O-Acetyl migration within the exocyclic glycerol-like side chain of mono-O-acetylated sialic acid reported previously was from the C7- to C9-hydroxyl group with or without an 8-O-acetyl intermediate, which resulted in an equilibrium that favors the formation of the 9-O-acetyl sialic acid. Herein, we provide direct experimental evidence demonstrating that O-acetyl migration is bidirectional, and the rate of equilibration is influenced predominantly by the pH of the sample. While the O-acetyl group on sialic acids and sialoglycans is stable under mildly acidic conditions (pH < 5, the rate of O-acetyl migration is extremely low), reversible O-acetyl migration is observed readily at neutral pH and becomes more significant when the pH increases to slightly basic. Sialoglycan microarray studies showed that esterase-inactivated porcine torovirus hemagglutinin-esterase bound strongly to sialoglycans containing a more stable 9-N-acetylated sialic acid analog, but these compounds were less resistant to periodate oxidation treatment compared to their 9-O-acetyl counterparts. Together with prior studies, the results support the possible influence of sialic acid O-acetylation and O-acetyl migration to host-microbe interactions and potential application of the more stable synthetic N-acetyl mimics.
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Affiliation(s)
- Yang Ji
- Glycobiology Research and Training Center, Departments of Medicine and Cellular and Molecular Medicine, University of California, San Diego, California 92093, United States
| | - Aniruddha Sasmal
- Glycobiology Research and Training Center, Departments of Medicine and Cellular and Molecular Medicine, University of California, San Diego, California 92093, United States
| | - Wanqing Li
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Lisa Oh
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Saurabh Srivastava
- Glycobiology Research and Training Center, Departments of Medicine and Cellular and Molecular Medicine, University of California, San Diego, California 92093, United States
| | - Audra A. Hargett
- Laboratory of Bacterial Polysaccharides, Food and Drug Administration (FDA), Silver Spring, Maryland 20993, United States
| | - Brian R. Wasik
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, United States
| | - Hai Yu
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Sandra Diaz
- Glycobiology Research and Training Center, Departments of Medicine and Cellular and Molecular Medicine, University of California, San Diego, California 92093, United States
| | - Biswa Choudhury
- Glycobiology Research and Training Center, Departments of Medicine and Cellular and Molecular Medicine, University of California, San Diego, California 92093, United States
| | - Colin R. Parrish
- Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, United States
| | - Darón I. Freedberg
- Laboratory of Bacterial Polysaccharides, Food and Drug Administration (FDA), Silver Spring, Maryland 20993, United States
| | - Lee-Ping Wang
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Ajit Varki
- Glycobiology Research and Training Center, Departments of Medicine and Cellular and Molecular Medicine, University of California, San Diego, California 92093, United States
| | - Xi Chen
- Department of Chemistry, University of California, Davis, California 95616, United States
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Berti F. NMR characterization of a multi-valent conjugate vaccine against Neisseria meningitidis A, C, W, Y and Haemophilus influenzae b infections. J Pharm Biomed Anal 2021; 205:114302. [PMID: 34388671 DOI: 10.1016/j.jpba.2021.114302] [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: 05/25/2021] [Revised: 07/21/2021] [Accepted: 07/30/2021] [Indexed: 11/18/2022]
Abstract
Physicochemical technologies are a powerful tool for the structural characterization of vaccine antigens both at bulk level as well as on the final formulation. High-field Nuclear Magnetic Resonance (NMR) spectroscopy has been found to be an extremely and robust tool for tracking the industrial process manufacturing of carbohydrate-based vaccines. I have applied NMR spectroscopy to the characterization of a penta-valent conjugate vaccine against Neisseria meninigitidis group A, C, W, Y (MenACWY) and Haemophilus influenzae type b (Hib) infections, constituted of capsule derived polysaccharide fragments independently conjugated to CRM197 protein carrier (CRM-MenA, CRM-MenC, CRM-MenW, CRM-MenY, CRM-Hib). 1H NMR has been used for the identity testing of the carbohydrate antigens and of the vaccine formulation. The application of NMR-based assays on multivalent conjugate vaccines looks to be a promising approach for identity and stability analyses useful for future vaccines development.
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Albers M, Schröter L, Belousov S, Hartmann M, Grove M, Abeln M, Mühlenhoff M. The sialyl-O-acetylesterase NanS of Tannerella forsythia encompasses two catalytic modules with different regiospecificity for O7 and O9 of sialic acid. Glycobiology 2021; 31:1176-1191. [PMID: 33909048 DOI: 10.1093/glycob/cwab034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/14/2021] [Accepted: 04/15/2021] [Indexed: 12/12/2022] Open
Abstract
The periodontal pathogen Tannerella forsythia utilizes host sialic acids as a nutrient source. To also make O-acetylated sialyl residues susceptible to the action of its sialidase and sialic acid up-take system, Tannerella produces NanS, an O-acetylesterase with two putative catalytic domains. Here, we analyzed NanS by homology modeling, predicted a catalytic serine-histidine-aspartate triad for each catalytic domain and performed individual domain inactivation by single alanine exchanges of the triad nucleophiles S32 and S311. Subsequent functional analyses revealed that both domains possess sialyl-O-acetylesterase activity, but differ in their regioselectivity with respect to position O9 and O7 of sialic acid. The 7-O-acetylesterase activity inherent to the C-terminal domain of NanS is unique among sialyl-O-acetylesterases and fills the current gap in tools targeting 7-O-acetylation. Application of the O7-specific variant NanS-S32A allowed us to evidence the presence of cellular 7,9-di-O-acetylated sialoglycans by monitoring the gain in 9-O-acetylation upon selective removal of acetyl groups from O7. Moreover, we established de-7,9-O-acetylation by wild-type NanS as an easy and efficient method to validate the specific binding of three viral lectins commonly used for the recognition of (7),9-O-acetylated sialoglycans. Their binding critically depends on an acetyl group in O9, yet de-7,9-O-acetylation proved advantageous over de-9-O-acetylation as the additional removal of the 7-O-acetyl group eliminated ligand formation by 7,9-ester migration. Together, our data show that NanS gained dual functionality through recruitment of two esterase modules with complementary activities. This enables Tannerella to scavenge 7,9-di-O-acetylated sialyl residues and provides a novel, O7-specific tool for studying sialic acid O-acetylation.
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Affiliation(s)
- Malena Albers
- Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Larissa Schröter
- Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Sergej Belousov
- Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Maike Hartmann
- Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Melanie Grove
- Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Markus Abeln
- Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Martina Mühlenhoff
- Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
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9
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Bartling B, Brüchle NC, Rehfeld JS, Boßmann D, Fiebig T, Litschko C, Fohrer J, Gerardy-Schahn R, Scheper T, Beutel S. Accelerated production of α2,8- and α2,9-linked polysialic acid in recombinant Escherichia coli using high cell density cultivation. BIOTECHNOLOGY REPORTS (AMSTERDAM, NETHERLANDS) 2020; 28:e00562. [PMID: 33304838 PMCID: PMC7711218 DOI: 10.1016/j.btre.2020.e00562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 10/05/2020] [Accepted: 11/17/2020] [Indexed: 11/29/2022]
Abstract
Polysialic acid (polySia) are α2,8- and/or α2,9-linked homopolymers with interesting properties for meningococcal vaccine development or the cure of human neurodegenerative disorders. With the goal to avoid large scale production of pathogenic bacteria, we compare in the current study the efficacy of conventional polySia production to recombinant approaches using the engineered laboratory safety strain E. coli BL21. High cell density cultivation (HCDC) experiments were performed in two different bioreactor systems. Increased cell densities of up to 11.3 (±0.4) g/L and polySia concentrations of up to 774 (±18) mg/L were reached in E. coli K1. However, cultivation of engineered E. coli BL21 strains delivered comparable cell densities but a maximum of only 133 mg/L polySia. Using established downstream procedures, host cell DNA and proteins were removed. All recombinant polySia products showed an identical degree of polymerization >90. Polymers with different glycosidic linkages could be successfully differentiated by nuclear magnetic resonance spectroscopy.
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Affiliation(s)
- Bastian Bartling
- Institute of Technical Chemistry, Leibniz University Hannover, D-30167 Hannover, Germany
| | - Nora C. Brüchle
- Institute of Technical Chemistry, Leibniz University Hannover, D-30167 Hannover, Germany
| | - Johanna S. Rehfeld
- Institute of Technical Chemistry, Leibniz University Hannover, D-30167 Hannover, Germany
| | - Daniel Boßmann
- Institute of Technical Chemistry, Leibniz University Hannover, D-30167 Hannover, Germany
| | - Timm Fiebig
- Institute of Clinical Biochemistry, Hannover Medical School, D-30625 Hannover, Germany
| | - Christa Litschko
- Institute of Clinical Biochemistry, Hannover Medical School, D-30625 Hannover, Germany
| | - Jörg Fohrer
- Institute of Organic Chemistry, Leibniz University Hannover, D-30167 Hannover, Germany
| | - Rita Gerardy-Schahn
- Institute of Clinical Biochemistry, Hannover Medical School, D-30625 Hannover, Germany
| | - Thomas Scheper
- Institute of Technical Chemistry, Leibniz University Hannover, D-30167 Hannover, Germany
| | - Sascha Beutel
- Institute of Technical Chemistry, Leibniz University Hannover, D-30167 Hannover, Germany
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10
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Li R, Kooner AS, Muthana SM, Yuan Y, Yu H, Chen X. A Chemoenzymatic Synthon Strategy for Synthesizing N-Acetyl Analogues of O-Acetylated N. meningitidis W Capsular Polysaccharide Oligosaccharides. J Org Chem 2020; 85:16157-16165. [PMID: 33164526 DOI: 10.1021/acs.joc.0c02134] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
O-Acetylated sialic acid has been found in the Neisseria meningitidis serogroup W (NmW) capsular polysaccharide (CPS) and is a required structural component of clinically used NmW CPS-based polysaccharide and polysaccharide-conjugate vaccines. The role of sialic acid O-acetylation in NmW CPS, however, is not clearly understood. This is partially due to the lack of a precise control of the percentage and the location of O-acetylation which is labile and susceptible to migration. We explore chemoenzymatic synthetic strategies for preparing N-acetylated analogues of O-acetylated NmW CPS oligosaccharides which can serve as structurally stable probe mimics. Substrate specificity studies of NmW CPS polymerase (NmSiaDW) identified 4-azido-4-deoxy-N-acetylmannosamine (ManNAc4N3) and 6-azido-6-deoxy-N-acetylmannosamine (ManNAc6N3) as suitable chemoenzymatic synthons for synthesizing N-acetyl analogues of NmW CPS oligosaccharides containing 7-O-acetyl-N-acetylneuraminic acid (Neu5,7Ac2) and/or 9-O-acetyl-N-acetylneuraminic acid (Neu5,9Ac2). The synthesis was achieved by NmSiaDW-dependent sequential one-pot multienzyme (OPME) strategy with in situ generation of the corresponding sugar nucleotides from simple monosaccharides or derivatives to form N3-oligosaccharides which were converted to the desired NAc-oligosaccharides by an efficient one-step chemical transformation.
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Affiliation(s)
- Riyao Li
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Anoopjit S Kooner
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Saddam M Muthana
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States.,Department of Chemistry, Alfaisal University, Riyadh 11533, Kingdom of Saudi Arabia
| | - Yue Yuan
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Hai Yu
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Xi Chen
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
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11
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Structure of a protective epitope reveals the importance of acetylation of Neisseria meningitidis serogroup A capsular polysaccharide. Proc Natl Acad Sci U S A 2020; 117:29795-29802. [PMID: 33158970 PMCID: PMC7703565 DOI: 10.1073/pnas.2011385117] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Meningococcal meningitis remains a substantial cause of mortality and morbidity worldwide. Until recently, countries in the African meningitis belt were susceptible to devastating outbreaks, largely attributed to serogroup A Neisseria meningitidis (MenA). Vaccination with glycoconjugates of MenA capsular polysaccharide led to an almost complete elimination of MenA clinical cases. To understand the molecular basis of vaccine-induced protection, we generated a panel of oligosaccharide fragments of different lengths and tested them with polyclonal and monoclonal antibodies by inhibition enzyme-linked immunosorbent assay, surface plasmon resonance, and competitive human serum bactericidal assay, which is a surrogate for protection. The epitope was shown to optimize between three and six repeating units and to be O-acetylated. The molecular interactions between a protective monoclonal antibody and a MenA capsular polysaccharide fragment were further elucidated at the atomic level by saturation transfer difference NMR spectroscopy and X-ray crystallography. The epitope consists of a trisaccharide anchored to the antibody via the O- and N-acetyl moieties through either H-bonding or CH-π interactions. In silico docking showed that 3-O-acetylation of the upstream residue is essential for antibody binding, while O-acetate could be equally accommodated at three and four positions of the other two residues. These results shed light on the mechanism of action of current MenA vaccines and provide a foundation for the rational design of improved therapies.
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12
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Fiebig T, Cramer JT, Bethe A, Baruch P, Curth U, Führing JI, Buettner FFR, Vogel U, Schubert M, Fedorov R, Mühlenhoff M. Structural and mechanistic basis of capsule O-acetylation in Neisseria meningitidis serogroup A. Nat Commun 2020; 11:4723. [PMID: 32948778 PMCID: PMC7501274 DOI: 10.1038/s41467-020-18464-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 08/20/2020] [Indexed: 02/08/2023] Open
Abstract
O-Acetylation of the capsular polysaccharide (CPS) of Neisseria meningitidis serogroup A (NmA) is critical for the induction of functional immune responses, making this modification mandatory for CPS-based anti-NmA vaccines. Using comprehensive NMR studies, we demonstrate that O-acetylation stabilizes the labile anomeric phosphodiester-linkages of the NmA-CPS and occurs in position C3 and C4 of the N-acetylmannosamine units due to enzymatic transfer and non-enzymatic ester migration, respectively. To shed light on the enzymatic transfer mechanism, we solved the crystal structure of the capsule O-acetyltransferase CsaC in its apo and acceptor-bound form and of the CsaC-H228A mutant as trapped acetyl-enzyme adduct in complex with CoA. Together with the results of a comprehensive mutagenesis study, the reported structures explain the strict regioselectivity of CsaC and provide insight into the catalytic mechanism, which relies on an unexpected Gln-extension of a classical Ser-His-Asp triad, embedded in an α/β-hydrolase fold.
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Affiliation(s)
- Timm Fiebig
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany.
| | | | - Andrea Bethe
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Petra Baruch
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Ute Curth
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Jana I Führing
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
- Fraunhofer International Consortium for Anti-Infective Research (iCAIR), Hannover, Germany
| | - Falk F R Buettner
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Ulrich Vogel
- Institute for Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Mario Schubert
- Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Roman Fedorov
- Institute for Biophysical Chemistry, Hannover Medical School, Hannover, Germany
| | - Martina Mühlenhoff
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany.
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13
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Enotarpi J, Tontini M, Balocchi C, van der Es D, Auberger L, Balducci E, Carboni F, Proietti D, Casini D, Filippov DV, Overkleeft HS, van der Marel GA, Colombo C, Romano MR, Berti F, Costantino P, Codeé JDC, Lay L, Adamo R. A stabilized glycomimetic conjugate vaccine inducing protective antibodies against Neisseria meningitidis serogroup A. Nat Commun 2020; 11:4434. [PMID: 32895393 PMCID: PMC7477203 DOI: 10.1038/s41467-020-18279-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 08/09/2020] [Indexed: 12/15/2022] Open
Abstract
Neisseria meningitidis serogroup A capsular polysaccharide (MenA CPS) consists of (1 → 6)-2-acetamido-2-deoxy-α-D-mannopyranosyl phosphate repeating units, O-acetylated at position C3 or C4. Glycomimetics appear attractive to overcome the CPS intrinsic lability in physiological media, due to cleavage of the phosphodiester bridge, and to develop a stable vaccine with longer shelf life in liquid formulation. Here, we generate a series of non-acetylated carbaMenA oligomers which are proven more stable than the CPS. An octamer (DP8) inhibits the binding of a MenA specific bactericidal mAb and polyclonal serum to the CPS, and is selected for further in vivo testing. However, its CRM197 conjugate raises murine antibodies towards the non-acetylated CPS backbone, but not the natural acetylated form. Accordingly, random O-acetylation of the DP8 is performed, resulting in a structure (Ac-carbaMenA) showing improved inhibition of anti-MenA CPS antibody binding and, after conjugation to CRM197, eliciting anti-MenA protective murine antibodies, comparably to the vaccine benchmark.
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MESH Headings
- Animals
- Antibodies, Bacterial/analysis
- Antibodies, Neutralizing/chemistry
- Bacterial Capsules/immunology
- Biomimetics/methods
- Glycoconjugates/chemical synthesis
- Glycoconjugates/immunology
- Mice
- Neisseria meningitidis, Serogroup A/chemistry
- Neisseria meningitidis, Serogroup A/drug effects
- Neisseria meningitidis, Serogroup A/immunology
- Polysaccharides, Bacterial/chemical synthesis
- Polysaccharides, Bacterial/chemistry
- Polysaccharides, Bacterial/immunology
- Vaccines, Conjugate/chemistry
- Vaccines, Conjugate/microbiology
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Affiliation(s)
- Jacopo Enotarpi
- Department of Chemistry and CRC Polymeric Materials (LaMPo), University of Milan, Milan, Italy
- Department of Bioorganic Synthesis, Leiden University, 2333, Leiden, The Netherlands
| | | | | | - Daan van der Es
- Department of Bioorganic Synthesis, Leiden University, 2333, Leiden, The Netherlands
| | - Ludovic Auberger
- Department of Chemistry and CRC Polymeric Materials (LaMPo), University of Milan, Milan, Italy
| | | | | | | | | | - Dmitri V Filippov
- Department of Bioorganic Synthesis, Leiden University, 2333, Leiden, The Netherlands
| | - Hermen S Overkleeft
- Department of Bioorganic Synthesis, Leiden University, 2333, Leiden, The Netherlands
| | | | - Cinzia Colombo
- Department of Chemistry and CRC Polymeric Materials (LaMPo), University of Milan, Milan, Italy
| | | | | | | | - Jeroen D C Codeé
- Department of Bioorganic Synthesis, Leiden University, 2333, Leiden, The Netherlands.
| | - Luigi Lay
- Department of Chemistry and CRC Polymeric Materials (LaMPo), University of Milan, Milan, Italy.
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14
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Abstract
The outer membrane (OM) of Gram-negative bacteria poses a barrier to antibiotic entry due to its high impermeability. Thus, there is an urgent need to study the function and biogenesis of the OM. In Enterobacterales, an order of bacteria with many pathogenic members, one of the components of the OM is enterobacterial common antigen (ECA). We have known of the presence of ECA on the cell surface of Enterobacterales for many years, but its properties have only more recently begun to be unraveled. ECA is a carbohydrate antigen built of repeating units of three amino sugars, the structure of which is conserved throughout Enterobacterales. There are three forms of ECA, two of which (ECAPG and ECALPS) are located on the cell surface, while one (ECACYC) is located in the periplasm. Awareness of the importance of ECA has increased due to studies of its function that show it plays a vital role in bacterial physiology and interaction with the environment. Here, we review the discovery of ECA, the pathways for the biosynthesis of ECA, and the interactions of its various forms. In addition, we consider the role of ECA in the host immune response, as well as its potential roles in host-pathogen interaction. Furthermore, we explore recent work that offers insights into the cellular function of ECA. This review provides a glimpse of the biological significance of this enigmatic molecule.
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Affiliation(s)
- Ashutosh K Rai
- Department of Biology, Texas A&M University, College Station, Texas, USA
| | - Angela M Mitchell
- Department of Biology, Texas A&M University, College Station, Texas, USA
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15
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Post-Glycosylation Modification of Sialic Acid and Its Role in Virus Pathogenesis. Vaccines (Basel) 2019; 7:vaccines7040171. [PMID: 31683930 PMCID: PMC6963189 DOI: 10.3390/vaccines7040171] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/08/2019] [Accepted: 10/23/2019] [Indexed: 01/20/2023] Open
Abstract
Sialic acids are a family of nine carbon keto-aldononulosonic acids presented at the terminal ends of glycans on cellular membranes. α-Linked sialoglycoconjugates often undergo post-glycosylation modifications, among which O-acetylation of N-acetyl neuraminic acid (Neu5Ac) is the most common in mammalian cells. Isoforms of sialic acid are critical determinants of virus pathogenesis. To date, the focus of viral receptor-mediated attachment has been on Neu5Ac. O-Acetylated Neu5Acs have been largely ignored as receptor determinants of virus pathogenesis, although it is ubiquitous across species. Significantly, the array of structures resulting from site-specific O-acetylation by sialic acid O-acetyltransferases (SOATs) provides a means to examine specificity of viral binding to host cells. Specifically, C4 O-acetylated Neu5Ac can influence virus pathogenicity. However, the biological implications of only O-acetylated Neu5Ac at C7-9 have been explored extensively. This review will highlight the biological significance, extraction methods, and synthetic modifications of C4 O-acetylated Neu5Ac that may provide value in therapeutic developments and targets to prevent virus related diseases.
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16
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Martini S, Aggravi M, Cianetti S, Egan W, Meppen M, Moriconi A, Simeone L, Berti F. NMR Assays for Estimating the O-Acetyl Content of Meningococcal Polysaccharide Serogroup A in Quadrivalent Conjugate Vaccine Formulation. ACS OMEGA 2019; 4:12827-12832. [PMID: 31460407 PMCID: PMC6681974 DOI: 10.1021/acsomega.9b01678] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 07/02/2019] [Indexed: 06/10/2023]
Abstract
The use of multivalent glycoconjugate vaccines has dramatically contributed to reduce the incidence of meningococcal infectious disease. The advanced structural characterization of polysaccharide conjugates leads to enhancements in the quality and control of the products. Here, we report a novel nuclear magnetic resonance (NMR) method to confirm the identity and structural conformity (e.g., O-acetyl content) of saccharide antigens that comprise a licensed tetravalent meningococcal serogroups A, C, W, and Y vaccine. For the first time, the NMR methodology is applied on a formulation (licensed vaccine) containing a large excess of excipient (i.e., sucrose) without analytical sample pretreatment. This work confirms the applicability of a rapid and easy NMR assay on a multivalent conjugate vaccine, which might be extended to other combination vaccines that are already licensed or in clinical development.
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Affiliation(s)
- Silvia Martini
- Technical R&D, GSK Vaccines
S.r.l., Via Fiorentina 1, 53100, Siena, Italy
| | - Marianna Aggravi
- Technical R&D, GSK Vaccines
S.r.l., Via Fiorentina 1, 53100, Siena, Italy
| | - Simona Cianetti
- Technical R&D, GSK Vaccines
S.r.l., Via Fiorentina 1, 53100, Siena, Italy
| | - William Egan
- Technical R&D, GSK Vaccines
S.r.l., Via Fiorentina 1, 53100, Siena, Italy
| | - Malte Meppen
- Technical R&D, GSK Vaccines
S.r.l., Via Fiorentina 1, 53100, Siena, Italy
| | - Alessio Moriconi
- Technical R&D, GSK Vaccines
S.r.l., Via Fiorentina 1, 53100, Siena, Italy
| | - Luca Simeone
- Technical R&D, GSK Vaccines
S.r.l., Via Fiorentina 1, 53100, Siena, Italy
| | - Francesco Berti
- Technical R&D, GSK Vaccines
S.r.l., Via Fiorentina 1, 53100, Siena, Italy
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17
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Jin R, Guo Y, Xu B, Wang H, Yuan C. Physicochemical properties of polysaccharides separated from Camellia oleifera Abel seed cake and its hypoglycemic activity on streptozotocin-induced diabetic mice. Int J Biol Macromol 2019; 125:1075-1083. [DOI: 10.1016/j.ijbiomac.2018.12.059] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/27/2018] [Accepted: 12/04/2018] [Indexed: 10/27/2022]
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18
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Bastos RC, Corrêa MB, de Souza IM, da Silva MN, da Silva Gomes Pereira D, Martins FO, da Silva Faria C, Ano Bom APD, de Lourdes Leal M, Jessouroun E, da Silva JG, de Andrade Medronho R, da Silveira IAFB. Brazilian meningococcal C conjugate vaccine: physicochemical, immunological, and thermal stability characteristics. Glycoconj J 2017; 35:3-13. [PMID: 28929266 DOI: 10.1007/s10719-017-9787-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 07/17/2017] [Accepted: 07/18/2017] [Indexed: 02/02/2023]
Abstract
High temperature is known to cause some instability in polysaccharide-protein conjugated vaccines and studies under stress conditions may be useful in determining whether short-term accidental exposure to undesired conditions can compromise product quality. In this study, we examined the structural stability of three industrial batches of Brazilian Meningococcal C conjugate bulk (MPCT) incubated at 4, 37, and 55 °C for 5 weeks. The effect of exposure to the storage temperatures was monitored by HPLC-SEC, CZE, CD and NMR techniques. The immunological significance of any physicochemical changes observed in MPCT was determined by SBA and ELISA assays of serum from immunized mice. Fluorescence emission spectra at 4 and 37 °C were similar among all samples and compatible with the native fold of the carrier protein. Fluorescence spectra of MPCT stored at 55 °C decreased in intensity and had a significant red-shift, indicating conformational changes. Far-UV CD spectra revealed a trend toward loss of structural conformation as storage temperature was increased to 55 °C. The NMR data showed modified signal intensity of the aromatic and aliphatic residues, mainly for samples incubated at 55 °C, suggesting a partial loss of tertiary structure. About 50% free saccharide content was found in bulks stored at 55 °C, but no difference was observed in the IgG or SBA titers. The present study showed physicochemical methods alone are insufficient to predict the biological activity of a MPCT conjugate vaccine without extensive validation against immunological data. However, they provide a sensitive means of detecting changes induced in a vaccine exposed to adverse environmental condition.
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Affiliation(s)
- Renata Chagas Bastos
- Laboratório de Macromoléculas, Bio-Manguinhos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
| | - Marilza Batista Corrêa
- Laboratório de Tecnologia Bacteriana, Bio-Manguinhos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | | | - Milton Neto da Silva
- Laboratório de Tecnologia Bacteriana, Bio-Manguinhos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | | | | | - Camila da Silva Faria
- Laboratório de Tecnologia Bacteriana, Bio-Manguinhos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Ana Paula Dinis Ano Bom
- Laboratório de Macromoléculas, Bio-Manguinhos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Maria de Lourdes Leal
- Laboratório de Tecnologia Bacteriana, Bio-Manguinhos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - Ellen Jessouroun
- Programa de Vacinas Bacterianas, Bio-Manguinhos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
| | - José Godinho da Silva
- Laboratório de Macromoléculas, Bio-Manguinhos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
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19
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Khatun R, Hunter H, Magcalas W, Sheng Y, Carpick B, Kirkitadze M. Nuclear Magnetic Resonance (NMR) Study for the Detection and Quantitation of Cholesterol in HSV529 Therapeutic Vaccine Candidate. Comput Struct Biotechnol J 2016; 15:14-20. [PMID: 28694932 PMCID: PMC5484764 DOI: 10.1016/j.csbj.2016.10.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/25/2016] [Accepted: 10/26/2016] [Indexed: 11/29/2022] Open
Abstract
This study describes the NMR-based method to determine the limit of quantitation (LOQ) and limit of detection (LOD) of cholesterol, a process-related impurity in the replication-deficient Herpes Simplex Virus (HSV) type 2 candidate vaccine HSV529. Three signature peaks from the 1D 1H NMR of a cholesterol reference spectrum were selected for the identification of cholesterol. The LOQ for a cholesterol working standard was found to be 1 μg/mL, and the LOD was found to be 0.1 μg/mL. The identity of cholesterol, separated from the formulation of growth supplement by thin layer chromatography (TLC), was confirmed by 1D 1H NMR and 2D 1H-13C HSQC NMR. The three signature peaks of cholesterol were detected only in a six-times concentrated sample of HSV529 candidate vaccine sample and not in the single dose HSV529 vaccine sample under similar experimental conditions. Taken together, the results demonstrated that NMR is a direct method that can successfully identify and quantify cholesterol in viral vaccine samples, such as HSV529, and as well as in the growth supplement used during the upstream stages of HSV529 manufacturing.
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Affiliation(s)
- Rahima Khatun
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, Canada
| | - Howard Hunter
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, Canada
| | - Webster Magcalas
- Analytical Research & Development, Sanofi Pasteur Ltd., 1755 Steeles Avenue West, Toronto, Ontario, Canada
| | - Yi Sheng
- Department of Biology, York University, 4700 Keele Street, Toronto, Ontario, Canada
| | - Bruce Carpick
- Analytical Research & Development, Sanofi Pasteur Ltd., 1755 Steeles Avenue West, Toronto, Ontario, Canada
| | - Marina Kirkitadze
- Analytical Research & Development, Sanofi Pasteur Ltd., 1755 Steeles Avenue West, Toronto, Ontario, Canada
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20
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Abdelhameed AS, Morris GA, Almutairi F, Adams GG, Duvivier P, Conrath K, Harding SE. Solution conformation and flexibility of capsular polysaccharides from Neisseria meningitidis and glycoconjugates with the tetanus toxoid protein. Sci Rep 2016; 6:35588. [PMID: 27782149 PMCID: PMC5080625 DOI: 10.1038/srep35588] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 09/21/2016] [Indexed: 12/13/2022] Open
Abstract
The structural integrity of meningococcal native, micro-fluidized and activated capsular polysaccharides and their glycoconjugates - in the form most relevant to their potential use as vaccines (dilute solution) - have been investigated with respect to their homogeneity, conformation and flexibility. Sedimentation velocity analysis showed that the polysaccharide size distributions were generally bimodal with some evidence for higher molar mass forms at higher concentration. Weight average molar masses Mw where lower for activated polysaccharides. Conjugation with tetanus toxoid protein however greatly increased the molar mass and polydispersity of the final conjugates. Glycoconjugates had an approximately unimodal log-normal but broad and large molar mass profiles, confirmed by sedimentation equilibrium "SEDFIT MSTAR" analysis. Conformation analysis using HYDFIT (which globally combines sedimentation and viscosity data), "Conformation Zoning" and Wales-van Holde approaches showed a high degree of flexibility - at least as great as the unconjugated polysaccharides, and very different from the tetanus toxoid (TT) protein used for the conjugation. As with the recently published finding for Hib-TT complexes, it is the carbohydrate component that dictates the solution behaviour of these glycoconjugates, although the lower intrinsic viscosities suggest some degree of compaction of the carbohydrate chains around the protein.
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Affiliation(s)
- Ali Saber Abdelhameed
- National Centre for Macromolecular Hydrodynamics, University of Nottingham, Sutton Bonington LE12 5RD, UK
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh, 11451, Kingdom of Saudi Arabia
| | - Gordon A. Morris
- Department of Chemical Sciences, School of Applied Science, University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, UK
| | - Fahad Almutairi
- Biochemistry Department, Faculty of Science, University of Tabuk, P.O. Box 741-Tabuk 71491 Saudi Arabia
| | - Gary G. Adams
- National Centre for Macromolecular Hydrodynamics, University of Nottingham, Sutton Bonington LE12 5RD, UK
- Insulin and Diabetes Experimental Research (IDER) Group, University of Nottingham, Faculty of Medicine and Health Science, Clifton Boulevard, Nottingham NG7 2RD, UK
| | - Pierre Duvivier
- GSK Vaccines, Rue de l’Institut 89, B1-330 Rixensart, Belgium
| | - Karel Conrath
- GSK Vaccines, Rue de l’Institut 89, B1-330 Rixensart, Belgium
| | - Stephen E. Harding
- National Centre for Macromolecular Hydrodynamics, University of Nottingham, Sutton Bonington LE12 5RD, UK
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21
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A High-Throughput Size Exclusion Chromatography Method to Determine the Molecular Size Distribution of Meningococcal Polysaccharide Vaccine. Int J Anal Chem 2016; 2016:9404068. [PMID: 27688770 PMCID: PMC5027369 DOI: 10.1155/2016/9404068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 07/28/2016] [Accepted: 07/31/2016] [Indexed: 11/25/2022] Open
Abstract
Molecular size distribution of meningococcal polysaccharide vaccine is a readily identifiable parameter that directly correlates with the immunogenicity. In this paper, we report a size exclusion chromatography method to determine the molecular size distribution and distribution coefficient value of meningococcal polysaccharide serogroups A, C, W, and Y in meningococcal polysaccharide (ACWY) vaccines. The analyses were performed on a XK16/70 column packed with sepharose CL-4B with six different batches of Ingovax® ACWY, a meningococcal polysaccharide vaccine produced by Incepta Vaccine Ltd., Bangladesh. A quantitative rocket immunoelectrophoresis assay was employed to determine the polysaccharide contents of each serogroup. The calculated distribution coefficient values of serogroups A, C, W, and Y were found to be 0.26 ± 0.16, 0.21 ± 0.11, 0.21 ± 0.11, and 0.14 ± 0.12, respectively, and met the requirements of British Pharmacopeia. The method was proved to be robust for determining the distribution coefficient values which is an obligatory requirement for vaccine lot release.
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22
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Zhang L, Muthana MM, Yu H, McArthur JB, Qu J, Chen X. Characterizing non-hydrolyzing Neisseria meningitidis serogroup A UDP-N-acetylglucosamine (UDP-GlcNAc) 2-epimerase using UDP-N-acetylmannosamine (UDP-ManNAc) and derivatives. Carbohydr Res 2015; 419:18-28. [PMID: 26598987 DOI: 10.1016/j.carres.2015.10.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Revised: 10/26/2015] [Accepted: 10/29/2015] [Indexed: 11/28/2022]
Abstract
Neisseria meningitidis serogroup A non-hydrolyzing uridine 5'-diphosphate-N-acetylglucosamine (UDP-GlcNAc) 2-epimerase (NmSacA) catalyzes the interconversion between UDP-GlcNAc and uridine 5'-diphosphate-N-acetylmannosamine (UDP-ManNAc). It is a key enzyme involved in the biosynthesis of the capsular polysaccharide [-6ManNAcα1-phosphate-]n of N. meningitidis serogroup A, one of the six serogroups (A, B, C, W-135, X, and Y) that account for most cases of N. meningitidis-caused bacterial septicemia and meningitis. N. meningitidis serogroup A is responsible for large epidemics in the developing world, especially in Africa. Here we report that UDP-ManNAc could be used as a substrate for C-terminal His6-tagged recombinant NmSacA (NmSacA-His6) in the absence of UDP-GlcNAc. NmSacA-His6 was activated by UDP-GlcNAc and inhibited by 2-acetamidoglucal and UDP. Substrate specificity study showed that NmSacA-His6 could tolerate several chemoenzymatically synthesized UDP-ManNAc derivatives as substrates although its activity was much lower than non-modified UDP-ManNAc. Homology modeling and molecular docking revealed likely structural determinants of NmSacA substrate specificity. This is the first detailed study of N. meningitidis serogroup A UDP-GlcNAc 2-epimerase.
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Affiliation(s)
- Lei Zhang
- Department of Chemistry, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Musleh M Muthana
- Department of Chemistry, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Hai Yu
- Department of Chemistry, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA
| | - John B McArthur
- Department of Chemistry, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Jingyao Qu
- Department of Chemistry, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Xi Chen
- Department of Chemistry, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA.
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23
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Brazilian meningococcal C conjugate vaccine: Scaling up studies. Vaccine 2015; 33:4281-7. [DOI: 10.1016/j.vaccine.2015.03.097] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 02/21/2015] [Accepted: 03/24/2015] [Indexed: 11/21/2022]
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24
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Anish C, Schumann B, Pereira CL, Seeberger PH. Chemical biology approaches to designing defined carbohydrate vaccines. ACTA ACUST UNITED AC 2015; 21:38-50. [PMID: 24439205 DOI: 10.1016/j.chembiol.2014.01.002] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 12/27/2013] [Accepted: 01/02/2014] [Indexed: 01/08/2023]
Abstract
Carbohydrate antigens have shown promise as important targets for developing effective vaccines and pathogen detection strategies. Modifying purified microbial glycans through synthetic routes or completely synthesizing antigenic motifs are attractive options to advance carbohydrate vaccine development. However, limited knowledge on structure-property correlates hampers the discovery of immunoprotective carbohydrate epitopes. Recent advancements in tools for glycan modification, high-throughput screening of biological samples, and 3D structural analysis may facilitate antigen discovery process. This review focuses on advances that accelerate carbohydrate-based vaccine development and various technologies that are driving these efforts. Herein we provide a critical overview of approaches and resources available for rational design of better carbohydrate antigens. Structurally defined and fully synthetic oligosaccharides, designed based on molecular understanding of antigen-antibody interactions, offer a promising alternative for developing future carbohydrate vaccines.
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Affiliation(s)
- Chakkumkal Anish
- Department for Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14424 Potsdam, Germany.
| | - Benjamin Schumann
- Department for Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14424 Potsdam, Germany; Institute of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany
| | - Claney Lebev Pereira
- Department for Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14424 Potsdam, Germany
| | - Peter H Seeberger
- Department for Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14424 Potsdam, Germany; Institute of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 22, 14195 Berlin, Germany.
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25
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Abstract
Physicochemical techniques are a powerful tool for the structural characterization of carbohydrate-based vaccines. High-field Nuclear Magnetic Resonance (NMR) spectroscopy has been established as an extremely useful and robust method for tracking the industrial manufacturing process of these vaccines from polysaccharide bulk antigen through to the final formulation. Here, we describe the use of proton NMR for structural identity and conformity testing of carbohydrate-based vaccines.
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26
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Neyra C, Paladino J, Le Borgne M. Mechanisms of depolymerization and activation of a polysialic acid and its tetramer by hydrogen peroxide. Carbohydr Polym 2014; 115:494-501. [PMID: 25439924 DOI: 10.1016/j.carbpol.2014.08.112] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 08/25/2014] [Accepted: 08/26/2014] [Indexed: 10/24/2022]
Abstract
Naturally occurring polysialic acid (PSA), appropriately functionalized, has been widely used in different biological products. The present paper describes an original approach which enables to both activate and depolymerize the PSA, by reacting with hydrogen peroxide. In order to understand the mechanisms, we investigate the course of H2O2 reactions with the native PSA and with a simpler model, the tetrasialic acid (4SA). Three recurrent reactions were observed. First, we detected a very fast and irreversible decarbonylation at the reducing end of the polysaccharide. Then, the hydroxyl radicals (generated via the Fenton reaction) were responsible for the depolymerization of glycosidic linkages by substitution reactions. Finally, the oxidation of hydroxyl groups led to the formation of carbonyl groups and the carbohydrate's activation.
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Affiliation(s)
- C Neyra
- Université de Lyon, Université Lyon 1, Faculté de Pharmacie - ISPB, EA 4446 Biomolécules Cancer et Chimiorésistances, SFR Santé Lyon-Est CNRS UMS3453 - INSERM US7, 8 avenue Rockefeller, F-69373, Lyon Cedex 8, France.
| | - J Paladino
- Université de Lyon, Université Lyon 1, Faculté de Pharmacie - ISPB, EA 4446 Biomolécules Cancer et Chimiorésistances, SFR Santé Lyon-Est CNRS UMS3453 - INSERM US7, 8 avenue Rockefeller, F-69373, Lyon Cedex 8, France.
| | - M Le Borgne
- Université de Lyon, Université Lyon 1, Faculté de Pharmacie - ISPB, EA 4446 Biomolécules Cancer et Chimiorésistances, SFR Santé Lyon-Est CNRS UMS3453 - INSERM US7, 8 avenue Rockefeller, F-69373, Lyon Cedex 8, France
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27
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Fiebig T, Freiberger F, Pinto V, Romano MR, Black A, Litschko C, Bethe A, Yashunsky D, Adamo R, Nikolaev A, Berti F, Gerardy-Schahn R. Molecular cloning and functional characterization of components of the capsule biosynthesis complex of Neisseria meningitidis serogroup A: toward in vitro vaccine production. J Biol Chem 2014; 289:19395-407. [PMID: 24849599 DOI: 10.1074/jbc.m114.575142] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The human pathogen Neisseria meningitidis (Nm) is a leading cause of bacterial meningitis and sepsis globally. A major virulence factor of Nm is the capsular polysaccharide (CPS), which in Nm serogroup A consists of N-acetyl-mannosamine-1-phosphate units linked together by phosphodiester linkages [ → 6)-α-D-ManNAc-(1 → OPO3 (-)→]n. Acetylation in O-3 (to a minor extent in O-4) position results in immunologically active polymer. In the capsule gene cluster (cps) of Nm, region A contains the genetic information for CPSA biosynthesis. Thereby the open reading frames csaA, -B, and -C are thought to encode the UDP-N-acetyl-D-glucosamine-2-epimerase, poly-ManNAc-1-phosphate-transferase, and O-acetyltransferase, respectively. With the aim to use a minimal number of recombinant enzymes to produce immunologically active CPSA, we cloned the genes csaA, csaB, and csaC and functionally characterized the purified recombinant proteins. If recombinant CsaA and CsaB were combined in one reaction tube, priming CPSA-oligosaccharides were efficiently elongated with UDP-GlcNAc as the donor substrate, confirming that CsaA is the functional UDP-N-acetyl-D-glucosamine-2-epimerase and CsaB the functional poly-ManNAc-1-phosphate-transferase. Subsequently, CsaB was shown to transfer ManNAc-1P onto O-6 of the non-reducing end sugar of priming oligosaccharides, to prefer non-O-acetylated over O-acetylated primers, and to efficiently elongate the dimer of ManNAc-1-phosphate. The in vitro synthesized CPSA was purified, O-acetylated with recombinant CsaC, and proven to be identical to the natural CPSA by (1)H NMR, (31)P NMR, and immunoblotting. If all three enzymes and their substrates were combined in a one-pot reaction, nature identical CPSA was obtained. These data provide the basis for the development of novel vaccine production protocols.
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Affiliation(s)
- Timm Fiebig
- From the Institute for Cellular Chemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Friedrich Freiberger
- From the Institute for Cellular Chemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Vittoria Pinto
- Novartis Vaccines, Research, Via Fiorentina 1, 53100 Siena, Italy
| | | | - Alan Black
- College of Life Sciences, University of Dundee, Dundee, DD1 5EH, Scotland, United Kingdom, and
| | - Christa Litschko
- From the Institute for Cellular Chemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Andrea Bethe
- From the Institute for Cellular Chemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Dmitry Yashunsky
- the Institute of Biomedical Chemistry, Russian Academy of Medical Sciences, Pogodinskaya Street 10, Moscow 119832, Russian Federation
| | - Roberto Adamo
- Novartis Vaccines, Research, Via Fiorentina 1, 53100 Siena, Italy
| | - Andrei Nikolaev
- College of Life Sciences, University of Dundee, Dundee, DD1 5EH, Scotland, United Kingdom, and
| | - Francesco Berti
- Novartis Vaccines, Research, Via Fiorentina 1, 53100 Siena, Italy,
| | - Rita Gerardy-Schahn
- From the Institute for Cellular Chemistry, Hannover Medical School, 30625 Hannover, Germany,
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Park IH, Lin J, Choi JE, Shin JS. Characterization of Escherichia coli K1 colominic acid-specific murine antibodies that are cross-protective against Neisseria meningitidis groups B, C, and Y. Mol Immunol 2014; 59:142-53. [PMID: 24603121 DOI: 10.1016/j.molimm.2014.01.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 01/24/2014] [Accepted: 01/27/2014] [Indexed: 10/25/2022]
Abstract
The capsular polysaccharide (PS) of Neisseria meningitidis serogroup B (NMGB) is α(2-8)-linked N-acetylneuraminic acid (Neu5Ac), which is almost identical to the O-acetylated colominic acid (CA) of Escherichia coli K1 Although E. coli K1 has long been known to elicit cross-protective antibodies against NMGB, limited information on these highly cross-reactive antibodies is available. In the present study, six new monoclonal antibodies (mAbs) specific to both E. coli K1 CA and NMGB PS were produced by immunizing Balb/c mice with E. coli K1, and their serological and molecular properties were characterized, together with 12 previously reported hybridoma mAbs. Among the bactericidal mAbs against NMGB, both HmenB5 and HmenB18, which are genetically identical though of different mouse origins, were able to kill serogroup C and Y meningococci. Based on SPR sensograms, the binding affinity of HmenB18 for PS was suggested to be associated with at least two different binding forces: the polyanionicity of Neu5Ac and an interaction with the O-acetyl groups of Neu5Ac. Molecular analysis showed that similar to most mAbs presenting a few restricted V region germline genes, the V region genes of HmenB18 were 979% and 986% identical to the closest IGHV1-1401 and IGLV15-10301 germline gene alleles, respectively, and V-D-J editing in this mAb generated an unusually long VH-CDR3 sequence (17 amino acid residues), containing one basic arginine, two hydrophobic isoleucine residues and a 'YAMDY' motif. Models of the mAb combining sites demonstrate that most of the mAbs exhibited a wide, shallow groove with a high overall positive charge, as seen in mAb735, which is specific for a polyanionic helical epitope. In contrast, the combining site of HmenB18 was shown to be wide but to present a relatively weak positive charge, consistent with the extensive recognition by HmenB18 of the various structural epitopes formed with the Neu5Ac residue and its O-acetylation.
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Affiliation(s)
- In Ho Park
- Ewha Center for Vaccine Evaluation and Study, Medical Research Institute, School of Medicine, Ewha Womans University, Seoul 158-710, Republic of Korea
| | - Jisheng Lin
- Department of Pathology, School of Medicine, Division of Laboratory Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Ji Eun Choi
- Department of Pediatrics, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul 156-707, Republic of Korea
| | - Jeon-Soo Shin
- Department of Microbiology, Yonsei University College of Medicine, Seoul 120-752, Republic of Korea; Severance Biomedical Science Institute and Institute for Immunology and Immunological Diseases, Yonsei University College of Medicine, Seoul 120-752, Republic of Korea.
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Halperin SA, Baine Y, Domachowske JB, Aggarwal N, Simon M, Langley JM, McNeil SA, Friedland LR, Bianco V, Baccarini CI, Miller JM. Comparison of the Safety and Immunogenicity of a Novel Quadrivalent Meningococcal ACWY-Tetanus Toxoid Conjugate Vaccine and a Marketed Quadrivalent Meningococcal ACWY-Diphtheria Toxoid Conjugate Vaccine in Healthy Individuals 10-25 Years of Age. J Pediatric Infect Dis Soc 2014; 3:33-42. [PMID: 24567843 PMCID: PMC3933042 DOI: 10.1093/jpids/pit058] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 06/25/2013] [Indexed: 11/17/2022]
Abstract
BACKGROUND Universal immunization of adolescents against meningococcal disease with a quadrivalent meningococcal ACWY (MenACWY) conjugate vaccine is recommended in a number of countries. METHODS In a randomized, controlled, observer-blinded, multicenter trial, 1016 participants, 10-25 years of age, were randomly allocated 1:1:1 to receive a single dose of 1 of 2 lots of an investigational tetanus toxoid-conjugated MenACWY vaccine (MenACWY-TT) or a marketed diphtheria toxoid-conjugated MenACWY vaccine (MenACWY-DT). The primary outcome was the noninferiority of the vaccine response after MenACWY-TT (lot A) compared with MenACWY-DT for all 4 serogroups. Vaccine response was defined as a postvaccination human serum bactericidal antibody (hSBA) titer against each of the serogroups of at least 1:8 in persons initially seronegative (<1:4) or as a 4-fold increase in titer pre- to postvaccination in persons initially seropositive (≥1:4). Adverse events (AEs) after immunization were measured 4 and 31 days postvaccination. RESULTS The mean age of participants was 16.3 years; 977 (96.6%) completed the study. The noninferiority of MenACWY-TT (lot A) to the control vaccine in terms of the percentage of participants with hSBA vaccine response was demonstrated for each serogroup. Vaccine response rates ranged from 51.0% to 82.5% for the 4 serogroups after MenACWY-TT (both lots) compared with 39.0%-76.3% for the 4 serogroups after MenACWY-DT. Pain was the most common injection-site reaction reported by 50.8%-55.4% across the 3 groups. Fatigue and headache were the most common systemic solicited AEs, reported by 27.3%-29.2% and 25.5%-26.4%, respectively. CONCLUSIONS Tetanus toxoid-conjugated MenACWY vaccine was well tolerated and elicited an immune response that was noninferior to that of a marketed MenACWY-DT (www.clinicaltrials.gov NCT01165242).
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Affiliation(s)
- Scott A Halperin
- Departments of Pediatrics and Medicine, Canadian Center for Vaccinology, Dalhousie University, Capital Health and the IWK Health Centre, Halifax, Nova Scotia, Canada
| | - Yaela Baine
- GlaxoSmithKline Vaccines, King of Prussia, Pennsylvania
| | | | | | - Michael Simon
- Pediatric and Adolescent Medicine, Nicholasville, Kentucky
| | - Joanne M Langley
- Departments of Pediatrics and Medicine, Canadian Center for Vaccinology, Dalhousie University, Capital Health and the IWK Health Centre, Halifax, Nova Scotia, Canada
| | - Shelly A McNeil
- Departments of Pediatrics and Medicine, Canadian Center for Vaccinology, Dalhousie University, Capital Health and the IWK Health Centre, Halifax, Nova Scotia, Canada
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Suker J, Feavers IM, Corbel MJ, Jones C, Bolgiano B. Control and lot release of meningococcal group C conjugate vaccines. Expert Rev Vaccines 2014; 3:533-40. [PMID: 15485333 DOI: 10.1586/14760584.3.5.533] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Meningococcal group C conjugate vaccines were first introduced to the UK in 1999. To date, the vaccines have been demonstrated to have an efficacy of approximately 90% and have since been adopted by other countries worldwide. The development of control tests used for lot release of meningococcal group C vaccines has been based on those used for Haemophilus influenzae type b conjugates, the key criteria being measurement of free saccharide and conjugate integrity by physicochemical means. In future, meningococcal group C vaccines are likely to be replaced by multivalent formulations containing different components in combination. This will present a new challenge for regulatory authorities and more extensive testing will be required to ensure vaccine safety and efficacy.
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Affiliation(s)
- Janet Suker
- National Institute for Biological Standards and Control, South Mimms Potters Bar, UK.
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31
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Noyes A, Boesch A, Godavarti R, Titchener-Hooker N, Coffman J, Mukhopadhyay T. High throughput quantification of capsular polysaccharides for multivalent vaccines using precipitation with a cationic surfactant. Vaccine 2013; 31:5659-65. [DOI: 10.1016/j.vaccine.2013.09.075] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 09/17/2013] [Accepted: 09/26/2013] [Indexed: 11/29/2022]
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Hung MC, Christodoulides M. The biology of Neisseria adhesins. BIOLOGY 2013; 2:1054-109. [PMID: 24833056 PMCID: PMC3960869 DOI: 10.3390/biology2031054] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 07/01/2013] [Accepted: 07/03/2013] [Indexed: 01/15/2023]
Abstract
Members of the genus Neisseria include pathogens causing important human diseases such as meningitis, septicaemia, gonorrhoea and pelvic inflammatory disease syndrome. Neisseriae are found on the exposed epithelia of the upper respiratory tract and the urogenital tract. Colonisation of these exposed epithelia is dependent on a repertoire of diverse bacterial molecules, extending not only from the surface of the bacteria but also found within the outer membrane. During invasive disease, pathogenic Neisseriae also interact with immune effector cells, vascular endothelia and the meninges. Neisseria adhesion involves the interplay of these multiple surface factors and in this review we discuss the structure and function of these important molecules and the nature of the host cell receptors and mechanisms involved in their recognition. We also describe the current status for recently identified Neisseria adhesins. Understanding the biology of Neisseria adhesins has an impact not only on the development of new vaccines but also in revealing fundamental knowledge about human biology.
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Affiliation(s)
- Miao-Chiu Hung
- Neisseria Research, Molecular Microbiology, Clinical and Experimental Sciences, Sir Henry Wellcome Laboratories, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK.
| | - Myron Christodoulides
- Neisseria Research, Molecular Microbiology, Clinical and Experimental Sciences, Sir Henry Wellcome Laboratories, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, SO16 6YD, UK.
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33
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Meningococcal polysaccharide A O-acetylation levels do not impact the immunogenicity of the quadrivalent meningococcal tetanus toxoid conjugate vaccine: results from a randomized, controlled phase III study of healthy adults aged 18 to 25 years. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2013; 20:1499-507. [PMID: 23885033 DOI: 10.1128/cvi.00162-13] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In this study, we compared the immunogenicities of two lots of meningococcal ACWY-tetanus toxoid conjugate vaccine (MenACWY-TT) that differed in serogroup A polysaccharide (PS) O-acetylation levels and evaluated their immunogenicities and safety in comparison to a licensed ACWY polysaccharide vaccine (Men-PS). In this phase III, partially blinded, controlled study, 1,170 healthy subjects aged 18 to 25 years were randomized (1:1:1) to receive one dose of MenACWY-TT lot A (ACWY-A) (68% O-acetylation), MenACWY-TT lot B (ACWY-B) (92% O-acetylation), or Men-PS (82% O-acetylation). Immunogenicity was evaluated in terms of serum bactericidal activity using rabbit complement (i.e., rabbit serum bactericidal activity [rSBA]). Solicited symptoms, unsolicited adverse events (AEs), and serious AEs (SAEs) were recorded. The immunogenicities, in terms of rSBA geometric mean titers, were comparable for both lots of MenACWY-TT. The vaccine response rates across the serogroups were 79.1 to 97.0% in the two ACWY groups and 73.7 to 94.1% in the Men-PS group. All subjects achieved rSBA titers of ≥1:8 for all serogroups. All subjects in the two ACWY groups and 99.5 to 100% in the Men-PS group achieved rSBA titers of ≥1:128. Pain was the most common solicited local symptom and was reported more frequently in the ACWY group (53.9 to 54.7%) than in the Men-PS group (36.8%). The most common solicited general symptoms were fatigue and headache, which were reported by 28.6 to 30.3% and 26.9 to 31.0% of subjects, respectively. Two subjects reported SAEs; one SAE was considered to be related to vaccination (blighted ovum; ACWY-B group). The level of serogroup A PS O-acetylation did not affect vaccine immunogenicity. MenACWY-TT (lot A) was not inferior to Men-PS in terms of vaccine response and was well tolerated.
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34
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Willis LM, Whitfield C. Structure, biosynthesis, and function of bacterial capsular polysaccharides synthesized by ABC transporter-dependent pathways. Carbohydr Res 2013; 378:35-44. [PMID: 23746650 DOI: 10.1016/j.carres.2013.05.007] [Citation(s) in RCA: 150] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 05/06/2013] [Accepted: 05/11/2013] [Indexed: 12/11/2022]
Abstract
Bacterial capsules are formed primarily from long-chain polysaccharides with repeat-unit structures. A given bacterial species can produce a range of capsular polysaccharides (CPSs) with different structures and these help distinguish isolates by serotyping, as is the case with Escherichia coli K antigens. Capsules are important virulence factors for many pathogens and this review focuses on CPSs synthesized via ATP-binding cassette (ABC) transporter-dependent processes in Gram-negative bacteria. Bacteria utilizing this pathway are often associated with urinary tract infections, septicemia, and meningitis, and E. coli and Neisseria meningitidis provide well-studied examples. CPSs from ABC transporter-dependent pathways are synthesized at the cytoplasmic face of the inner membrane through the concerted action of glycosyltransferases before being exported across the inner membrane and translocated to the cell surface. A hallmark of these CPSs is a conserved reducing terminal glycolipid composed of phosphatidylglycerol and a poly-3-deoxy-d-manno-oct-2-ulosonic acid (Kdo) linker. Recent discovery of the structure of this conserved lipid terminus provides new insights into the early steps in CPS biosynthesis.
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Affiliation(s)
- Lisa M Willis
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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35
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Zandomeneghi G, Ilg K, Aebi M, Meier BH. On-Cell MAS NMR: Physiological Clues from Living Cells. J Am Chem Soc 2012; 134:17513-9. [DOI: 10.1021/ja307467p] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Karin Ilg
- Microbiology, ETH Zurich, Wolfgang-Pauli Str. 10, 8093 Zurich Switzerland
| | - Markus Aebi
- Microbiology, ETH Zurich, Wolfgang-Pauli Str. 10, 8093 Zurich Switzerland
| | - Beat H. Meier
- Physical Chemistry, ETH Zurich, Wolfgang-Pauli Str. 10, 8093 Zurich Switzerland
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36
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Cyran MR, Ceglińska A, Kolasińska I. Depolymerization degree of water-extractable arabinoxylans in rye bread: characteristics of inbred lines used for breeding of bread cultivars. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:8720-8730. [PMID: 22897110 DOI: 10.1021/jf301573v] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The water-extractable arabinoxylans (WE AXs) present in rye bread govern its viscous properties, which may be related to reduced risk of cardiovascular diseases and diabetes. Breads made from rye cultivars generally exhibit higher AX-dependent extract viscosities (Cyran, M. R.; Saulnier, L. Food Chemistry2012, 131, 667-676) when compared with those produced from inbred lines used for their breeding. To give further details about this trend, the WE AXs were isolated from breads of lines and structurally characterized by HPSEC and (1)H NMR spectroscopy. The extract viscosities of endosperm and whole-meal breads were usually comparable, in contrast to those made from rye cultivars with higher viscosity of endosperm bread. The WE AXs present in breads obtained from inbred lines were characterized by the higher degradation degrees than those in breads from cultivars, as indicated by their HPSEC-RI profiles. This was associated with considerably lower proportions of 2-Xylp in their backbones. Besides, a level of endoxylanase activity in flours from inbred lines was much higher than that in flours from cultivars. Breeding of hybrid rye cultivars for production of high-viscosity bread requires the proper components. They may be preliminarily selected from populations with high WE AX contents and relatively low levels of endoxylanase activity by using the overall viscosity test for starting flours. However, further measurement of AX-dependent extract viscosity in test breads made from such lines may verify their usefulness completely.
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Affiliation(s)
- Malgorzata R Cyran
- Department of Plant Biochemistry and Physiology, Plant Breeding and Acclimatization Institute, National Research Institute, Blonie, Poland.
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37
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Evaluation of a candidate International Standard for Meningococcal Group C polysaccharide. Biologicals 2012; 40:353-63. [DOI: 10.1016/j.biologicals.2012.03.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 03/15/2012] [Accepted: 03/18/2012] [Indexed: 11/30/2022] Open
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Berti F, Romano MR, Micoli F, Pinto V, Cappelletti E, Gavini M, Proietti D, Pluschke G, MacLennan CA, Costantino P. Relative stability of meningococcal serogroup A and X polysaccharides. Vaccine 2012; 30:6409-15. [PMID: 22921741 DOI: 10.1016/j.vaccine.2012.08.021] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2012] [Revised: 07/02/2012] [Accepted: 08/11/2012] [Indexed: 10/28/2022]
Abstract
Prior to the introduction of the MenAfriVac™ serogroup A glycoconjugate vaccine in September 2010, serogroup A was the major epidemic disease-causing meningococcal serogroup in the African meningitis belt. However, recently serogroup X meningococcal (MenX) disease has received increased attention because of outbreaks recorded in this region, with increased endemic levels of MenX disease over the past 2 years. Whereas polysaccharide-protein conjugate vaccines against meningococcal serogroups A, C, W and Y (MenA, MenC, MenW, MenY) are on the market, a vaccine able to protect against MenX has never been achieved. The structure of serogroup A, C, W and Y meningococcal polysaccharides has been already fully elucidated by NMR. MenX capsular polysaccharide (MenX CPS) structure is also documented but fewer characterization data have been published. We have applied here (1)H NMR, (31)P NMR and HPLC to evaluate the stability of MenX CPS in aqueous solution as compared to MenA capsular polysaccharide (MenA CPS). The stability study demonstrated that MenA CPS is more susceptible to hydrolytic degradation than MenX CPS. The different stereochemistry of the N-acetyl group at position C(2) of mannosamine (MenA CPS) and glucosamine (MenX CPS) respectively might play a fundamental role in this susceptibility to polysaccharide chain degradation. The satisfactory stability of MenX CPS predicts the possibility that a stable fully-liquid MenX polysaccharide or glycoconjugate vaccine could be developed.
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Affiliation(s)
- F Berti
- Novartis Vaccines, Via Fiorentina 1, I-53100 Siena, Italy.
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39
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Knirel YA, Shevelev SD, Perepelov AV. Higher aldulosonic acids: components of bacterial glycans. MENDELEEV COMMUNICATIONS 2011. [DOI: 10.1016/j.mencom.2011.07.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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40
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Abstract
Meningococcal meningitis is feared because of the rapid onset of severe disease from mild symptoms and, therefore, is an important target for vaccine research. Five serogroups, defined by the structures of their capsular polysaccharides, are responsible for the vast majority of disease. Protection against four of these five serogroups can be obtained with polysaccharide or glycoconjugate vaccines, in which fragments of the capsular polysaccharides attached to a carrier protein generate anticarbohydrate immune responses, whilst protection against group B disease requires protein immunogens, often presented in vesicles containing outer membrane proteins. Glycoconjugate vaccines are now an established technology, but outer-membrane protein vaccines are still under development and present significant challenges. This review discusses physicochemical approaches to the characterization and quality control of these vaccines, as well as highlighting the problems and differences in vaccine design required for protection against different serogroups of the same species of pathogen.
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41
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Pace D. Novel quadrivalent meningococcal A, C, W-135 and Y glycoconjugate vaccine for the broader protection of adolescents and adults. Future Microbiol 2010; 5:1629-40. [DOI: 10.2217/fmb.10.137] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Meningococcal meningitis and septicemia are a persistent public health concern owing to the associated mortality and devastating long-term sequelae. People of all ages may be affected, with the disease burden being higher in at-risk groups. Vaccination is the most rational approach to the prevention of invasive meningococcal disease. A novel quadrivalent meningococcal (Men) serogroup A, C, W-135 and Y polysaccharide–protein conjugate vaccine (MenACWY-CRM), has recently been licensed for use in individuals aged at least 11 years old in the USA, Canada and Europe. One dose of MenACWY-CRM is well tolerated, and induces robust immunity to all constituent vaccine serogroups in 11–65 year old individuals. MenACWY-CRM was found to be noninferior to the quadrivalent meningococcal ACWY-diphtheria toxoid glycoconjugate vaccine, which is also licensed in the USA and Canada. In Europe, MenACWY-CRM is the first quadrivalent meningococcal glycoconjugate vaccine available to provide broader protection against Neisseria meningitidis serogroups A, C, W-135 and Y.
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Affiliation(s)
- David Pace
- Department of Paediatrics, Mater Dei Hospital, Tal-Qroqq, Msida, MSD 2090, Malta
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42
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Lee HJ, Rakić B, Gilbert M, Wakarchuk WW, Withers SG, Strynadka NCJ. Structural and kinetic characterizations of the polysialic acid O-acetyltransferase OatWY from Neisseria meningitidis. J Biol Chem 2009; 284:24501-11. [PMID: 19525232 DOI: 10.1074/jbc.m109.006049] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The neuroinvasive pathogen Neisseria meningitidis has 13 capsular serogroups, but the majority of disease is caused by only 5 of these. Groups B, C, Y, and W-135 all display a polymeric sialic acid-containing capsule that provides a means for the bacteria to evade the immune response during infection by mimicking host sialic acid-containing cell surface structures. These capsules in serogroups C, Y, and W-135 can be further acetylated by a sialic acid-specific O-acetyltransferase, a modification that correlates with decreased immunoreactivity and increased virulence. In N. meningitidis serogroup Y, the O-acetylation reaction is catalyzed by the enzyme OatWY, which we show has clear specificity toward the serogroup Y capsule ([Glc-(alpha1-->4)-Sia](n)). To understand the underlying molecular basis of this process, we have performed crystallographic analysis of OatWY with bound substrate as well as determined kinetic parameters of the wild type enzyme and active site mutants. The structure of OatWY reveals an intimate homotrimer of left-handed beta-helix motifs that frame a deep active site cleft selective for the polysialic acid-bearing substrate. Within the active site, our structural, kinetic, and mutagenesis data support the role of two conserved residues in the catalytic mechanism (His-121 and Trp-145) and further highlight a significant movement of Tyr-171 that blocks the active site of the enzyme in its native form. Collectively, our results reveal the first structural features of a bacterial sialic acid O-acetyltransferase and provide significant new insight into its catalytic mechanism and specificity for the capsular polysaccharide of serogroup Y meningococci.
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Affiliation(s)
- Ho Jun Lee
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
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Marc LaForce F, Ravenscroft N, Djingarey M, Viviani S. Epidemic meningitis due to Group A Neisseria meningitidis in the African meningitis belt: a persistent problem with an imminent solution. Vaccine 2009; 27 Suppl 2:B13-9. [PMID: 19477559 DOI: 10.1016/j.vaccine.2009.04.062] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Epidemic meningitis in Africa remains an important and unresolved public health problem. Bacteriologic and epidemiologic data collected over the past 30 years have consistently established the importance of Group A Neisseria meningitidis as the dominant etiologic agent. The meningococcal Group A capsule is the major virulence factor; it is a polysaccharide comprised of a repeating unit of partly O-acetylated alpha-1,6-linked N-acetylmannosamine phosphate. Meningitis epidemics occur annually during the dry season (January to May) and stop with the first rains. Until now, control of these meningitis epidemics has relied on a reactive vaccination strategy with polysaccharide vaccines that is logistically complicated and has not put an end to recurrent epidemics. A meningococcal A conjugate vaccine (MenAfriVac) has been developed and tested in Phase II clinical trials in Africa. The vaccine has been shown to be safe and to generate a sustained immunologic response with functional antibody 20 times higher than that seen with polysaccharide vaccine. Widespread use of such a vaccine is likely to generate herd immunity and to put an end to Group A meningococcal epidemics.
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Affiliation(s)
- F Marc LaForce
- PATH, 13 Chemin du Levant, Ferney-Voltaire 01210, France.
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Lee CH, Kuo WC, Beri S, Kapre S, Joshi JS, Bouveret N, LaForce FM, Frasch CE. Preparation and characterization of an immunogenic meningococcal group A conjugate vaccine for use in Africa. Vaccine 2009; 27:726-32. [DOI: 10.1016/j.vaccine.2008.11.065] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Revised: 10/26/2008] [Accepted: 11/04/2008] [Indexed: 10/21/2022]
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Bergfeld AK, Claus H, Lorenzen NK, Spielmann F, Vogel U, Mu Hlenhoff M. The polysialic acid-specific O-acetyltransferase OatC from Neisseria meningitidis serogroup C evolved apart from other bacterial sialate O-acetyltransferases. J Biol Chem 2008; 284:6-16. [PMID: 18986988 DOI: 10.1074/jbc.m807518200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Neisseria meningitidis serogroup C is a major cause of bacterial meningitis and septicaemia. This human pathogen is protected by a capsule composed of alpha2,9-linked polysialic acid that represents an important virulence factor. In the majority of strains, the capsular polysaccharide is modified by O-acetylation at C-7 or C-8 of the sialic acid residues. The gene encoding the capsule modifying O-acetyltransferase is part of the capsule gene complex and shares no sequence similarities with other proteins. Here, we describe the purification and biochemical characterization of recombinant OatC. The enzyme was found as a homodimer, with the first 34 amino acids forming an efficient oligomerization domain that worked even in a different protein context. Using acetyl-CoA as donor substrate, OatC transferred acetyl groups exclusively onto polysialic acid joined by alpha2,9-linkages and did not act on free or CMP-activated sialic acid. Motif scanning revealed a nucleophile elbow motif (GXS286XGG), which is a hallmark of alpha/beta-hydrolase fold enzymes. In a comprehensive site-directed mutagenesis study, we identified a catalytic triad composed of Ser-286, Asp-376, and His-399. Consistent with a double-displacement mechanism common to alpha/beta-hydrolase fold enzymes, a covalent acetylenzyme intermediate was found. Together with secondary structure prediction highlighting an alpha/beta-hydrolase fold topology, our data provide strong evidence that OatC belongs to the alpha/beta-hydrolase fold family. This clearly distinguishes OatC from all other bacterial sialate O-acetyltransferases known so far because these are members of the hexapeptide repeat family, a class of acyltransferases that adopt a left-handed beta-helix fold and assemble into catalytic trimers.
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Affiliation(s)
- Anne K Bergfeld
- Department of Cellular Chemistry, Medical School Hannover, 30623 Hannover, Germany and the Institute for Hygiene and Microbiology, University of Wu¨rzburg, 97080 Wu¨rzburg, Germany
| | - Heike Claus
- Department of Cellular Chemistry, Medical School Hannover, 30623 Hannover, Germany and the Institute for Hygiene and Microbiology, University of Wu¨rzburg, 97080 Wu¨rzburg, Germany
| | - Nina K Lorenzen
- Department of Cellular Chemistry, Medical School Hannover, 30623 Hannover, Germany and the Institute for Hygiene and Microbiology, University of Wu¨rzburg, 97080 Wu¨rzburg, Germany
| | - Fabian Spielmann
- Department of Cellular Chemistry, Medical School Hannover, 30623 Hannover, Germany and the Institute for Hygiene and Microbiology, University of Wu¨rzburg, 97080 Wu¨rzburg, Germany
| | - Ulrich Vogel
- Department of Cellular Chemistry, Medical School Hannover, 30623 Hannover, Germany and the Institute for Hygiene and Microbiology, University of Wu¨rzburg, 97080 Wu¨rzburg, Germany
| | - Martina Mu Hlenhoff
- Department of Cellular Chemistry, Medical School Hannover, 30623 Hannover, Germany and the Institute for Hygiene and Microbiology, University of Wu¨rzburg, 97080 Wu¨rzburg, Germany.
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Filatova MP, Kotel’nikova OV, Chibiskova OV, Lakhtina OE, Nesmeyanov VA, Alliluev AP, Koroev DO, Titova MA, Volkova TD, Vol’pina OM, Ivanov VT. Synthesis and biological properties of polysaccharide-peptide conjugates as potential antigens for a vaccine against meningococci of serogroups A and B. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2008; 34:630-8. [DOI: 10.1134/s1068162008050051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Uria MJ, Zhang Q, Li Y, Chan A, Exley RM, Gollan B, Chan H, Feavers I, Yarwood A, Abad R, Borrow R, Fleck RA, Mulloy B, Vazquez JA, Tang CM. A generic mechanism in Neisseria meningitidis for enhanced resistance against bactericidal antibodies. J Exp Med 2008; 205:1423-34. [PMID: 18504306 PMCID: PMC2413038 DOI: 10.1084/jem.20072577] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The presence of serum bactericidal antibodies is a proven correlate of protection against systemic infection with the important human pathogen Neisseria meningitidis. We have identified three serogroup C N. meningitidis (MenC) isolates recovered from patients with invasive meningococcal disease that resist killing by bactericidal antibodies induced by the MenC conjugate vaccine. None of the patients had received the vaccine, which has been successfully introduced in countries in North America and Europe. The increased resistance was not caused by changes either in lipopolysaccharide sialylation or acetylation of the α2-9–linked polysialic acid capsule. Instead, the resistance of the isolates resulted from the presence of an insertion sequence, IS1301, in the intergenic region (IGR) between the sia and ctr operons, which are necessary for capsule biosynthesis and export, respectively. The insertion sequence led to an increase in the transcript levels of surrounding genes and the amount of capsule expressed by the strains. The increased amount of capsule was associated with down-regulation of the alternative pathway of complement activation, providing a generic mechanism by which the bacterium protects itself against bactericidal antibodies. The strains with IS1301 in the IGR avoided complement-mediated lysis in the presence of bactericidal antibodies directed at the outer membrane protein, PorA, or raised against whole cells.
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Affiliation(s)
- Maria Jose Uria
- Centre for Molecular Microbiology and Infection, Department of Microbiology, Imperial College London, London SW7 2AZ, England, UK
- Reference Laboratory for Neisseria, National Center of Microbiology, Institute of Health Carlos III, 28220 Majadahonda, Madrid, Spain
| | - Qian Zhang
- Centre for Molecular Microbiology and Infection, Department of Microbiology, Imperial College London, London SW7 2AZ, England, UK
| | - Yanwen Li
- Centre for Molecular Microbiology and Infection, Department of Microbiology, Imperial College London, London SW7 2AZ, England, UK
| | - Angel Chan
- Centre for Molecular Microbiology and Infection, Department of Microbiology, Imperial College London, London SW7 2AZ, England, UK
| | - Rachel M. Exley
- Centre for Molecular Microbiology and Infection, Department of Microbiology, Imperial College London, London SW7 2AZ, England, UK
| | - Bridget Gollan
- Centre for Molecular Microbiology and Infection, Department of Microbiology, Imperial College London, London SW7 2AZ, England, UK
| | - Hannah Chan
- National Institute of Biological Standards and Control, South Mimms, Potters Bar, Hertfordshire EN6 3QG, England, UK
| | - Ian Feavers
- National Institute of Biological Standards and Control, South Mimms, Potters Bar, Hertfordshire EN6 3QG, England, UK
| | - Andy Yarwood
- JEOL (UK) Ltd., JEOL House, Silvercourt, Watchmead, Welwyn Garden City, Hertfordshire AL7 1LT, England, UK
| | - Raquel Abad
- Reference Laboratory for Neisseria, National Center of Microbiology, Institute of Health Carlos III, 28220 Majadahonda, Madrid, Spain
| | - Ray Borrow
- Vaccine Evaluation Unit, North West Regional HPA Laboratory, Manchester Royal Infirmary, Manchester M13 9WZ, England, UK
| | - Roland A. Fleck
- National Institute of Biological Standards and Control, South Mimms, Potters Bar, Hertfordshire EN6 3QG, England, UK
| | - Barbara Mulloy
- National Institute of Biological Standards and Control, South Mimms, Potters Bar, Hertfordshire EN6 3QG, England, UK
| | - Julio A. Vazquez
- Reference Laboratory for Neisseria, National Center of Microbiology, Institute of Health Carlos III, 28220 Majadahonda, Madrid, Spain
| | - Christoph M. Tang
- Centre for Molecular Microbiology and Infection, Department of Microbiology, Imperial College London, London SW7 2AZ, England, UK
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Bardotti A, Averani G, Berti F, Berti S, Carinci V, D’Ascenzi S, Fabbri B, Giannini S, Giannozzi A, Magagnoli C, Proietti D, Norelli F, Rappuoli R, Ricci S, Costantino P. Physicochemical characterisation of glycoconjugate vaccines for prevention of meningococcal diseases. Vaccine 2008; 26:2284-96. [DOI: 10.1016/j.vaccine.2008.01.022] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2007] [Revised: 12/23/2007] [Accepted: 01/11/2008] [Indexed: 11/16/2022]
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Silveira IAFB, Bastos RC, Neto MS, Laranjeira AP, Assis EF, Fernandes SAR, Leal ML, Silva WC, Lee CH, Frasch CE, Peralta JM, Jessouroun E. Characterization and immunogenicity of meningococcal group C conjugate vaccine prepared using hydrazide-activated tetanus toxoid. Vaccine 2007; 25:7261-70. [PMID: 17719147 DOI: 10.1016/j.vaccine.2007.07.037] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2006] [Revised: 06/27/2007] [Accepted: 07/12/2007] [Indexed: 10/23/2022]
Abstract
The steps to produce, purify and control an immunogenic Brazilian conjugate vaccine against group C meningococcus (MenCPS-TT) using hydrazide-activated tetanus toxoid were developed. The conjugation methodology reduced the reaction time easily allowing scale-up. One freeze-dried pilot vaccine lot purified by tangential filtration, showed satisfactory quality control results including safety and stability. The pilot vaccine was immunogenic in mice in a dose-dependent fashion generating a 10-20-fold rise in IgG response in mice. The vaccine also induced high bactericidal titers. Vaccine concentrations of 1 and 0.1 microg showed higher avidity indices, suggesting induction of immunologic memory. These results support initiation of Phase I clinical studies with the MenCPS-TT conjugate vaccine.
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Affiliation(s)
- I A F B Silveira
- Laboratório de Tecnologia Bacteriana, Bio-Manguinhos, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.
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Bergfeld AK, Claus H, Vogel U, Mühlenhoff M. Biochemical Characterization of Thepolysialic Acid-specific O-Acetyltransferase NeuO of Escherichia coli K1. J Biol Chem 2007; 282:22217-27. [PMID: 17519228 DOI: 10.1074/jbc.m703044200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Escherichia coli K1 is a leading pathogen in neonatal sepsis and meningitis. The K1 capsule, composed of alpha2,8-linked polysialic acid, represents the major virulence factor. In some K1 strains, phase-variable O-acetylation of the capsular polysaccharide is observed, a modification that is catalyzed by the prophage-encoded O-acetyltransferase NeuO. Phase variation is mediated by changes in the number of heptanucleotide repeats within the 5'-coding region of neuO, and full-length translation is restricted to repeat numbers that are a multiple of three. To understand the biochemical basis of K1 capsule O-acetylation, NeuO encoded by alleles containing 0, 12, 24, and 36 repeats was expressed and purified to homogeneity via a C-terminal hexahistidine tag. All NeuO variants assembled into hexamers and were enzymatically active with a high substrate specificity toward polysialic acid with >14 residues. Remarkably, the catalytic efficiency (k(cat)/K(m)(donor)) increased linearly with increasing numbers of repeats, revealing a new mechanism for modulating NeuO activity. Using homology modeling, we predicted a three-dimensional structure primarily composed of a left-handed parallel beta-helix with one protruding loop. Two amino acids critical for catalytic activity were identified and corresponding alanine substitutions, H119A and W143A, resulted in a complete loss of activity without affecting the oligomerization state. Our results indicate that in NeuO typical features of an acetyltransferase of the left-handed beta-helix family are combined with a unique regulatory mechanism based on variable N-terminal protein extensions formed by tandem copies of an RLKTQDS heptad.
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Affiliation(s)
- Anne K Bergfeld
- Department of Cellular Chemistry, Medical School Hannover, Carl-Neuberg-Strasse 1, Hannover, Germany
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