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Huan YW, Fa-Arun J, Wang B. The Role of O-antigen in P1 Transduction of Shigella flexneri and Escherichia coli with its Alternative S' Tail Fibre. J Mol Biol 2022; 434:167829. [PMID: 36116540 DOI: 10.1016/j.jmb.2022.167829] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/03/2022] [Accepted: 09/12/2022] [Indexed: 11/30/2022]
Abstract
Enterobacteria phage P1 expresses two types of tail fibre, S and S'. Despite the wide usage of phage P1 for transduction, the host range and the receptor for its alternative S' tail fibre was never determined. Here, a ΔS-cin Δpac E. coli P1 lysogenic strain was generated to allow packaging of phagemid DNA into P1 phage having either S or S' tail fibre. P1(S') could transduce phagemid DNA into Shigella flexneri 2a 2457O, Shigella flexneri 5a M90T and Escherichia coli O3 efficiently. Mutational analysis of the O-antigen assembly genes and LPS inhibition assays indicated that P1(S') transduction requires at least one O-antigen unit. E. coli O111:B4 LPS produced a high neutralising effect against P1(S') transduction, indicating that this E. coli strain could be susceptible to P1(S')-mediated transduction. Mutations in the O-antigen modification genes of S. flexneri 2a 2457O and S. flexneri 5a M90T did not cause significant changes to P1(S') transduction efficiency. A higher transduction efficiency of P1(S') improved the delivery of a cas9 antimicrobial phagemid into both S. flexneri 2457O and M90T. These findings provide novel insights into P1 tropism-switching, by identifying the bacterial strains which are susceptible to P1(S')-mediated transduction, as well as demonstrating its potential for delivering a DNA sequence-specific Cas9 antimicrobial into clinically relevant S. flexneri.
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Affiliation(s)
- Yang W Huan
- Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, United Kingdom
| | - Jidapha Fa-Arun
- Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, United Kingdom
| | - Baojun Wang
- College of Chemical and Biological Engineering & ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 310058, China; Research Centre of Biological Computation, Zhejiang Laboratory, Hangzhou 311100, China.
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2
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Clarkson KA, Porter CK, Talaat KR, Kapulu MC, Chen WH, Frenck RW, Bourgeois AL, Kaminski RW, Martin LB. Shigella-Controlled Human Infection Models: Current and Future Perspectives. Curr Top Microbiol Immunol 2022. [PMID: 35616717 DOI: 10.1007/82_2021_248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Shigella-controlled human infection models (CHIMs) are an invaluable tool utilized by the vaccine community to combat one of the leading global causes of infectious diarrhea, which affects infants, children and adults regardless of socioeconomic status. The impact of shigellosis disproportionately affects children in low- and middle-income countries (LMICs) resulting in cognitive and physical stunting, perpetuating a cycle that must be halted. Shigella-CHIMs not only facilitate the early evaluation of enteric countermeasures and up-selection of the most promising products but also provide insight into mechanisms of infection and immunity that are not possible utilizing animal models or in vitro systems. The greater understanding of shigellosis obtained in CHIMs builds and empowers the development of new generation solutions to global health issues which are unattainable in the conventional laboratory and clinical settings. Therefore, refining, mining and expansion of safe and reproducible infection models hold the potential to create effective means to end diarrheal disease and associated co-morbidities associated with Shigella infection.
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Affiliation(s)
- Kristen A Clarkson
- Department of Diarrheal Disease Research, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA
| | - Chad K Porter
- Enteric Disease Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA
| | - Kawsar R Talaat
- Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, 624 North Broadway Street Hampton House, Baltimore, MD, 21205, USA
| | - Melissa C Kapulu
- Department of Biosciences, KEMRI-Wellcome Trust Research Programme, Kilifi County Hospital, Off Bofa Road, Kilifi, 80108, Kenya
| | - Wilbur H Chen
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD, 21201, USA
| | - Robert W Frenck
- Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH, 45229, USA
| | - A Louis Bourgeois
- PATH Center for Vaccine Innovation and Access, 455 Massachusetts Avenue NW, Washington, DC, 20001, USA
| | - Robert W Kaminski
- Department of Diarrheal Disease Research, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA
| | - Laura B Martin
- GSK Vaccines Institute for Global Health, Via Fiorentina 1, 53100, Siena, Italy.
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Influence of Shigella flexneri 2a O Antigen Acetylation on Its Bacteriophage Sf6 Receptor Activity and Bacterial Interaction with Human Cells. J Bacteriol 2020; 202:JB.00363-20. [PMID: 32989087 DOI: 10.1128/jb.00363-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 09/21/2020] [Indexed: 11/20/2022] Open
Abstract
Shigella flexneri is a major causative agent of bacillary dysentery in developing countries, where serotype 2a2 is the prevalent strain. To date, approximately 30 serotypes have been identified for S. flexneri, and the major contribution to the emergence of new serotypes is chemical modifications of the lipopolysaccharide (LPS) component O antigen (Oag). Glucosylation, O-acetylation, and phosphoethanolamine (PEtN) modifications increase the Oag diversity, providing benefits to S. flexneri LPS Oag acts as a primary receptor for bacteriophage Sf6, which infects only a limited range of S. flexneri serotypes (Y and X). It uses its tailspike protein (Sf6TSP) to establish initial interaction with LPS Oags that it then hydrolyzes. Currently, there is a lack of comprehensive study on the parent and serotype variant strains from the same genetic background and an understanding of the importance of LPS Oag O-acetylations. Therefore, a set of isogenic strains (based on S. flexneri 2457T [2a2]) with deletions of different Oag modification genes (oacB, oacD, and gtrII) that resemble different naturally occurring serotype Y and 2a strains was created. The impacts of these Oag modifications on S. flexneri sensitivity to Sf6 and the pathogenesis-related properties were then compared. We found that Sf6TSP can hydrolyze serotype 2a LPS Oag, identified that 3/4-O-acetylation is essential for resistance of serotype 2a strains to Sf6, and showed that serotype 2a strains have better invasion ability. Lastly, we revealed two new serotype conversions for S. flexneri, thereby contributing to understanding the evolution of this important human pathogen.IMPORTANCE The emergence of antibiotic-resistant strains and lack of efficient vaccines have made Shigella a priority organism for the World Health Organization (1). Therefore, bacteriophage therapy has received increasing attention as an alternative therapeutic approach. LPS Oag is the most variable part of LPS due to chemical modifications and is the target of bacteriophage Sf6 (S. flexneri specific). We dissected the evolution of S. flexneri serotype Y to 2a2, which revealed a new role for a gene acquired during serotype conversion and furthermore identified new specific forms of LPS receptor for Sf6. Collectively, these results unfold the importance of the acquisition of those Oag modification genes and further our understanding of the relationship between Sf6 and S. flexneri.
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Additional Og-Typing PCR Techniques Targeting Escherichia coli-Novel and Shigella-Unique O-Antigen Biosynthesis Gene Clusters. J Clin Microbiol 2020; 58:JCM.01493-20. [PMID: 32817086 DOI: 10.1128/jcm.01493-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 08/12/2020] [Indexed: 11/20/2022] Open
Abstract
The O-serogrouping of pathogenic Escherichia coli is a standard method for subtyping strains for epidemiological studies and controls. O-serogroup diversification shows a strong association with the genetic diversity in some O-antigen biosynthesis gene clusters. Through genomic studies, in addition to the types of O-antigen biosynthesis gene clusters (Og-types) from conventional O-serogroup strains, a number of novel Og-types have been found in E. coli isolates. To assist outbreak investigations and surveillance of pathogenic E. coli at inspection institutes, in previous studies, we developed PCR methods that could determine almost all conventional O-serogroups and some novel Og-types. However, there are still many Og-types that may not be determined by simple genetic methods such as PCR. Thus, in the present study, we aimed to develop an additional Og-typing PCR system. Based on the novel Og-types, including OgN32, OgN33, and OgN34, presented in this study, we designed an additional 24 PCR primer pairs targeting 14 novel and 2 diversified E. coli Og-types and 8 Shigella-unique Og-types. Subsequently, we developed 5 new multiplex PCR sets consisting of 33 primers, including the aforementioned 24 primers and 9 primers reported in previous studies. The accuracy and specificity of the PCR system was validated using approximately 260 E. coli and Shigella O-serogroup and Og-type reference strains. The Og-typing PCR system reported here can determine a wide range of Og-types of E. coli and may help epidemiological studies, in addition to the surveillance of pathogenic E. coli.
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Vaccination with Shigella flexneri 2a conjugate induces type 2a and cross-reactive type 6 antibodies in humans but not in mice. Vaccine 2017; 35:4990-4996. [PMID: 28797729 DOI: 10.1016/j.vaccine.2017.07.070] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 07/12/2017] [Accepted: 07/21/2017] [Indexed: 11/22/2022]
Abstract
Shigella flexneri (S. flexneri) 6 has emerged as an important cause of shigellosis. Our efficacy study of Shigella sonnei and S. flexneri 2a O-specific polysaccharide (O-SP) conjugates in 1-4year-olds had too few S. flexneri 2a cases for efficacy evaluation but surprisingly showed protection of 3-4year-olds, S. flexneri 2a-recipients, from S. flexneri 6 infection. To investigate this cross-protection antibodies to both Shigella types were investigated in all sera remaining from previous studies. Twenty to 30% of 3-44year-old humans injected with S. flexneri 2a conjugate responded with ≥4-fold increases of IgG anti type 6, p<0.00001. The specificity of these antibodies was shown by inhibition studies. S. flexneri 6 infection of 2 children induced besides S. flexneri 6, also S. flexneri 2a antibodies, at levels of S. flexneri 2a vaccinees. S. flexneri 2a antibodies induced by S. flexneri 6 conjugates could not be studied since no such conjugate was assessed in humans and mice responded almost exclusively to the O-SP of the injected conjugate, with no cross-reactive antibodies. Our results indicate induction of cross-reactive protective antibodies. The O-acetylated disaccharide shared by S. flexneri 6 and 2a O-SPs, is the likely basis for their cross-reactivity. S. flexneri 6 O-SP conjugates, alone and in combination with S. flexneri 2a, merit further investigation for broad S. flexneri protection.
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Hu Z, Bongat White AF, Mulard LA. Efficient Iterative Synthesis of O-Acetylated Tri- to Pentadecasaccharides Related to the Lipopolysaccharide ofShigella flexneriType 3 a through Di- and Trisaccharide Glycosyl Donors. Chem Asian J 2017; 12:419-439. [DOI: 10.1002/asia.201600819] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Zhaoyu Hu
- Chemistry of Biomolecules; Institut Pasteur; 28 rue du Dr. Roux 75724 Paris Cedex 15 France
- CNRS UMR 3523; Institut Pasteur; 28 rue du Dr. Roux 75015 Paris France
| | - Aileen F. Bongat White
- Chemistry of Biomolecules; Institut Pasteur; 28 rue du Dr. Roux 75724 Paris Cedex 15 France
- CNRS UMR 3523; Institut Pasteur; 28 rue du Dr. Roux 75015 Paris France
- Dextra Laboratories Ltd.; Science and Technology Centre; Earley Gate Reading RG6 6BZ U. K
| | - Laurence A. Mulard
- Chemistry of Biomolecules; Institut Pasteur; 28 rue du Dr. Roux 75724 Paris Cedex 15 France
- CNRS UMR 3523; Institut Pasteur; 28 rue du Dr. Roux 75015 Paris France
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Knirel YA, Sun Q, Senchenkova SN, Perepelov AV, Shashkov AS, Xu J. O-antigen modifications providing antigenic diversity of Shigella flexneri and underlying genetic mechanisms. BIOCHEMISTRY (MOSCOW) 2016; 80:901-14. [PMID: 26542003 DOI: 10.1134/s0006297915070093] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
O-Antigens (O-specific polysaccharides) of Shigella flexneri, a primary cause of shigellosis, are distinguished by a wide diversity of chemical modifications following the oligosaccharide O-unit assembly. The present review is devoted to structural, serological, and genetic aspects of these modifications, including O-acetylation and phosphorylation with phosphoethanolamine that have been identified recently. The modifications confer the host with specific immunodeterminants (O-factors or O-antigen epitopes), which accounts for the antigenic diversity of S. flexneri considered as a virulence factor of the pathogen. Totally, 30 O-antigen variants have been recognized in these bacteria, the corresponding O-factors characterized using specific antibodies, and a significant extension of the serotyping scheme of S. flexneri on this basis is suggested. Multiple genes responsible for the O-antigen modifications and the resultant serotype conversions of S. flexneri have been identified. The genetic mechanisms of the O-antigen diversification by acquisition of mobile genetic elements, including prophages and plasmids, followed occasionally by gene mobilization and inactivation have been revealed. These findings further our understanding of the genetics and antigenicity of S. flexneri and assist control of shigellosis.
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Affiliation(s)
- Y A Knirel
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, 119991, Russia.
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Gauthier C, Chassagne P, Theillet FX, Guerreiro C, Thouron F, Nato F, Delepierre M, Sansonetti PJ, Phalipon A, Mulard LA. Non-stoichiometric O-acetylation of Shigella flexneri 2a O-specific polysaccharide: synthesis and antigenicity. Org Biomol Chem 2016; 12:4218-32. [PMID: 24836582 DOI: 10.1039/c3ob42586j] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Synthetic functional mimics of the O-antigen from Shigella flexneri 2a are seen as promising vaccine components against endemic shigellosis. Herein, the influence of the polysaccharide non-stoichiometric di-O-acetylation on antigenicity is addressed for the first time. Three decasaccharides, representing relevant internal mono- and di-O-acetylation profiles of the O-antigen, were synthesized from a pivotal protected decasaccharide designed to tailor late stage site-selective O-acetylation. The latter was obtained via a convergent route involving the imidate glycosylation chemistry. Binding studies to five protective mIgGs showed that none of the acetates adds significantly to broad antibody recognition. Yet, one of the five antibodies had a unique pattern of binding. With IC50 in the micromolar to submicromolar range mIgG F22-4 exemplifies a remarkable tight binding antibody against diversely O-acetylated and non-O-acetylated fragments of a neutral polysaccharide of medical importance.
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Affiliation(s)
- Charles Gauthier
- Institut Pasteur, Chimie des Biomolécules, Dépt de Biologie Structurale et Chimie, 28 rue du Dr Roux, 75724 Paris Cedex 15, France.
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9
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Knirel YA, Wang J, Luo X, Senchenkova SN, Lan R, Shpirt AM, Du P, Shashkov AS, Zhang N, Xu J, Sun Q. Genetic and structural identification of an O-acyltransferase gene (oacC) responsible for the 3/4-O-acetylation on rhamnose III in Shigella flexneri serotype 6. BMC Microbiol 2014; 14:266. [PMID: 25327486 PMCID: PMC4206707 DOI: 10.1186/s12866-014-0266-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 10/09/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND O-antigen (O-polysaccharide) of the lipopolysaccharide is a highly variable cell component of the outer membrane in Shigella flexneri. It defines the serospecificity and plays an important role in the pathogenesis of shigellosis. There are two distinct O-antigen forms for the 19 serotypes of S. flexneri: one for serotypes 1-5, X, Y, 7 (and their subtypes), and the other for serotype 6. Although having different basal O-polysaccharide structures, the two forms share a common disaccharide fragment [→2)-α-l-Rhap III-(1 → 2)-α-l-Rhap II]. In serotype 6 and some non-6 serotypes, RhaIII is O-acetylated at position either 3 or 4 (3/4-O-acetylation), conferring to the hosts a novel antigenic determinant named O-factor 9. An acyltransferase gene (oacB) responsible for this modification has been identified in serotypes 1a, 1b, 2a, 5a, and Y, but not in serotype 6. RESULTS Using genetic, serological, and chemical approaches, another acyltransferase gene named oacC was demonstrated to be responsible for the 3/4-O-acetylation on RhaIII in the O-antigen of S. flexneri serotype 6. Inactivation of the oacC gene resulted in the loss of the 3/4-O-acetyltion, and the cloned oacC gene restored this modification upon transformation. In accordance with the similarity in the acceptor substrate structure and high sequence homology (72% identity) between oacC and oacB, oacC has the interchangeable function with the oacB gene in mediation of the 3/4-O-acetylation. The oacC gene is located in a prophage on the chromosome and presented in all 77 serotype 6 strains tested. CONCLUSIONS Identification and functional characterization of the O-acetyltransferase encoding gene, oacC, shows that it is involved in O-antigen modification by 3/4-O-acetylation on RhaIII specific to serotype 6.
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Serotype-converting bacteriophage SfII encodes an acyltransferase protein that mediates 6-O-acetylation of GlcNAc in Shigella flexneri O-antigens, conferring on the host a novel O-antigen epitope. J Bacteriol 2014; 196:3656-66. [PMID: 25112477 DOI: 10.1128/jb.02009-14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Shigella flexneri O-antigen is an important and highly variable cell component presented on the outer leaflet of the outer membrane. Most Shigella flexneri bacteria share an O-antigen backbone composed of →2)-α-L-Rhap(III)-(1→2)-α-L-Rhap(II)-(1→3)-α-L-Rhap(I)-(1→3)-β-D-GlcpNAc-(1→ repeats, which can be modified by adding various chemical groups to different sugars, giving rise to diverse O-antigen structures and, correspondingly, to various serotypes. The known modifications include glucosylation on various sugar residues, O-acetylation on Rha(I) or/and Rha(III), and phosphorylation with phosphoethanolamine on Rha(II) or/and Rha(III). Recently, a new O-antigen modification, namely, O-acetylation at position 6 of N-acetylglucosamine (GlcNAc), has been identified in S. flexneri serotypes 2a, 3a, Y, and Yv. In this study, the genetic basis of the 6-O-acetylation of GlcNAc in S. flexneri was elucidated. An O-acyltransferase gene designated oacD was found to be responsible for this modification. The oacD gene is carried on serotype-converting bacteriophage SfII, which is integrated into the host chromosome by lysogeny to form a prophage responsible for the evolvement of serotype 2 of S. flexneri. The OacD-mediated 6-O-acetylation also occurs in some other S. flexneri serotypes that carry a cryptic SfII prophage with a dysfunctional gtr locus for type II glucosylation. The 6-O-acetylation on GlcNAc confers to the host a novel O-antigen epitope, provisionally named O-factor 10. These findings enhance our understanding of the mechanisms of the O-antigen variation and enable further studies to understand the contribution of the O-acetylation to the antigenicity and pathogenicity of S. flexneri.
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Van de Verg LL, Venkatesan MM. Editorial commentary: a Shigella vaccine against prevalent serotypes. Clin Infect Dis 2014; 59:942-3. [PMID: 24958237 DOI: 10.1093/cid/ciu471] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - Malabi M Venkatesan
- Bacterial Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, Maryland
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Diversity of o-antigen repeat unit structures can account for the substantial sequence variation of wzx translocases. J Bacteriol 2014; 196:1713-22. [PMID: 24532778 DOI: 10.1128/jb.01323-13] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The most common system for synthesis of cell surface polysaccharides is the Wzx/Wzy-dependent pathway, which involves synthesis, on the cytoplasmic face of the cell membrane, of repeat units, which are then translocated to the periplasmic face by a Wzx translocase and then polymerized by Wzy to generate the polysaccharide. One such polysaccharide is O antigen, which is incorporated into lipopolysaccharide (LPS). The O antigen is extremely variable, with over 186 forms in Escherichia coli. Wzx proteins are also very diverse, but they have been thought to be specific only for the first sugar of the repeat units. However, recent studies demonstrated examples in which Wzx translocases have considerable preference for their native repeat unit, showing that specificity can extend well beyond the first sugar. These results appear to be in conflict with the early conclusions, but they involved specificity for side branch residues and could be a special case. Here we take six Wzx translocases that were critical in the earlier studies on the importance of the first sugar and assess their ability to translocate the Escherichia coli O16 and O111 repeat units. We use gene replacements to optimize maintenance of expression level and show that under these conditions the native translocases are the most effective for their native repeat unit, being, respectively, 64-fold and 4-fold more effective than the next best. We conclude that Wzx translocases are commonly adapted to their native repeat unit, which provides an explanation for the great diversity of wzx genes.
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13
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Identification of an O-acyltransferase gene (oacB) that mediates 3- and 4-O-acetylation of rhamnose III in Shigella flexneri O antigens. J Bacteriol 2014; 196:1525-31. [PMID: 24509314 DOI: 10.1128/jb.01393-13] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
O antigen (O polysaccharide) is an important and highly variable cell component present on the surface of cells which defines the serospecificity of Gram-negative bacteria. Most O antigens of Shigella flexneri, a cause of shigellosis, share a backbone composed of →2)-α-l-Rhap(III)-(1→2)-α-l-Rhap(II)-(1→3)-α-l-Rhap(I)-(1→3)-β-d-GlcpNAc-(1→ repeats, which can be modified by adding various substituents, giving rise to 19 serotypes. The known modifications include glucosylation on various sugar residues, O-acetylation on Rha(I), and phosphorylation with phosphoethanolamine on Rha(II) or/and Rha(III). Recently, two new O-antigen modifications, namely, O-acetylation at position 3 or 4 of Rha(III) and position 6 of GlcNAc, have been identified in several S. flexneri serotypes. In this work, the genetic basis for the 3/4-O-acetylation on Rha(III) was elucidated. Bioinformatic analysis of the genome of S. flexneri serotype 2a strain Sf301, which carries 3/4-O-acetylation on Rha(III), revealed an O-acyltransferase gene designated oacB. Genetic studies combined with O-antigen structure analysis demonstrated that this gene is responsible for the 3/4-O-acetylation in serotypes 1a, 1b, 2a, 5a, and Y but not serotype 6, which has a different O-antigen backbone structure. The oacB gene is carried by a transposon-like structure located in the proA-adrA region on the chromosome, which represents a novel mechanism of mobilization of O-antigen modification factors in S. flexneri. These findings enhance our knowledge of S. flexneri O-antigen modifications and shed light on the origin of new O-antigen variants.
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Knirel YA, Lan R, Senchenkova SN, Wang J, Shashkov AS, Wang Y, Perepelov AV, Xiong Y, Xu J, Sun Q. O-antigen structure of Shigella flexneri serotype Yv and effect of the lpt-O gene variation on phosphoethanolamine modification of S. flexneri O-antigens. Glycobiology 2013; 23:475-85. [PMID: 23283000 DOI: 10.1093/glycob/cws222] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Shigella flexneri is the major human pathogen causing shigellosis. O-antigens of all S. flexneri serotypes (except for serotype 6) share the →2)-α-l-Rhap(III)-(1 → 2)-α-l-Rhap(II)-(1 → 3)-α-l-Rhap(I)-(1 → 3)-β-d-GlcpNAc-(1→ basic O-unit, whereas differences between the serotypes are conferred by phage-encoded glucosylation and/or O-acetylation at various positions. Recently, in serotype X and 4a variants called Xv and 4av, respectively, O-antigen modification with phosphoethanolamine (PEtN) has been identified, which is encoded by a plasmid-borne gene (lpt-O) for a PEtN-transferase and confers the monoclonal antibody IV-1(MASF IV-1) determinant to the bacteria. In this study, we elucidated the O-antigen structure of serotype Yv, another MASF IV-1-positive novel variant of S. flexneri. The serotype Yv O-antigen has the same basic carbohydrate backbone structure as that of the "classical" serotype Y, but differs in the presence of PEtN at position 3 of Rha(III) (major) or both Rha(II) and Rha(III) (minor). This pattern is similar to that of serotype 4av, but different from the pattern of serotype Xv, which is characterized by major PEtN modification on Rha(II). In serotype Yv, mono- and bisphosphorylated O-units generate a block-copolymeric structure, the former being partially O-acetylated at position 6 of GlcNAc and the latter lacking O-acetylation. Functional analysis revealed a correlation between the serotype-specific PEtN modification pattern and the lpt-O variation in different serotypes: lpt-O(RII) in serotype Xv is better tuned for phosphorylation of Rha(II) and lpt-O(RIII) in serotypes Yv and 4av for phosphorylation of Rha(III). These data enhance our knowledge of S. flexneri serotype conversion mechanisms and help to understand the biosynthesis process of the new O-antigen variants.
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Affiliation(s)
- Yuriy A Knirel
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russian Federation
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Perepelov AV, Shekht ME, Liu B, Shevelev SD, Ledov VA, Senchenkova SN, L'vov VL, Shashkov AS, Feng L, Aparin PG, Wang L, Knirel YA. Shigella flexneriO-antigens revisited: final elucidation of the O-acetylation profiles and a survey of the O-antigen structure diversity. ACTA ACUST UNITED AC 2012; 66:201-10. [DOI: 10.1111/j.1574-695x.2012.01000.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 05/18/2012] [Accepted: 06/14/2012] [Indexed: 11/28/2022]
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Szczepina MG, Bleile DW, Müllegger J, Lewis AR, Pinto BM. WaterLOGSY NMR Experiments in Conjunction with Molecular-Dynamics Simulations Identify Immobilized Water Molecules That Bridge Peptide Mimic MDWNMHAA to Anticarbohydrate Antibody SYA/J6. Chemistry 2011; 17:11438-45. [DOI: 10.1002/chem.201101464] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Indexed: 11/11/2022]
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17
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Szczepina MG, Bleile DW, Pinto BM. Investigation of the Binding of a Carbohydrate-Mimetic Peptide to its Complementary Anticarbohydrate Antibody by STD-NMR Spectroscopy and Molecular-Dynamics Simulations. Chemistry 2011; 17:11446-55. [DOI: 10.1002/chem.201100222] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 04/05/2011] [Indexed: 11/07/2022]
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Structural elucidation of the O-antigen of the Shigella flexneri provisional serotype 88-893: structural and serological similarities with S. flexneri provisional serotype Y394 (1c). Carbohydr Res 2011; 346:872-6. [PMID: 21392735 DOI: 10.1016/j.carres.2011.02.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Revised: 02/10/2011] [Accepted: 02/11/2011] [Indexed: 11/23/2022]
Abstract
The structure of the repeating unit of the O-antigen polysaccharide from Shigella flexneri provisional serotype 88-893 has been determined. (1)H and (13)C NMR spectroscopy as well as 2D NMR experiments were employed to elucidate the structure. The carbohydrate part of the hexasaccharide repeating unit is identical to the previously elucidated structure of the O-polysaccharide from S. flexneri prov. serotype Y394. The O-antigen of S. flexneri prov. serotype 88-893 carries 0.7 mol O-acetyl group per repeating unit located at O-2 of the 3-substituted rhamnosyl residue, as identified by H2BC and BS-CT-HMBC NMR experiments. The O-antigen polysaccharide is composed of hexasaccharide repeating units with the following structure: →2)-α-L-Rhap-(1→2)-α-L-Rhap-(1→3)-α-L-Rhap2Ac-(1→3)[α-D-Glcp-(1→2)-α-D-Glcp-(1→4)]-β-D-GlcpNAc-(1→. Serological studies showed that type antigens for the two provisional serotypes are identical; in addition 88-893 expresses S. flexneri group factor 6 antigen. We propose that provisional serotypes Y394 and 88-893 be designated as two new serotypes 7a and 7b, respectively, in the S. flexneri typing scheme.
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Kondakova AN, Vinogradov EV, Shekht ME, Markina AA, Lindner B, L'vov VL, Aparin PG, Knirel' IA. [Structure of the oligosaccharide region (core) of the lipopolysaccharides of Shigella flexneri types 2a and 5b]. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2010; 36:429-32. [PMID: 20644600 DOI: 10.1134/s1068162010030179] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The full structure of the lipopolysaccharide core of bacteria Shigella flexneri types 2a and 5b, the causative agents of bacillary dysentery (shigellosis), was established by chemical methods, high-resolution electrospray ionization mass spectrometry, and two-dimensional NMR spectroscopy. The structure of the O-antigen repeating unit and the configuration and position of the linkage between the O-antigen and the core were determined in the lipopolysaccharide of S. flexneri type 2a.
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Passwell JH, Ashkenazi S, Banet-Levi Y, Ramon-Saraf R, Farzam N, Lerner-Geva L, Even-Nir H, Yerushalmi B, Chu C, Shiloach J, Robbins JB, Schneerson R. Age-related efficacy of Shigella O-specific polysaccharide conjugates in 1-4-year-old Israeli children. Vaccine 2010; 28:2231-2235. [PMID: 20056180 DOI: 10.1016/j.vaccine.2009.12.050] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Revised: 10/28/2009] [Accepted: 12/22/2009] [Indexed: 10/20/2022]
Abstract
BACKGROUND Despite its high worldwide morbidity and mortality, there is yet no licensed vaccine for shigellosis. We reported the safety and immunogenicity of Shigella O-specific polysaccharide-protein conjugates in adults and young children and efficacy of Shigella sonnei conjugate in young adults. METHODS A double-blinded, randomized and vaccine-controlled Phase 3 evaluation of S. sonnei and Shigella flexneri 2a O-SP-rEPA conjugates, 25 microg, injected IM twice, 6 weeks apart, into healthy 1-4 years old, is reported. The children were followed for 2 years by telephone every other week and stool cultures were obtained for each episode of acute diarrhea (> or =3 loose stools/day or a bloody/mucous stool). Sera were taken randomly from 10% of the participants for IgG anti-LPS and anti-carrier levels. RESULTS Of the 2799 enrollees, 1433 received S. sonnei and 1366 S. flexneri 2a conjugates; 2699 (96.4%) completed the 2-year follow-up. Local reactions occurred in approximately 5% and approximately 4% had temperatures > or =38.0 degrees C lasting 1-2 days. There were no serious adverse events attributable to the vaccines. Of the 3295 stool cultures obtained, 125 yielded S. sonnei and 21 S. flexneri 2a. Immunogenicity and efficacy were age-related. The overall efficacy of the S. sonnei conjugate was 27.5%; 71.1% (P=0.043) in the 3-4 years old. The numbers for S. flexneri 2a were too few for meaningful analysis. Cross-protection by S. flexneri 2a for non-vaccine S. flexneri types was found, but the numbers were too few for statistical significance. There was an age-related rise of vaccine-specific IgG anti-LPS in both groups, peaking at about 10 weeks and declining thereafter, but remaining > or =4-fold higher than in the controls 2 years after the second dose. CONCLUSIONS Shigella conjugates are safe and immunogenic in 1-4 years old. The S. sonnei conjugate elicited 71.1% efficacy in the 3-4 years old and can be predicted to be efficacious in individuals older than 3 years of age. These results urge studies with our improved conjugates.
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Affiliation(s)
- Justen H Passwell
- Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 52621, Israel
| | - Shai Ashkenazi
- Schneider Children's Medical Center, Petach Tikva 49202, Israel
| | - Yonit Banet-Levi
- Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 52621, Israel
| | - Reut Ramon-Saraf
- Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 52621, Israel
| | - Nahid Farzam
- Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 52621, Israel
| | - Liat Lerner-Geva
- Gertner Institute for Epidemiology and Health Policy Research, Tel Hashomer 52621, Israel
| | - Hadas Even-Nir
- Safra Children's Hospital, Sheba Medical Center, Tel Hashomer 52621, Israel
| | - Baruch Yerushalmi
- Saban Pediatric Center, Soroka Medical Center, Beer Sheva 84141, Israel
| | - Chiayung Chu
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA
| | - Joseph Shiloach
- National Institute of Diabetes, Digestive Diseases and Kidney, NIH, Bethesda, MD 20892, USA
| | - John B Robbins
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA
| | - Rachel Schneerson
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA.
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21
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Perepelov AV, L'vov VL, Liu B, Senchenkova SN, Shekht ME, Shashkov AS, Feng L, Aparin PG, Wang L, Knirel YA. A similarity in the O-acetylation pattern of the O-antigens of Shigellaflexneri types 1a, 1b, and 2a. Carbohydr Res 2009; 344:687-92. [PMID: 19246033 DOI: 10.1016/j.carres.2009.01.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2008] [Revised: 12/30/2008] [Accepted: 01/07/2009] [Indexed: 11/16/2022]
Abstract
Shigella flexneri type 2a is the first, and type 1b is the second, most prevalent isolates from patients with shigellosis in Russia. The O-specific polysaccharides (OPSs, O-antigens) of S. flexneri types 1-5 possess a common -->2)-alpha-l-RhapIII-(1-->2)-alpha-l-RhapII-(1-->3)-alpha-l-RhapI-(1-->3)-beta-d-GlcpNAc-(1--> backbone and differ from each other in its glucosylation or/and O-acetylation at various positions, the modifications being responsible for various O-factors. It was suggested that O-factor 6 expressed by type 1b is associated with O-acetylation of RhaI at position 2 but more than one O-acetyl group has been detected in the type 1b OPS [Kenne, L. et al. Eur. J. Biochem.1978, 91, 279-284]. In this work, O-acetylation of RhapI in the type 1b OPS was confirmed by NMR spectroscopy and location of an additional O-acetyl group at position either 3 (major) or 4 (minor) of RhapIII was determined. Type 1a differs from type 1b in the lack of O-acetylation of RhapI only. In type 2a, in addition to two reported major O-acetyl groups at position 6 of GlcNAc and position 3 of RhapIII [Kubler-Kielb, J. et al. Carbohydr. Res.2007, 342, 643-647], a minor O-acetyl group was found at position 4 of RhaIII. Therefore, RhapIII is O-acetylated in the same manner in all three S. flexneri serotypes studied.
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Affiliation(s)
- Andrei V Perepelov
- N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russian Federation.
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22
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Liu B, Knirel YA, Feng L, Perepelov AV, Senchenkova SN, Wang Q, Reeves PR, Wang L. Structure and genetics ofShigellaO antigens. FEMS Microbiol Rev 2008; 32:627-53. [DOI: 10.1111/j.1574-6976.2008.00114.x] [Citation(s) in RCA: 241] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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23
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Kubler-Kielb J, Vinogradov E, Chu C, Schneerson R. O-Acetylation in the O-specific polysaccharide isolated from Shigella flexneri serotype 2a. Carbohydr Res 2006; 342:643-7. [PMID: 17087926 PMCID: PMC1885374 DOI: 10.1016/j.carres.2006.09.017] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2006] [Accepted: 09/16/2006] [Indexed: 11/30/2022]
Abstract
Shigella flexneri causes diarrheal diseases especially in infants and children in developing countries. Modifications of the lipopolysaccharide (LPS) molecule, like bacteriophage-mediated glucosylation and acetylation of the O-specific chain (O-SP), are important for the LPS antigenicity and consequently for the immunogenicity of the polysaccharide-based vaccines against shigellosis. Here, we report the degree of O-acetylation and the localisation of O-acetyl groups and side-chain glucose substitution in the O-SP (scheme) in different preparations of S. flexneri type 2a LPS. [structure: see text]
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Affiliation(s)
- Joanna Kubler-Kielb
- National Institute of Child Health and Human Development, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.
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24
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Lemanski G, Ziegler T. Synthesis of Pentasaccharide Fragments Related to theO-Specific Polysaccharide ofShigella flexneri Serotype 1a. European J Org Chem 2006. [DOI: 10.1002/ejoc.200600078] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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25
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West NP, Sansonetti P, Mounier J, Exley RM, Parsot C, Guadagnini S, Prévost MC, Prochnicka-Chalufour A, Delepierre M, Tanguy M, Tang CM. Optimization of virulence functions through glucosylation of Shigella LPS. Science 2005; 307:1313-7. [PMID: 15731456 DOI: 10.1126/science.1108472] [Citation(s) in RCA: 235] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Shigella, the leading cause of bacillary dysentery, uses a type III secretion system (TTSS) to inject proteins into human cells, leading to bacterial invasion and a vigorous inflammatory response. The bacterium is protected against the response by the O antigen of lipopolysaccharide (LPS) on its surface. We show that bacteriophage-encoded glucosylation of Shigella O antigen, the basis of different serotypes, shortens the LPS molecule by around half. This enhances TTSS function without compromising the protective properties of the LPS. Thus, LPS glucosylation promotes bacterial invasion and evasion of innate immunity, which may have contributed to the emergence of serotype diversity in Shigella.
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Affiliation(s)
- Nicholas P West
- Centre for Molecular Microbiology and Infection, Department of Infectious Diseases, Faculty of Medicine, Flowers Building, Imperial College London, London SW7 2AZ, UK
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26
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Hossany RB, Johnson MA, Eniade AA, Pinto BM. Synthesis and immunochemical characterization of protein conjugates of carbohydrate and carbohydrate-mimetic peptides as experimental vaccines. Bioorg Med Chem 2004; 12:3743-54. [PMID: 15186860 DOI: 10.1016/j.bmc.2004.03.075] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2003] [Accepted: 03/10/2004] [Indexed: 10/26/2022]
Abstract
The peptides DRPVPY and MDWNMHAA, which were identified as mimics of the cell-surface polysaccharides of Streptococcus Group A and Shigella flexneri Y, respectively, were used in this study to develop experimental vaccines directed against these two bacteria. Both oligopeptides were synthesized employing the Fmoc solid-phase strategy and linked via the amino end to a bifunctional linker, diethylsquarate. These adducts were then conjugated to the two carrier proteins, bovine serum albumin (BSA) and tetanus toxoid (TT) to yield the peptide conjugate vaccines. The average level of incorporation of DRPVPY and MDWNMHAA on TT was 65% and 75%, respectively, whereas that of both peptide haptens on BSA was 100%. A polysaccharide conjugate against S. flexneri Y, which comprises about 10 tetrasaccharide repeating units, was also prepared based on reductive amination at the reducing end with 1,3-diaminopropane, followed by coupling of the aminated polysaccharide to diethylsquarate, and subsequent coupling of the adduct to TT. An average incorporation of 73% of polysaccharide haptens was achieved. The glycoconjugate and the oligopeptide conjugates were shown to bind effectively to the respective monoclonal antibodies directed against the cell-surface polysaccharides.
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Affiliation(s)
- Rehana B Hossany
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada V5A 1S6
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27
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Korres H, Verma NK. Topological analysis of glucosyltransferase GtrV of Shigella flexneri by a dual reporter system and identification of a unique reentrant loop. J Biol Chem 2004; 279:22469-76. [PMID: 15028730 DOI: 10.1074/jbc.m401316200] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Lipopolysaccharide, particularly the O-antigen component, is one of many virulence determinants necessary for Shigella flexneri pathogenesis. O-Antigen modification is mediated by glucosyltransferase genes (gtr) encoded by temperate serotype-converting bacteriophages. The gtrV gene encodes the GtrV glucosyltransferase, an integral membrane protein that catalyzes the transfer of a glucosyl residue via an alpha1,3 linkage to rhamnose II of the O-antigen unit. This mediates conversion of S. flexneri serotype Y to serotype 5a. Analysis of the GtrV amino acid sequence using computer prediction programs indicated that GtrV had 9-11 transmembrane segments. The computer prediction models were tested by genetically fusing C-terminal deletions of GtrV to a dual reporter system composed of alkaline phosphatase and beta-galactosidase. Sandwiched GtrV-PhoA/LacZ fusions were also constructed at predetermined positions. The enzyme activities of cells with the GtrV-PhoA/LacZ fusions and the particular location of the fusions in the gtrV indicated that GtrV has nine transmembrane segments and one large N-terminal periplasmic loop with the N and C termini located on the cytoplasmic and periplasmic sides of the membrane, respectively. The existence of a unique reentrant loop was discovered after transmembrane segment IV, a feature not documented in other bacterial glycosyltransferases. Its potential role in mediating serotype conversion in S. flexneri is discussed.
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Affiliation(s)
- Haralambos Korres
- School of Biochemistry and Molecular Biology, Faculty of Science, The Australian National University, Canberra ACT 0200, Australia
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28
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Johnson MA, Pinto BM. Saturation-transfer difference NMR studies for the epitope mapping of a carbohydrate-mimetic peptide recognized by an anti-carbohydrate antibody. Bioorg Med Chem 2004; 12:295-300. [PMID: 14697795 DOI: 10.1016/j.bmc.2003.09.041] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Saturation-transfer difference NMR spectroscopy (STD-NMR) experiments have been performed to analyze the topography or epitope of the octapeptide MDWNMHAA recognized by the anti-carbohydrate antibody SYA/J6 in solution; the antibody is directed against the Shigella flexneri Y O-antigen polysaccharide. The results permit a valuable comparison of solution versus crystal-structure data, and provide insight for the design of the next-generation binding ligands.
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Affiliation(s)
- Margaret A Johnson
- Departments of Chemistry and of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada V5A 1S6
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29
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Chen JH, Hsu WB, Chiou CS, Chen CM. Conversion of Shigella flexneri serotype 2a to serotype Y in a shigellosis patient due to a single amino acid substitution in the protein product of the bacterial glucosyltransferase gtrII gene. FEMS Microbiol Lett 2003; 224:277-83. [PMID: 12892893 DOI: 10.1016/s0378-1097(03)00470-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Conversion of serotype from 2a to Y was demonstrated with five Shigella flexneri isolates recovered from an infected patient. When introduced into the serotype Y isolate, the glucosyltransferase (gtr) II gene of the serotype 2a isolate is capable of inducing the conversion from serotype Y to 2a. In contrast, the gtrII of the serotype Y isolate lacks the capacity to change serotype, resulting from a Cys-->Tyr substitution in its predicted protein sequence. The protein product of the gtrII gene was detected. This is the first report of serotype conversion of S. flexneri in humans, and successful detection of the protein product from a gtr gene.
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Affiliation(s)
- Jiann-Hwa Chen
- Institute of Molecular Biology, National Chung Hsing University, Taichung, Taiwan, Republic of China.
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30
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Johnson MA, Eniade AA, Pinto BM. Rational design and synthesis of peptide ligands for an anti-carbohydrate antibody and their immunochemical characterization. Bioorg Med Chem 2003; 11:781-8. [PMID: 12538009 DOI: 10.1016/s0968-0896(02)00449-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Molecular mimics of carbohydrates present an alternative source of compounds to target pathways involving protein-carbohydrate interactions. Certain peptides act as molecular mimics of carbohydrates in binding to anti-carbohydrate antibodies. A series of potential peptide ligands for the anti-carbohydrate antibody SYA/J6, directed against Shigella flexneri Y, was designed by molecular modeling based on a crystal structure of the antibody complex with a carbohydrate-mimetic peptide. These octapeptides were synthesized using solid-phase peptide synthesis, and their recognition by the antibody was investigated. The results shed light on the nature of peptide-carbohydrate mimicry.
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Affiliation(s)
- Margaret A Johnson
- Department of Chemistry, Simon Fraser University, Burnaby, B.C., Canada V5A 1S6
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31
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The biosynthesis and properties of anti-carbohydrate antibodies. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1572-5995(03)80014-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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32
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Lerouge I, Vanderleyden J. O-antigen structural variation: mechanisms and possible roles in animal/plant-microbe interactions. FEMS Microbiol Rev 2002; 26:17-47. [PMID: 12007641 DOI: 10.1111/j.1574-6976.2002.tb00597.x] [Citation(s) in RCA: 322] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Current data from bacterial pathogens of animals and from bacterial symbionts of plants support some of the more general proposed functions for lipopolysaccharides (LPS) and underline the importance of LPS structural versatility and adaptability. Most of the structural heterogeneity of LPS molecules is found in the O-antigen polysaccharide. In this review, the role and mechanisms of this striking flexibility in molecular structure of the O-antigen in bacterial pathogens and symbionts are illustrated by some recent findings. The variation in O-antigen that gives rise to an enormous structural diversity of O-antigens lies in the sugar composition and the linkages between monosaccharides. The chemical composition and structure of the O-antigen is strain-specific (interstrain LPS heterogeneity) but can also vary within one bacterial strain (intrastrain LPS heterogeneity). Both LPS heterogeneities can be achieved through variations at different levels. First of all, O-polysaccharides can be modified non-stoichiometrically with sugar moieties, such as glucosyl and fucosyl residues. The addition of non-carbohydrate substituents, i.e. acetyl or methyl groups, to the O-antigen can also occur with regularity, but in most cases these modifications are again non-stoichiometric. Understanding LPS structural variation in bacterial pathogens is important because several studies have indicated that the composition or size of the O-antigen might be a reliable indicator of virulence potential and that these important features often differ within the same bacterial strain. In general, O-antigen modifications seem to play an important role at several (at least two) stages of the infection process, including the colonization (adherence) step and the ability to bypass or overcome host defense mechanisms. There are many reports of modifications of O-antigen in bacterial pathogens, resulting either from altered gene expression, from lysogenic conversion or from lateral gene transfer followed by recombination. In most cases, the mechanisms underlying these changes have not been resolved. However, in recent studies some progress in understanding has been made. Changes in O-antigen structure mediated by lateral gene transfer, O-antigen conversion and phase variation, including fucosylation, glucosylation, acetylation and changes in O-antigen size, will be discussed. In addition to the observed LPS heterogeneity in bacterial pathogens, the structure of LPS is also altered in bacterial symbionts in response to signals from the plant during symbiosis. It appears to be part of a molecular communication between bacterium and host plant. Experiments ex planta suggest that the bacterium in the rhizosphere prepares its LPS for its roles in symbiosis by refining the LPS structure in response to seed and root compounds and the lower pH at the root surface. Moreover, modifications in LPS induced by conditions associated with infection are another indication that specific structures are important. Also during the differentiation from bacterium to bacteroid, the LPS of Rhizobium undergoes changes in the composition of the O-antigen, presumably in response to the change of environment. Recent findings suggest that, during symbiotic bacteroid development, reduced oxygen tension induces structural modifications in LPS that cause a switch from predominantly hydrophilic to predominantly hydrophobic molecular forms. However, the genetic mechanisms by which the LPS epitope changes are regulated remain unclear. Finally, the possible roles of O-antigen variations in symbiosis will be discussed.
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Affiliation(s)
- Inge Lerouge
- Centre of Microbial and Plant Genetics, Katholieke Universtiteit Leuven, Kasteelpark Arenberg 20, B-3001, Heverlee, Belgium
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Brooks BW, Robertson RH, Lutze-Wallace CL, Pfahler W. Identification, characterization, and variation in expression of two serologically distinct O-antigen epitopes in lipopolysaccharides of Campylobacter fetus serotype A strains. Infect Immun 2001; 69:7596-602. [PMID: 11705938 PMCID: PMC98852 DOI: 10.1128/iai.69.12.7596-7602.2001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Monoclonal antibodies (MAbs) to the lipopolysaccharide (LPS) O-antigens of Campylobacter fetus serotype A and B strains were produced. Eight MAbs specific for serotype A LPS were characterized on immunoblots of C. fetus serotype A LPS. Two immunoblot patterns were observed and were used to divide the eight MAbs into two groups. MAbs M1177 and M1194 were selected as representative of the two groups and were used in an enzyme-linked immunosorbent assay (ELISA) to examine the LPS O-antigen epitopes of 37 serotype A C. fetus subsp. fetus and C. fetus subsp. venerealis strains. Thirty-three strains (89%) reacted with both M1177 and M1194, 2 strains reacted only with M1177, and 2 strains reacted only with M1194. To further characterize the O-antigen epitopes, purified serotype A LPS was treated using various temperature and pH conditions and the effect of the treatments on the reactivity of the LPS with MAbs M1177 and M1194 was evaluated by ELISA. While no difference among several treatments was observed, heating serotype A LPS under alkaline conditions decreased the reaction with M1177 to background levels and increased the reaction with M1194. MAbs M1177 and M1194 were also used with ELISA to investigate in vivo and in vitro expression of the two O-antigen epitopes. There was substantial variation in expression of the two epitopes among weekly isolates of two C. fetus serotype A strains recovered from experimentally infected heifers. There was minimal variation in expression of the two epitopes in successive subcultures of three C. fetus serotype A strains.
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Affiliation(s)
- B W Brooks
- Animal Diseases Research Institute, Canadian Food Inspection Agency, Nepean, Ontario, Canada K2H 8P9.
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Pavliakova D, Moncrief JS, Lyerly DM, Schiffman G, Bryla DA, Robbins JB, Schneerson R. Clostridium difficile recombinant toxin A repeating units as a carrier protein for conjugate vaccines: studies of pneumococcal type 14, Escherichia coli K1, and Shigella flexneri type 2a polysaccharides in mice. Infect Immun 2000; 68:2161-6. [PMID: 10722615 PMCID: PMC97399 DOI: 10.1128/iai.68.4.2161-2166.2000] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Unlike the native protein, a nontoxic peptide (repeating unit of the native toxin designated rARU) from Clostridium difficile toxin A (CDTA) afforded an antigen that could be bound covalently to the surface polysaccharides of pneumococcus type 14, Shigella flexneri type 2a, and Escherichia coli K1. The yields of these polysaccharide-protein conjugates were significantly increased by prior treatment of rARU with succinic anhydride. Conjugates, prepared with rARU or succinylated (rARUsucc), were administered to mice by a clinically relevant dosage and immunization scheme. All conjugates elicited high levels of serum immunoglobulin G both to the polysaccharides and to CDTA. Conjugate-induced anti-CDTA had neutralizing activity in vitro and protected mice challenged with CDTA, similar to the rARU alone. Conjugates prepared with succinylated rARU, therefore, have potential for serving both as effective carrier proteins for polysaccharides and for preventing enteric disease caused by C. difficile.
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Affiliation(s)
- D Pavliakova
- National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
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35
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Mulard LA, Ughetto-Monfrin J. Linear Synthesis of The Methyl Glycosides of Tri-, Tetra-, and Pentasaccharide Fragments of TheShigella FlexneriSerotype 5AO-Antigen. J Carbohydr Chem 2000. [DOI: 10.1080/07328300008544096] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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36
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Allison GE, Verma NK. Serotype-converting bacteriophages and O-antigen modification in Shigella flexneri. Trends Microbiol 2000; 8:17-23. [PMID: 10637639 DOI: 10.1016/s0966-842x(99)01646-7] [Citation(s) in RCA: 227] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
O-antigen modification (serotype conversion) in Shigella flexneri, which is an important virulence determinant, is conferred by temperate bacteriophages. Several serotype-converting phages have been isolated and preliminary characterization has identified the genes involved in O-antigen modification, and has also provided insight into the molecular biology of these phages.
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Affiliation(s)
- G E Allison
- Divn of Biochemistry and Molecular Biology, Faculty of Science, Australian National University, Canberra, ACT, 0200, Australia
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37
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Pavliakova D, Chu C, Bystricky S, Tolson NW, Shiloach J, Kaufman JB, Bryla DA, Robbins JB, Schneerson R. Treatment with succinic anhydride improves the immunogenicity of Shigella flexneri type 2a O-specific polysaccharide-protein conjugates in mice. Infect Immun 1999; 67:5526-9. [PMID: 10496944 PMCID: PMC96919 DOI: 10.1128/iai.67.10.5526-5529.1999] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Seroepidemiological data and a clinical trial with a Shigella sonnei O-specific polysaccharide (O-SP)-Pseudomonas aeruginosa recombinant exoprotein A (rEPA) conjugate provide evidence that a critical level of immunoglobulin G (IgG) lipopolysaccharide (LPS) antibodies in serum confers protection against shigellosis. We evaluated the immunogenicity of conjugates whose carrier proteins and O-SPs were treated with succinic anhydride (SA), which reacts with amino groups at neutral pH to form amide-linked carboxyls (succinylation). Conjugates were synthesized with either of two genetically inactivated medically useful toxins, the diphtheria protein CRM9 or rEPA, bound to the O-SP of Shigella flexneri type 2a. Conjugates composed of the succinylated protein, succinylated O-SP, or both succinylated components were administered to mice by a clinically relevant scheme, and their levels of serum IgG anti-LPS and anti-proteins were assayed 7 days after the second and third injections. CRM9 served as a more immunogenic carrier than rEPA. Conjugates composed of succinylated components were more immunogenic than the conjugates composed of the native components. SA treatment of both the carrier protein and the O-SP did not confer an advantage over the succinylated protein alone. Conjugates prepared with native proteins, in general, elicited slightly higher levels of IgG protein antibodies than conjugates composed of the SA-treated proteins.
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Affiliation(s)
- D Pavliakova
- National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-2720, USA
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38
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Stenutz R, Jansson PE, Widmalm G. Computer-assisted structural analysis of oligo- and polysaccharides: an extension of CASPER to multibranched structures. Carbohydr Res 1998; 306:11-7. [PMID: 9691437 DOI: 10.1016/s0008-6215(97)10047-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The CASPER program which is used for determination of the structure of oligo- and polysaccharides has been extended. It can now handle a reduced number of experimental signals from an NMR spectrum in the comparison to the simulated spectra of structures that it generates, an improvement which is of practical importance since all signals in NMR spectra cannot always be identified. Furthermore, the program has been enhanced to simulate NMR spectra of multibranched oligo- and polysaccharides. The new developments were tested on four saccharides of known structure but of different complexity and were shown to predict the correct structures.
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Affiliation(s)
- R Stenutz
- Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, Sweden
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39
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Bastin DA, Lord A, Verma NK. Cloning and analysis of the glucosyl transferase gene encoding type I antigen in Shigella flexneri. FEMS Microbiol Lett 1997; 156:133-9. [PMID: 9368372 DOI: 10.1111/j.1574-6968.1997.tb12718.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The O-antigen of most Shigella flexneri serotypes contains an identical tetrasaccharide repeating unit. Apart from serotype Y, the O-antigen is modified by addition of a glucosyl and/or O-acetyl residue to a specific position in the O-unit. In this study the glucosyl transferase gene from a serotype 1 a has been cloned and identified. The bacteriophage SfV integrase (int) gene was used to probe a S. flexneri Y53 (serotype 1 a) cosmid library and 18 unique clones were identified. Southern hybridisation of these clones indicated two unlinked regions of the chromosome contained the int homologue. When expressed in a live candidate vaccine strain of S. flexneri serotype Y (SFL124), clones with one region produced type I antigen, whereas clones containing the other region produced mainly type Y antigen. One of the cosmid clones positive for type I antigen by agglutination and Western blotting was selected for further study. Genes involved in O-antigen glucosyl modification were mapped on a 5.8 kb fragment and subclones were produced which fully or partially expressed the type I antigen, depending on the extent of the clone. Fully and partially expressing clones may be useful vaccine candidate strains for protection against disease caused by two serotypes of S. flexneri.
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Affiliation(s)
- D A Bastin
- Division of Biochemistry and Molecular Biology, School of Life Sciences, Faculty of Science, Australian National University, Canberra, Australia
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40
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Huan PT, Whittle BL, Bastin DA, Lindberg AA, Verma NK. Shigella flexneri type-specific antigen V: cloning, sequencing and characterization of the glucosyl transferase gene of temperate bacteriophage SfV. Gene 1997; 195:207-16. [PMID: 9305766 DOI: 10.1016/s0378-1119(97)00144-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
With lysogeny by bacteriophage SfV, Shigella flexneri serotype Y is converted to serotype 5a. The glucosyl transferase gene (gtr) from bacteriophage SfV of S. flexneri, involved in serotype-specific conversion, was cloned and characterized. The DNA sequence of a 3.7 kb EcoRI-BamHI fragment of bacteriophage SfV which includes the gtr gene was determined. This gene, encoding a polypeptide of 417 aa with 47.67 kDa molecular mass, caused partial serotype conversion of S. flexneri from serotype Y to type V antigen as demonstrated by Western blotting and the sensitivity of the hybrid strain to phage Sf6. The deduced protein of the partially sequenced open reading frame upstream of the gtr showed similarity to various glycosyl transferases of other bacteria. Orf3, separated from the gtr by a non-coding region and transcribed convergently, codes for a 167 aa (18.8 kDa) protein found to have homology with tail fibre genes of phage lambda and P2.
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Affiliation(s)
- P T Huan
- Division of Biochemistry and Molecular Biology, School of Life Sciences, The Australian National University, Canberra
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41
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Kreis UC, Varma V, Pinto B. Oligosaccharides corresponding to biological repeating units of Shigella flexneri variant Y polysaccharide Part 5. Conformational analysis of a heptasaccharide hapten utilizing a combined molecular dynamics and NMR spectroscopic protocol. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s0166-1280(96)04541-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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42
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Hartman AB, Van de Verg LL, Mainhart CR, Tall BD, Smith-Gill SJ. Specificity of monoclonal antibodies elicited by mucosal infection of BALB/c mice with virulent Shigella flexneri 2a. CLINICAL AND DIAGNOSTIC LABORATORY IMMUNOLOGY 1996; 3:584-9. [PMID: 8877140 PMCID: PMC170411 DOI: 10.1128/cdli.3.5.584-589.1996] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Protective immunity against shigellosis is thought to be determined by the O-antigen side chains of the lipopolysaccharide (LPS) molecule. To study possible common protective epitopes, monoclonal antibodies reacting with Shigella flexneri 2a LPS were generated from BALB/c mice infected ocularly with the virulent serotype 2a strain S. flexneri 2457T and tested against a panel of S. flexneri LPSs by enzyme-linked immunosorbent and immunoblot assays. Four monoclonal antibodies were identified, all of which showed restricted specificity patterns. Three different patterns of reactivity to LPS possessing the 3,4 group antigen were seen: (i) 2a only, (ii) 2a and 5a, and (iii) 2a, 4a, 5a, and Y. These results have implications for designing a Shigella vaccine that will be protective against related serotypes. Electron microscopy studies showed that the monoclonal antibodies bind to the bacterial surface in a patchy pattern, suggesting their potential use for examining the LPS distribution on the surface of the bacteria.
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Affiliation(s)
- A B Hartman
- Department of Enteric Infections, Walter Reed Army Institute of Research, Washington, DC 20307-5100, USA.
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43
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Fält IC, Schweda EK, Klee S, Singh M, Floderus E, Timmis KN, Lindberg AA. Expression of Shigella dysenteriae serotype 1 O-antigenic polysaccharide by Shigella flexneri aroD vaccine candidates and different S. flexneri serotypes. J Bacteriol 1995; 177:5310-5. [PMID: 7545156 PMCID: PMC177324 DOI: 10.1128/jb.177.18.5310-5315.1995] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The potential utility of Shigella flexneri aroD vaccine candidates for the development of bi- or multivalent vaccines has been explored by the introduction of the genetic determinants rfp and rfb for heterologous O antigen polysaccharide from Shigella dysenteriae serotype 1. The serotype Y vaccine strain SFL124 expressed the heterologous antigen qualitatively and quantitatively well, qualitatively in the sense of the O antigen polysaccharide being correctly linked to the S. flexneri lipopolysaccharide R3 core oligosaccharide and quantitatively in the sense that typical yields were obtained, with ratios of homologous to heterologous O antigen being 4:1 for one construct and 1:1 for another. Moreover, both polysaccharide chains were shown to be linked to position O-4 of the subterminal D-glucose residue of the R3 core. In contrast to the hybrid serotype Y SFL124 derivatives, analogous derivatives of serotype 2a vaccine strain SFL1070 did not elaborate a complete heterologous O antigen. Such derivatives, and analogous derivatives of rough, O antigen-negative mutants of SFL1070, formed instead a hybrid lipopolysaccharide molecule consisting of the S. flexneri lipid A R3 core with a single repeat unit of the S. dysenteriae type 1 O antigen. Introduction of the determinants for the S. dysenteriae type 1 O antigen into a second serotype 2a strain and into strains representing other serotypes of S. flexneri, revealed the following for the expression of the heterologous O antigen: serotypes 1a, 1b, 2a, and 5a did not produce the heterologous O antigen, whereas serotypes 2b, 3a, 3b, 4a, 4b, 5b, and X did.
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Affiliation(s)
- I C Fält
- Department of Immunology, Microbiology, Pathology, and Infectious Diseases, Karolinska Institute, Huddinge, Sweden
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44
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Huan PT, Taylor R, Lindberg AA, Verma NK. Immunogenicity of the Shigella flexneri serotype Y (SFL 124) vaccine strain expressing cloned glucosyl transferase gene of converting bacteriophage SfX. Microbiol Immunol 1995; 39:467-72. [PMID: 8569531 DOI: 10.1111/j.1348-0421.1995.tb02230.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The glucosyl transferase gene (gtr) from bacteriophage phage X (SfX) caused partial conversion of serotype Y (group antigen 3, 4) to X (group antigen 7, 8) when introduced into a candidate vaccine strain of Shigella flexneri serotype Y (SFL124). The gtr gene caused conversion of O-antigens but did not eliminate the adsorption of the corresponding phage SfX. The hybrid strain expressing both group antigens 7, 8 and 3, 4 showed 75% protection when immunized guinea pigs were challenged with a wild-type S. flexneri serotype X strain. No protection was observed against serotype Y challenge, although group antigen 3, 4 was detected in the LPS of the hybrid strain. This suggests the importance of O-antigen immunity in the host defense against shigellosis.
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Affiliation(s)
- P T Huan
- Division of Biochemistry and Molecular Biology, Faculty of Science, School of Life Sciences, Australian National University, Canberra, Australia
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45
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Polotsky VY, Robbins JB, Bryla D, Schneerson R. Comparison of conjugates composed of lipopolysaccharide from Shigella flexneri type 2a detoxified by two methods and bound to tetanus toxoid. Infect Immun 1994; 62:210-4. [PMID: 8262629 PMCID: PMC186088 DOI: 10.1128/iai.62.1.210-214.1994] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Shigella flexneri type 2a lipopolysaccharide (LPS) was detoxified with acetic acid (O-SP) or with hydrazine (DeALPS). DeALPS, but not O-SP, retained part of its lipid A. Both gave an identical line of precipitation with typing antiserum by double immunodiffusion, and both had low levels of LPS activity by the Limulus amoebocyte lysate assay. O-SP had an M(r) of approximately 17,000. DeALPS had two components of M(r)s approximately 30,00 (major and approximately 10,000 (minor). Adipic acid hydrazide derivatives of O-SP and DeALPS were conjugated to tetanus toxoid (TT), purified by gel filtration through CL-6B Sepharose, and designated O-SP-TT and DeALPS-TT, respectively. Saccharide (2.5 micrograms) as O-SP, DeALPS, or their conjugates was injected subcutaneously into 5-week-old mice three times 2 weeks apart. The mice were bled before the second injection and 7 days after the second and third. O-SP alone did not elicit immunoglobulin M (IgM) or IgG LPS antibodies. DeALPS elicited low levels of IgM LPS antibodies after the third injection only. Two of three lots of O-SP-TT induced significant levels of IgM LPS antibodies after the third injection. One O-SP-TT lot elicited IgG LPS antibodies after the second injection, and all three lots elicited significant levels of IgG after the third. DeALPS-TT induced low levels of anti-LPS IgM and IgG only after the third injection. The geometric mean antibody titers of both immunoglobulin classes induced by O-SP-TT were higher than those induced by DeALPS-TT. By these criteria, O-SP provided a more immunogenic saccharide than DeALPS for S. flexneri type 2a conjugates.
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Affiliation(s)
- V Y Polotsky
- Laboratory of Developmental and Molecular Immunity, National Institute of Child Health and Human Development, Bethesda, Maryland 20892
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46
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Altman E, Bundle DR. Polysaccharide affinity columns for purification of lipopolysaccharide-specific murine monoclonal antibodies. Methods Enzymol 1994; 247:243-53. [PMID: 7534862 DOI: 10.1016/s0076-6879(94)47019-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- E Altman
- Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario
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47
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Taylor DN, Trofa AC, Sadoff J, Chu C, Bryla D, Shiloach J, Cohen D, Ashkenazi S, Lerman Y, Egan W. Synthesis, characterization, and clinical evaluation of conjugate vaccines composed of the O-specific polysaccharides of Shigella dysenteriae type 1, Shigella flexneri type 2a, and Shigella sonnei (Plesiomonas shigelloides) bound to bacterial toxoids. Infect Immun 1993; 61:3678-87. [PMID: 8359890 PMCID: PMC281064 DOI: 10.1128/iai.61.9.3678-3687.1993] [Citation(s) in RCA: 125] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The theoretic basis for developing conjugate vaccines, to induce immunoglobulin G (IgG) lipopolysaccharide (LPS) antibodies for the prevention of shigellosis, has been described (J. B. Robbins, C.-Y. Chu, and R. Schneerson, Clin. Infect. Dis. 15:346-361, 1992). The O-specific polysaccharides (O-SPs) of Shigella dysenteriae type 1, S. flexneri type 2a, and S. sonnei were covalently bound to carrier proteins. Alone, the O-SPs were not immunogenic in mice. Conjugates of these O-SPs, injected into young outbred mice subcutaneously as saline solutions containing 2.5 micrograms of saccharide, elicited serum IgG and IgM antibodies with booster responses; adsorption onto alum enhanced their immunogenicity. Injection of 25 micrograms of these conjugates into adult volunteers elicited mild local reactions only. Each conjugate induced a significant rise of the geometric mean serum IgG, IgM, and IgA LPS antibody levels. A second injection 6 weeks later did not elicit booster responses, and adsorption of the conjugates onto alum did not enhance their immunogenicity. Conjugate-induced levels of IgA, but not IgG or IgM, declined to preimmunization levels at day 56. The levels of postimmunization antibodies of the three immunoglobulin classes were similar to or higher than those of recruits in the Israel Defense Force following shigellosis caused by S. flexneri type 2a or S. sonnei. These data provide the basis for evaluating these conjugates to prevent shigellosis.
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Affiliation(s)
- D N Taylor
- Division of Communicable Diseases and Immunology, Walter Reed Army Institute of Research, Washington, D.C. 20307-5100
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48
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Verma NK, Verma DJ, Huan PT, Lindberg AA. Cloning and sequencing of the glucosyl transferase-encoding gene from converting bacteriophage X (SFX) of Shigella flexneri. Gene X 1993; 129:99-101. [PMID: 8335266 DOI: 10.1016/0378-1119(93)90702-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Shigella flexneri type Y strains (-;3,4) are converted to type X (-;7,8) by bacteriophage X (SFX) that causes glucosylation of the O-antigenic polysaccharide chain. The gene (gtr) encoding glucosyl transferase from bacteriophage X has been cloned and sequenced. The protein encoded by gtr consists of 416 amino acids with a M(r) of 47,369. The cloned gtr product was able to convert a S. flexneri strain type Y (SFL 124, a live attenuated candidate vaccine strain) to type X. The importance of the hybrid strain in vaccine development is discussed.
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Affiliation(s)
- N K Verma
- Department of Clinical Bacteriology, Karolinska Institute, Huddinge Hospital, Stockholm, Sweden
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49
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Yao Z, Liu H, Valvano MA. Acetylation of O-specific lipopolysaccharides from Shigella flexneri 3a and 2a occurs in Escherichia coli K-12 carrying cloned S. flexneri 3a and 2a rfb genes. J Bacteriol 1992; 174:7500-8. [PMID: 1280255 PMCID: PMC207459 DOI: 10.1128/jb.174.23.7500-7508.1992] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Most of the Shigella flexneri O-specific serotypes result from O-acetyl and/or glucosyl groups added to a common O-repeating unit of the lipopolysaccharide (LPS) molecule. The genes involved in acetylation and/or glucosylation of S. flexneri LPS are physically located on lysogenic bacteriophages, whereas the rfb cluster contains the biosynthesis genes for the common O-repeating unit (D.A.R. Simmons and E. Romanowska, J. Med. Microbiol. 23:289-302, 1987). Using a cosmid cloning strategy, we have cloned the rfb regions from S. flexneri 3a and 2a. Escherichia coli K-12 containing plasmids pYS1-5 (derived from S. flexneri 3a) and pEY5 (derived from S. flexneri 2a) expressed O-specific LPS which reacted immunologically with S. flexneri polyvalent O antiserum. However, O-specific LPS expressed in E. coli K-12 also reacted with group 6 antiserum, indicating the presence of O-acetyl groups attached to one of the rhamnose components of the O-repeating unit. This was confirmed by measuring the amounts of acetate released from purified LPS samples and also by the chemical removal of O-acetyl groups, which abolished group 6 reactivity. The O-acetylation phenotype was absent in an E. coli strain with an sbcB-his-rfb chromosomal deletion and could be restored upon conjugation of F' 129, which carries sequences corresponding to a portion of the deleted region. Our data demonstrate that E. coli K-12 strains possess a novel locus which directs the O acetylation of LPS and is located in the sbcB-rfb region of the chromosomal map.
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Affiliation(s)
- Z Yao
- Department of Molecular Microbiology, Chinese Academy of Preventive Medicine, Beijing
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50
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Gupta DS, Shashkov AS, Jann B, Jann K. Structures of the O1B and O1C lipopolysaccharide antigens of Escherichia coli. J Bacteriol 1992; 174:7963-70. [PMID: 1281148 PMCID: PMC207532 DOI: 10.1128/jb.174.24.7963-7970.1992] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The O-specific moieties of the O1B antigen (lipopolysaccharide) from Escherichia coli O1B:K1 and the O1C antigen from E. coli O1C:K- both consist of L-rhamnose, D-galactose, N-acetyl-D-glucosamine, and N-acetyl-D-mannosamine in a molar ratio of 2:1:1:1. By using fragmentation procedures, methylation analysis, and one- and two-dimensional nuclear magnetic resonance spectroscopy, the structures of these polysaccharides were found to be [formula: see text] In the O1B polysaccharide X is 2, and in the O1C polysaccharide X is 3. With the recently published structure of the O1A polysaccharides (B. Jann, A. S. Shashkov, D. S. Gupta, S. M. Panasenko, and K. Jann, Carbohydr. Polym. 18:51-57 1992), three related O1 antigens are now known. Their common (O1-specific) epitope is suggested to be the side-chain N-acetyl-D-mannosamine residue.
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Affiliation(s)
- D S Gupta
- Max-Planck-Institut für Immunobiologie, Freiburg, Germany
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