18 results on '"Chantelle M. Cairns"'
Search Results
2. Cross-reactivity of Haemophilus influenzae type a and b polysaccharides: molecular modeling and conjugate immunogenicity studies
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Neil Ravenscroft, Andrew D. Cox, Chantelle M. Cairns, Michelle M. Kuttel, Frank St. Michael, and Nicole Inge Richardson
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conformation ,Serotype ,biology ,molecular modeling ,Immunogenicity ,Haemophilus influenzae type a ,Cell Biology ,immunogenicity ,medicine.disease_cause ,Biochemistry ,Cross-reactivity ,capsular polysaccharide ,Haemophilus influenzae ,Microbiology ,cross protection ,Antigen ,Conjugate vaccine ,medicine ,biology.protein ,Antibody ,Molecular Biology ,Conjugate - Abstract
Haemophilus influenzae is a leading cause of meningitis disease and mortality, particularly in young children. Since the introduction of a licensed conjugate vaccine (targeting the outer capsular polysaccharide) against the most prevalent serotype, Haemophilus influenzae serotype b, the epidemiology of the disease has changed and Haemophilus influenzae serotype a is on the rise, especially in Indigenous North American populations. Here we apply molecular modeling to explore the preferred conformations of the serotype a and b capsular polysaccharides as well as a modified hydrolysis resistant serotype b polysaccharide. Although both serotype b and the modified serotype b have similar random coil behavior, our simulations reveal some differences in the polysaccharide conformations and surfaces which may impact antibody cross-reactivity between these two antigens. Importantly, we find significant conformational differences between the serotype a and b polysaccharides, indicating a potential lack of cross-reactivity that is corroborated by immunological data showing little recognition or killing between heterologous serotypes. These findings support the current development of a serotype a conjugate vaccine.
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- 2021
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3. Structural Characterization and Evaluation of an Epitope at the Tip of the A-Band Rhamnan Polysaccharide of
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Chantelle M, Cairns, Frank St, Michael, Mohammad, Jamshidi, Henk, van Faassen, Qingling, Yang, Kevin A, Henry, Greg, Hussack, Janelle, Sauvageau, Evgeny V, Vinogradov, and Andrew D, Cox
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Mannans ,Epitopes ,Mice ,Polysaccharides ,Deoxy Sugars ,Pseudomonas aeruginosa ,Animals ,Antibodies, Monoclonal ,Rabbits ,Trisaccharides - Published
- 2022
4. Structural analysis of the lipopolysaccharide O-antigen from Fusobacterium nucleatum strain CC 7/3 JVN3 C1 and development of a mouse monoclonal antibody specific to the O-antigen
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Evgeny Vinogradov, Chantelle M. Cairns, Frank St. Michael, Andrew D. Cox, and Perry Fleming
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Serotype ,Lipopolysaccharide ,Colorectal cancer ,medicine.drug_class ,Immunology ,Monoclonal antibody ,01 natural sciences ,Applied Microbiology and Biotechnology ,Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,Mouse monoclonal antibody ,Antigen ,Genetics ,medicine ,Molecular Biology ,030304 developmental biology ,0303 health sciences ,biology ,Strain (chemistry) ,010405 organic chemistry ,General Medicine ,biology.organism_classification ,medicine.disease ,0104 chemical sciences ,chemistry ,Fusobacterium nucleatum - Abstract
Fusobacterium nucleatum is becoming increasingly recognised as an emerging pathogen, gaining attention as a potential factor for exacerbating colorectal cancer and is strongly linked with pregnancy complications including pre-term and still births. Little is known about the virulence factors of this organism; thus, we have initiated studies to examine the bacterium’s surface glycochemistry. In an effort to characterise the surface carbohydrates of F. nucleatum, the aims of this study were to investigate the structure of the lipopolysaccharide (LPS) O-antigen of the cancer-associated isolate F. nucleatum strain CC 7/3 JVN3 C1 (hereafter C1) and to develop monoclonal antibodies (mAbs) to the LPS O-antigen that may be beneficial to the growing field of F. nucleatum research. In this study, we combined several technologies, including nuclear magnetic resonance (NMR) spectroscopy, to elucidate the structure of the LPS O-antigen repeat unit as -[-4-β-Gal-3-α-FucNAc4N-4-α-NeuNAc-]-. We have previously identified this structure as the LPS O-antigen repeat unit from strain 10953. In this present study, we developed a mAb to the C1 LPS O-antigen and confirmed the mAbs cross-reactivity to the 10953 strain, thus confirming the structural identity.
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- 2020
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5. The capsular polysaccharides of Pasteurella multocida serotypes B and E: Structural, genetic and serological comparisons
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Evgeny Vinogradov, John D. Boyce, Chantelle M. Cairns, Perry Fleming, Frank St. Michael, Andrew D. Cox, and Marina Harper
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Serotype ,Pasteurella multocida ,040301 veterinary sciences ,Glycoconjugate ,Polysaccharide ,Biochemistry ,Serology ,Microbiology ,0403 veterinary science ,03 medical and health sciences ,0302 clinical medicine ,capsular polysaccharides ,Polysaccharides ,Carbohydrate Conformation ,structure ,Repeat unit ,chemistry.chemical_classification ,biology ,Organic solvent ,04 agricultural and veterinary sciences ,biology.organism_classification ,serotyping ,NMR ,chemistry ,Polyclonal antibodies ,biology.protein ,030215 immunology - Abstract
We describe the structural characterization of the capsular polysaccharides (CPSs) of Pasteurella multocida serotypes B and E. CPS was isolated following organic solvent precipitation of the supernatant from flask grown cells. Structural analysis utilizing nuclear magnetic resonance spectroscopy enabled the determination of the CPS structures and revealed significant structural similarities between the two serotypes, but also provided an explanation for the serological distinction. This observation was extended by the development of polyclonal sera to the glycoconjugate of serotype B CPS that corroborated the structural likenesses and differences. Finally, identification of these structures enabled a more comprehensive interrogation of the genetic loci and prediction of roles for some of the encoded proteins in repeat unit biosynthesis.
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- 2020
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6. Development and Characterization of Mouse Monoclonal Antibodies Specific for Clostridiodes (Clostridium) difficile Lipoteichoic Acid
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Nicolas Gisch, Martin A Rossotti, Wouter F. J. Hogendorf, Susan M. Logan, Henk van Faassen, Chantelle M. Cairns, Kevin A. Henry, Annie Aubry, Greg Hussack, Andrew D. Cox, Frank St. Michael, and Christian Pedersen
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0301 basic medicine ,biology ,010405 organic chemistry ,Chemistry ,medicine.drug_class ,General Medicine ,Pseudomembranous colitis ,Clostridium difficile ,Monoclonal antibody ,01 natural sciences ,Biochemistry ,Epitope ,0104 chemical sciences ,Microbiology ,03 medical and health sciences ,030104 developmental biology ,Antigen ,biology.protein ,medicine ,Molecular Medicine ,Lipoteichoic acid ,Antibody ,Antitoxin - Abstract
Clostridiodes (Clostridium) difficile is an anaerobic Gram-positive, spore-forming nosocomial, gastrointestinal pathogen causing C. difficile-associated disease with symptoms ranging from mild cases of antibiotic-associated diarrhea to fatal pseudomembranous colitis. We developed murine monoclonal antibodies (mAbs) specific for a conserved cell surface antigen, lipoteichoic acid (LTA)of C. difficile. The mAbs were characterized in terms of their thermal stability, solubility, and their binding to LTA by surface plasmon resonance and competitive ELISA. Synthetic LTA molecules were prepared in order to better define the minimum epitope required to mimic the natural antigen, and three repeat units of the polymer were required for optimal recognition. One of the murine mAbs was chimerized with human constant region domains and was found to recognize the target antigen identically to the mouse version. These mAbs may be useful as therapeutics (standalone, in conjunction with known antitoxin approaches, or as delivery vehicles for antibody drug conjugates targeting the bacterium), as diagnostic agents, and in infection control applications.
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- 2020
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7. Structural analysis of the lipopolysaccharide O-antigen from
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Chantelle M, Cairns, Frank, St Michael, Perry, Fleming, Evgeny V, Vinogradov, and Andrew D, Cox
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Antigens, Bacterial ,Mice ,Mice, Inbred BALB C ,Magnetic Resonance Spectroscopy ,Fusobacterium nucleatum ,Virulence Factors ,Animals ,Antibodies, Monoclonal ,O Antigens ,Enzyme-Linked Immunosorbent Assay ,Cross Reactions ,Serotyping ,Antibodies, Bacterial - Published
- 2020
8. Development and Characterization of Mouse Monoclonal Antibodies Specific for
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Chantelle M, Cairns, Henk, van Faassen, Frank, St Michael, Annie, Aubry, Kevin A, Henry, Martin A, Rossotti, Susan M, Logan, Greg, Hussack, Nicolas, Gisch, Wouter F J, Hogendorf, Christian M, Pedersen, and Andrew D, Cox
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Lipopolysaccharides ,Teichoic Acids ,Antibodies, Monoclonal, Murine-Derived ,Mice ,Clostridioides difficile ,Protein Stability ,Animals ,Humans ,Amino Acid Sequence - Published
- 2020
9. Maintenance of balanced traction care chart to minimize complications of femoral fracture in children
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Chantelle M. Cairns, Mazhar Iqbal, F. St. Michael, Mahbubur Rahman, M. Salman, A CHayes, Ahmadian Ali, A. Haque, Andrew Cox, and Abdul Jabbar
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chemistry.chemical_classification ,Salmonella ,Salmonella typhi O ,Chemistry ,medicine ,medicine.disease_cause ,Polysaccharide ,Microbiology ,Conjugate - Published
- 2018
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10. Investigating the candidacy of the serotype specific rhamnan polysaccharide based glycoconjugates to prevent disease caused by the dental pathogen Streptococcus mutans
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Annie Aubry, Alexander C. Hayes, Andrew D. Cox, Chantelle M. Cairns, Frank St. Michael, Evgeny Vinogradov, Perry Fleming, and Qingling Yang
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0301 basic medicine ,Serotype ,Glycoconjugate ,Heterologous ,rhamnan ,Serogroup ,Biochemistry ,Microbiology ,Mannans ,Streptococcus mutans ,Mice ,03 medical and health sciences ,Immune system ,Conjugate vaccine ,Cell Line, Tumor ,Deoxy Sugars ,Animals ,Humans ,Molecular Biology ,Pathogen ,chemistry.chemical_classification ,Mice, Inbred BALB C ,Vaccines, Conjugate ,serotype polysaccharide ,biology ,Cell Biology ,biology.organism_classification ,Virology ,030104 developmental biology ,chemistry ,conjugate vaccine ,Female ,Rabbits ,Glycoconjugates ,Bacteria - Abstract
Dental caries remains a major health issue and the Gram-positive bacterium Streptococcus mutans is considered as the major pathogen causing caries. More recently, S. mutans has been recognised as a cause of endocarditis, ulcerative colitis and fatty acid liver disease along with the likelihood of increased cerebral hemorrhage following a stroke if S. mutans is present systemically. We initiated this study to examine the vaccine candidacy of the serotype specific polysaccharides elaborated by S. mutans. We have confirmed the carbohydrate structures for the serotype specific rhamnan containing polysaccharides from serotypes c, f and k. We have prepared glycoconjugate vaccines using the rhamnan containing polymers from serotypes f and k and immunised mice and rabbits. We consistently obtained a robust immune response to the glycoconjugates with cross-reactivity consistent with the structural similarities of the polymers from the different serotypes. We developed an opsonophagocytic assay which illustrated the ability of the post-immune sera to facilitate opsonophagocytic killing of the homologous and heterologous serotypes at titers consistent with the structural homologies. We conclude that glycoconjugates of the rhamnan polymers of S. mutans are a potential vaccine candidate to target dental caries and other sequelae following the escape of S. mutans from the oral cavity.
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- 2017
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11. Investigating the candidacy of a capsular polysaccharide-based glycoconjugate as a vaccine to combat Haemophilus influenzae type a disease: A solution for an unmet public health need
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Andrew D. Cox, Chantelle M. Cairns, Wei Zou, Mélanie Arbour, Evgeny Vinogradov, Luke Masson, Perry Fleming, Frank St. Michael, and Dean Williams
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0301 basic medicine ,Bacterial capsule ,Serotype ,Canada ,Haemophilus Infections ,Glycoconjugate ,Disease ,Biology ,medicine.disease_cause ,Haemophilus influenzae serotype a ,Microbiology ,Haemophilus influenzae ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Conjugate vaccine ,medicine ,Animals ,Humans ,030212 general & internal medicine ,Serotyping ,Pathogen ,Bacterial Capsules ,Haemophilus Vaccines ,chemistry.chemical_classification ,Mice, Inbred BALB C ,General Veterinary ,General Immunology and Microbiology ,Polysaccharides, Bacterial ,Vaccination ,Public Health, Environmental and Occupational Health ,Virology ,capsular polysaccharide ,030104 developmental biology ,Infectious Diseases ,chemistry ,conjugate vaccine ,Molecular Medicine ,Female ,Public Health ,Rabbits ,Glycoconjugates ,Alaska - Abstract
After the introduction of the glycoconjugate vaccine based upon the capsular polysaccharide of Haemophilus influenzae type b in the mid 1980s there was a remarkable decrease in the number of invasive cases reported for this organism. Since the 1990s several groups have observed the emergence of Haemophilus influenzae type a (Hia), especially in indigenous communities in the northern regions of Canada and Alaska, to a stage where a solution is warranted to prevent further unnecessary deaths due to this pathogen. A glycoconjugate vaccine solution based upon the type a capsular polysaccharide (CPS) was investigated pre-clinically in an effort to illustrate the proof of concept for this approach. In this study we describe the growth of Hia and the isolation, purification and conjugation of the CPS to several carrier proteins. The resulting glycoconjugates were immunised in mice and rabbits provoking sera that facilitated bactericidal killing against all type a strains that we tested. This study has illustrated the pre-clinical proof of concept of a glycoconjugate vaccine based on the CPS of Hia as a solution to this emerging disease.
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- 2017
12. First characterization of immunogenic conjugates of Vi negative Salmonella Typhi O-specific polysaccharides with rEPA protein for vaccine development
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Ahmadian Ali, F. St. Michael, Alexander C. Hayes, Mahbubur Rahman, Chantelle M. Cairns, M. Salman, Abdul Jabbar, Andrew D. Cox, A. Haque, and Mazhar Iqbal
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0301 basic medicine ,Salmonella ,Glycoconjugate ,Proton Magnetic Resonance Spectroscopy ,rEPA ,medicine.disease_cause ,Salmonella typhi ,chemistry.chemical_compound ,0302 clinical medicine ,Typhoid ,Immunology and Allergy ,030212 general & internal medicine ,Amination ,chemistry.chemical_classification ,ADP Ribose Transferases ,Mice, Inbred BALB C ,biology ,Immunogenicity ,Polysaccharides, Bacterial ,Antibody titer ,O Antigens ,Antibodies, Bacterial ,Recombinant Proteins ,OSP antigen ,Electrophoresis, Polyacrylamide Gel ,Female ,Antibody ,Oxidation-Reduction ,Injections, Intraperitoneal ,Virulence Factors ,030106 microbiology ,Immunology ,Bacterial Toxins ,Blotting, Western ,Exotoxins ,Serum Albumin, Human ,Microbiology ,03 medical and health sciences ,medicine ,Animals ,Immunization Schedule ,Serum Albumin ,Vaccines, Conjugate ,Salmonella Typhi Vi negative ,Typhoid-Paratyphoid Vaccines ,Conjugate vaccines ,chemistry ,biology.protein ,Immunization ,Adipic acid dihydrazide ,Conjugate - Abstract
Efficacious typhoid vaccines for young children will significantly reduce the disease burden in developing world. The Vi polysaccharide based conjugate vaccines (Vi-rEPA) against Salmonella Typhi Vi positive strains has shown high efficacy but may be ineffective against Vi negative S. Typhi. In this study, for the first time, we report the synthesis and evaluation of polysaccharide-protein conjugates of Vi negative S. Typhi as potential vaccine candidates. Four different conjugates were synthesized using recombinant exoprotein A of Pseudomonas aeruginosa (rEPA) and human serum albumin (HSA) as the carrier proteins, using either direct reductive amination or an intermediate linker molecule, adipic acid dihydrazide (ADH). Upon injection into mice, a significantly higher antibody titer was observed in mice administrated with conjugate-1 (OSP-HSA) (P = 0.0001) and conjugate 2 (OSP-rEPA) (P ≤ 0.0001) as compared to OSP alone. In contrast, the antibody titer elicited by conjugate 3 (OSPADH-HSA) and conjugate 4 (OSPADH-rEPA) were insignificant (P = 0.1684 and P = 0.3794, respectively). We conclude that reductive amination is the superior method to prepare the S. Typhi OSP glycoconjugate. Moreover, rEPA was a better carrier protein than HSA. Thus OSP-rEPA conjugate seems to be efficacious typhoid vaccines candidate, it may be evaluated further and recommended for the clinical trials.
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- 2017
13. Investigating the candidacy of a lipoteichoic acid-based glycoconjugate as a vaccine to combat Clostridium difficile infection
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Philippa C. R. Strong, Alexander C. Hayes, Susan M. Logan, Chantelle M. Cairns, Andrew D. Cox, Frank St. Michael, and Annie Aubry
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Lipopolysaccharides ,Glycoconjugate ,Biochemistry ,Microbiology ,Mice ,Immune system ,Antigen ,Conjugate vaccine ,Animals ,Molecular Biology ,Antiserum ,chemistry.chemical_classification ,Vaccines, Conjugate ,biology ,Clostridioides difficile ,Cell Biology ,Clostridium difficile ,Antibodies, Bacterial ,Teichoic Acids ,chemistry ,Bacterial Vaccines ,biology.protein ,Immunization ,Rabbits ,Lipoteichoic acid ,Antibody - Abstract
A lipoteichoic acid has recently been shown to be conserved in the majority of strains from Clostridium difficile and as such is being considered as a possible vaccine antigen. In this study we examine the candidacy of the conserved lipoteichoic acid by demonstrating that it is possible to elicit antibodies against C. difficile strains following immunisation of rabbits and mice with glycoconjugates elaborating the conserved lipoteichoic acid antigen. The present study describes a conjugation strategy that utilises an amino functionality, present at approximately 33 % substitution of the N-acetyl-glucosamine residues within the LTA polymer repeating unit, as the attachment point for conjugation. A maleimide-thiol linker strategy with the maleimide linker on the carboxyl residues of the carrier protein and the thiol linker on the carbohydrate was employed. Immunisation derived antisera from rabbits and mice, recognised all strains of C. difficile vegetative cells examined, despite an immune response to the linkers also being observed. These sera recognised live cells in an immunofluorescence assay and were also able to recognise the spore form of the bacterium. This study has illustrated that the LTA polymer is a highly conserved surface polymer of C. difficile that is easily accessible to the immune system and as such merits consideration as a vaccine antigen to combat C. difficile infection. © 2013 Her Majesty the Queen in Right of Canada.
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- 2013
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14. Investigating the candidacy of LPS-based glycoconjugates to prevent invasive meningococcal disease: immunology of glycoconjugates with high carbohydrate loading
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Frank St. Michael, Suzanne Lacelle, Alessia Biolchi, J. Claire Hoe, Andrew D. Cox, E. Richard Moxon, Chantelle M. Cairns, Marzia Monica Giuliani, Dhamodharan Neelamegan, and James C. Richards
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Lipopolysaccharides ,LPS ,Lipopolysaccharide ,Glycoconjugate ,Meningococcal Vaccines ,Neisseria meningitidis ,medicine.disease_cause ,Biochemistry ,Epitope ,Microbiology ,chemistry.chemical_compound ,Immune system ,Conjugate vaccine ,Antigen ,medicine ,Animals ,Molecular Biology ,chemistry.chemical_classification ,biology ,Immune Sera ,Antibody titer ,Cell Biology ,Antibodies, Bacterial ,Meningococcal Infections ,chemistry ,Immunology ,biology.protein ,Rabbits ,Antibody ,Glycoconjugates - Abstract
We investigated the immune responses of rabbits that were immunised with lipopolysaccharide (LPS)-based glycoconjugates by measuring the reactivity of the derived sera to a panel of selected wild-type and mutant strains of Neisseria meningitidis. In all cases, high titers of antibodies capable of recognising LPS elaborating the identical structure as presented on the immunising glycoconjugate were obtained, and in most cases the derived sera also recognised heterologous strains including wild-type, but at lower titers. However, although serum bactericidal antibodies were consistently obtained against strains elaborating the same LPS structure as the immunising antigen, this functional response was not observed against wild-type strains. We identified several potentially competing neo-epitopes that had been introduced via our conjugation strategies, which might compete with the conserved inner core oligosaccharide target region, thus reducing the antibody titers to epitopes which could facilitate bactericidal killing. This study has therefore identified key factors that are crucial to control in order to increase the likelihood of obtaining bactericidal antibodies to wild-type meningococcal cells with LPS-derived glycoconjugates. Glycoconjugates utilised in this study, have been found to contain epitopes that do not contribute to the derivation of antibodies that may facilitate bactericidal killing of wild-type strains and must be avoided in future LPS-based glycoconjugate preparations.
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- 2010
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15. Investigating the candidacy of LPS-based glycoconjugates to prevent invasive meningococcal disease: conjugates based on core oligosaccharides
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James C. Richards, F. St. Michael, Amy Lea Filion, Andrew D. Cox, Brunella Brunelli, Chantelle M. Cairns, Alessia Biolchi, and Marzia Monica Giuliani
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Lipopolysaccharides ,Lipopolysaccharide ,Glycoconjugate ,Oligosaccharides ,Biology ,Neisseria meningitidis ,Biochemistry ,Epitope ,Microbiology ,Lipid A ,chemistry.chemical_compound ,Epitopes ,Immune system ,Antigen ,Conjugate vaccine ,Animals ,Molecular Biology ,chemistry.chemical_classification ,Vaccines, Conjugate ,Cell Biology ,Meningococcal Infections ,chemistry ,Bacterial Vaccines ,Rabbits ,Linker - Abstract
In this study we have prepared glycoconjugates with core oligosaccharides (OS) from the lipopolysaccharide (LPS) of Neisseria meningitidis, thus avoiding the neo-epitopes of the deacylated lipid A region of the derived LPS molecule identified in our previous studies. A comprehensive investigation was performed with glycoconjugates prepared from the most extended to the most truncated core OS still maintaining the conserved inner core epitope. As previously, we have established reproducible bactericidal killing of the homologous antigen elaborating strain, but a failure to kill wild-type strains. In these studies it was evident that the linker molecules used in the conjugation methodologies were dominating the immune response. However, when galE core OS based conjugates were prepared without utilizing linkers, via direct reductive amination, we failed to generate an immune response to even the homologous antigen. We also identified that immunisation with the galE antigen via linker methodologies provoked an immune response that was dependent upon key residues of the conserved inner core OS structure, whereas the immune responses to lgtB and lgtA antigens did not involve the inner core OS. This comprehensive study has, despite our best efforts, cast significant doubt as to the utility of the conserved inner core region of the meningococcal LPS as a potential vaccine antigen. © 2013 Her Majesty the Queen in Right of Canada.
- Published
- 2013
16. Investigating the candidacy of lipopolysaccharide-based glycoconjugates as vaccines to combat Mannheimia haemolytica
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Amy Lea Filion, Frank St. Michael, Suzanne Lacelle, Chantelle M. Cairns, Dhamodharan Neelamegan, and Andrew D. Cox
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Lipopolysaccharides ,LPS ,Lipopolysaccharide ,Glycoconjugate ,Blotting, Western ,Enzyme-Linked Immunosorbent Assay ,Biochemistry ,Microbiology ,chemistry.chemical_compound ,Mice ,Antigen ,Conjugate vaccine ,Amidase activity ,Animals ,Molecular Biology ,Actinobacillus pleuropneumoniae ,Mannheimia haemolytica ,Antiserum ,chemistry.chemical_classification ,Vaccines ,biology ,Cell Biology ,biology.organism_classification ,Virology ,chemistry ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Bacterial Vaccines ,biology.protein ,Electrophoresis, Polyacrylamide Gel ,Rabbits ,Antibody ,Pasteurellaceae Infections ,Glycoconjugates - Abstract
Inner core lipopolysaccharide (LPS) has been shown to be conserved in the majority of veterinary strains from the species Mannheimia haemolytica, Actinobacillus pleuropneumoniae and Pasteurella multocida and as such is being considered as a possible vaccine antigen. The proof-in-principle that a LPS-based antigen could be considered as a vaccine candidate has been demonstrated from studies with monoclonal antibodies raised to the inner core LPS of Mannheimia haemolytica, which were shown to be both bactericidal and protective in a mouse model of disease. In this study we confirm and extend the candidacy of the inner core LPS by demonstrating that it is possible to elicit functional antibodies against Mannheimia haemolytica wild-type strains following immunisation of rabbits with glycoconjugates elaborating the conserved inner core LPS antigen. The present study describes a conjugation strategy that uses amidases produced by Dictyostelium discoideum, targeting the amino functionality created by the amidase activity as the attachment point on the LPS molecule. To protect the amino functionality on the phosphoethanolamine (PEtn) residue of the inner core, we developed a novel blocking and unblocking strategy with t-butyl oxycarbonyl. A maleimide-thiol linker strategy with the thiol linker on the carboxyl residues of the carrier protein and the maleimide linker on the carbohydrate resulted in a high loading of carbohydrates per carrier protein. Immunisation derived antisera from rabbits recognised fully extended Mannheimia haemolytica LPS and whole cells from serotypes 1 and 2, despite a somewhat immunodominant response to the linkers also being observed. Moreover, bactericidal activity was demonstrated to a strain elaborating the immunising carbohydrate antigen and crucially to wild-type cells of serotypes 1 and 2, thus further supporting the consideration of inner core LPS as a potential vaccine antigen to combat disease caused by Mannheimia haemolytica.
- Published
- 2011
17. Investigating the potential of conserved inner core oligosaccharide regions of Moraxella catarrhalis lipopolysaccharide as vaccine antigens: accessibility and functional activity of monoclonal antibodies and glycoconjugate derived sera
- Author
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Suzanne Lacelle, Andrew D. Cox, Amy Lea Filion, Chantelle M. Cairns, James C. Richards, Dhamodharan Neelamegan, Heather Horan, Cory Q. Wenzel, and Frank St. Michael
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Monoclonal antibody ,Lipopolysaccharides ,LPS ,medicine.drug_class ,Glycoconjugate ,Mutant ,Molecular Sequence Data ,Oligosaccharides ,Biology ,Biochemistry ,Epitope ,Microbiology ,Lipid A ,Moraxella catarrhalis ,Mice ,Conjugate vaccine ,Antigen ,Amidase activity ,medicine ,Animals ,Molecular Biology ,chemistry.chemical_classification ,Antigens, Bacterial ,Antibodies, Monoclonal ,Cell Biology ,Core oligosaccharide ,biology.organism_classification ,Antibodies, Bacterial ,chemistry ,Carbohydrate Sequence ,Bacterial Vaccines ,Rabbits ,Glycoconjugates - Abstract
We investigated the conservation and antibody accessibility of inner core epitopes of Moraxella catarrhalis lipopolysaccharide (LPS) in order to assess their potential as vaccine candidates. Two LPS mutants, a single mutant designated lgt2 and a double mutant termed lgt2/lgt4, elaborating truncated inner core structures were generated in order to preclude expression of host-like outer core structures and to create an inner core structure that was shared by all three serotypes A, B and C of M. catarrhalis. Murine monoclonal antibodies (mAbs), designated MC2-1 and MC2-10 were obtained by immunising mice with the lgt2 mutant of M. catarrhalis serotype A strain. We showed that mAb MC2-1 can bind to the core LPS of wild-type (wt) serotype A, B and C organisms and concluded that mAb MC2-1 defines an immunogenic inner core epitope of M. catarrhalis LPS. We were unsuccessful in obtaining mAbs to the lgt2/lgt4 mutant. MAb MC2-10 only recognised the lgt2 mutant and the wt serotype A strain, and exhibited a strong requirement for the terminal N-acetyl-glucosamine residue of the lgt2 mutant core oligosaccharide, suggesting that this residue was immunodominant. Subsequently, we showed that both mAbs MC2-1 and MC2-10 could facilitate bactericidal killing of the lgt2 mutant, however neither mAb could facilitate bactericidal killing of the wt serotype A strain. We then confirmed and extended the candidacy of the inner core LPS by demonstrating that it is possible to elicit functional antibodies against M. catarrhalis wt strains following immunisation of rabbits with glycoconjugates elaborating the conserved inner core LPS antigen. The present study describes three conjugation strategies that either uses amidases produced by Dictyostelium discoideum, targeting the amino functionality created by the amidase activity as the attachment point on the LPS molecule, or a strong base treatment to remove all fatty acids from the LPS, thus creating amino functionalities in the lipid A region to conjugate via maleimide-thiol linker strategies targeting the carboxyl residues of the carrier protein and the free amino functionalities of the derived lipid A region of the carbohydrate resulted in a high loading of carbohydrates per carrier protein from these carbohydrate preparations. Immunisation derived antisera from rabbits recognised fully extended M. catarrhalis LPS and whole cells. Moreover, bactericidal activity was demonstrated to both the immunising carbohydrate antigen and importantly to wt cells, thus further supporting the consideration of inner core LPS as a potential vaccine antigen to combat disease caused by M. catarrhalis.
- Published
- 2011
18. Lymphotactin expression by engineered myeloma cells drives tumor regression: mediation by CD4+ and CD8+ T cells and neutrophils expressing XCR1 receptor
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Chantelle M. Cairns, Terence Moyana, Maria E. Baca-Estrada, John R. Gordon, Fang Li, and Jim Xiang
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CD4-Positive T-Lymphocytes ,Graft Rejection ,XCR1 ,Chemokine ,Neutrophils ,T cell ,Injections, Subcutaneous ,Sialoglycoproteins ,Immunology ,Mice, Nude ,Receptors, Cell Surface ,Biology ,CD8-Positive T-Lymphocytes ,Protein Engineering ,Cancer Vaccines ,Receptors, G-Protein-Coupled ,Mice ,medicine ,Tumor Cells, Cultured ,Immunology and Allergy ,Cytotoxic T cell ,Animals ,Lymphokines ,Mice, Inbred BALB C ,Cell growth ,Membrane Proteins ,Transfection ,Molecular biology ,In vitro ,Chemokines, C ,Chemotaxis, Leukocyte ,medicine.anatomical_structure ,biology.protein ,Female ,Multiple Myeloma ,CD8 ,Neoplasm Transplantation - Abstract
The C chemokine lymphotactin has been characterized as a T cell chemoattractant both in vitro and in vivo. To determine whether lymphotactin expression within tumors could influence tumor growth, we transfected an expression vector for lymphotactin into SP2/0 myeloma cells and tested their ability to form tumors in BALB/c and nude mice. Transfection did not alter cell growth in vitro. Whereas SP2/0 cells gave rise to a 100% tumor incidence, lymphotactin-expressing SP2/0-Lptn tumors invariably regressed in BALB/c mice and became infiltrated with CD4+ and CD8+ T cells and neutrophils. Regression of the SP2/0-Lptn tumors was associated with a type 1 cytokine response and dependent on both CD4+ and CD8+ T cells, but not NK cells. Both SP2/0 and SP2/0-Lptn tumors grew in nude mice, but growth of the latter tumors was retarded and associated with heavy neutrophil responses; this retardation of SP2/0-Lptn tumor growth was reversed by neutrophil depletion of the mice. Our data also indicate that mouse neutrophils express the lymphotactin receptor XCR1 and that lymphotactin specifically chemoattracts these cells in vitro. Thus, lymphotactin has natural adjuvant activities that may augment antitumor responses via effects on both T cells and neutrophils and thereby could be important in gene transfer immunotherapies for some cancers.
- Published
- 2001
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