title: A Synthetic Carbohydrate Conjugate Vaccine Candidate against Shigellosis: Improved Bioconjugation and Impact of Alum on Immunogenicity.
abstract: Conjugation chemistry is among the most important parameters governing the efficacy of glycoconjugate vaccines. High robustness is required to ensure high yields and batch to batch reproducibility. Herein, we have established a robust bioconjugation protocol based on the thiol-maleimide addition. Major variables were determined and acceptable margins were investigated for a synthetic pentadecasaccharide-tetanus toxoid conjugate, which is a promising vaccine candidate against Shigella flexneri serotype 2a infection. The optimized process is applicable to any thiol-equipped hapten and provides an efficient control of the hapten:carrier ratio. Moreover, comparison of four S. flexneri 2a glycoconjugates only differing by their pentadecasaccharide:tetanus toxoid ratio confirmed preliminary findings indicating that hapten loading is critical for immunogenicity with an optimal ratio here in the range of 17 ± 5. In addition, the powerful influence of alum on the immunogenicity of a Shigella synthetic carbohydrate-based conjugate vaccine candidate is demonstrated for the first time, with a strong anti-S. flexneri 2a antibody response sustained for more than one year.
authors.affiliation: Institute for Translational Vaccinology (Intravacc) , P.O. Box 450, 3720 AL Bilthoven, The Netherlands.
authors.forename: Robert M F
authors.initials: RM
authors.lastname: van der Put
authors.affiliation: Unité de Chimie des Biomolécules, Institut Pasteur , 28 rue du Dr Roux, 75 724 Paris Cedex 15, France.|CNRS UMR 3523, Institut Pasteur , F-75015 Paris, France.
authors.forename: Tae Hee
authors.initials: TH
authors.lastname: Kim
authors.affiliation: Unité de Chimie des Biomolécules, Institut Pasteur , 28 rue du Dr Roux, 75 724 Paris Cedex 15, France.|CNRS UMR 3523, Institut Pasteur , F-75015 Paris, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Guerreiro
authors.affiliation: Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur , 28 rue du Dr Roux, 75 724 Paris Cedex 15, France.|INSERM U1202, Institut Pasteur , F75015 Paris, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Thouron
authors.affiliation: Institute for Translational Vaccinology (Intravacc) , P.O. Box 450, 3720 AL Bilthoven, The Netherlands.
authors.forename: Peter
authors.initials: P
authors.lastname: Hoogerhout
authors.affiliation: Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur , 28 rue du Dr Roux, 75 724 Paris Cedex 15, France.|INSERM U1202, Institut Pasteur , F75015 Paris, France.
authors.forename: Philippe J
authors.initials: PJ
authors.lastname: Sansonetti
authors.affiliation: Institute for Translational Vaccinology (Intravacc) , P.O. Box 450, 3720 AL Bilthoven, The Netherlands.
authors.forename: Janny
authors.initials: J
authors.lastname: Westdijk
authors.affiliation: Institute for Translational Vaccinology (Intravacc) , P.O. Box 450, 3720 AL Bilthoven, The Netherlands.
authors.forename: Michiel
authors.initials: M
authors.lastname: Stork
authors.affiliation: Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur , 28 rue du Dr Roux, 75 724 Paris Cedex 15, France.|INSERM U1202, Institut Pasteur , F75015 Paris, France.
authors.forename: Armelle
authors.initials: A
authors.lastname: Phalipon
authors.affiliation: Unité de Chimie des Biomolécules, Institut Pasteur , 28 rue du Dr Roux, 75 724 Paris Cedex 15, France.|CNRS UMR 3523, Institut Pasteur , F-75015 Paris, France.
authors.forename: Laurence A
authors.initials: LA
authors.lastname: Mulard
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D000534:Alum Compounds / Q000008:administration & dosage*; D002241:Carbohydrates / Q000737:chemistry*; D002850:Chromatography, Gel; D004405:Dysentery, Bacillary / Q000628:therapy*; D009682:Magnetic Resonance Spectroscopy; D015203:Reproducibility of Results; D012760:Shigella / Q000276:immunology; D014614:Vaccines, Synthetic / Q000737:chemistry / Q000276:immunology / Q000627:therapeutic use*
chemical_list: D000276:Adjuvants, Immunologic; D000534:Alum Compounds; D002241:Carbohydrates; D014614:Vaccines, Synthetic; C041524:aluminum sulfate