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  5. Characterization of Bacterial Glycoconjugates and Development of Associated Vaccine Technologies
  1. Biologics Research Projects

Characterization of Bacterial Glycoconjugates and Development of Associated Vaccine Technologies

Principal Investigator: Willie F. Vann, PhD
Office / Division / Lab: OVRR / DBPAP / LBP

General Overview

Disease-causing bacteria coat themselves with a variety of complex chains of sugar molecules called polysaccharides. These polysaccharide coats are essential for the survival of these bacteria in the human blood stream. Since these structures are important for survival of bacteria in the blood stream they are perfect targets the body's defense mechanisms. Scientists have learned that these polysaccharide chains can be made into effective vaccines against disease causing microorganisms.

Our laboratory is studying how bacteria make these polysaccharide coats so we can develop new techniques to make vaccines against bacteria coated with these polysaccharides. Specifically, we are investigating new ways to prepare and analyze vaccines prepared from bacterial polysaccharide coats using molecular biology and biochemical techniques. What we learn from this work will be of great help to us in understanding and evaluating current and future techniques for manufacturing carbohydrate vaccines.

Scientific Overview

Bacterial pathogens are often coated with polysaccharide virulence factors and some pathogens produce toxins that bind to host oligosaccharides using those host molecules as receptors for entry into the cell. These polysaccharides and toxins are excellent targets for preventing and controlling disease. Indeed, both polysaccharides and polysaccharides conjugated to inactivated toxins are the key components of vaccines that are very effective in preventing disease caused by Haemophilus influenzae, Streptococcus pneumonia, and several serogroups (i.e., "variations of") of Neisseria meningitidis.

The goals of this research project are 1) to determine the metabolic pathway for the synthesis of polysaccharides in gram negative pathogens and use this knowledge to develop methods for preparing glycoconjugate vaccines using metabolic engineering; and 2) to improve the manufacture of current conjugate vaccines through the investigation of conjugation chemistry.

While the currently licensed polysaccharide vaccines have been successful, manufacture and control of quality and efficacy of these products present regulatory challenges due to lack of a detailed definition of the immunogens. The novel technology developed and knowledge gained by this work will help to us to better characterize vaccines and predict if alternative vaccines will be effective.

In recent years workers and manufacturers in the vaccine field have begun to employ metabolic engineering technologies to develop vaccines against the carbohydrate structures on pathogens for which no current vaccine exist. Our work in the research program described here will provide us with the necessary expertise to evaluate these new vaccines.


FEBS J 2017 Jun;284(11):1688-99
In vitro generation of polysialylated cervical mucins by bacterial polysialyltransferases to counteract cytotoxicity of extracellular histones.
Galuska SP, Galuska CE, Tharmalingam T, Zlatina K, Prem G, Husejnov FC, Rudd PM, Vann WF, Reid C, Vionnet J, Gallagher ME, Carrington FA, Hassett SL, Carrington SD

Chembiochem 2017 Apr 18;18(8):799-815
Conjugate vaccines from bacterial antigens by squaric acid chemistry: a closer look.
Xu P, Kelly M, Vann WF, Qadri F, Ryan ET, Kovac P

PLoS Negl Trop Dis 2015 Jul 8;9(7):e0003881
A cholera conjugate vaccine containing O-specific polysaccharide (OSP) of V. cholerae O1 inaba and recombinant fragment of tetanus toxin heavy chain (OSP:rTTHc) induces serum, memory and lamina proprial responses against OSP and is protective in mice.
Sayeed MA, Bufano MK, Xu P, Eckhoff G, Charles RC, Alam MM, Sultana T, Rashu MR, Berger A, Gonzalez-Escobedo G, Mandlik A, Bhuiyan TR, Leung DT, LaRocque RC, Harris JB, Calderwood SB, Qadri F, Vann WF, Kovac P, Ryan ET

Glycobiology 2014 Feb;24(2):139-49
Characterization of the meningococcal serogroup X capsule N-acetylglucosamine-1-phosphotransferase.
Muindi KM, McCarthy PC, Wang T, Vionnet J, Battistel M, Jankowska E, Vann WF

PLoS Negl Trop Dis 2014 Feb 6;8(2):e2683
Evaluation in mice of a conjugate vaccine for cholera made from Vibrio cholerae O1 (Ogawa) O-specific polysaccharide.
Alam MM, Bufano MK, Xu P, Kalsy A, Yu Y, Freeman YW, Sultana T, Rashu MR, Desai I, Eckhoff G, Leung DT, Charles RC, Larocque RC, Harris JB, Clements JD, Calderwood SB, Qadri F, Vann WF, Kovac P, Ryan ET

Glycoconj J 2013 Dec;30(9):857-70
Chemoenzymatic synthesis of immunogenic meningococcal group C polysialic acid-tetanus Hc fragment glycoconjugates.
McCarthy PC, Saksena R, Peterson DC, Lee CH, An Y, Cipollo JF, Vann WF

PLoS One 2013 Nov 14;8(11):e79304
The Development of an Experimental Multiple Serogroups Vaccine for Neisseria meningitidis.
Pinto VB, Burden R, Wagner A, Moran EE, Lee CH

J Mass Spectrom 2013 Oct;48(10):1083-90
Mapping the glycation sites in the neoglycoconjugate from hexasaccharide antigen of Vibrio cholerae, serotype Ogawa and the recombinant tetanus toxin C-fragment carrier.
Jahouh F, Xu P, Vann WF, Kovac P, Banoub JH

J Bacteriol 2011 Apr;193(7):1576-82
Characterization and acceptor preference of a soluble meningococcal group C polysialyltransferase.
Peterson DC, Arakere G, Vionnet J, McCarthy P, Vann WF

Glycoconj J 2010 Jan;27(1):69-77
Multimeric bivalent immunogens from recombinant tetanus toxin HC fragment, synthetic hexasaccharides, and a glycopeptide adjuvant.
Bongat AF, Saksena R, Adamo R, Fujimoto Y, Shiokawa Z, Peterson DC, Fukase K, Vann WF, Kovac P

Biocatal Biotransformation 2010 Jan-Feb;28(1):41-50
Chemoenzymatic synthesis of conjugatable oligosialic acids
Mosley SL, Rancy PC, Peterson DC, Vionnet J, Saksena R, Vann WF

Vaccine 2007 Nov 14;25(46):7972-80
Comparison of Neisseria meningitidis serogroup W135 polysaccharide-tetanus toxoid conjugate vaccines made by periodate activation of O-acetylated, non-O-acetylated and chemically de-O-acetylated polysaccharide.
Gudlavalleti SK, Lee CH, Norris SE, Paul-Satyaseela M, Vann WF, Frasch CE

Mol Microbiol 2007 Sep;65(5):1258-75
Biochemical characterization of a Neisseria meningitidis polysialyltransferase reveals novel functional motifs in bacterial sialyltransferases.
Freiberger F, Claus H, Günzel A, Oltmann-Norden I, Vionnet J, Mühlenhoff M, Vogel U, Vann WF, Gerardy-Schahn R, Stummeyer K

Glycobiology 2007 Jul;17(7):735-43
Successive glycosyltransfer of sialic acid by Escherichia coli K92 polysialyltransferase in elongation of oligosialic acceptors.
Vionnet J, Vann WF

Proc Natl Acad Sci U S A 2007 Jul 10;104(28):11557-61
Extracellular structure of polysialic acid explored by on cell solution NMR.
Azurmendi HF, Vionnet J, Wrightson L, Trinh LB, Shiloach J, Freedberg DI

Altern Lab Anim 2007 Jun;35(3):323-31
The potential of physicochemical and immunochemical assays to replace animal tests in the quality control of toxoid vaccines. The report and recommendations of ECVAM workshop 61.
Metz B, Brunel F, Chamberlin C, van der Gun J, Halder M, Jiskoot W, Kersten G, van Opstal O, Petersen JW, Ravetkar SD, Redhead K, Schwanig M, Wilhelmsen ES, Vann WF, Hendriksen C

Gene 2006 Dec 15;384:113-9
Escherichia coli BL21(DE3) chromosome contains a group II capsular gene cluster.
Andreishcheva EN, Vann WF

Biochemistry 2006 Nov 14;45(45):13511-13516
Functional Molecular Mass of Escherichia coli K92 Polysialyltransferase As Determined by Radiation Target Analysis.
Vionnet J, Kempner ES, Vann WF

J Bacteriol 2006 Sep;188(17):6195-206
Separate pathways for O acetylation of polymeric and monomeric sialic acids and identification of sialyl O-acetyl esterase in Escherichia coli K1.
Steenbergen SM, Lee YC, Vann WF, Vionnet J, Wright LF, Vimr ER

Biochem J 2006 Jul 1;397(1):195-201
Elimination of 2-keto-3-deoxy-D-glycero-D-galacto-nonulosonic acid 9-phosphate synthase activity from human N-acetylneuraminic acid 9-phosphate synthase by a single mutation.
Hao J, Vann WF, Hinderlich S, Sundaramoorthy M

J Bacteriol 2006 Mar;188(5):1786-97
Gene Products Required for De Novo Synthesis of Polysialic Acid in Escherichia coli K1.
Andreishcheva EN, Vann WF