Giuseppe
Emeritus
[Source: mBio, full page: (LINK). Abstract, edited.]
A Poly-N-Acetylglucosamine−Shiga Toxin Broad-Spectrum Conjugate Vaccine for Shiga Toxin-Producing Escherichia coli
Xi Lu<SUP>a</SUP>,<SUP>b</SUP>, David Skurnik<SUP>a</SUP>, Clarissa Pozzi<SUP>a</SUP>, Damien Roux<SUP>a</SUP>*, Colette Cywes-Bentley<SUP>a</SUP>, Jennifer M. Ritchie<SUP>a</SUP>*, Diana Munera<SUP>a</SUP>, Marina L. Gening<SUP>c</SUP>, Yury E. Tsvetkov<SUP>c</SUP>, Nikolay E. Nifantiev<SUP>c</SUP>, Matthew K. Waldor<SUP>a,d</SUP>, Gerald B. Pier<SUP>a,d</SUP>
<SUP></SUP>
Author Affiliations: <SUP>a</SUP>Division of Infectious Diseases, Department of Medicine, Brigham and Women?s Hospital, Boston, Massachusetts, USA <SUP>b</SUP>Institute of Medicinal Biotechnology, Academy of Medical Sciences and Peking Union Medical College, Beijing, China <SUP>c</SUP>Laboratory of Glycoconjugate Chemistry, ND Zelinsky Institute of Organic Chemistry, Moscow, Russia <SUP>d</SUP>Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, USA
Author Notes: * Present address: Damien Roux, IAME, UMR 1137, Institut National de la Sant? et de la Recherche M?dicale (INSERM), Paris, France; IAME, UMR 1137, Univ Paris Diderot, Sorbonne Paris Cit?, Paris, France; and AP-HP, H?pital Louis Mourier, Service de R?animation M?dico-Chirurgicale, Colombes, France. Jennifer M. Ritchie, University of Surrey, Guildford, United Kingdom.
Address correspondence to Gerald B. Pier, gpier@rics.bwh.harvard.edu.
X.L. and D.S. contributed equally to this article.
Editor Frederick Ausubel, Mass General Hospital
ABSTRACT
Many pathogens produce the β-(1−6)-linked poly-N-acetylglucosamine (PNAG) surface polysaccharide that is being developed as a broadly protective antimicrobial vaccine. However, it is unknown whether systemically injected PNAG vaccines or antibodies would provide protective immunity against pathogens confined to the gastrointestinal tract such as Shiga toxin (Stx)-producing Escherichia coli (STEC), an important group of gastrointestinal (GI) pathogens for which effective immunotherapeutics are lacking. To ascertain whether systemic IgG antibody to PNAG impacts this infectious situation, a vaccine consisting of a synthetic nonamer of nonacetylated PNAG, 9GlcNH<SUB>2</SUB>, conjugated to the Shiga toxin 1b subunit (9GlcNH<SUB>2</SUB>-Stx1b) was produced. Rabbit antibodies raised to the conjugate vaccine were tested for bacterial killing and toxin neutralization in vitro and protection against infection in infant mice. Cell surface PNAG was detected on all 9 STEC isolates tested, representing 6 STEC serogroups, including E. coli O157:H7. Antibody to the 9GlcNH<SUB>2</SUB>-Stx1b conjugate neutralized Stx1 potently and Stx2 modestly. For O157:H7 and O104:H4 STEC strains, antibodies elicited by the 9GlcNH<SUB>2</SUB>-Stx1b conjugate possessed opsonic killing and bactericidal activity. Following intraperitoneal injection, antibodies to both PNAG and Stx were needed for infant mouse protection against O157 STEC. These antibodies also mediated protection against the Stx2-producing O104:H4 strain that was the cause of a recent outbreak in Germany, although sufficient doses of antibody to PNAG alone were protective against this strain in infant mice. Our observations suggest that vaccination against both PNAG and Stx, using a construct such as the 9GlcNH<SUB>2</SUB>-Stx1b conjugate vaccine, would be protective against a broad range of STEC serogroups.
IMPORTANCE
The presence of poly-N-acetylglucosamine (PNAG) on many pathogens presents an opportunity to target this one structure with a multispecies vaccine. Whether antibodies to PNAG can protect against pathogens confined to the gastrointestinal tract is not known. As Shiga toxin (Stx)-producing Escherichia coli (STEC) bacteria are serious causes of infection whose virulence is dependent on elaboration of Stx, we prepared a vaccine containing a synthetic nonamer of PNAG (9GlcNH<SUB>2</SUB>) conjugated to Shiga toxin 1b subunit (9GlcNH<SUB>2</SUB>-Stx1b) to evaluate bacterial killing, toxin neutralization, and protective efficacy in infant mice. All nine (100%) clinical strains of STEC from different serogroups expressed PNAG. Vaccine-induced antibody mediated in vitro killing of STEC and neutralization of both Stx1 and Stx2. Passive administration of antibody to the conjugate showed protection requiring immunity to both PNAG and Stx for O157 strains, although for an O104 strain, antibody to PNAG alone was protective. Immunity to PNAG may contribute to protection against STEC infections.
Footnotes
Citation Lu X, Skurnik D, Pozzi C, Roux D, Cywes-Bentley C, Ritchie JM, Munera D, Gening ML, Tsvetkov YE, Nifantiev NE, Waldor MK, Pier GB. 2014. A poly-N-acetylglucosamine−Shiga toxin broad-spectrum conjugate vaccine for Shiga toxin-producing Escherichia coli. mBio 5(2):00974-14. doi:10.1128/mBio.00974-14.
Received 18 February 2014 - Accepted 24 February 2014 - Published 25 March 2014 - Copyright ? 2014 Lu et al.
This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-ShareAlike 3.0 Unported license, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original author and source are credited.
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A Poly-N-Acetylglucosamine−Shiga Toxin Broad-Spectrum Conjugate Vaccine for Shiga Toxin-Producing Escherichia coli
Xi Lu<SUP>a</SUP>,<SUP>b</SUP>, David Skurnik<SUP>a</SUP>, Clarissa Pozzi<SUP>a</SUP>, Damien Roux<SUP>a</SUP>*, Colette Cywes-Bentley<SUP>a</SUP>, Jennifer M. Ritchie<SUP>a</SUP>*, Diana Munera<SUP>a</SUP>, Marina L. Gening<SUP>c</SUP>, Yury E. Tsvetkov<SUP>c</SUP>, Nikolay E. Nifantiev<SUP>c</SUP>, Matthew K. Waldor<SUP>a,d</SUP>, Gerald B. Pier<SUP>a,d</SUP>
<SUP></SUP>
Author Affiliations: <SUP>a</SUP>Division of Infectious Diseases, Department of Medicine, Brigham and Women?s Hospital, Boston, Massachusetts, USA <SUP>b</SUP>Institute of Medicinal Biotechnology, Academy of Medical Sciences and Peking Union Medical College, Beijing, China <SUP>c</SUP>Laboratory of Glycoconjugate Chemistry, ND Zelinsky Institute of Organic Chemistry, Moscow, Russia <SUP>d</SUP>Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, USA
Author Notes: * Present address: Damien Roux, IAME, UMR 1137, Institut National de la Sant? et de la Recherche M?dicale (INSERM), Paris, France; IAME, UMR 1137, Univ Paris Diderot, Sorbonne Paris Cit?, Paris, France; and AP-HP, H?pital Louis Mourier, Service de R?animation M?dico-Chirurgicale, Colombes, France. Jennifer M. Ritchie, University of Surrey, Guildford, United Kingdom.
Address correspondence to Gerald B. Pier, gpier@rics.bwh.harvard.edu.
X.L. and D.S. contributed equally to this article.
Editor Frederick Ausubel, Mass General Hospital
ABSTRACT
Many pathogens produce the β-(1−6)-linked poly-N-acetylglucosamine (PNAG) surface polysaccharide that is being developed as a broadly protective antimicrobial vaccine. However, it is unknown whether systemically injected PNAG vaccines or antibodies would provide protective immunity against pathogens confined to the gastrointestinal tract such as Shiga toxin (Stx)-producing Escherichia coli (STEC), an important group of gastrointestinal (GI) pathogens for which effective immunotherapeutics are lacking. To ascertain whether systemic IgG antibody to PNAG impacts this infectious situation, a vaccine consisting of a synthetic nonamer of nonacetylated PNAG, 9GlcNH<SUB>2</SUB>, conjugated to the Shiga toxin 1b subunit (9GlcNH<SUB>2</SUB>-Stx1b) was produced. Rabbit antibodies raised to the conjugate vaccine were tested for bacterial killing and toxin neutralization in vitro and protection against infection in infant mice. Cell surface PNAG was detected on all 9 STEC isolates tested, representing 6 STEC serogroups, including E. coli O157:H7. Antibody to the 9GlcNH<SUB>2</SUB>-Stx1b conjugate neutralized Stx1 potently and Stx2 modestly. For O157:H7 and O104:H4 STEC strains, antibodies elicited by the 9GlcNH<SUB>2</SUB>-Stx1b conjugate possessed opsonic killing and bactericidal activity. Following intraperitoneal injection, antibodies to both PNAG and Stx were needed for infant mouse protection against O157 STEC. These antibodies also mediated protection against the Stx2-producing O104:H4 strain that was the cause of a recent outbreak in Germany, although sufficient doses of antibody to PNAG alone were protective against this strain in infant mice. Our observations suggest that vaccination against both PNAG and Stx, using a construct such as the 9GlcNH<SUB>2</SUB>-Stx1b conjugate vaccine, would be protective against a broad range of STEC serogroups.
IMPORTANCE
The presence of poly-N-acetylglucosamine (PNAG) on many pathogens presents an opportunity to target this one structure with a multispecies vaccine. Whether antibodies to PNAG can protect against pathogens confined to the gastrointestinal tract is not known. As Shiga toxin (Stx)-producing Escherichia coli (STEC) bacteria are serious causes of infection whose virulence is dependent on elaboration of Stx, we prepared a vaccine containing a synthetic nonamer of PNAG (9GlcNH<SUB>2</SUB>) conjugated to Shiga toxin 1b subunit (9GlcNH<SUB>2</SUB>-Stx1b) to evaluate bacterial killing, toxin neutralization, and protective efficacy in infant mice. All nine (100%) clinical strains of STEC from different serogroups expressed PNAG. Vaccine-induced antibody mediated in vitro killing of STEC and neutralization of both Stx1 and Stx2. Passive administration of antibody to the conjugate showed protection requiring immunity to both PNAG and Stx for O157 strains, although for an O104 strain, antibody to PNAG alone was protective. Immunity to PNAG may contribute to protection against STEC infections.
Footnotes
Citation Lu X, Skurnik D, Pozzi C, Roux D, Cywes-Bentley C, Ritchie JM, Munera D, Gening ML, Tsvetkov YE, Nifantiev NE, Waldor MK, Pier GB. 2014. A poly-N-acetylglucosamine−Shiga toxin broad-spectrum conjugate vaccine for Shiga toxin-producing Escherichia coli. mBio 5(2):00974-14. doi:10.1128/mBio.00974-14.
Received 18 February 2014 - Accepted 24 February 2014 - Published 25 March 2014 - Copyright ? 2014 Lu et al.
This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-ShareAlike 3.0 Unported license, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original author and source are credited.
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