A bacterial lipooligosaccharide that naturally mimics the epitope of the HIV-neutralizing antibody 2G12 as a template for vaccine design

Chem Biol. 2012 Feb 24;19(2):254-63. doi: 10.1016/j.chembiol.2011.12.019.

Abstract

The broadly neutralizing antibody 2G12 binds a fairly conserved cluster of oligomannose sugars on the HIV surface glycoprotein gp120, which has led to the hypothesis that these sugars pose potential vaccine targets. Here, we present the chemical analysis, antigenicity, and immunogenicity of a bacterial lipooligosaccharide (LOS) comprised of a manno-oligosaccharide sequence analogous to the 2G12 epitope. Antigenic similarity of the LOS to oligomannose was evidenced by 2G12 binding to the LOS and the inability of sera elicited against synthetic oligomannosides, but incapable of binding natural oligomannose, to bind the LOS. Immunization with heat-killed bacteria yielded epitope-specific serum antibodies with the capacity to bind soluble gp120. Although these sera did not exhibit specific anti-HIV activity, our data suggest that this LOS may find utility as a template for the design of glycoconjugates to target HIV.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • AIDS Vaccines / immunology
  • AIDS Vaccines / metabolism*
  • Animals
  • Antibodies, Monoclonal / immunology
  • Antibodies, Monoclonal / metabolism
  • Antibodies, Neutralizing / immunology
  • Antibodies, Neutralizing / metabolism*
  • Carbohydrate Sequence
  • Epitopes / immunology
  • HIV Envelope Protein gp120 / immunology
  • HIV Envelope Protein gp120 / metabolism
  • HIV Infections / immunology
  • HIV Infections / prevention & control*
  • Humans
  • Lipopolysaccharides / immunology
  • Lipopolysaccharides / metabolism*
  • Mice
  • Molecular Sequence Data
  • Protein Binding
  • Rhizobium / metabolism*

Substances

  • AIDS Vaccines
  • Antibodies, Monoclonal
  • Antibodies, Neutralizing
  • Epitopes
  • HIV Envelope Protein gp120
  • Lipopolysaccharides
  • lipid-linked oligosaccharides