Exploiting glycan topography for computational design of Env glycoprotein antigenicity

PLoS Comput Biol. 2018 Apr 20;14(4):e1006093. doi: 10.1371/journal.pcbi.1006093. eCollection 2018 Apr.

Abstract

Mounting evidence suggests that glycans, rather than merely serving as a "shield", contribute critically to antigenicity of the HIV envelope (Env) glycoprotein, representing critical antigenic determinants for many broadly neutralizing antibodies (bNAbs). While many studies have focused on defining the role of individual glycans or groups of proximal glycans in bNAb binding, little is known about the effects of changes in the overall glycan landscape in modulating antibody access and Env antigenicity. Here we developed a systems glycobiology approach to reverse engineer the complexity of HIV glycan heterogeneity to guide antigenicity-based de novo glycoprotein design. bNAb binding was assessed against a panel of 94 recombinant gp120 monomers exhibiting defined glycan site occupancies. Using a Bayesian machine learning algorithm, bNAb-specific glycan footprints were identified and used to design antigens that selectively alter bNAb antigenicity as a proof-of concept. Our approach provides a new design strategy to predictively modulate antigenicity via the alteration of glycan topography, thereby focusing the humoral immune response on sites of viral vulnerability for HIV.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Amino Acid Sequence
  • Antibodies, Neutralizing
  • Bayes Theorem
  • Binding Sites
  • Computational Biology
  • Epitopes / chemistry
  • Epitopes / genetics
  • Glycosylation
  • HIV / chemistry
  • HIV / immunology
  • HIV Antibodies
  • HIV Antigens / chemistry*
  • HIV Antigens / genetics
  • HIV Antigens / immunology*
  • HIV Envelope Protein gp120 / chemistry*
  • HIV Envelope Protein gp120 / genetics
  • HIV Envelope Protein gp120 / immunology*
  • Humans
  • Machine Learning
  • Models, Molecular
  • Polysaccharides / chemistry*
  • Polysaccharides / immunology*
  • Protein Engineering
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / immunology
  • Systems Biology

Substances

  • Antibodies, Neutralizing
  • Epitopes
  • HIV Antibodies
  • HIV Antigens
  • HIV Envelope Protein gp120
  • Polysaccharides
  • Recombinant Proteins

Grants and funding

The study was funded by Bill and Melinda Gates Foundation OPP1097381 [https://www.gatesfoundation.org/]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.