Holes in the Glycan Shield of the Native HIV Envelope Are a Target of Trimer-Elicited Neutralizing Antibodies

Cell Rep. 2016 Aug 30;16(9):2327-38. doi: 10.1016/j.celrep.2016.07.074. Epub 2016 Aug 18.

Abstract

A major advance in the search for an HIV vaccine has been the development of a near-native Envelope trimer (BG505 SOSIP.664) that can induce robust autologous Tier 2 neutralization. Here, potently neutralizing monoclonal antibodies (nAbs) from rabbits immunized with BG505 SOSIP.664 are shown to recognize an immunodominant region of gp120 centered on residue 241. Residue 241 occupies a hole in the glycan defenses of the BG505 isolate, with fewer than 3% of global isolates lacking a glycan site at this position. However, at least one conserved glycan site is missing in 89% of viruses, suggesting the presence of glycan holes in most HIV isolates. Serum evidence is consistent with targeting of holes in natural infection. The immunogenic nature of breaches in the glycan shield has been under-appreciated in previous attempts to understand autologous neutralizing antibody responses and has important potential consequences for HIV vaccine design.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • AIDS Vaccines / biosynthesis*
  • AIDS Vaccines / genetics
  • AIDS Vaccines / immunology
  • Animals
  • Antibodies, Neutralizing / biosynthesis
  • Antibodies, Neutralizing / chemistry*
  • Antibodies, Neutralizing / genetics
  • Antibodies, Viral / biosynthesis
  • Antibodies, Viral / chemistry*
  • Antibodies, Viral / genetics
  • Antibody Specificity
  • Binding Sites
  • HIV Antigens / chemistry*
  • HIV Antigens / immunology
  • HIV Antigens / metabolism
  • HIV Envelope Protein gp120 / chemistry*
  • HIV Envelope Protein gp120 / immunology
  • HIV Envelope Protein gp120 / metabolism
  • HIV Infections / immunology
  • HIV Infections / prevention & control
  • HIV Infections / virology
  • HIV-1 / chemistry
  • HIV-1 / immunology
  • Humans
  • Immunization
  • Models, Molecular
  • Mutagenesis, Site-Directed
  • Neutralization Tests
  • Polysaccharides / chemistry*
  • Polysaccharides / immunology
  • Protein Binding
  • Protein Interaction Domains and Motifs
  • Protein Multimerization
  • Protein Structure, Secondary
  • Rabbits

Substances

  • AIDS Vaccines
  • Antibodies, Neutralizing
  • Antibodies, Viral
  • HIV Antigens
  • HIV Envelope Protein gp120
  • Polysaccharides