Integrity of Glycosylation Processing of a Glycan-Depleted Trimeric HIV-1 Immunogen Targeting Key B-Cell Lineages

J Proteome Res. 2018 Mar 2;17(3):987-999. doi: 10.1021/acs.jproteome.7b00639. Epub 2018 Feb 8.


Broadly neutralizing antibodies (bNAbs) that target the trimeric HIV-1 envelope glycoprotein spike (Env) are tools that can guide the design of recombinant Env proteins intended to engage the predicted human germline precursors of bNAbs (gl-bNAbs). The protein components of gl-bNAb epitopes are often masked by glycans, while mature bNAbs can evolve to accommodate or bypass these shielding glycans. The design of germline-targeting Env immunogens therefore includes the targeted deletion of specific glycan sites. However, the processing of glycans on Env trimers can be influenced by the density with which they are packed together, a highly relevant point given the essential contributions under-processed glycans make to multiple bNAb epitopes. We sought to determine the impact of the removal of 15 potential N-glycan sites (5 per protomer) from the germline-targeting soluble trimer, BG505 SOSIP.v4.1-GT1, using quantitative, site-specific N-glycan mass spectrometry analysis. We find that, compared with SOSIP.664, there was little overall change in the glycan profile but only subtle increases in the extent of processing at sites immediately adjacent to where glycans had been deleted. We conclude that multiple glycans can be deleted from BG505 SOSIP trimers without perturbing the overall integrity of the glycan shield.

Keywords: Env; HIV-1 vaccine design; envelope; glycoproteomics; glycosylation; immunogen design; mass spectrometry; virus.

Publication types

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

MeSH terms

  • Amino Acid Motifs
  • Animals
  • Antibodies, Neutralizing / chemistry*
  • Antibodies, Neutralizing / genetics
  • Antibodies, Neutralizing / immunology
  • Antibodies, Neutralizing / metabolism
  • B-Lymphocytes / immunology
  • B-Lymphocytes / metabolism
  • Binding Sites
  • CHO Cells
  • Carbohydrate Sequence
  • Cell Lineage / immunology
  • Cricetulus
  • Epitopes / chemistry*
  • Epitopes / genetics
  • Epitopes / immunology
  • Epitopes / metabolism
  • Gene Expression
  • Glycosylation
  • HIV Antibodies / chemistry*
  • HIV Antibodies / genetics
  • HIV Antibodies / immunology
  • HIV Antibodies / metabolism
  • HIV-1 / genetics
  • HIV-1 / immunology
  • HIV-1 / metabolism*
  • Polysaccharides / chemistry*
  • Polysaccharides / immunology
  • Polysaccharides / metabolism
  • Promoter Regions, Genetic
  • Protein Binding
  • Protein Interaction Domains and Motifs
  • Protein Multimerization
  • Protein Processing, Post-Translational*
  • Protein Structure, Secondary
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / immunology
  • Recombinant Proteins / metabolism
  • Spectrometry, Mass, Electrospray Ionization
  • env Gene Products, Human Immunodeficiency Virus / chemistry*
  • env Gene Products, Human Immunodeficiency Virus / genetics
  • env Gene Products, Human Immunodeficiency Virus / immunology
  • env Gene Products, Human Immunodeficiency Virus / metabolism


  • Antibodies, Neutralizing
  • Epitopes
  • HIV Antibodies
  • Polysaccharides
  • Recombinant Proteins
  • env Gene Products, Human Immunodeficiency Virus