Glycosylation patterns of HIV-1 gp120 depend on the type of expressing cells and affect antibody recognition

J Biol Chem. 2010 Jul 2;285(27):20860-9. doi: 10.1074/jbc.M109.085472. Epub 2010 May 3.

Abstract

Human immunodeficiency virus type 1 (HIV-1) entry is mediated by the interaction between a variably glycosylated envelope glycoprotein (gp120) and host-cell receptors. Approximately half of the molecular mass of gp120 is contributed by N-glycans, which serve as potential epitopes and may shield gp120 from immune recognition. The role of gp120 glycans in the host immune response to HIV-1 has not been comprehensively studied at the molecular level. We developed a new approach to characterize cell-specific gp120 glycosylation, the regulation of glycosylation, and the effect of variable glycosylation on antibody reactivity. A model oligomeric gp120 was expressed in different cell types, including cell lines that represent host-infected cells or cells used to produce gp120 for vaccination purposes. N-Glycosylation of gp120 varied, depending on the cell type used for its expression and the metabolic manipulation during expression. The resultant glycosylation included changes in the ratio of high-mannose to complex N-glycans, terminal decoration, and branching. Differential glycosylation of gp120 affected envelope recognition by polyclonal antibodies from the sera of HIV-1-infected subjects. These results indicate that gp120 glycans contribute to antibody reactivity and should be considered in HIV-1 vaccine design.

Publication types

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

MeSH terms

  • Acquired Immunodeficiency Syndrome / immunology
  • Antibodies / immunology*
  • Antibody Specificity
  • Cell Line
  • Cell Line, Tumor
  • DNA, Complementary / genetics
  • Enzyme-Linked Immunosorbent Assay / methods
  • Glycoside Hydrolases / metabolism
  • Glycosylation
  • HIV Envelope Protein gp120 / genetics
  • HIV Envelope Protein gp120 / immunology*
  • HIV Envelope Protein gp120 / isolation & purification
  • HIV Envelope Protein gp120 / metabolism*
  • HIV Seropositivity / immunology
  • HIV Seropositivity / metabolism
  • HIV-1 / immunology
  • HIV-1 / metabolism
  • Hep G2 Cells / metabolism
  • Humans
  • Jurkat Cells / metabolism
  • Mannose / metabolism
  • Mannose-Binding Lectin / genetics
  • Mass Spectrometry
  • Oligosaccharides / chemistry
  • Oligosaccharides / isolation & purification
  • Plasmids
  • Polysaccharides / chemistry
  • Polysaccharides / isolation & purification

Substances

  • Antibodies
  • DNA, Complementary
  • HIV Envelope Protein gp120
  • Mannose-Binding Lectin
  • Oligosaccharides
  • Polysaccharides
  • gp120 protein, Human immunodeficiency virus 1
  • Glycoside Hydrolases
  • Mannose