N-glycan mediated adhesion strengthening during pathogen-receptor binding revealed by cell-cell force spectroscopy

Sci Rep. 2017 Jul 27;7(1):6713. doi: 10.1038/s41598-017-07220-w.

Abstract

Glycan-protein lateral interactions have gained increased attention as important modulators of receptor function, by regulating surface residence time and endocytosis of membrane glycoproteins. The pathogen-recognition receptor DC-SIGN is highly expressed at the membrane of antigen-presenting dendritic cells, where it is organized in nanoclusters and binds to different viruses, bacteria and fungi. We recently demonstrated that DC-SIGN N-glycans spatially restrict receptor diffusion within the plasma membrane, favoring its internalization through clathrin-coated pits. Here, we investigated the involvement of the N-glycans of DC-SIGN expressing cells on pathogen binding strengthening when interacting with Candida fungal cells by using atomic force microscope (AFM)-assisted single cell-pathogen adhesion measurements. The use of DC-SIGN mutants lacking the N-glycans as well as blocking glycan-mediated lateral interactions strongly impaired cell stiffening during pathogen binding. Our findings demonstrate for the first time the direct involvement of the cell membrane glycans in strengthening cell-pathogen interactions. This study, therefore, puts forward a possible role for the glycocalyx as extracellular cytoskeleton contributing, possibly in connection with the intracellular actin cytoskeleton, to optimize strengthening of cell-pathogen interactions in the presence of mechanical forces.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding Sites
  • Biomechanical Phenomena
  • CHO Cells
  • Candida albicans / chemistry*
  • Candida albicans / metabolism
  • Cell Adhesion
  • Cell Adhesion Molecules / chemistry*
  • Cell Adhesion Molecules / genetics
  • Cell Adhesion Molecules / metabolism
  • Cricetulus
  • Dendritic Cells / metabolism
  • Dendritic Cells / microbiology*
  • Dendritic Cells / ultrastructure
  • Gene Expression
  • Glycocalyx / chemistry*
  • Glycocalyx / metabolism
  • Host-Pathogen Interactions*
  • Humans
  • Lectins, C-Type / chemistry*
  • Lectins, C-Type / genetics
  • Lectins, C-Type / metabolism
  • Microscopy, Atomic Force
  • Mutation
  • Polysaccharides / chemistry*
  • Polysaccharides / metabolism
  • Primary Cell Culture
  • Protein Domains
  • Receptors, Cell Surface / chemistry*
  • Receptors, Cell Surface / genetics
  • Receptors, Cell Surface / metabolism
  • Transgenes

Substances

  • Cell Adhesion Molecules
  • DC-specific ICAM-3 grabbing nonintegrin
  • Lectins, C-Type
  • Polysaccharides
  • Receptors, Cell Surface