Super-resolution imaging of C-type lectin and influenza hemagglutinin nanodomains on plasma membranes using blink microscopy

Biophys J. 2012 Apr 4;102(7):1534-42. doi: 10.1016/j.bpj.2012.02.022. Epub 2012 Apr 3.

Abstract

Dendritic cells express DC-SIGN, a C-type lectin (CTL) that binds a variety of pathogens and facilitates their uptake for subsequent antigen presentation. DC-SIGN forms remarkably stable microdomains on the plasma membrane. However, inner leaflet lipid markers are able to diffuse through these microdomains suggesting that, rather than being densely packed with DC-SIGN proteins, an elemental substructure exists. Therefore, a super-resolution imaging technique, Blink Microscopy (Blink), was applied to further investigate the lateral distribution of DC-SIGN. Blink indicates that DC-SIGN, another CTL (CD206), and influenza hemagglutinin (HA) are all localized in small (∼80 nm in diameter) nanodomains. DC-SIGN and CD206 nanodomains are randomly distributed on the plasma membrane, whereas HA nanodomains cluster on length scales up to several microns. We estimate, as a lower limit, that DC-SIGN and HA nanodomains contain on average two tetramers or two trimers, respectively, whereas CD206 is often nonoligomerized. Two-color Blink determined that different CTLs rarely occupy the same nanodomain, although they appear colocalized using wide-field microscopy. What to our knowledge is a novel domain structure emerges in which elemental nanodomains, potentially capable of binding viruses, are organized in a random fashion; evidently, these nanodomains can be clustered into larger microdomains that act as receptor platforms for larger pathogens like yeasts.

Publication types

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

MeSH terms

  • Animals
  • Cell Adhesion Molecules / chemistry*
  • Cell Adhesion Molecules / metabolism
  • Cell Membrane / chemistry*
  • Cell Membrane / metabolism
  • Glass / chemistry
  • Hemagglutinin Glycoproteins, Influenza Virus / chemistry*
  • Hemagglutinin Glycoproteins, Influenza Virus / metabolism
  • Humans
  • Lectins, C-Type / chemistry*
  • Lectins, C-Type / metabolism
  • Mannose-Binding Lectins / chemistry
  • Mannose-Binding Lectins / metabolism
  • Mice
  • Microscopy / methods*
  • Molecular Imaging / methods*
  • NIH 3T3 Cells
  • Nanostructures*
  • Protein Structure, Tertiary
  • Protein Transport
  • Receptors, Cell Surface / chemistry*
  • Receptors, Cell Surface / metabolism

Substances

  • Cell Adhesion Molecules
  • DC-specific ICAM-3 grabbing nonintegrin
  • Hemagglutinin Glycoproteins, Influenza Virus
  • Lectins, C-Type
  • Mannose-Binding Lectins
  • Receptors, Cell Surface
  • mannose receptor