title: Super-resolution imaging of C-type lectin and influenza hemagglutinin nanodomains on plasma membranes using blink microscopy.
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.
authors.affiliation: Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
authors.forename: Michelle S
authors.initials: MS
authors.lastname: Itano
authors.forename: Christian
authors.initials: C
authors.lastname: Steinhauer
authors.forename: Jürgen J
authors.initials: JJ
authors.lastname: Schmied
authors.forename: Carsten
authors.initials: C
authors.lastname: Forthmann
authors.forename: Ping
authors.initials: P
authors.lastname: Liu
authors.forename: Aaron K
authors.initials: AK
authors.lastname: Neumann
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Thompson
authors.forename: Philip
authors.initials: P
authors.lastname: Tinnefeld
authors.forename: Ken
authors.initials: K
authors.lastname: Jacobson
mesh_terms: D000818:Animals; D015815:Cell Adhesion Molecules / Q000737:chemistry* / Q000378:metabolism; D002462:Cell Membrane / Q000737:chemistry* / Q000378:metabolism; D005898:Glass / Q000737:chemistry; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D037181:Lectins, C-Type / Q000737:chemistry* / Q000378:metabolism; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D008853:Microscopy / Q000379:methods*; D057054:Molecular Imaging / Q000379:methods*; D041681:NIH 3T3 Cells; D049329:Nanostructures; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000378:metabolism; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin
chemical_list: D015815:Cell Adhesion Molecules; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D037181:Lectins, C-Type; D000090323:Mannose Receptor; D037241:Mannose-Binding Lectins; D011956:Receptors, Cell Surface; D000099215:DC-Specific ICAM-3 Grabbing Nonintegrin