Published in

Wiley, Journal of Leukocyte Biology, 5(77), p. 699-709, 2005

DOI: 10.1189/jlb.0904529

Links

Tools

Export citation

Search in Google Scholar

Regulated recruitment of DC-SIGN to cell-cell contact regions during zymosan-induced human dendritic cell aggregation

This paper is made freely available by the publisher.
This paper is made freely available by the publisher.

Full text: Download

Green circle
Preprint: archiving allowed
Orange circle
Postprint: archiving restricted
Red circle
Published version: archiving forbidden
Data provided by SHERPA/RoMEO

Abstract

Abstract Zymosan is a β-glucan, mannan-rich yeast particle widely used to activate the inflammatory response of immune cells. We studied the zymosan-binding potential of human dendritic cells (hDCs) by using specific carbohydrate inhibitors and blocking monoclonal antibodies. We show that DC-specific intercellular adhesion molecule-grabbing nonintegrin (DC-SIGN) is a major nonopsonic recognition receptor for zymosan on hDCs. Indeed, blocking of DC-SIGN inhibited the inflammatory response of DCs to zymosan. We compared the zymosan-binding capacity of hDC-SIGN to that of Dectin-1 and complement receptor 3 (CR3), which are receptors involved in the nonopsonic recognition of these yeast-derived particles. Dectin-1- and DC-SIGN-K562 cells bound to zymosan particles, whereas CR3-K562 cells did not. DC-SIGN and Dectin-1 were also expressed in COS cells to compare their ability to trigger particle internalization in a nonphagocytic cell line. DC-SIGN transfectants were unable to internalize bound particles, indicating that DC-SIGN is primarily involved in recognition but not in particle internalization. Zymosan induced a rapid DC aggregation that was accompanied by a dramatic change of DC-SIGN distribution in the plasma membrane. Under resting conditions, DC-SIGN was diffusely distributed through the cell surface, displaying clusters at the free leading edge. Upon zymosan treatment, DC-SIGN was markedly redistributed to cell–cell contacts, supporting an adhesion role in DC–DC interactions. The mechanism(s) supporting DC-SIGN-mediated intercellular adhesion were further investigated by using DC-SIGN-K562 aggregation. DC-SIGN was highly concentrated at points of cell–cell contact, suggesting a role for enhanced avidity during DC-SIGN-mediated intercellular adhesion.