CD 209 (Cluster of Differentiation 209), aka DC-SIGN (acronym for: Dendritic Cell-Specific Intercellular adhesion molecule-3-Grabbing Non-integrin), is a protein that in humans is encoded by the CD209 gene. DC-SIGN is a C-type lectin receptor present on the surface of both macrophages and dendritic cells.
DC-SIGN on macrophages recognizes and binds with high affinity to high mannose N-glycans, a class of pathogen-associated molecular patterns (PAMPs) commonly found on viruses, bacteria, and fungi. This binding interaction activates phagocytosis. On myeloid and preplasmacytoid dendritic cells, DC-SIGN mediates dendritic cell rolling interactions with blood endothelium and CD4+ T cell activation, as well as pathogen hapten recognition. DC-SIGN is a C-type lectin and has a high affinity for the ICAM3 molecule. CD209 plays a key role as a receptor for various ligands such as ICAM-2, ICAM-3, HIV-1 gp120.
It binds various microorganisms by recognizing high mannose glycoproteins on their envelopes and particularly acts as a receptor for various viruses such as HIV, Hepatitis C and various Filoviridae. Binding to DC-SIGN can promote infection of dendritic cell-derived T cells by HIV and hepatitis C viruses. Thus, binding to DC-SIGN is an essential process for HIV infection. In addition to functioning as an adhesion molecule, recent studies have also shown that DC-SIGN can initiate innate immunity through modulation of Toll-like receptors, although the detailed mechanism is not yet known. DC-SIGN, along with other C-type lectins, is involved in tumor recognition by dendritic cells. DC-SIGN is also a potential development target for a dendritic cell-based cancer vaccine.
Application: FACS, IHC (G)