CD209 antigen (Dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin) (DC-SIGN)

CD209, widely known as DC-SIGN, is a C-type lectin receptor primarily expressed on dendritic cells and certain macrophage populations. It functions as a pattern recognition receptor that identifies high-mannose and fucose-containing glycans on the surface of various pathogens, including viruses, bacteria, and fungi (UniProt P49763). A specific and significant interaction occurs between DC-SIGN on human macrophages and the native Vi capsular polysaccharide of Salmonella Typhi. This interaction allows the pathogen to subvert the host immune response by promoting an anti-inflammatory M2-like macrophage polarization and increasing the production of IL-10, which facilitates bacterial persistence (PMID: 24935955). Beyond its role in typhoid fever, DC-SIGN is implicated in the transmission of HIV-1 and the entry of other viruses like Ebola and Dengue. It also plays a role in cell-cell adhesion by binding to ICAM-2 and ICAM-3, which is essential for dendritic cell trafficking and T-cell synapse formation. Consequently, it is a target for therapeutic intervention using glycomimetics and carbohydrate-based inhibitors designed to block pathogen binding and restore effective immune signaling (PubMed: 28251786). Therapeutic strategies often focus on blocking the carbohydrate-recognition domain to prevent the 'Trojan horse' mechanism used by viruses to infect host cells.

Other names

CD209CLEC4LDendritic cell-specific ICAM-3-grabbing non-integrin

Competitive inhibition of the carbohydrate-recognition domain (CRD) to block pathogen attachment and prevent the induction of immune-evasive signaling pathways.