An assay for functional dendritic cell-specific ICAM-3-grabbing nonintegrin (DC–SIGN) inhibitors of human dendritic cell adhesion

We report a new dendritic cell adhesion assay, using either immature or mature dendritic cells, for identifying functional dendritic cell-specific ICAM-3-grabbing nonintegrin (DC–SIGN) inhibitors. Because immature dendritic cells are responsible for pathogen binding and invasion, this in vitro assay provides an important link between in vitro results and pathogen-based in vivo assays. Furthermore, this assay does not require laborious expression, refolding, and purification of DC–SIGN carbohydrate recognition domain or extracellular domain as receptor-based assays. The assay power evaluated with Z and Z′ parameters enables screening of compound libraries and determination of IC50 values in the first stage of DC–SIGN inhibitor development.