The 5H10 monoclonal antibody specifically binds to mouse CD209a, or CIRE, which is the most closely related homolog of human DC-SIGN. In the mouse, several homologs of human CD209 (DC-SIGN) have been described. CD209a is a 238-amino acid type-II transmembrane C-type lectin, with an extracellular carbohydrate recognition domain. It can bind to mannosylated ligands in a Ca++ dependent manner. CD209a is expressed by some conventional CD4+ and CD4-CD8- dendritic cells (DC) but not by CD8+ DC. It is also expressed on monocytes, splenic plasmacytoid pre-DC, macrophages, and resident peritoneal cells. CD209a expression is downregulated upon cellular activation. CD209a is thought to play a role in the internalization and presentation of antigens to initiate immune responses.
The antibody was conjugated to BD Horizon™ BV711 which is part of the BD Horizon Brilliant™ Violet family of dyes. This dye is a tandem fluorochrome of BD Horizon BV421 with an Ex Max of 405-nm and an acceptor dye with an Em Max at 711-nm. BD Horizon BV711 can be excited by the violet laser and detected in a filter used to detect Cy™5.5 / Alexa Fluor® 700-like dyes (eg, 712/20-nm filter). Due to the excitation and emission characteristics of the acceptor dye, there may be moderate spillover into the Alexa Fluor® 700 and PerCP-Cy5.5 detectors. However, the spillover can be corrected through compensation as with any other dye combination.