The 7H11 monoclonal antibody specifically recognizes mouse CD370 which is also known as DNGR-1 (Dendritic cell natural killer lectin group receptor 1). CD370 is an ~27 kDa single-pass type II transmembrane glycoprotein that is encoded by Clec9A (C-type lectin domain family member 9A) which belongs to the C-type lectin superfamily. CD370 (Clec9a) is selectively expressed as a disulfide-linked homodimer on plasmacytoid dendritic cells and CD8+ myeloid dendritic cells. This receptor is comprised of an extracellular region that contains a C-type lectin domain with a single carbohydrate recognition domain (CRD), followed by a transmembrane segment and a cytoplasmic tail with an immunoreceptor tyrosine-based activation motif (ITAM). CD370 (Clec9a) acts as a damage-associated molecular pattern receptor, ie, an endocytic receptor for damage-associated molecular patterns (DAMPs) that are expressed by necrotic cells, eg, cells dying due to infection or transformation. This receptor binds by its extracellular domain to exposed F-actin-myosin complexes of dead cells. Intracellular signaling mediated through ligand-bound CD370 (Clec9a) leads to phosphorylation of Syk tyrosine kinase. Further downstream signaling can foster MHC Class I-mediated cross-presentation of dead-cell associated antigens by dendritic cells to CD8+ T cells.
The antibody was conjugated to BD Horizon™ BV650 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 650-nm. BD Horizon BV650 can be excited by the violet laser and detected in a filter used to detect APC-like dyes (eg, 660/20-nm filter). Due to the excitation and emission characteristics of the acceptor dye, there will be spillover into the APC and Alexa Fluor™ 700 detectors. However, the spillover can be corrected through compensation as with any other dye combination.