The 9A1.5 monoclonal antibody specifically binds to an extracellular domain of Delta-Like Protein 4 that is encoded by the Dll4 gene. Delta-Like Protein 4 is a type 1 transmembrane glycoprotein that is also known as Delta-like 4, Delta-like Ligand 4, Delta4 and DL4. It is a member of the Delta/Serrate/Jagged Family of Notch ligands. Notch ligands are classified by the presence of specific structural motifs including an N-terminal Delta-Serrate-LAG-2 (DSL) domain necessary for Notch binding, EGF repeats, and the DOS domain (a specialized EGF repeat). The Notch family of transmembrane receptors and their ligands control cell-fate "decisions" during the development of many organs in a wide variety of animal species. Delta-Like Protein 4 activates cellular signaling pathways by binding to Notch1 and Notch4 receptors. It is involved in embryonic vascular development and tumor angiogenesis, and is induced by vascular endothelial growth factor (VEGF)-A and hypoxia. Delta-Like Protein 4 and Notch receptor signaling are also intimately involved in the regulation of innate and adaptive immunity. Delta-Like Protein 4 is highly expressed by cortical thymic epithelial cells (TEC). Interaction between Delta-Like Protein 4-positive TEC and Notch1 expressed by T cell precursors drives T cell lineage commitment, expansion and maturation within the thymus. Delta-Like Protein 4 is also expressed by dendritic cells and plays a role in peripheral T helper cell differentiation. Blocking of Delta-Like Protein 4 and Notch receptor interactions serves to diminish autoimmune diseases in mouse model systems.
This antibody is conjugated to BD Horizon™ BV605 which is part of the BD Horizon Brilliant™ Violet family of dyes. With an Ex Max of 407-nm and Em Max of 602-nm, BD Horizon BV605 can be excited by a violet laser and detected with a standard 610/20-nm filter set. BD Horizon BV605 is a tandem fluorochrome of BD Horizon BV421 and an acceptor dye with an Em max at 605-nm. Due to the excitation of the acceptor dye by the green (532 nm) and yellow-green (561 nm) lasers, there will be significant spillover into the PE and BD Horizon PE-CF594 detectors off the green or yellow-green lasers. BD Horizon BV605 conjugates are very bright, often exhibiting brightness equivalent to PE conjugates and can be used as a third color off of the violet laser.