The B-D44 monoclonal antibody specifically recognizes CD263 which is also known as, TNF-related apoptosis-inducing ligand receptor 3 (TRAIL Receptor 3/TRAIL-R3), Decoy receptor 1 (DCR1), Lymphocyte inhibitor of TRAIL (LIT), or TRID. CD263 is a glycosylphosphatidylinositol (GPI)-anchored glycoprotein that belongs to the TNF Receptor Superfamily which includes other TRAIL (CD253/APO-2 Ligand) Receptors: CD261 (TRAIL-R1), CD262 (TRAIL-R2), and CD264 (TRAIL-R4). Unlike CD261 or CD262 that contain an intracellular signaling death domain, CD263 (and CD264) lacks a cytoplasmic death domain and is unable to transduce apoptotic signals upon binding TRAIL. CD263 thus serves as a decoy receptor for TRAIL. It functions as a negative regulator of apoptotic signaling by competing with CD261 and CD262 for the binding of TRAIL. Overexpression of CD263 can reportedly attenuate TRAIL-induced apoptosis.
The antibody was conjugated to BD Horizon™ BV421 which is part of the BD Horizon Brilliant™ Violet family of dyes. With an Ex Max of 407-nm and Em Max at 421-nm, BD Horizon BV421 can be excited by the violet laser and detected in the standard Pacific Blue™ filter set (eg, 450/50-nm filter). BD Horizon BV421 conjugates are very bright, often exhibiting a 10 fold improvement in brightness compared to Pacific Blue conjugates.