Receptor activator of nuclear factor κB (RANK/TRANCE receptor, TNFRSF11A) is a member of the tumor necrosis factor receptor (TNFR) family. Binding of its ligand RANKL to the receptor regulates osteoclast formation, activation and survival in bone modeling and remodeling as well as several pathologic conditions characterized by increased bone turnover. RANKL is initially produced as a type II transmembrane protein (mRANKL) that is cleaved by proteases, resulting in soluble RANKL. Binding of RANKL-targeted antibodies to mRANKL-expressing cells may induce effector functions such as antibody-dependent cell-mediated cytotoxicity (ADCC) or complement-dependent cytotoxicity (CDC) to destroy the mRANKL-expressing cells.
mRANKL Target Cells are a genetically engineered cell line stably expressing a cleavage-resistant form of mRANKL that enforces its surface expression. They are designed to be used as target cells in assays that measure the effector functions, such as ADCC and CDC, of anti-RANKL blockers. In addition, they can be used to measure antibody binding affinity to mRANKL.