ICOS Bioassay, Propagation Model
The ICOS Bioassays are bioluminescent cell-based assays used to measure the potency and stability of ligands or agonist antibodies that activate ICOS. ICOS (CD278) binds to its ligand ICOSL (B7-H2, CD275), which is constitutively expressed on B cells, monocytes and dendritic cells, and can be induced on endothelial and epithelial cells during inflammation. ICOS co-stimulation induces the production of effector T cell cytokines such as interferon (IFN)-gamma, interleukin (IL)-4 and IL-10. The ICOS Bioassay reflects the mechanism of action (MOA) of biologics designed to activate ICOS.