Fig. 7.

Schematic model for the selective role of ADAP in macrophage-mediated platelet phagocytosis by targeting the STAT1-importin α5-FcγR axis. ADAP interacts and competes with STAT1 binding to importin α5 to keep a portion of IFN-γ-activated STAT1 anchored in the cytosol so that the activation of macrophages is maintained within a desired physiological range. This restraint is removed when ADAP is underexpressed in macrophages, leading to an enhancement of STAT1-dependent transactivation of FcγRI and FcγRIV. As such, the heightened phagocytic ability of macrophages is induced, causing excessive phagocytic clearance of platelets and contributing to ITP pathogenesis