[Fcγ receptor and systemic autoimmune disease]

The systemic autoimmune disease such as systemic lupus erythematosus (SLE) is characterized by the deposition of immune complexes in multiple organs. Fcγ receptors (FcγR) recognize the Fc portion of IgG and are important in determining the response of leukocytes to deposited immune complexes. FcγR also provide positive and negative regulation of immune cell responses. The activatory FcγR including the FcR common γ chain take balance with Fcγ RIIB, the only inhibitory FcγR. Development of lupus-like autoimmune disease as well as monocytosis in BXSB mice is dependent on the activatory and inhibitory FcγR. In human SLE, dysregulated expression of FcγRIIB on memory B cells is reported and numbers of associations with genetic polymorphism are also reported. The cell-specific modulation of these activatory or inhibitory FcγRs are expected for the new therapeutic strategy in autoimmune diseases.