P31994

FCGR2B also designated Fc gamma RIIb, CD32b is a low affinity receptor for the Fc region of immunoglobulin gamma complexes. FCGR2B plays a crucial role in the immune response by mediating the clearance of immune complexes through macrophages. This function is vital for maintaining homeostasis and preventing autoimmune reactions. Additionally, FCGR2B is involved in the regulation of antibody production by B cells, where FCGR2B interaction with IgG delivers a negative signal that modulates B cell activity. FCGR2B exists in several isoforms, produced by alternative splicing of three distinct genes (A, B, and C), which are designated FcgRIIA, FcgRIIB1, FcgRIIB3, and FcgRIIC. These isoforms are expressed on various immune cells, including monocytes, placental trophoblasts, and endothelial cells, with specific forms present on B lymphocytes and neutrophils, highlighting FCGR2B′s diverse roles in immune regulation and response.