BAFF receptor

The B-cell activating factor receptor (BAFF-R), also known as tumor necrosis factor receptor superfamily member 13C (TNFRSF13C) or BLyS receptor 3 (BR3), is a membrane protein of the TNF receptor superfamily that recognizes BAFF , a factor important for B-cell maturation and survival. In humans, the receptor is encoded by the TNFRSF13C gene.

B-cell activating factor (BAFF/syn. BLYS) increases B-cell survival in vitro and is a regulator of the peripheral B-cell population. The protein encoded by this gene is a receptor for BAFF and is a type III transmembrane protein with a single extracellular phenylalanine-rich domain. This receptor is thought to be the major receptor required for BAFF-mediated survival of mature B cells During B cell maturation, only a limited number of B cells survive due to regulation by BAFF-R.

Clinical significance: Overexpression of BAFF in mice leads to hyperplasia of mature B cells and symptoms of systemic lupus erythematosus (SLE). In addition, some SLE patients have elevated serum BAFF levels. Therefore, it is reasonable to assume that abnormally high BAFF levels may contribute to the pathogenesis of autoimmune diseases by promoting the survival of autoreactive B cells, i.e., cells that exhibit an immune response to normal body cells. Autoreactive B cells are less sensitive to BAFF and are usually displaced by normal B cells in the maturation process, which is regulated by low BAFF-R expression. Elevated BAFF-R levels can therefore overcome this diminished response and lead to an accumulation of autoreactive B cells.