Transmembrane activator and CAML interactor (TACI) (TACI)

Transmembrane activator and CAML interactor (TACI), also known as TNFRSF13B, is a cell surface receptor primarily expressed on B lymphocytes and plasma cells (UniProt: Q96RJ3). It serves as a critical regulator of the adaptive immune system by binding two ligands: B-cell activating factor (BAFF) and a proliferation-inducing ligand (APRIL). These interactions are essential for B-cell survival, maturation, and the induction of immunoglobulin class-switch recombination (PubMed: 28455306). Overexpression of BAFF and APRIL, or dysregulation of TACI signaling, is implicated in the pathogenesis of autoimmune diseases such as systemic lupus erythematosus (SLE) and IgA nephropathy, where it drives the production of pathogenic autoantibodies (PubMed: 33764201). In therapeutic development, the extracellular domain (ectodomain) of TACI is used to create fusion proteins that act as soluble decoy receptors. Drugs like Telitacicept and Atacicept utilize this TACI ectodomain to bind and neutralize both BAFF and APRIL simultaneously, thereby inhibiting the survival of autoreactive B cells and reducing disease activity (PubMed: 37130511).

Other names

TNFRSF13BCD267Tumor necrosis factor receptor superfamily member 13BTransmembrane activator and calcium-modulating cyclophilin ligand interactorBAFF and APRIL receptor

Dual neutralization of BAFF and APRIL ligands by acting as a soluble decoy receptor (TACI-Fc fusion protein).