Pascal Schneider * , Fabienne MacKay ¶ , Véronique Steiner * , Kay Hofmann ‡ , Jean-Luc Bodmer * , Nils Holler * , Christine Ambrose ¶ , Pornsri Lawton ¶ , Sarah Bixler ¶ , Hans Acha-Orbea * , Danila Valmori § , Pedro Romero § , Christiane Werner-Favre ‖ , Rudolph H. Zubler ‖ , Jeffrey L. Browning ¶ , Jürg Tschopp *
7 June 1999
Members of the tumor necrosis factor (TNF) family induce pleiotropic biological responses, including cell growth, differentiation, and even death. Here we describe a novel member of the TNF family, designated BAFF (for B cell activating factor belonging to the TNF family), which is expressed by T cells and dendritic cells. Human BAFF was mapped to chromosome 13q32-34. Membrane-bound BAFF was processed and secreted through the action of a protease whose specificity matches that of the furin family of proprotein convertases. The expression of BAFF receptor appeared to be restricted to B cells. Both membrane-bound and soluble BAFF induced proliferation of anti-immunoglobulin M–stimulated peripheral blood B lymphocytes. Moreover, increased amounts of immunoglobulins were found in supernatants of germinal center–like B cells costimulated with BAFF. These results suggest that BAFF plays an important role as costimulator of B cell proliferation and function.