THE FAS ANTIGEN AND FAS-MEDIATED APOPTOSIS IN B-CELL DIFFERENTIATION

In the B-cell lineage, Fas, a type 1 membrane protein belonging to the tumor necrosis factor receptor (TNF) family, is expressed on B-cells at a restricted developmental stage and on activated B-cells, but not on naive mature B-cells. Apoptosis mediated by Fas-Fas ligand interact ions may be involved in the peripheral elimination of autoreactive B-c ells and in the regulation of the immune response through deletion of B-cells activated by foreign antigens, as for the T-cell lineage. Fas- mediated apoptosis associated with B-cell activation is affected by co stimulation through other accessory signaling molecules like CD40, who se ligands are on T-cells.