Activated B cells express functional Fas ligand.
Fas ligand (FasL, Apo-1L) is a member of the tumor necrosis factor protein family and binding to its receptor (Fas, Apo-1, CD95) triggers cell death through apoptosis. Ligand expression is restricted to cells with known cytolytic activity and found on hematopoietic cells of the T cell and natural killer lineage. Here we provide evidence that B lymphocytes can express FasL. Flow cytometric analysis revealed that FasL is expressed on the surface of B cells upon stimulation with either lipopolysaccharide or phorbol 12-myristate 13-acetate/ionomycin. FasL expression on activated B cells was confirmed by western blot and reverse transcriptase polymerase chain reaction analysis. FasL on B cells is functional since lipopolysaccharide-activated B lymphocytes derived from wild type, but not from gld mutant mice, were able to kill Fas-sensitive target cells. Our data suggest that the Fas system may contribute to the control of B cell homeostasis.
Hahne
M
M
Institute of Biochemistry, University of Lausanne, Epalinges, Switzerland.
Renno
T
T
Schroeter
M
M
Irmler
M
M
French
L
L
Bornard
T
T
MacDonald
H R
HR
Tschopp
J
J
D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism*; D001483:Base Sequence; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D053222:Fas Ligand Protein; D008024:Ligands; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology; D019014:fas Receptor / Q000096:biosynthesis / Q000502:physiology*
D053222:Fas Ligand Protein; C505658:Fasl protein, mouse; D008024:Ligands; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D014409:Tumor Necrosis Factor-alpha; D019014:fas Receptor