title: Cutting edge: SDS-stable Fas microaggregates: an early event of Fas activation occurring with agonistic anti-Fas antibody but not with Fas ligand.
abstract: The 45 kDa Fas or CD95 receptor triggers apoptosis via the caspase cascade when stimulated by its ligand FasL or by agonistic Abs. Activated Fas receptors seem to oligomerize very early into SDS-stable and reducing agent-resistant microaggregates of 200-250 kDa on SDS-PAGE. However, these microaggregates have so far only been reported using agonistic anti-Fas Abs, and no results have been reported using FasL. Here, we demonstrate that the microaggregates do not form in response to FasL, while they always appear in response to the agonistic Ab, in four different cell lines and in normal lymphocytes from human blood. Therefore, the Fas microaggregates are not required for the induction of apoptosis via FasL. These results also suggest that subtle differences exist in the apoptotic pathways triggered by anti-Fas agonistic Abs and by FasL.
authors.affiliation: Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5540, Université de Bordeaux II, Bordeaux, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Legembre
authors.forename: Marie
authors.initials: M
authors.lastname: Beneteau
authors.forename: Sophie
authors.initials: S
authors.lastname: Daburon
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Moreau
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Taupin
mesh_terms: D000911:Antibodies, Monoclonal / Q000502:physiology*; D017209:Apoptosis / Q000276:immunology; D002460:Cell Line; D045744:Cell Line, Tumor; D053222:Fas Ligand Protein; D006801:Humans; D007106:Immune Sera / Q000502:physiology*; D019169:Jurkat Cells; D007700:Kinetics; D008024:Ligands; D008562:Membrane Glycoproteins / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction / Q000276:immunology; D012967:Sodium Dodecyl Sulfate / Q000378:metabolism*; D013501:Surface-Active Agents; D019014:fas Receptor / Q000276:immunology* / Q000378:metabolism* / Q000502:physiology
chemical_list: D000911:Antibodies, Monoclonal; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D007106:Immune Sera; D008024:Ligands; D008562:Membrane Glycoproteins; D013501:Surface-Active Agents; D019014:fas Receptor; D012967:Sodium Dodecyl Sulfate