Biphasic control of NF-kappa B activation induced by the triggering of HLA-DR antigens expressed on B cells RID A-5515-2008

The regulation of NF-kappa B activation following the triggering of HLA-DR antigens by mAb L243 has been studied at various times in Raji cells, Electrophoretic mobility shift assays demonstrated a strong increase of NF-kappa B DNA binding after triggering of HLA-DR antigens, Using TNF-alpha-activity neutralizing antibodies, the authors demonstrated that the upregulation of NF-kappa B was found to depend, at later time point, on an autocrine effect of TNF-alpha secreted following triggering of HLA-DR antigens, In contrast, it was found to be TNF-alpha independent in the early time point, Moreover, the upregulation of NF-kappa B binding activity is regulated by the triggering of selected epitopes of HLA-DR antigens, In fact, mAb L243 but not the staphylococcal superantigens, staphylococcal exotoxin toxic shock syndrome toxin-1 or staphylococcal enterotoxin B, regulate the NF-kappa B binding activity. (C) Academic Press Limited.