NUCLEAR-LEVELS OF NF-KAPPA-B CORRELATE WITH SYNCYTIUM-FORMING CAPACITY OF 8E51 CELLS, EXPRESSING A DEFECTIVE HIV VIRUS

The double NF-kappa B site identified in the LTR of the human immunode ficiency virus-1 (HIV-1) has been demonstrated to be necessary for eff icient viral transcription, In this report we present the characterisa tion of NF-kappa B subunits engaged in complexes binding to the HIV-1 NF-kappa B site in human 8e51 T-cells, that harbour a defective HIV-1, At least four different specific NF-kappa B complexes are present in the nucleus of these cells, With the use of specific antibodies we hav e determined the composition of each complex using electrophoretic mob ility shift assays, The results show the presence of several NF-kappa B family members, with the transactivating RelA being engaged in multi ple complexes, The importance of NF-kappa B complexes in viral functio ns has been established comparing the level of NF-kappa B DNA-binding complexes with syncytia-forming activity of 8e51 cells, In fact, 8e51 cells that had almost lost their syncytia-forming capacity were found to contain at least 10 times less active NF-kappa B DNA-binding comple x than the actively fusing cells, The correlation is specific as the l evel of at least three other transcription factors did not change. (C) 1997 Federation of European Biochemical Societies.