FIG. 5.

TNF and, to a lesser extent, IL-1 are involved in the permanently induced NF-κB activity present in thymocytes during the coculture with TEC. Thymocytes were freshly isolated (lanes 1 and 2) or cultured for 45 h (lanes 3 to 11) either alone (lane 3 [Control thymocytes]) or in the presence of TEC under conditions avoiding contact (lanes 4 to 9) or allowing contact (lanes 10 and 11). During the coculture, the cells were either left untreated (lane 4 [Control coculture, 45 hours] and lane 10 [Control coculture]) or were treated at the start of the coculture with antibodies respectively raised against TNF (lane 5), IL-6 (lane 6), and IL-1β (lane 8), with the antagonist of the IL-1 receptor (lane 7), or with αTNF plus IL-1 ra plus αIL-6 (lanes 9 and 11). Whole-cell extracts from these various samples were incubated with a ³²P-labeled oligonucleotide representing the HIV LTR-derived κB motif. Competition (comp [lane 1]) with a 40-fold molar excess of unlabeled oligonucleotide was used to confirm the specificity of the DNA-binding activity detected. NF-κB activity is indicated. The positions of two nonspecific (n.s 1 and n.s 2) binding activities are indicated. The positions of two nonspecific (n.s 1 and n.s 2) binding activities are indicated. This experiment is representative of three independent experiments, each carried out on a different thymus.