κB sites located 3′ downstream of human IFN-β loci are required for maximal gene induction. (A) The molecular organization of the luciferase constructs is shown. Construct 1: −102/+75 (promoter/enhanceosome [P]); construct 2: −2036/+75 (cluster 2 [C2] and promoter [P]); construct 3: −102/+75 and +639/+1840 (promoter [P] and cluster 3 [C3]); construct 4: −3030/+75 (cluster 1 [C1], cluster 2 [C2], and promoter [P]); construct 5: −3030/+75 and +639/+1840 (cluster 1 [C1], cluster 2 [C2], promoter [P], cluster 3 [C3]). (B) LPS-stimulated gene reporter activity of the respective constructs in HEK293-TLR4/CD14-Md2: data shown are the mean + SEM from 5 independent experiments each performed in triplicate; ***P < .001 (1-way ANOVA). (C) RelA-induced gene-reporter activity of the luciferase constructs: data shown are the mean + SEM from 4 independent experiments each performed in triplicate; ***P < .001 (1-way ANOVA). (D) The molecular organization of the luciferase construct with site-specific mutations in κB sites in cluster 3 (C3). (E) RelA-induced gene-reporter activity of the wild-type construct 5 (5.wt) and the construct with site-specific mutations in κB sites (5.mut): results are shown as mean + SEM from 3 independent experiments each performed in triplicate and expressed as percent stimulated control (wild-type = 100%), **P < .01 (Student t test).