Pattern of restriction enzyme digestion of chromatin within the IL-12(p35) promoter region. Nuclei from untreated (–) or LPS/IFN-γ–treated (+) THP-1 cells were digested with the indicated restriction enzymes. After purification of genomic DNA and in vitro digestion with EcoRI, DNA samples were examined using Southern blotting and the indirect end-labeling technique. Molecular weight markers are described in “Material and methods.” When several restriction sites for the same enzyme are found within the region under study, symbols are used (°, *, and $) to differentiate them. Fold induction refers to the ratio between stimulated and untreated samples after quantification of the bands with a PhosphorImager.