Increasing NF-Y binding to the CCAAT box region of the promoters of genes upmodulated during monocyte to macrophage differentiation. (A) Whole cell extracts obtained from human primary monocytes at day 0, 3, and 7 of culture were incubated with labeled oligonucleotides, corresponding to sequences surrounding the CCAAT box present in the promoters of the MHC class II, gp91-phox, fibronectin, and mig and analyzed by EMSA. (B) HLA-DR expression on the cell surface of in vitro grown monocytes. Monocytes were grown for the indicated time and processed for membrane fluorescence using anti–HLA-DR monoclonal antibody, as described in Materials and Methods.