Kinetics of IFN-γ–induced upregulation of B7-2 mRNA. MM6 cells were stimulated in the presence or absence of 500 U/mL of IFN-γ for the indicated times. Total cellular RNA was isolated, and Northern blot analysis for B7-2 mRNA expression was performed. The same filter was subsequently probed with GAPDH to ensure that comparable amounts of RNA were loaded in each lane. Data shown are from 1 representative experiment of 2 performed. Northern blot analysis for B7-2 mRNA expression (upper panel). Quantitative analysis of B7-2 mRNA expression (lower panel). As explained in Materials and Methods, the bands’ intensities were normalized to the GAPDH housekeeping gene control, and the graph was generated with the relative values obtained after normalization.