Kinetics of mRNA expression of five immune genes (the CD40, IFN-γ, IL-2, TNF-α, and IL-10 genes) in PBMCs isolated from three different pigs. RNAs obtained from unstimulated and PMA-Iono-stimulated PBMCs which had been cultured for different times (0, 3, 24, and 48 h) were reverse transcribed, labeled, and hybridized to the macroarray. Relative mRNA levels for each gene plotted against time are presented as the mean levels of intensity of expression standardized to HPRT gene expression. In each panel, unstimulated and PMA-Iono-stimulated PBMCs from the same pig are represented by the same symbol. Open symbols represent unstimulated PBMCs. Filled symbols represent PMA-Iono-stimulated PBMCs.