IL-12 and IFN-α regulate expression of unique gene sets in human CD8⁺ T cells. (A-B) Negatively isolated CD8⁺CD45RA⁺ T cells were polarized in vitro for 3 days under the defined conditions as indicated: neutralized (◊), IL-12 (■), IFN-α (○), and IL-12 + IFN-α (▴) and CFSE^lo (shown in orange in Figure 1A) and CFSE^hi (shown in teal in Figure 1A) cells were sorted for RNA extraction and microarray analysis. A statistically significant gene list (P ≤ .01) was obtained using normalized expression values of the 5 donors, and ANOVA Unequal Variance (Welch) was used as the statistical test. Cytokine-stimulated samples were compared with the neutralized condition to obtain a list of genes with at least 1.7-fold difference. Hierarchical clustering of both conditions and entities (genes) is represented in the heat-maps of normalized expression values, both within divided (A) and undivided (B) populations. Individual donors are indicated as numbers under the dendrogram. The bracket in panel B indicates a cluster of IFN-α–stimulated genes. (C) Genes regulated by IL-12 (compared with neutralized) were hierarchically clustered based on their expression pattern within the divided and undivided populations.