Induction of the CD69 surface expression by IL-15 in CD8⁺ gated T cells from IM subjects. PBLs triggered or not with anti-CD3 mAbs were incubated for 3 days in the absence or presence of increasing concentrations of IL-15 or 100 IU/mL of IL-2, and then double-stained for CD69 and CD8 and analyzed by flow cytometry, as described in “Flow cytometry.” Percentage of CD69⁺ cells in CD8⁺ gated T cells is indicated for each cell treatment. Data are representative of 4 identical experiments.