FIG. 2.

Effects of IL-15 on CD3⁺ CD8⁺ receptor expression of MNC from healthy adult controls (A) and umbilical cord blood (B). MNC were left untreated (no cytokine) or incubated with various concentrations of IL-15 (0.1, 1, and 10 ng/ml) at 37°C in 5% CO₂. Flow cytometry assays were conducted at weekly intervals to determine receptor expression. The data shown were compiled from samples from 22 cords and 13 adults and are expressed as means ± SEMs (error bars). The P value compares percent expression without cytokines to that of samples with cytokines.