IL-15/HC–activated CD56⁺ cells express high levels of GILZ mRNA. (A) Isolated CD56⁺ cells activated with IL-15 in the absence (•) or presence of HC at 10^–6 M (▪) and/or 10^–4 M (▴) were monitored for GILZ mRNA relative expression by real-time PCR. Total CD56⁺ cells were tested over a 35-day culture period. (B) Cells obtained from CD56⁺ cultures stimulated with IL-15 in the absence (open symbols) or presence of 10^–4 M HC (filled symbols), at the indicated time points, were first fixed and then immunomagnetically separated into CD3^– (circles) and CD3⁺ (triangles) fractions, as described in “Materials and methods.” Squares indicate total CD56⁺ population. All fixed populations were tested for GILZ mRNA levels. Data represent the mean plus or minus SD from 3 (A) and 2 (B) independently performed experiments.