Table 1.
Percent NK Cells Within Splenocyte Population Following 4- or 24-hour Stimulation With Cytokine(s)
| 4 h | 24 h | |||
| Young | Aged | Young | Aged | |
| Prestimulated | 2.77 ± 0.09 | 2.35 ± 0.13 | 1.99 ± 0.09 | 1.46 ± 0.13 |
| Unstimulated | 2.80 ± 0.09 | 2.40 ± 0.12 | 1.99 ± 0.08 | 1.63 ± 0.13 |
| IL-12 | 2.79 ± 0.10 | 2.36 ± 0.14 | 2.07 ± 0.08 | 1.61 ± 0.12 |
| IL-18 | 2.75 ± 0.08 | 2.26 ± 0.13 | 2.05 ± 0.09 | 1.45 ± 0.13 |
| IL-2 | 2.79 ± 0.08 | 2.35 ± 0.13 | 2.11 ± 0.09 | 1.59 ± 0.12 |
| IL-15 | NT | NT | 2.21 ± 0.09 | 1.65 ± 0.14 |
| IFN-I | NT | NT | 2.14 ± 0.10 | 1.67 ± 0.12 |
| IL-12 + 18 | 2.77 ± 0.08 | 2.35 ± 0.13 | NT | NT |
| IL-12 + 2 | 2.76 ± 0.09 | 2.40 ± 0.14 | NT | NT |
| IL-18 + 2 | 2.72 ± 0.08 | 2.34 ± 0.14 | NT | NT |
| All three | 2.78 ± 0.09 | 2.37 ± 0.14 | NT | NT |
Note: NK cells were identified as CD8−/NK1.1+. Values represent mean ± S E M. NT stands for not tested. Total n = 12 per age group in each treatment, with results of three separate experiments combined. No statistical significance was found. IFN = interferon; IL = interleukin.