IL-15 induces CD4⁺ effector memory T cell production and tissue emigration in nonhuman primates
J. Clin. Invest. Louis J. Picker, et al. 116:1514 doi:10.1172/JCI27564 [Go to this article.]

Figure 6
The progeny of IL-15–stimulated T cells are long-lived and rapidly migrate into an extralymphoid effector site. The 6 RMs that received a 2-dose IL-15 regimen (10 μg/kg 3 days apart) were pulsed with 30 mg/kg BrdU on the 4 days after the second IL-15 dose, and then subsequently assessed for BrdU incorporation and decay in the CD28^– (CD4⁺ and CD8⁺) memory subsets in peripheral blood (A) and the overall (CD4⁺ and CD8⁺) memory populations in BAL specimens (B). These IL-15–treated RMs were compared with a cohort of 12 (A) or 16 (B) untreated RMs that were subjected to the same 4-day BrdU labeling regimen. The figure shows the mean percentage BrdU⁺ cells (± SEM) in the populations indicated in the IL-15–treated (filled diamonds) versus control RMs (open diamonds), with the day of the last BrdU dose designated day 0. Note that for many data points, the SEM is sufficiently small so that the error bars are obscured by the symbols. The difference in BrdU⁺ cell frequencies between IL-15–treated and control RMs in the blood effector memory populations was significant at P < 0.0001 and P < 0.0004 at all time points for CD4⁺ and CD8⁺ T cells, respectively. In BAL, this difference was significant at P < 0.0004 at all time points for both CD4⁺ and CD8⁺ T cells.