Rapamycin programs memory CTLs in the presence of IL-12 in early activation.

<p>Sorted OT1 cells were stimulated with antigen+B7+IL-12 in the presence of rapamycin at different concentrations. Programmed CTLs were harvested at 72 hrs, and transfer into naïve B 6 mice at 10⁶/mouse through tail injection. (A) Memory OT1 cells in spleen at day 30 after transfer. (B–D) Comparison of molecular expression in memory CTLs programmed by rapamycin (at 250 ng/ml) with control (no rapamycin). (E) Spleen cells containing 10⁵ memory OT1 from (B) were transferred into naïve B6 mice, which were challenged the next day with 5×10⁵ CFU LM-OVA through i.v. Bacterium counts were examined 3 days after LM-OVA challenge in spleen. Every group was compared to control group (OT1 naïve–10⁵ naive OT1 transfer group). These are representatives of two independent experiments with similar results. Every group was compared to control group (rapamycin 0) in A and D. Asterisks indicate statistical significance. *, P<0.05; **, P<0.01; ***, P<0.001. ns: not significant.