Figure 1. OVA323–339-induced OT-II T cell peripheral deletion results in OVA-specific tolerance that is dependent on TRAIL, even when a second infusion of naïve OT-II T cells occurs.
(A and B) WT, Trail−/−, or Dr5−/− OT-II T cells (106) were adoptively transferred into B6, Trail−/−, or Dr5−/− recipients, respectively, and OVA323–339 (300 μg) was injected i.p. 24 h later. After 28 days, mice were immunized with CFA/OVA and then challenged with 33 μl 3 mg/ml OVA in the right footpad and PBS in the left footpad 7 days later. (C) B6 were seeded with 106 WT OT-II T cells and injected with OVA323–339, as in A. After 28 days, the B6 mice received a second infusion of 106 freshly isolated, naive WT or Dr5−/− OT-II T cells. On the same day as the second infusion, the mice were immunized s.c. with CFA/OVA. The mice were footpad-challenged with OVA 7 days later. (D) B6 mice were seeded with 106 WT OT-II T cells and injected with OVA323–339, as in A. After 28 days, the mice were immunized with CFA/OVA or CFA/HEL. Challenge with OVA or HEL in the footpad occurred 7 days later. X, CFA/OVA or CFA/HEL. (A–D) Measurements were taken 24 h after footpad challenge using an engineer's micrometer, and the difference between the right (Ag challenge) and left (PBS challenge) footpad showed the intensity of the DTH response. *P < 0.05 versus immune control group. All groups consisted of at least four mice, and data presented are representative of at least two independent experiments.