Figure 1
COX-2-dependent PGs are essential during oral tolerance induction. Effect of COX-2 inhibitor (NS-398) on orally induced suppression of a DTH response in BALB/c mice (a). Mice were IP injected six times with 1 mg kg−1 of the selective COX-2 inhibitor, NS-398, saline, or 1% DMSO at 8 h intervals. The first IP injection was given 5 h before tolerance induction via i.g. treatment with 25 mg OVA. Five days after OVA feed, mice were sensitized SC in the tailbase with 100 μg OVA in IFA. At day 11, mice were challenged with 10 μg OVA in 10 μl saline in the auricle of both ears, and after 24 h increases in ear thickness were determined and compared with values before challenge. *Statistically significant (P<0.05). Effect of COX-2 inhibitor (NS-398) on orally induced suppression of a DTH response in DO11.10 reconstituted mice (b). BALB/c mice were injected with 1 × 107 CD4+ KJ1-26+ cells i.v., Starting the next day, mice were treated with NS-398 as described above. The first i.p. injection was 5 h before tolerance induction by a single i.g. dose of 70 mg OVA. Five days after i.g. OVA administration, mice were sensitized SC with OVA in IFA, at day 11 mice were challenged with OVA in the ears and 24 h thereafter increases in ear thickness were determined and compared with values before challenge. *Statistically significant (P<0.001). COX-2, cyclooxygenase-2; DMSO, dimethyl sulfoxide; i.g., intragastric; i.p., intraperitoneal; i.v., intravenous; OVA, ovalbumin; PG, prostaglandin; SC, subcutaneously.
