Figure 6.

Supernatants of TLA-stimulated PBMC obtained from T. gondii-infected animals induce IDO activity and antiparasitic effects in porcine PCP-R cells. 3 × 10⁵ PCP-R cells were stimulated with serially diluted supernatants from TLA-activated porcine PBMC. (a) After three days of PBMC culture, supernatants were harvested and the kynurenine concentration was determined using Ehrlich's reagent. (b) Identical cell cultures were infected with T. gondii (3 × 10⁴ ME49 tachyzoites per well) after stimulation with T cell supernatants. In some cultures, L-tryptophan (100 μg/ml) or 1 MT (100 μg/ml) was added. After three days, toxoplasma growth was monitored using ³H-uracil incorporation. Data are given as mean ± SD of triplicate cultures; significant differences were marked with asterisks (n.s. = not significant; ^∗p ≤ 0.05, ^∗∗p ≤ 0.01, and ^∗∗∗p ≤ 0.0001).