Figure 5.

Foxp3 expression in human CD4⁺ T cells cultured with Kyns. CD4⁺ T cells were activated with anti-CD3/CD28 beads in the presence or absence of the indicated Kyns. At 5 days, cells were retrieved and the proportion of CD4⁺ T cells that were Foxp3-positive was determined by intracellular flow cytometry. Results are representative of at least three independent experiments. L-Kyn, kynurenine. CD, cluster of differentiation; Foxp3, forkhead box p3; 3-HK, 3-hydroxykynurenine; 3-HAA, 3-hydroxyanthranilic acid.