Fig. 1

Effects of 5-hydroxytryptophan (5-HTP) on the activation of splenocytes. Splenocytes were treated with 5-HTP and stimulated with anti-CD3 plus anti-CD28 Abs. a Percentages of annexin V⁺ 7-aminoactinomycin D (7-AAD)⁺ cells (annexin V⁺ 7-AAD⁺ cells/total cells, mean ± SD). b Percentages of active caspase-3⁺CD4⁺ cells (active caspase-3⁺CD4⁺ cells/CD4⁺ cells, mean ± SD). c, WST-1 assay. Cell proliferation (mean ± SD) was defined as optical density (OD)₄₅₀–OD₆₉₀. (–): cells without activation. d Percentages (mean ± SD) of IFNγ⁺CD4⁺ T cells (IFNγ⁺CD4⁺CD3⁺ cells/CD4⁺CD3⁺ cells) and IL-17⁺CD4⁺ T cells (IL-17⁺CD4⁺CD3⁺ cells/CD4⁺CD3⁺ cells). e mRNA levels (mean ± SD) of IL-17, TNFα and IFNγ. f Protein levels (mean ± SD) of IL-2, IL-17, TNFα and IFNγ in culture supernatant. g Percentages of IFNγ⁺CD4⁺ T cells and IL-17⁺CD4⁺ T cells (mean ± SD). *Significant compared with no 5-HTP treatment. Multiple comparisons were performed using the Kruskal–Wallis test, if significant (p <0.05), then the Duncan test was used to find out which pairs were different