Fig. 7: LβhL, a leucine analog, attenuates IL-17A production.

a Uptake of ³H-leucine by TCR-stimulated CD4⁺ T cells in the presence of L-leucine, D-leucine, or LβhL (400 mg/L for each) (n = 3). b, c CFSE-labeled CD4⁺ naive (b) and memory (c) T cells were stimulated with anti-CD3/CD28-coated microbeads with or without L-leucine, LβhL (400 mg/L), or Bi2 (10 μM) (n = 5). The proportion of proliferating cells was measured by CFSE dilution assay. d The amount of cytokines in culture supernatant from TCR-stimulated CD4⁺ naive T cells (left) and CD4⁺ memory T cells (right) stimulated with anti-CD3/CD28-coated microbeads for 3 days under the indicated conditions (n = 5). Cells were treated with Bi2 and LβhL for 1 h before TCR stimulation. e Clinical scores of EAE mice. Bi2 (10 mg/kg) or LβhL (1 g/kg) was intraperitoneally administered to MOG-immunized mice 4 h before immunization, and the treatment was repeated three times per week for 14 days. f Flow cytometry analysis of IL-17A- and IFN-γ-producing CD3⁺CD4⁺ T cells in the iLN of EAE mice (n = 5 per group). g Quantification of SCMCs from EAE mice in the three groups (n = 6–7 per group). h Flow cytometry analysis of IL-17A- and IFN-γ-producing CD3⁺CD4⁺ T cells in the SCMCs of EAE mice (n = 5 per group). i A representative histogram plot of intracellular HIF-1α in CD3⁺CD4⁺ T cells among CD45⁺ SCMCs from EAE mice (n = 5 per group). The graphs show the means ± SEMs. **p < 0.01, ***p < 0.001, and ****p < 0.0001 by one-way ANOVA with Tukey’s test (a), the Mann‒Whitney U test (b, c–f, g–i), or two-way ANOVA (e).