Fig. 1 |. Activation of HIF-1α by lactate inhibits the pro-inflammatory activities of DCs.

a–c, Ingenuity pathway analysis (IPA) (a), hypoxia score (b) and Hif1a expression (c) in total DCs from the CNS of EAE mice. d, Expression of HIF-1α in DCs isolated from the CNS, draining lymph nodes (dLNs) and spleen of wild-type mice before (‘naive’, n = 3), 12 days (‘onset’) or 17 days (‘peak’) after EAE induction (n = 4 for CNS peak and spleen onset, n = 5 otherwise). e, EAE in wild-type (WT) (n = 15) and HIF-1α^Itgax (n = 9) mice. Experiment repeated three times. f, IFNγ⁺, IL-17⁺ and IFNγ⁺IL-17⁺GM-CSF⁺ CD4⁺ T cells in the CNS of wild-type and HIF-1α^Itgax mice 15 days after EAE induction (n = 5 mice per group). g, RNA sequencing (RNA-seq) analysis of splenic DCs at peak EAE (n = 5 mice per group). h,i, IPA (h) and GSEA for the human phenotype ontology term ‘abnormal activity of mitochondrial respiratory chain’ (i) in wild-type and HIF-1α^Itgax splenic DCs at peak EAE. NES, normalized enrichment score. j, Mean fluorescence intensity (MFI) of HIF-1α expression in splenic DCs treated with metabolites and LPS for 6 h, normalized to LPS stimulation. DMF, dimethyl fumarate; Pyr, pyruvate; Mal, malonate; Succ, succinate; 4-OI, 4-octyl itaconate; α-KG, α-ketoglutarate; L-LA, L-sodium lactate (n = 4 per condition). k, HIF-1α⁺ DCs after treatment with L-LA (0.1, 1 and 10 mM) and LPS for 6 h (n = 3 for medium, L-LA 0.1 mM, L-LA 10 mM, LPS + L-LA 10 mM, n = 4 otherwise). l, mRNA expression in wild-type BMDCs after treatment with LPS, L-LA, GPR81 antagonist or MCT1 inhibitor (n = 3 per group). m, Ifng, Il17a and Csf2 expression in 2D2⁺CD4⁺ T cells co-cultured with wild-type BMDCs pre-stimulated with L-LA and LPS (n = 4 for Il17a LPS + L-LA 0.1 mM, n = 3 otherwise). n, IFNG and IL17A expression in human T cells co-cultured with DCs (n = 3 per group). siNT, non-targeting siRNA. Statistical analysis was performed using one-way ANOVA with Dunnett’s or Šídák’s post-hoc test for selected multiple comparisons for d,k,l–n, unpaired Student’s t-test for f and two-way ANOVA for e. Data are mean ± s.e.m.