Extended Data Fig. 8: IL-15-treated CXCR6⁺ CD8 T cells become auto-aggressive after exposure to acetate.

a, Auto-aggressive activity of IL-15-treated CXCR6⁺FOXO1^low CD8 T cells against hepatocytes (n = 3). b, GzmB-expression levels in CXCR6⁺ CD8 T cells exposed for 24 h to different concentrations of acetate in vitro (n = 4). c–e, Fluorospot assay with representative images to quantify TNF and IFNγ release from IL-15-stimulated CXCR6⁻ and CXCR6⁺ CD8 T cells after acetate exposure and from peptide-specific stimulation of OT1 CD8 T cells (n = 5). f, GSEA for differentially expressed genes from hepatic CXCR6⁺ and CXCR6⁻ CD8 T cells of mice fed a CD-HFD compared to in vitro-generated memory CD8 T cells exposed to acetate or butyrate. g, Acetate concentrations in supernatants of primary mouse hepatocytes after exposure to palmitate for 24 h (250 μM) or with an agonistic trimeric FasL (25 ng ml⁻¹) to induce cell death (n = 6). h, Cytotoxic activity of acetate-exposed polyclonal CD8 T cells after FOXO1 inhibition (AS1842856, 100 nM) against hepatocytes (n = 3) and quantification. i, GzmB expression in acetate-exposed, GFP-expressing CD8 T cells after retroviral transduction with pMP71-GFP-Foxo1 or pMP71-GFP (n = 3). j, k, sALT at day 2 after adoptive transfer of IL-15-stimulated or FOXO1-inhibited and acetate-exposed CD8 T cells (n ≥ 3). l, Calculation of liver-damage-inducing potential per cell for auto-aggressive CD8 T cells (n = 8). m, Surface LAMP1 expression on CXCR6⁺ CD8 T cells after a 24-h exposure to acetate (15 mM) (n = 9). n, o, Liver damage quantified by NAS and sALT in Prf1^−/− and littermate control mice after CD-HFD feeding for 1 year. p, ICAM1 expression on hepatocytes in coculture with IL-15-stimulated, acetate-exposed CXCR6⁺ CD8 T cells (n = 7). q, Liver immunohistochemistry with representative images and quantification of ICAM1 clusters per mm² of liver tissue in mice fed a normal diet (n = 5), NASH mice (n = 6) and NASH mice treated with anti-CD122 antibody (n = 6). Scale bar, 100 μm. r, Representative microscopic images of IL-15-stimulated, acetate-exposed CXCR6⁺ CD8 T cells in contact with hepatocytes and quantification of the distance. Arrows indicate polarized LFA1 orientation on T cell interacting with hepatocyte. Scale bars, 30 μm (left), 15 μm (right). s, Auto-aggressive activity of IL-15-treated CXCR6⁺ CD8 T cells against hepatocytes in presence of acetate (15 mM) or TNF (5 ng ml⁻¹) and anti-LFA1 antibodies (n = 3). t, sALT at day 2 after adoptive transfer of auto-aggressive CD8 T cells and injection of anti-LFA1 (100 μg per mouse) or control immunoglobulin. Two independent experiments. u, v, TNF expression in livers from unaffected individuals (n = 6) or patients with NASH (n = 7) (u) and correlation with sALT (healthy, n = 6; NASH, n = 10)(v). Cytotoxic activity results are representative of at least three independent experiments. Exact P (a, b, d, e, g–v) and n (n, o, t) values are presented in Source Data. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. Two-way ANOVA with Sidak’s multiple comparison test (d, e), one-way ANOVA with Tukey’s (j, k, s, t) or with Dunnett’s (b, g, h) multiple comparison test and unpaired two-tailed t-test (a, i, l–n, p, r, u). In a, b, d, e, g–v, data are mean ± s.e.m., error is reported as s.d.

Source data