Fig 2: Sharpin predisposes mice to spontaneous T cell-dependent dermatitis. a Representative appearance of 12-week-old control, healthy, and sick Sharpinfl/flLckCre (left) mice and photos of H/E-stained skin (right). Scale bar: 200 µm. b Incidence of spontaneous dermatitis. All mice were monitored over a period of 6 months. c Percentage of effector CD44hiCD62Llo or memory CD44hiCD62Lhi subsets within the CD4+ or CD8+ T cell populations in the spleen and pLNs from 12-week-old healthy Sharpinfl/flLckCre mice. n = 6 biological independent animals. d Percentage of recently activated CD69+ cells within the CD8 T cell population in pLNs. n = 4 biological independent animals. e MFI of I?Ba in T cells at 10 min after CD3/28 antibody-based TCR stimulation. Intracellular staining was performed. n = 6 biological independent animals. f MFI of Nur77 in T cells at 3 h after CD3 or CD3/CD28 antibody-based TCR stimulation. n = 3 biological independent animals. g CD69 and CD25 expression by CD4+ or CD8+ T cells at the indicated times after TCR stimulation. h Experimental induction of colitis by naïve CD4+ T cells. Rag2-/- mice were intravenously injected with HBSS alone or with 2.5 × 105 sorted naïve CD4+ T cells (CD45RBhiCD25-CD4+CD3e+), which were obtained from pooled cells isolated from the spleen and pLNs of 4-week-old mice. Bodyweight of injected Rag2-/- mice was monitored twice or thrice weekly. Data indicate average values. i Representative photos of H/E and immunofluorescent staining against CD3+ T cells within the inflamed colon of mice in h. j Percentage of CD25+CD4 T cells in the mesenteric LN (mLN) of mice in h. n = 4 biological independent animals. Small horizontal lines indicate the mean (±s.e.m.). ns, p > 0.05; *p < 0.05; **p < 0.01; ***p < 0.001. Kruskal–Wallis test with Bonferroni correction (a value = 0.05) was used for h, while two-tailed Mann–Whitney U-test was used for c–f and j. Data are pooled from at least three independent experiments (c–g, j). Also, see Supplementary Fig. 2. Source data are provided in a Source Data file

Fig 3: Effects of treatment with ascorbate and/or anti−PD1 on mouse organs and tumors. (A) H&E staining of lung, liver, gut, kidney, and spleen from animals after treatment either with ascorbate (3 g/kg i.p., daily), anti−PD1 (2 mg/kg i.p., twice per week), or the combination of ascorbate and anti−PD1. (B) Weight progression curves of animals treated with ascorbate (3 g/kg i.p., daily), anti−PD1 (2 mg/kg i.p., twice per week), or the combination of ascorbate and anti−PD1. (C) Percentage change in mouse weight during the experimental procedure. (D) H&E staining of the tumors of the groups treated with ascorbate (3 g/kg i.p., daily), anti−PD1 (2 mg/kg i.p., twice per week), or the combination of both. (E) Immunohistochemical tumor staining for Pcna, Glut−1, and CD3 after treatment with ascorbate (3 g/kg i.p., daily), anti−PD1 (2 mg/kg i.p., twice per week), or the combination of ascorbate and anti−PD1. Representative images are shown at 200× magnification. (F) Quantification of Pcna from tumors treated with ascorbate (3 g/kg i.p., daily), anti−PD1 (2 mg/kg i.p., twice per week), and the combination of both (n = 5 in every group). Displayed are the percentages of positive cells. (G) Quantification of Glut−1 from tumors treated with ascorbate (3 g/kg i.p., daily), anti−PD1 (2 mg/kg i.p., twice per week), and the combination of both (n = 5 in every group, except the combination which represents n = 4). Displayed is the IHC score. (H) Quantification of CD3-positive cells in tumors treated with ascorbate (3 g/kg i.p., daily), anti−PD1 (2 mg/kg i.p., twice weekly), and the combination of both (n = 5 in every group). Plotted is the number of CD3-stained cells per mm2. Treatment groups were statistically compared by using the Kruskal–Wallis test with Dunn’s post hoc analysis. Significant differences between groups are denoted with asterisks. *: p ≤ 0.05; **: p ≤ 0.01. Glut−1, glucose transporter 1; H&E, hematoxylin and eosin; IHC, immunohistochemistry; i.p., intraperitoneal; Pcna, proliferating cell nuclear antigen; PD1, programmed cell death protein 1.