FIGURE 3.

Absence of SIRT3 in donor T cells ameliorates GVHD. (A–C) BALB/c mice received 8.5 Gy on day −1 and were transplanted with 0.5 × 10⁶ CD90.2⁺ splenic T cells from either syngeneic BALB/c or allogeneic major histocompatibility Ag–mismatched B6-WT or SIRT3^−/− mice along with 5 × 10⁶ TCDBM cells from either BALB/c or B6 donors (n = 10–23 mice per group). Data are pooled from two independent experiments. (A) Overall survival; p = 0.009 when B6-WT versus SIRT3^−/− mice were compared. (B) GVHD clinical score. (C) Percent weight loss. ***p < 0.001, **p < 0.01, *p < 0.05 when B6-WT versus SIRT3^−/− mice were compared. (D and E) B6D2F1 mice were used as recipients and received 11 Gy on day −1 and 3 × 10⁶ CD90.2⁺ T cells along with 5 × 10⁶ TCDBM cells from either syngeneic B6D2F1 or allogeneic B6 donors on day 0. (D) Overall survival (n = 10–28 mice per group). Data are pooled from three independent experiments. (E) Clinical GVHD score. **p < 0.01 when B6-WT versus SIRT3^−/− mice were compared. (F) B10.BR mice were used as recipients and received 9.5 Gy on day −1 and 1 × 10⁶ CD90.2⁺ T cells along with 5 × 10⁶ TCDBM cells from either syngeneic B10.BR or allogeneic B6 donors on day 0. Overall survival is displayed (n = 6–14 mice per group). Data are pooled from two independent experiments. *p < 0.05 when B6-WT versus SIRT3^−/− mice were compared. (G–M) Used the B6 into BALB/c GVHD model described in (A–C). (G–I) CD25⁺(G), CD69⁺ (H), and CXCR3⁺ (I) expression in splenic donor T cells at day 10 after allo-BMT (n = 7–8 mice per group, pooled from two experiments). *p < 0.05 when B6-WT versus SIRT3^−/− mice were compared. (J) Donor T cell (H-2kb⁺CD4⁺CD8⁺) expansion in intestinal epithelial lymphocytes of the GI tract on day 10 after allo-BMT (n = 7–8 mice per group, pooled from two experiments). *p < 0.05 when B6-WT versus SIRT3^−/− mice were compared. (K) The histopathological GVHD grade in GI tract (small and large intestine) and liver on day 10 and day 43 after allo-BMT (n = 8–10 mice per group, pooled from three experiments). **p = 0.038 for GI GVHD and p = 0.07 for liver GVHD; recipients of B6-WT versus SIRT3^−/− mice. (L) Donor T cell (H-2kb⁺CD4⁺CD8⁺) expansion in the spleen on day 10 after allo-BMT (n = 7–8 mice per group, pooled from two experiments) (M) Serum IFN-γ levels on day 10 after allo-BMT (n = 8–10 mice per group, pooled from three experiments). *p < 0.05 when B6-WT versus SIRT3^−/− mice were compared. Error bars show the mean ± SEM.