Figure 1. STAT3 deficiency in donor T cells prevents both acute and chronic GVHD.

Lethally irradiated BALB/c recipients were engrafted with TCD-BM cells (5 × 10⁶) from WT C57BL/6 donors and CD90.2⁺ T cells (2.5 × 10⁶) from STAT3^–/– or WT C57BL/6 donors. (A) Curves of percentages of body weight change, clinical GVHD score, and percentage survival. n = 5 (TCD-BM); n = 10 (TCD-BM+WT T cells); n = 10 (TCD-BM+STAT3^–/– T cells) combined from 2 replicated experiments. (B) Serum concentrations of ALT, AST, and albumin (ALB) on day 6 are shown. n = 7–8 per group combined from 2 replicated experiments. (C) Serum concentration of IFN-γ, ST2, and TNF-α on day 6 after HCT are shown. n = 4–8 per group combined from 2 replicated experiments. (D and E) Histopathology of liver (left), small intestine (middle), and colon (right) evaluated on day 7 after HCT. Representative micrographic photos of liver, small intestine, and colon (D) and pathological scores of liver, small intestine, and colon are shown (E). Arrows point to infiltrating T cells or tissue damage area. Original magnification, ×200. n = 5 per group combined from 2 replicate experiments. Crosses indicate deaths. Data are represented as mean ± SEM. P values were calculated using nonlinear regression (curve fit) for body weight and clinical GVHD score comparisons (A), log-rank test for survival comparisons (A), and 2-tailed, unpaired Student’s t test for mean comparisons (B, C, and E). NS, P ≥ 0.05; *P < 0.05; **P < 0.01; ***P < 0.001, ****P < 0.0001.