MiR-100 antagonism enhances GvHD. (A) Allo-HCT was performed as described in the “Methods” section. MiR-100 expression on days 2, 6, and 12 after allo-HCT is displayed for the small bowel using qRT-PCR. MiR-100 expression is downregulated on day 2 (P = .013), day 6 (P = .003), and day 12 (P = .005) after allo-HCT as compared with untreated animals. The experiment was performed 3 times with at least 3 mice in each group. (B-E) Mice were transplanted with 5 million BM cells and 100 000 CD4⁺/CD8⁺ Tc’s to induce a delayed GvHD phenotype. The number of mice is indicated for the respective groups. (B) Survival was reduced in the group treated with antag-100 compared with antag-cont2–treated animals (P < .0001), untreated mice (P < .0001), BM controls (P < .0001), or antag-100+cilengitide treatment (P < .0001). The experiment was performed 3 times, and the resulting data were pooled. (C) The number of CD34⁺ ECs was analyzed by immunohistochemistry in small and large bowels from the indicated groups, isolated on day 14 after allo-HCT. Antag-100 treatment significantly increased the number of CD34⁺ ECs in the small (P < .0001) and large intestines (P < .0001) as compared with antag-cont2–treated animals. The experiment was performed once with 6 individual animals per group. Representative pictures from the small bowel stained for CD34 (peroxidase staining) are shown. (D) Histopathology of the intestines was quantified as indicated in the “Methods” section. The mean score ± SD for cumulative histopathology (apoptosis and inflammation) is shown for 1 of 2 independent experiments, each performed with 6 individual animals per group. (E) Animals were euthanized on day 13 after allo-HCT, and serum was isolated from the indicated groups. The mean values for IL-6, IFN-γ, monocyte chemoattractant protein 1, and TNF ± SD are displayed for 1 of 2 independent experiments, representing 6 individual animals per group.