Objective: To study the role of Th17 cells in acute intestine graft-versus-host disease following allogenetic bone marrow transplantation(allo-BMT).
Methods: Mice were split randomly into five groups: normal control, irradiated, allo-BMT, allo-BMT + DMSO and allo-BMT + Halofuginone (HF) groups. HF was given intraperitoneally at a dose of 5 µg per mouse from -1 d to 10 d after allo-BMT. aGVHD symptoms were followed-up to perform clinical and pathogenic scores. The levels of Th1/Th17, interleukin-17 and interferon-γ were measured by flow cytometry at day 7 d. mRNA expressions of T-bet, RORγT, CXCL9, CXCL10, CXCL11 and CCL20 in intestine were evaluated by real-time PCR.
Results: Intestinal damages in allo-BMT-HF mice was more serious than in normal control and allo-BMT groups at day 14 after transplantation. At day 7, Th17 ratio in allo-BMT + HF group was significantly lower than in allo-BMT group. IL-17A was not detected, but Th1 ratio was higher in allo-BMT + HF. There was a similar increment in the relative expressions of T-bet in both allo-BMT and allo-BMT + HF groups. Expressions of CXCL9 and CXCL10 elevated in allo-BMT + HF group, which were significantly higher than those in allo-BMT group (P < 0.01). CCL20 expression significantly increased in allo-BMT group, but it was not detected in allo-BMT + HF group.
Conclusion: Blockage of th17 cells differentiation exacerbated acute intestine graft versus-host disease.