Objective: To explore the role of Th17 cells in early onset of acute graft-versus-host disease (aGVHD) and its mechanism.
Methods: Mice aGVHD model was established by irradiated BABL/c mice inoculated with mixed suspension of C57BL/6 bone marrow cells and splenocytes. The mice were divided into 4 groups: (1) normal control, (2) irradiated group, (3) allo-BMT + DMSO group, (4) allo-BMT + halofuginone (HF) group. HF was given intraperitoneally at 5 µg per mouse from -1 d to +10 d after allogeneic bone marrow transplantation(allo-BMT).Mice aGVHD symptoms and survival were observed. Th1/Th17 cells ratio was evaluated by flow cytometry.
Results: All the experimental groups (3) and (4) developed aGVHD after transplantation. More severe aGVHD was observed in group (4) than in group (3). HF prevented cutaneous aGVHD in all the mice, but augmented hepatic and small intestine GVHD. The percentage of Th17 cells and the ratio of Th1/Th17 were significantly higher while the percentage of Th1 cells was significantly lower in group (4) at day +6 (P < 0.05).
Conclusion: Early blockage of Th17 cell results in increase of Th1 cell percentage, which exacerbates aGVHD.