RESUMEN
AIM:To investigate the role of mesenchymal stem cell-induced regulatory dendritic cells ( MSC-DCregs) in mouse acute graft-versus-host disease( aGVHD) model.METHODS: Bone marrow cells from BALB/c ( H-2 d ) mice were isolated and were induced to differentiate into DCs.The DCs were selected by flow cytometry, and after 10 d co-culture with MSCs, they were induced to be MSC-DCregs.Male 8-week-old C57BL/6 (H-2b) mice were used as do-nor mice.The female 8-week-old BALB/c (H-2d) mice, who had received 100 cm source-skin distance, 30 cm ×30 cm radiation field, 700 cGy total body irradiation (TBI) pretreatment were used as recipient mice.The recipients were divided into 5 groups:control group, TBI group ( injected with medium only) , bone marrow transplantation group ( injected with 1 ×107 bone marrow cells), aGVHD group (injected with 1 ×107 bone marrow cells and 1 ×107 spleen cells), and MSC-DCregs group (injected with 1 ×107 bone marrow cells, 1 ×107 spleen cells and 1 ×106 MSC-DCregs).The white blood cell count, recipients’ chimerism, clinical evaluation of aGVHD, survival analysis and pathological changes were deter-mined.RESULTS:Hematopoieic recovery was seen at 10 d after transplantation.The recipients’ chimerism was parallel to the donors’ at 30 d.The median survival time of the mice in aGVHD group and MSC-DCregs group was 27 d and 33 d, and the survival rates at 30 d were 20% and 100% (P<0.01), respectively.The clinical scores of the mice in MSC-DCregs group were lower than those in aGVHD group ( P<0.01) .Moreover, the pathological changes in the skin and liver of the mice in MSC-DCregs group were less serious than those in aGVHD group.CONCLUSION: The MSC-DCregs in-duce an aGVHD tolerance in vivo, and further research of its mechanism is still in great necessary.