Objective To explore the effect of α-galactosyleramide (α-GalCer) on immune reconstitu-tion under acute graft-versus-host disease (aGVHD). Methods BALB/c mice were transplanted with allogeneic C57BL/6 bone marrow cells and splenocytes (both 1×107) after receiving lethal total-body irradiation. α-GalCer (100 ug/kg) or vehicle (dimethylsulfoxide) was administered intraperitoneally immediately after transplantation. The effects of α-GalCer on immune reconstitution, proliferation of T cells and B cells, hemato-poiesis, and thymic microenvironment were assessed. Results The α-GalCer group exhibited higher percentages of CD3+, CD4+, CD8+, B220+, CD40+, and CD86+ cells compared with the vehicle group. The number of colony forming unit per 1000 CD34+ cells in the α-GalCer group was higher than in the vehicle group (P=0.0012). In vitro proliferation assays showed that the α-GalCer group had higher percentages of CD3+, CD4+, CD8+, and B220+ cells compared with the vehicle group. As for the results of in vivo prolifera-tion assays, the numbers of CD3+, CD4+, CD8+, and B220+ cells were higher in the α-GalCer group than in the normal group, especially the number of B220+ cells (P=0.007). Significant difference was not found in thymocyte count between the α-GalCer group and the vehicle group, nor in the percentages of CD3+, CD4+, and CD8+ cells. Conclusion Administration of α-GalCer after allogeneic bone marrow transplantation may promote immune reconstitution in the presence of aGVHD.
