Transplanted mesenchymal stem cells can inhibit the three developmental stages of murine acute graft-versus-host disease.

Background: Recent data have demonstrated that mesenchymal stem cells (MSCs) have potent immune regulation capacity in vitro, enhancing their therapeutic appeal for their utilisation in the management of acute graft-versus-host disease (aGvHD). However, their immunoregulatory activity in vivo is largely unknown.
Materials and Methods: Using murine compact bone-derived MSCs in an aGvHD model, the phenotypic status of splenocytes of aGvHD and aGvHD+MSC groups of mice were examined by flow cytometry.
Results: MSC infusion decreased the expression of MHC-II and CD69 molecules on splenic CD11b+ cells of aGvHD mice, which resulted in decreased maturation of antigen-presenting cells. Moreover, the down-regulated ratio of CD3+CD69+ to CD3+ cells, leading to restrained early activation and effector T-cell formation, resulted in the enhancement of the absolute and relative number of splenic CD3+ cells by MSCs co-transfer.
Conclusion: This study demonstrated that MSCs can inhibit the three developmental stages of aGvHD.