Bone marrow-derived mesenchymal stem cells (MSCs) can produce significant levels of transforming growth factor beta and interleukin-6. These two cytokines represent the key factors that reciprocally regulate the development of naive T-cells into regulatory T-cell (Treg) population or proinflammatory T helper 17 (Th17) cells.
We demonstrated that MSCs and their products effectively regulate expression of transcription factors Foxp3 and RORgammat and control the development of Tregs and Th17 cells in a population of alloantigen-activated mouse spleen cells. The immunomodulatory effects of MSCs were more pronounced when these cells were stimulated by addition of anti-inflammatory or proinflammatory cytokines.
The results showed that MSCs represent important players that reciprocally regulate the differentiation of naive T-cells into anti-inflammatory Tregs or proinflammatory Th17 cell population and thereby can modulate immunopathological or transplantation reactions.