Cotransfer of regulatory T cells improve the therapeutic effectiveness of mesenchymal stem cells in treating a colitis mouse model.

Inflammatory bowel disease (IBD) is a severe inflammatory condition in the colon. To date, clinical solutions for this disease have been limited. Mesenchymal stem cells (MSCs), multipotential cells with immune regulation and anti-inflammatory functions, have been applied to treatment of IBD. However, the therapeutic effectiveness of MSCs still needs to be improved. Here, we were interested in whether regulatory T cells (Tregs) could enhance the immune regulation function of MSCs in treatment of mouse colitis. We generated a dextran sulfate sodium (DSS)-induced IBD mouse model. Combined cell therapy with both MSCs and Tregs was able to help increase body weight and preserve a better colon morphology compared with single cell therapy with MSCs or Tregs alone. Further studies demonstrated that combined cell therapy could reduce pro-inflammatory cytokines such as TNF-α,IL-10, IFN-γ, IL-17A, IL-1β and at the same time promote CD3+ T cells apoptosis. In conclusion, our study indicates that combined cell therapy could prevent the development of colitis in a mouse model, which may lead to a new effective therapeutic approach for treatment of human IBD.