Dual expression of CXCR4 and IL-35 enhances the therapeutic effects of BMSCs on TNBS-induced colitis in rats through expansion of Tregs and suppression of Th17 cells.

Bone marrow-derived mesenchymal stem cells (BMSCs) hold great promise for the treatment of inflammatory bowel disease owing to their immunosuppressive property and tissue healing potential. The balance between regulatory T cells (Tregs) and T helper (Th)17 cells plays a crucial role in BMSC-mediated immunosuppression. Interleukin (IL)-35 is a newly identified anti-inflammatory cytokine required for the expansion of Tregs and suppression of Th17 cell differentiation. IL-35 can amplify the immunosuppressive property of BMSCs when overexpressed in these cells. However, the reparative capability of BMSCs in vivo is limited, partly due to the poor homing efficiency of BMSCs to inflamed colons. Up-regulation of CXC chemokine receptor 4 (CXCR4) expression in BMSCs may affect the directional homing of implanted BMSCs via stromal-derived factor-1. In this study, by lentivirus-mediated introduction of CXCR4 and IL-35 genes to modify rat BMSCs, we observed enhanced migration and strengthened immunomodulatory activities of the genetically engineering BMSCs. These results suggest that modification of BMSCs by dual expression of CXCR4 and IL-35 may provide an effective therapeutic strategy for inflammatory bowel disease.