Adoptive transfer of transforming growth factor-?1-induced CD4+CD25+ regulatory T cells prevents immune response-mediated spontaneous abortion.

The effects of adoptive transfer of transforming growth factor (TGF)-β1-induced regulatory T (Treg) cells in preventing spontaneous abortion in mice were investigated. CD4+CD25- cells were isolated from the spleens of pregnant CBA/J mice and induced into Treg cells positive for CD4, CD25 and forkhead box P3 (FOXP3) ex vivo using interleukin (IL)-2 and TGF-β1. CBA/J mice were mated with DBA/2J mice to establish a model of spontaneous abortion and, on the first day of pregnancy, mice were injected intravenously with 2 × 105 either freshly isolated Treg cells or those induced with TGF-β1. After 14 days, the surviving and reabsorbed fetuses in both groups were counted, and serum cytokine concentrations were measured by ELISA. Adoptive transfer of CD4+CD25+ or TGF-β1-induced Treg cells significantly reduced the fetal resorption rate, increased serum IL-10 and TGF-β1 concentrations and decreased interferon-γ levels. In conclusion, the results of the present study indicate that adoptive transfer of TGF-β1-induced Treg cells prevents spontaneous abortion in mice by increasing the secretion of T helper (Th) 2 cytokines and decreasing the secretion of Th1 cytokines.