BACKGROUND: At present, the nature CD4+CD25+Foxp3+ regulatory T cells are too rare to meet the clinical requirement.
OBJECTIVE: To establish an effective amplification system of murine CD4+CD25+T cells in vitro.
METHODS: Mature dendritic cells from C57/BL6 mouse bone marrow were combined with different doses of transforming growth factor β were used to amplify autologous or allogeneic CD4+CD25+T cells in vitro.
RESULTS AND CONCLUSION: After 2 weeks culture, magnetic bead sorted CD4+CD25+T cells in the amplification factor for natural regulatory T cells were (17.3±10.6) times, 0.2 and 2 μg/L concentration had the strongest amplification on T cells. The expansion CD4+CD25+ positive rate was (85.38±1.82)%, CD127 positive rate was (78.86±0.91)%; The expansion of regulatory T cells with high expression of FOXP3 mRNA was 1.5 folds than nature ones in vitro. The regulatory T cells inhibitory test showed that regulatory T cells could inhibit the proliferation of auto-and allo-CD4+T cells in vitro in a cell dose-dependent manner. The inhibit rate of CD4+CD25+T cells to autologous CD4+T cells was (60.1±0.71) %, the inhibit rate of allogeneic CD4+T cells was (35.5±0.57)% (P < 0.05). We successfully amplified CD4+CD25+T cells in vitro. The cells expanded have inhibitory effects in vitro, and as the method can obtain large quantity and purity cells, which may be used in clinical trials in future.

Fan SS, Luo RC, Duan HX, Shi YZ, Yuan YH, Xiao PL. Combination of mature dendritic cells and transforming growth factor beta for in vitro amplification of regulatory T cells in mice. Zhongguo Zuzhi Gongcheng Yanjiu. 2012;16(15): 2728-2732.    
[http://www.crter.cn  http://en.zglckf.com]