In Vitro Amplification of CD4~+ CD25~+ Regulatory T Cells and Identlfication of Amplified T Cell Immunoinhibitory Function

This study was purposed to compare the effect of 3 different cell components for expansing CD4+CD25+Treg in vitro,and identify their immunoinhibitory function.CD4+T cells,CD4+CD25-T cells and CD4+CD25+T cells were isolated from mouse splenocytes by MACS and then expanded in vitro.Phenotype of the T cell lines and expression of the FOXP3 was determined by flow cytometry.The inhibitory effect of expanded CD4+CD25+T cells on CD4+CD25-T cells was tested by MLR method.The results showed that the Treg cells from all the three groups were expanded significantly after culture for 2 weeks.In the CD4+T cells group,the proliferation rate was(77.8±5.32) folds with a percentage of Treg cells increasing from(6.61±1.00) % to(15.33±1.31) %.The proliferation rate in the CD4+CD25-T cells group was(95.20±7.67) folds,with the percentage of CD4+CD25+T cells raising from(0.37±0.13) % to(9.84±0.98) %.The proliferation rate in the CD4+CD25+T cells group was(41.20±6.92) folds,the proportion of Treg cells decreased from(86.75±1.25) % to(85.32±1.62) %,and the expression of Foxp3 decreased from(76.92±1.72) % to(75.33±2.11) % during the culture,there were not significant differences in the cell purity and the expression of Foxp3,compared with pre-amplification.The inhibitory test showed that the expanded CD4+CD25+T cells could inhibit the proliferation of CD4+CD25-T cells in vitro in a cell dose-dependent manner.It is concluded that the amplification of CD4+CD25+Treg cells is successful in vitro,especially in the CD4+CD25+T cells group,the cell purity and Foxp3 gene is not obviouly changes after amplification.