Foxp3转染小鼠CD4^＋CD25^-T细胞抑制树突状细胞功能

为了研究Foxp3基因表达与CD4^＋T细胞免疫活性的关系,用逆转录病毒转染Foxp3基因,在幼稚CD4^＋CD25^-T细胞内强制性表达FOXP3蛋白,进而研究转染后的CD4^＋CD25^-T细胞对树突状细胞的免疫共刺激分子和免疫功能的影响,并通过Transwell试验研究转染Foxp3的CD4^＋CD25^-T细胞对树突状细胞的作用是否依赖于细胞之间的直接接触。结果表明：通过逆转录病毒载体转染,成功建立了表达Foxp3的CD4^＋CD25^-T细胞模型,转染后1周Foxp3阳性表达的T细胞比例为38%。强制性表达Foxp3的CD4^＋CD25^-T细胞可以在体外发挥免疫抑制作用,可以诱导树突状细胞表面免疫共刺激分子CD80和CD86表达水平的下调。体外淋巴细胞增殖试验结果表明,Foxp3转染小鼠CD4^＋CD25^-T细胞可以抑制树突状细胞对异基因淋巴细胞的活化。结论：转染Foxp3的CD4^＋CD25^-T细胞对树突状细胞发挥的作用依赖于细胞之间的直接接触。

Foxp3-transfected CD4+CD25-T Cells Suppress Function of Dendritic Cells

To explore the relationship between expression of Foxp3 gene and immune activity of CD4(+) T cells, the Foxp3 gene was transfected with retroviral vector and applied to forcedly express Foxp3 protein in naive CD4(+)CD25(-) T cells, and then the effect of transfected CD4(+)CD25(-) T cells on immune co-stimulatory molecules and immune function of dendritic cells (DCs) was investigated, and the dependence of direct contact between Foxp3-transfected CD4(+)CD25(-) T cells and DCs was clarified by Transwell test. The results showed that through transfection of retroviral vector, CD4(+)CD25(-) T cells model expressing Foxp3 was established. At 1 week after transfection, proportion of T cells expressing Foxp3 was 38%. CD4(+)CD25(-) T cells forcedly expressing Foxp3 could play immune suppression role in vitro and induce down-regulation of CD80 and CD86 expression on the membrane of DCs. The lymphocyte proliferation test in vitro indicated that Foxp3 transfected CD4(+)CD25(-) T cells could inhibit effect of DCs on activation of allo-lymphocytes. It is concluded that the effect of Foxp3-transfected CD4(+)CD25(-) T cells on DC depends on intercellular direct contact.