[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.