Abstract:

Objective To observe the distribution of CD4+Foxp3+ regulatory T cells (CD4+Foxp3+ Treg) and the subsets in CD4+T cells in peripheral blood of adults with minimal change disease (MCD), and explore the significance of CD4+Foxp3+Treg in the pathogenesis of MCD. Methods Twenty-seven adults with MCD initially diagnosed by renal biopsy were selected. The antibody combination of Foxp3-FITC/CD45RA-PE/CD3-ECD/CD4-PC7 was adopted and flow cytometry was employed to determine the percentage of CD4+Foxp3+ Treg and the subsets in CD4+T cells in peripheral mononuclear cells (PBMCs). The expression of Foxp3, RORc, TGF-β1, IL-6, IL-17A and IL-23 mRNA in PBMCs was detected by Real-Time PCR. Besides, normal controls were established. Results Flow cytometry revealed that CD4+Foxp3+Treg were divided into three subsets: CD45RA+Foxp3lowcells(Fr.Ⅰ, resting Treg), CD45RA-Foxp3highcells (Fr.Ⅱ, active Treg) and CD45RA-Foxp3lowcells (Fr.Ⅲ). The percentages of cells of Fr.Ⅰ+Fr.Ⅱ and cells of Fr.Ⅱ in CD4+ T cells in MCD group were significantly lower than those in control group (P<0.01). The expression of Foxp3 mRNA in PBMCs in MCD group was significantly lower than that in control group （P<0.05）, while the expression of RORc mRNA in PBMCs in MCD group was significantly higher than that in control group （P<0.05）, and the expression of IL-6, IL-17A and IL-23 mRNA was significantly higher than that in control group （P<0.05, P<0.01）. Correlation analysis revealed that the expression of IL-17A mRNA was negatively related to the percentage of cells of Fr.II in CD4+T cells in MCD group （r=-0.81，P<0.05）. Conclusion In adults with MCD, there is decreased expression of Treg and active Treg subsets and increased expression of Th17-related gene and cytokines in peripheral blood, which suggests that the down-regulated expression of Treg Foxp3 mRNA and Treg/Th17 imbalance might be involved in the pathogenesis of MCD.

Key words: minimal change disease, adult, regulatory T cells, Foxp3