滤泡辅助性T细胞和滤泡调节性T细胞在儿童过敏性紫癜发病中的作用

Roles of follicular helper T cells and follicular regulatory T cells in pathogenesis of Henoch-Schönlein purpura in children

摘要:

目的 探讨外周血滤泡辅助性T 细胞(Tfh 细胞)和滤泡调节性T 细胞(Tfr 细胞)表达的变化在儿童过敏性紫癜(HSP)发病中的意义。方法 采用流式细胞术检测40 例HSP 患儿及25 例对照组儿童外周血Tfh 和Tfr 细胞的表达水平;实时荧光定量聚合酶链反应(RT-PCR)检测外周血中相关调控因子Bcl-6、c-MAF、Blimp-1、PD-1 mRNA 的表达。结果 与对照组儿童相比,HSP 患儿外周血Tfh 细胞比例显著升高(P<0.05),Tfr细胞比例显著下降(P<0.05),Tfh/Tfr 比值显著升高(P<0.05)。与对照组相比,HSP 患儿CD4⁺ T 细胞Bcl-6、c-MAF mRNA 的表达水平显著升高(P<0.05);Blimp-1 mRNA 表达水平显著下降(P<0.05)。CD4⁺CD25⁺ 调节性T 细胞PD-1 mRNA 表达水平显著升高(P<0.05);Blimp-1 mRNA 表达水平显著下降(P<0.05)。结论 Tfh及Tfr 细胞的异常表达可能参与了儿童HSP 的发病过程;Bcl-6、c-MAF 和PD-1 的过表达及Blimp-1 的抑制表达可能是导致Tfh 及Tfr 细胞异常表达的重要原因。

Abstract:

Objective To study the roles of follicular helper T (Tfh) cells and follicular regulatory T (Tfr) cells in the pathogenesis of Henoch-Schönlein purpura (HSP) in children. Methods Peripheral blood samples were collected from 40 HSP children and 25 healthy controls. The percentages of Tfh and Tfr cells were measured by flow cytometry;the mRNA expression levels of Bcl-6, c-MAF, Blimp-1, and PD-1 in peripheral blood were measured by real-time polymerase chain reaction. Results Compared with the controls, the children with HSP had significantly increased percentage of Tfh cells and Tfh/Tfr ratio but a significantly reduced percentage of Tfr cells in the peripheral blood (P<0.05). Compared with the controls, the children with HSP had significantly increased mRNA expression of Bcl-6 and c-MAF but significantly reduced mRNA expression of Blimp-1 in CD4⁺ T cells (P<0.05), and had significantly increased mRNA expression of PD-1 but significantly reduced mRNA expression of Blimp-1 in CD4⁺CD25⁺ regulatory T cells (P<0.05). Conclusions Abnormal percentages of Tfh and Tfr cells may be involved in the pathogenesis of HSP in children, and over-expression of Bcl-6, c-MAF, and PD-1 mRNA and inhibited expression of Blimp-1 mRNA may be considered as important reasons for abnormal percentages of Tfh and Tfr cells.