重症肌无力患者CD40配体表达的信号传导途径初步探讨

Signal Transduction Pathway of CD40 Ligand on Peripheral Blood Mononuclear Cell in Patients with Myasthenia Gravis

目的 研究重症肌无力(MG)患者CD40配体(CD40L)的表达,探讨MG患者CD40L表达的信号传导途径。方法 研究对象为急性期MG患者13例。分离血中单个核细胞,分组用刺激剂刺激进行单个核细胞培养:(1)纯培养组:不加任何刺激剂进行细胞培养;(2)PMA组:用PMA和A23187刺激;(3)PHA组;用PHA刺激;(4)BLM组:加PKC抑制剂BLM后再加PHA刺激培养。培养后用流式细胞仪检测CD40L阳性细胞率及RT-PCR法检测单个核细胞CD40L mRNA表达。结果 MG急性期BLM组CD40L阳性细胞率和CD40L mRNA与纯培养组差异无显著性(P>0.05),而显著低于PMA组和PHA组(P<0.01)。结论 在MG中,CD40L的表达可能依赖于PKC活性介导的T细胞活化途径。

Objective To investigate the signal transduction pathway involved in CD40L expression of patients with MG. Methods Peripheral blood of 13 patients with acute MG was collected. Mononuclear cells (PBMC) were isolated and cultured in the RPMI-1640 medium supplemented with PMA and A23187 or PHA. After 6 hours, cell samples were collected and CD40L expression was tested by flow cytometry and reverse tran-scription-polymerase chain reaction (RT-RCR). Except for PMA and A23187 or PHA treatment, a specific inhibitor of PKC, bisindolylmaleimide (BLM), was added to the cells media before exposure to PHA in patients with acute MG. Meanwhile, the medium without activator in PBMC cultures was used as controls in acute MG. Cells in different culture medium were collected and CD40L expression was tested . Results CD40L expression of patient with acute MG after activation with PHA was not different from that after activation with PMA, but there was increasing markedly in contrast to that of medium without activator. CD40L expression in the presence of the PKC inhibitor was no significant difference compared with that of the status of medium without activator. Conclusions CD40L expression in MG is mediated by PKC activity.