探讨沉默信号转导与转录激活因子-4及细胞因子信号负调控因子-3对辅助性T细胞分化的影响  

Experimental investigation of roles of STAT4 and SOCS3 in differentiation and cytokine secretion of T helper cells by RNA interference

作　　者：孙蕾[1] 魏晓丽[1] 王青山[1] 郑慧琳[1] 向荣[1] 王悦[1] 

机构地区：[1]南开大学医学院免疫学室,天津300071

出　　处：《中华医学杂志》2009年第17期1197-1202,共6页National Medical Journal of China

基　　金：国家重点基础研究计划基金（2007CB914804）;国家高技术研究发展计划基金（2007AA021010）;教育部留学归国科研基金;天津市科技支撑计划重点项目（07ZCKFSH03700）

摘　　要：目的探讨沉默信号转导与转录激活因子_4（STAT4）及细胞因子信号负调控因子-3（SOCS3）后对白细胞介素（IL）-12及IL4诱导的辅助性T（Th）淋巴细胞分化中的影响以及对于Th1及Th2细胞亚群分泌细胞因子的影响。方法以IL-12和IL-4分别诱导初始Th细胞（Th0细胞）分化为Th1或Th2细胞；通过RNA干扰技术分别沉默Th0，Th1和Th2细胞中的STAT4和SOCS3的表达，然后继续给予相应的IL-12或IL4刺激培养细胞。采用逆转录聚合酶链反应（RT-PCR）和酶联免疫吸附分析（ELISA）分别检测Th1／Th2特异性细胞因子的mRNA及蛋白质的变化，通过比较沉默前后Th1／Th2细胞特异性细胞因子量的变化以评价沉默STAT4或SOCS3对于Th0细胞分化方向的影响以及对Th1／Th2细胞分泌细胞因子的影响。结果沉默STAT4使Th0和Th1细胞的Th1型细胞因子明显减少，而Th0和Th2细胞的Th2型细胞因子增多；沉默SOCS3后，Th0，Th1和Th2细胞的Th1及Th2型细胞因子均无明显改变。结论STAT4介导IL-12诱导的Th1分化、维持Th1细胞分泌细胞因子，并推测其可能具有直接抑制Th2分化的作用；而SOCS3在IL-12及IL4诱导的Th0细胞分化中不具有关键性作用。Objective To investigate the roles of signal transducer and activator of transcription d （STAT4） and suppressor of cytokine signaling 3 （SOCS3） in differentiation and cytokine secretion of T helper （Th） cells by separate silencing. Methods Th0 cells were induced to differentiate to Thl or Th2 cells by interleukin 12 （IL-12） or interleukin d （IL4）. The mRNAs of STAT4 and SOCS3 were silenced separately by small interfering RNA （siRNA） in Th0, Thl and Th2 cells and then the lymphocytes cultured in Thl or Th2 medium with IL-12 or IL-4 for another 48 h before cells and supernatants were collected for the detection of Thl and Th2 type cytokines by reverse transcriptase polymerase chain reaction （RT-PCR） and enzyme-linked immunosorbent assay （ELISA）. By comparing different amounts of cytokines between before and after silencing the target mRNAs, the roles of STAT4 and SOCS3 in the differentiation and cytokine secretion in T helper ceils were evaluated. Results Thl type cytokine significandy decreased and Th2 type cytokine increased after silencing STAT4 in Th0 and Thl cells; minimal changes were detected in both Thl and Th2 type cytokines after silencing SOCS3. Conclusion STAT4 mediates the IL-12- induced differentiation of T cells to Thl subset and maintains the cytokine secretion of Thl cells; STAT4 directly inhibits the development and cytokine secretion of Th2 cells; STAT4 deficiency results in impaired development and cytokines secretion of Thl cells and the enhanced development and cytokines secretion of Th2 cells. SOCS3 has minimal effects on IL-12 or IL-4 induced differentiation and cytokine secretion of T helper cells.

关 键 词：辅助性T细胞 细胞分化 转录激活因子 信号负调控因子 

分 类 号：R686[医药卫生—骨科学]