T-bet在较低危骨髓增生异常综合征骨髓衰竭发病中的作用

Myelodysplastic syndromes(MDS) are characterized by ineffective hematopoiesis, directly caused by the excessive apoptosis of hematopoietic cells in the bone marrow that is induced by autologous activation of T lymphocytes. Selectivity intervention of T lymphocytes in pathogenesis of myelodysplastic syndromes is still clinical challenge. Recently, studies showed that key transcription factor T-bet could regulate activation of CD4T in model of autoimmune diseases. Our preliminary experiments showed that the expression of T-bet accompanied with autologous CD4T lymphocytes of Th1 and Th17 subsets in lower risk MDS were increased, and the expression of T-bet have positive correlations with apoptosis of bone marrow cells. Based on the previous data, we speculated that T-bet play important role in selectively activation of CD4T lymphocytes in MDS. Here, we will utilize a combination of tools and methods, such as western-blotting, immunocytochemistry and EMSA to explore location expression and transcription activity of T-bet in CD4T of lower risk MDS patients, and then employe lenti-virus mediated RNAi, gene overexpreesion, flow cytometry and functional analysis to identify the mechanism of T-bet regulating CD4T subsets, and explore the role of T-bet on pathogenesis of bone marrow failure. This study will provide us new insights into the pathogenesis underlying bone marrow failure of MDS, and help to develop novel potential targets and more effencient therapeutic strategy against it.

自体T淋巴细胞激活所致骨髓造血细胞过度凋亡是骨髓增生异常综合征（MDS）无效造血的直接原因,选择性干预T淋巴细胞功能仍是亟待解决的临床难题。最近，自身免疫性疾病模型的研究表明T-bet是CD4+T功能活化的关键转录因子。我们前期预实验中亦发现T-bet在较低危MDS患者中的表达显著增高，伴随CD4+T亚群Th1及Th17高水平表达, T-bet表达与骨髓造血细胞凋亡相关。由此我们假设T-bet在MDS的CD4T细胞选择性激活中起重要作用。本研究将使用免疫标记、EMSA等方法分析T-bet在较低危MDS患者骨髓CD4T细胞内的定位和转录活性；应用病毒介导的RNAi和基因过表达、流式细胞术及细胞功能学分析等方法，分析T-bet对CD4T亚群细胞的调控机制,探讨T-bet在较低危MDS骨髓衰竭中扮演的作用。该项目有助于我们理解T细胞介导的骨髓衰竭生物学本质，为拓展新的靶向干预及治疗措施提供依据。

自体T淋巴细胞激活所致骨髓造血细胞过度凋亡是骨髓增生异常综合征（MDS）无效造血的直接原因，选择性干预T淋巴细胞功能仍是亟待解决的临床难题。我们前期研究显示，T-bet表达与MDS骨髓衰竭密切相关。本研究将使用免疫标记、EMSA等方法分析T-bet在较低危MDS患者骨髓CD4T细胞内的定位和转录活性；应用病毒介导的RNAi和基因过表达、流式细胞术及细胞功能学分析等方法，分析T-bet对CD4T亚群细胞的调控机制,探讨T-bet在较低危MDS骨髓衰竭中扮演的作用。研究结果显示，T-bet在较低危MDS患者中的表达显著增高，伴随CD4+T亚群Th1及Th17高水平表达, T-bet表达与MDS骨髓造血细胞凋亡密切相关。进一步，研究去甲基化药物对MDS特别是较低危MDS骨髓免疫微环境的影响。去甲基化治疗上调INF-γ转录因子STAT1的表达，亦上调免疫检查点分子PDL-1/PD-1的表达。PD-1/STAT1及PD-1/STAT1比值变化决定较低危MDS去甲基化治疗后的预后。在此基础上，我们探究去甲基化药物对MDS癌胚抗原生成的影响，发现去甲基化药物能够上调MDS癌胚抗原表达，进而活化和刺激体内细胞免疫，抑制MDS恶性克隆，发挥免疫监视作用，为MDS进一步免疫治疗提供依据。该项目有助于我们理解T细胞介导的骨髓衰竭生物学本质，为拓展新的靶向干预及治疗措施提供依据。