IL-33/ST2信号通路及sST2在脐血移植后植入前综合征发生中的作用及分子机制研究

Pre-engraftment syndrome ( PES ) was discovered as a high incidence of immue response following cord blood transplantation ( CBT ).Mild PES can promote hematopoietic reconstruction and reduce primary graft failure rate after CBT,but severe PES patients would be life threatening and with a high transplant related mortality. At present the pathogenesis of PES is unclear. According to our early stage of researches about PES, we found that the major effector cells of PES were donor monocyte-macrophages. When PES occurred, the levels of MCP-1,IL-1B,IL-6,IL-18 increased significantly. Further study found that the levels of IL-33 and sST2 increased as a result of CBT pretreatment damage,and sST2 levels rised further when PES occurred. We speculate that IL-33/ST2 signaling pathway plays an important role in PES .This project intends to detect the levels of IL-33 and sST2 before, after CBT,when PES happens and be controlled after treatment respectively for CBT patients , looking for a reliable predictor of the occurrence and severity of PES; In vitro experiment, to explore the role and the specific molecular mechanism of IL-33/ST2 signal pathway in PES, we will observe the changes of immune cells,cytokines and IL-33/ST2 signaling pathway related molecules on umbilical cord blood,peripheral blood and bone marrow mononuclear cells stimulated by IL-33,sST2.Finally, the role of IL-33/ST2 in PES will be confirmed in PES animal model. This project will help fill the blank of the mechanism in PES and provides new thinking and target for the clinical diagnosis and treatment of PES.

植入前综合征(PES)是脐血移植(CBT)后高发的免疫反应。轻症PES可促进造血重建，重症患者死亡率高。PES发生机制尚不明确。我们前期研究发现，PES的效应细胞为供者的单核巨噬细胞，PES发生时MCP-1、IL-1B、IL-6、IL-18水平明显升高，CBT患者预处理后血清IL-33、sST2水平升高，发生PES时sST2极度升高，推测IL-33/ST2信号通路在PES发生中起重要作用。本项目拟检测患者CBT前、后、发生PES时、治疗控制后IL-33、sST2的变化，明确其在PES发生中作用并找出预测PES严重程度的指标；使用IL-33、sST2体外刺激脐血、外周血和骨髓单个核细胞，检测免疫细胞、细胞因子和IL-33/ST2信号通路相关分子，阐明IL-33/ST2通路在CBT后PES发生分子机制，建立PES动物模型证实IL-33/ST2在其发生中作用。为临床PES诊治提供新的思路和途径。

植入前综合征(PES)是脐血移植(CBT)后高发的免疫反应。PES发生机制尚不明确。我们前期研究发现，PES发生时MCP-1、IL-1β、IL-6、IL-18水平明显升高，sST2极度升高，推测IL-33/ST2信号通路在PES发生中起重要作用。本项目拟检测患者CBT前、发生PES时、治疗控制后IL-33、sST2的变化，明确其在PES发生中作用并找出预测PES严重程度的指标；IL-33、sST2体外刺激脐血、外周血和骨髓单个核细胞，检测免疫细胞、细胞因子和IL-33/ST2信号通路相关分子，为临床PES诊治提供新的思路和途径。结果：（1).STR-PCR检测结果显示：UCBT+7d供者的嵌合度在PES组明显高于未发生PES组，分别为70.58±22.86%与37.18±18.96%，P＜0.0001。(2).发生PES时细胞因子IL-6、MCP-1和sST2在PES组明显高于无PES组（P<0.05）；PES组患者自身比较结果显示发生PES时炎性细胞因子显著高于移植前、移植当天的水平（P<0.05）。PES患者治疗有效者细胞因子仅IL-6明显下降并恢复至发生前水平（P<0.01），而MCP-1和sST2与PES发生时相比虽有所下降但无统计学差异。发生PES时IFN-γ、IL-2、IL-1Rα、IL-4、IL-8、IL-17A、IL-33、MIP-1α、MIP-1β和TNF-α表达水平两组相近无统计学差异，同时PES组患者在不同的时间点，自身对比其表达水平相近无统计学差异。(3).应用IL-33,sST2刺激新鲜脐血、外周血干细胞，每种类型的细胞分4组：实验组：A．IL-33+sST2组；对照组：B．sST2组；C．IL-33组；D．空白组。经体外培养0、12、24和72小时后，1).各组刺激前后细胞数量无明显增加；2).实验各组细胞不同培养时间点的细胞亚群比例无统计学差异；3).实验各组细胞不同培养时间点各细胞亚群ST2表达无显著变化。结果表明，PES可能是移植后早期脐血细胞大量增殖产生多种细胞因子诱导的，供者的早期嵌合是PES发生的高危因素。PES患者血清中单核细胞相关的趋化因子（MCP-1）、IL-6浓度明显升高。脐血单核细胞炎性因子表达上调，具有炎性特征。脐血中的单核细胞介导了PES的发生。