口服调节性T细胞源性exosomes对大鼠移植肾存活的影响

发布时间：2018-05-13 12:14

本文选题：Treg细胞 + Exosomes　；参考：《第三军医大学》2014年硕士论文

【摘要】：背景和目的:肾移植术后的慢性排斥反应是导致移植肾失功的主要原因，探索减轻慢性排斥反应，建立免疫耐受状态的有效途径，确保移植肾长期存活是器官移植领域的重要课题之一[1]。CD4+CD25+Treg是一群具有重要免疫调节功能的细胞，在进行器官移植手术之后，它可以调节机体内的免疫应答向免疫耐受状态发展，并促使机体维持免疫耐受状态[2]。外泌体（exosomes）是体内多种活细胞以胞吐的方式分泌到细胞外的囊性小泡，直径40~100nm[3]，携带多种母体细胞的蛋白，RNA等物质，且不同细胞来源的exosomes具有不同的功能[4]，例如：肿瘤细胞来源的exosomes能异常地高表达Fas配体(FasL)，成功诱导活化的细胞死亡。我们前期的研究显示，通过静脉回输的方式，，CD4+CD25+Treg细胞分泌的exosomes可发挥免疫调节作用[5]，诱导机体产生免疫耐受状态，但其作用机制尚不明确，是否能通过直接口服Treg源性exosomes途径诱导耐受，相关文献也鲜有报道，因此，我们设计了相关实验，研究口服CD4+CD25+Treg源性exosomes是否会产生口服耐受，进而影响大鼠移植肾存活情况。方法：肾移植术前5天开始，给实验组受体大鼠用Treg细胞源性exosomes悬液灌胃（浓度为1.15g/ml，0.5ml/d），给对照组受体大鼠以同样方式灌饲PBS溶液。观测记录两组大鼠术后的存活时间，活动状态，精神饮食情况等。分别在术后第3、7、10、13天，通过颈静脉穿刺抽血，检测受体血肌酐（Scr）和尿素氮（UN）含量。移植术后第10天，取大鼠移植肾做病理切片并观察。结果：实验组受体大鼠存活的时间相对于对照组受体大鼠明显延长(P＜0.05)。术后，实验组受体大鼠Scr和UN水平保持相对稳定，而对照组受体大鼠Scr和UN在术后第10天、13天相对于实验组明显升高(P＜0.05)。病理结果显示，实验组大鼠移植肾病理损伤与对照组相比明显较轻。结论：通过给受体大鼠灌饲Treg细胞所分泌的exosomes，明显延长了移植肾的存活时间，且功能得到了明显改善。
[Abstract]:Background and objective: chronic rejection after renal transplantation is the main cause of kidney failure. Ensuring the long-term survival of the transplanted kidney is one of the important subjects in the field of organ transplantation [1]. CD4 CD25 Treg is a group of cells with important immunomodulation function, after organ transplantation, It can regulate the immune response to the immune tolerance state, and promote the maintenance of immune tolerance state [2]. Exocrine exosomes (exosomeses) is a variety of living cells in the body secreted into the extracellular vesicles in the form of exocytosis, diameter of 40~100nm [3], carrying a variety of mother cells, such as protein RNA, etc. Exosomes from different cell sources have different functions [4]. For example, exosomes derived from tumor cells can overexpression Fas ligand Fas ligand and successfully induce activated cell death. Our previous studies have shown that exosomes secreted by CD4 CD25 Treg cells via intravenous infusion may play an immunomodulatory role [5] and induce immune tolerance, but the mechanism is not clear. Whether the tolerance can be induced by direct oral Treg derived exosomes pathway is rarely reported. Therefore, we have designed a related experiment to study whether oral CD4 CD25 Treg derived exosomes can induce oral tolerance, and then affect the survival of the transplanted kidney in rats. Methods: five days before renal transplantation, experimental group rats were treated with Treg cell-derived exosomes suspension (1.15g / ml / ml 0.5 ml / d) and control group rats were given PBS solution in the same way. The survival time, activity state and mental diet of the two groups were observed and recorded. The levels of creatinine (SCR) and urea nitrogen (UNN) were measured by jugular vein puncture on the 3rd day after operation. On the 10th day after transplantation, the grafts were taken and observed. Results: the survival time of the experimental group was significantly longer than that of the control group (P < 0.05). After operation, the levels of Scr and UN in the experimental group were relatively stable, while the Scr and UN levels in the control group were significantly higher than those in the experimental group on the 10th day after operation (P < 0.05). The pathological results showed that the pathological injury of transplanted nephropathy in the experimental group was significantly less than that in the control group. Conclusion: the exosomes secreted by Treg cells significantly prolonged the survival time and improved the function of the transplanted kidney.
【学位授予单位】：第三军医大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R699.2

【共引文献】