我国约有200万需角膜移植的角膜盲患者，移植排斥是导致手术失败的主要原因。已知抑制T淋巴细胞介导的迟发型超敏反应是防治移植排斥的关键，但是现有调控T细胞的治疗方法并不能有效控制排斥。近年，miRNAs通过对T细胞的基因调控来调节免疫系统引起了免疫学界的高度关注，本项目在前期工作观察到miRNA-21对CD4+T细胞活化有明显的调控作用的基础上，拟建立小鼠角膜移植模型，采用分子生物学、免疫学、流式细胞等技术，1）研究miRNA-21在基因表达调控水平调控角膜移植排斥时眼内Th1、Th2、Th17、Treg细胞活化的作用机制；2）研究NF-κB-miRNA-21信号转导通路在角膜移植排斥时对T细胞的影响；3）观察以miRNA-21进行靶向治疗，对排斥发生率的影响。通过本研究探讨miRNA-21对T细胞的基因调控来影响角膜移植排斥反应的作用机制，以期探寻防治角膜移植术后免疫排斥的新途径。

The main reason for the failure of corneal transplantation is corneal allograft rejection, there are 2 million corneal blindness who need corneal transplantation in our country. As we all known ,the key to prevent transplant rejection is to inhibit T-lymophocyte-mediated delayed-type hypersensitivity. But the existing treatment of regulating T-lymophocyte can not control rejection effectively. In recent years, immune academia gives high concerning on gene acommodation of T-cell immune regulation with miRNAs. Our study had some preliminary works .On the basis of observing that miRNA-21 regulate T-cell seriously, we will set up the model of mouse corneal transplantation, using the technology of molecular biology, immunology, flow cytometry , 1) study the mechanism about how the miRNA-21 regulate activated Treg,Th1,Th2 ,Th17 cells on the time of corneal allograft rejection ; 2) study how the NF-kB-miRNA21 signal transduction pathways influence various types of T cells in corneal allograft rejection; 3) observe how the miRNA-21 influence rejection rate when it is target regulating . By this study , we can probe into the mechanism on how the miRNA-21 influence corneal allograft rejection by regulating CD4+ T cell. We can explore the new ways of prevention and treatment of immune rejection after corneal transplantation through this study.